Cucumber, Muskmelon, and Watermelon

Cucumber & Melon Disease Control Cucumber & Melon Insect Control Cucumber & Melon Weed Control

Introduction

Cucumbers and muskmelons (genus Cucumis) and watermelons (genus Citrullus) are related crops that have similar cultural requirements. All 3 are tender, warm season vegetables that will not tolerate chilling or soil temperatures below 55°F.

Types and Varieties

Cucumber types include pickling (short, with spines), slicing (long, with spines), Asian and European (long, slender, and seedless), and beit alpha (tender, mild tasing, and spineless). Muskmelons (aka cantaloupes) have orange, musky flesh, and are the most common type of melon grown in New England. Specialty melons with white or green flesh include casaba, galia, crenshaw, Asian, and honeydew types. Watermelons exhibit a range of flesh colors (red, yellow, orange) and both seeded and seedless varieties are available.

Type	Varieties
Pickling Cucumber	Avenger (48) - A, CMV, DM, WMV, ZYMV, S Chaperon (52) - A, ALS, CMV, DM, PM, S Citadel (52) - A, ALS, CMV, DM, PM, S Diamondback (54) - A, DM, PM, CMV Eureka (57) - A, ALS, CMV, PM, PV Gershwin (49) - PM, S, P Supremo (56) - A, ALS, CMV, PM, PV, S
Slicing Cucumber	Bristol (54) -A, ALS, CMV, DM, PM, S Dasher II (58) - A, ALS, CMV, PM, S General Lee (66) - CMV, PM, S Intimidator (61) - A, ALS, CMV, PM, S Marketmore 76 (58) - CMV, PM, S, OP Speedway (56) - A, ALS, CMV, PM, S SVC0025 (60) - CMV, DM, PM, S
Protected Culture/High Tunnel Cucumber	Corinto (slicing - 48) - CMV, PM, P Excelsior (pickling - 50) - ALS, CMV, PM, S, P Katrina (beit alpha - 49) - CMV, PM, S, P Lisboa (slicing - 45) - CMV, PM, S, P Picolini (beit alpha - 50) - CMV, PM, S, P Poniente (European - 56) - CMV, CVYV, PM, S, P Qwerty (beit alpha - 50) - CMV, PM, S, P Sashimi (Asian - 50) - PM, P Socrates (beit alpha - 52) - PM, S, P Tyria (beit alpha - 56) - PM, S, P Unistars (pickling - 42) - PM, S, P
Specialty Melon	Brilliant (canary - 75) Charlotte (honeydew - 90) - FW Diplomat (galia - 71) - PM Lilly (crenshaw - 78) Passport (galia - 70) Summerdew (honeydew - 88) - FW Torpedo (Asian - 65) - PM
Muskmelon	Athena (79) - FW, PM Caribbean Gold RZ (LSL/Harper - 80 to 110) - FW, PM Divergent (75) - FW, PM Goddess (68) - FW, PM Halona (73) - FW, PM Sarah's Choice (76) - FW, PM Sugar Cube (80) - FW, PM, PV
Watermelon - Seeded	Crimson Sweet (85) - A, FW, OP Sangria (87) - FW, A Sugar Baby (80) - OP
Watermelon - Seedless	Gypsy (82) - A
The number in parentheses is the approximate number of days to maturity from seeding. Resistant or tolerant to: A: Anthracnose; ALS: Angular leaf spot, DM: Downy mildew, CMV: Cucumber mosaic virus, FW: Fusarium wilt, PM: Powdery mildew, PV: Potyviruses, S: Scab, WMV: Watermelon mosaic virus, ZYMV: Zucchini yellow mosaic virus OP: open-pollinated, P: parthenocarpic (sets fruit without pollination)

Soil Fertility

Soils that warm up quickly in the spring are preferred over heavier soils that remain cool. Muskmelon should be grown on very well-drained soil for optimum quality. Raised beds provide additional benefits. The soil should be fertile and high in organic matter. On sandy soils, irrigation is necessary. In non-irrigated fields, apply the lower rates of fertilizer recommended.

Apply lime according to soil test to maintain soil pH at 6.0-6.8. Watermelon can tolerate pH as low as 5.5. If the fertilizer cannot be banded at planting, add the band fertilizer amount to preplant broadcast application. If growing plants on plastic mulch, nitrogen can be applied through trickle or overhead irrigation or sidedressed along the edge of the plastic mulch. Nitrogen under the plastic mulch is protected from leaching. Foliar feeding rate is 8-10 lb actual N (4-5 lb urea) per acre. Wet foliage is conducive to disease development, so avoid foliar feeding after the 5-leaf stage.

If using transplants, use of a liquid starter fertilizer at planting time is beneficial. This is especially true with cool soil conditions because phosphorous (P) uptake by plants is slow in colder soils. Although the specific analysis of the product is not critical, starter fertilizers usually contain higher amounts of P. Follow the recommended mixing rates on the product.

Plant Nutrient Recommendations According to Soil Test Results for Cantaloupe and Watermelon

SOIL TEST RESULTS	NITROGEN (N) - LBS PER ACRE	PHOSPHORUS (P) - LBs P₂O₅ PER ACRE				POTASSIUM (K) - LBs K₂O PER ACRE
SOIL TEST RESULTS	NITROGEN (N) - LBS PER ACRE	VERY LOW	LOW	OPTIMUM	ABOVE OPTIMUM	VERY LOW	LOW	OPTIMUM	ABOVE OPTIMUM
Broadcast and incorporate (transplants)	50	110	60	0	0	150	90	0-40	0
Band-place when direct-seeding*	20-40	40	40	25-50	0	30	30	30	0
Sidedress when vines start to run**	20-40	0	0	0	0	0	0	0	0
TOTAL RECOMMENDED	80-130**	150	100	25-50	0	180	120	30-70	0
* For direct-seeded cucumbers. For melon transplants, add the band fertilizer amount to pre-plant broadcast application. Total N and K₂O in the band should not exceed 5.5 lb/1000' of row. Banded P₂O₅ may not be of benefit in warm soils. Sidedressing may not be necessary when using plastic mulch, or if organic matter can supply sufficient N; repeat sidedress in 2-3 weeks. * Watermelon requires a maximum of 100 lb/A of N; excessive N may cause hollow heart in seedless varieties.

Planting

Cucumbers may be direct-seeded or transplanted. Because of the long season required for muskmelon and watermelon, transplants are used. Transplants are preferred for early crops. The plants should be about 3 weeks old, with just 1-2 true leaves, at transplanting time. Older transplants that have begun to run are difficult to handle and suffer greater transplant shock.

Recommended spacing for slicing cucumbers, muskmelons, and watermelons is 2' between plants and 6' between rows. Pickling cucumbers should be direct-seeded at 6-8" between plants and 3-6' between rows, depending on the cultivar. Most cultivars should be planted at 3' between rows.

Seedless watermelons require special growing conditions. Seedless cultivars are sterile because they are triploid, and this negatively affects their germination ability. They require high temperatures (85-95°F) during germination, and excess soil moisture should be avoided. To ensure fruit set, a diploid (seeded) variety or a “pollenizer” variety must be planted among seedless watermelons in a ratio of at least 1 for every 3 seedless plants. Growers have moved to using “pollenizer” instead of diploid varieties because they are bred to produce a large number of male flowers with viable pollen, are less competitive, and take up less field space than diploid varieties. Different pollinizer configurations can be used successfully; however, placing pollenizers in-row with seedless varieties at like spacing or interplanting pollinizers between every 3rd and 4th seedless plant tends to promote better yields compared to dedicating separate rows to pollinizers. The latter strategy is preferred if growing triploid (seedless) and diploid (seeded) varieties within the same field.

In some growing seasons, vine crops that have recently been transplanted or have just germinated suddenly wilt and die. Most often, this situation occurs just following a period of 4-5 days of rainy or cloudy weather. Without sunshine, soil temperatures drop below 55-60°F. At these soil temperatures the plant roots cannot absorb water from the soil. Consequently, when the sun does reappear, water transpires from the leaves much more rapidly than the roots absorb water, resulting in sudden wilting and death. There is no control for this problem, except to attempt to manipulate planting around weather forecasts. Earlier planting dates increase the likelihood of this problem. Transplants can also be injured by excessive heat, especially when planted into black plastic mulch when temperatures are high and air pockets under the mulch get superheated, and/or when stems touch black plastic and are scorched. White-on-black plastic, which does not absorb as much heat, can be used for late-season cucurbits to avoid this outcome.

Field Culture

Early and total yields are increased with black plastic mulch. For summer plantings when daytime temperatures are 85°F or greater, more growers are using white-on-black plastic mulch to avoid high soil temperatures that develop under black plastic. Before the plastic is laid, be sure the soil is fertilized and the soil surface is smooth. The plastic should fit snugly against the surface. Do not lay plastic on dry soil; either irrigate or wait for rain to ensure the soil is moist prior to laying the mulch. In conjunction with plastic mulching, using hoops and spunbonded row covers early in the season will provide earlier and higher yields, while also helping to control insects such as striped cucumber beetle. Apply the covers at the time of planting and leave on until flowers are present to allow for pollination by bees. These crops can withstand high temperatures under the covers. A sufficient number of pollinating insects should be present to ensure adequate fruit set in cucumber and melons. If honeybees are to be used, one strong hive of honeybees per acre as flowers just begin to open is recommended.

Cucumber Protected Culture

For greenhouse or high tunnel production, growers may choose to use varieties that are parthenocarpic, meaning that they set fruit without pollination. Other types can be grown, but will require pollination which could be prevented or limited by the structure and other exclusion techniques employed for pest management. However, if parthenocarpic varieties are pollinated, fruit quality is reduced. In more open high tunnel structures where pollinators are likely to visit, it may be better to avoid parthenocarpic varieties and use gynoecious varieties, which produce mostly female flowers.

Cucumbers are vigorous plants and often exceed the height of the trellis system. In protected systems, cucumbers are best trellised to use space efficiently, promote an easier harvest, and encourage airflow. This can be done by using netting (commonly used with unpruned field types) or by wrapping or clipping to strings (similar to high tunnel tomato production). Cucumbers can be pruned back to 1 or 2 leaders in these systems and subsequent pruning is needed on a regular basis to remove future lateral branches, known as suckers.

Growers have managed this by heading the top of the plant above a node and allowing two lateral branches to develop and grow down in an “umbrella” system. Other growers simply allow the single or double leaders to hang and grow back down. A third system involves lowering and leaning cucumbers just like indoor tomato plants.

Protected culture cucumbers have been grown successfully with various spacings. A common spacing is 18-24” in-row spacing on beds with single rows. However, single rows using 12” in-row spacing and double rows using staggered 24” spacing are both used. Between-row spacing should be 4-6'. Match spacing with needs, varieties, pruning, and management systems.

Harvest and Storage

Cucumber. Harvest 3-4 times per week to obtain the maximum number of fruits. Cucumbers are sensitive to chilling injury; optimum storage temperature is 50-55°F.

Muskmelon. Melons change color as they ripen, generally taking on a yellow hue. Harvest cantaloupe and galia-types from half- to full-slip, when the melon receptacle becomes corky and a slight push of the stem will cause the melon to separate from the vine. At half-slip they are less ripe and shelf life is increased, but some flavor may be compromised.

Only well-netted cantaloupes should be harvested; fruits with poor netting have generally been stunted in growth and lack good flavor. Other muskmelon types require different harvesting techniques which can be specific to individual varieties. Generally, honeydews lose their fuzzy feel and must be cut from the vine at peak ripeness. Canary and crenshaw melons are harvested at forced-slip. Hold muskmelons for 1-2 days at 70°F for final ripening; for longer periods of storage, maintain a temperature of 50-55°F. Long shelf life (LSL) or ‘harper’ style melons have been bred to hold for controlled pick harvests.

Watermelon. Varieties vary in maturity indicators. The proper time to harvest must be learned by experience (and perhaps by wasting a few fruits). Dried (brown) tendrils and ground spots are two generally reliable indicators of ripeness. When the tendril on the vine at the juncture of the fruit stem turns brown, the watermelon is close to maturity. A bright yellow ground spot on the underside of the fruit also indicates maturity. The thumping method to identify ripe melons can work, after some experience is developed. Store watermelons at 50-55°F.

Cucumber, Muskmelon and Watermelon Disease Control

Cucumber & Melon - General Cucumber & Melon Insect Control Cucumber & Melon Weed Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 26 and Fungicides and Bactericides Alphabetically Listed by Trade Name for more information on products with the same active ingredients.

The symbol ^OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

PESTICIDE USE IN GREENHOUSES AND HIGH TUNNELS:

Pesticides can be used on high tunnel and greenhouse crops if: 1) the crop and pest/disease is on the label, AND the products specifically says it can be used in the greenhouse; OR 2) the crop and pest/disease is on the label, AND the product is ‘silent’ about use in the greenhouse in the greenhouse. Products that specifically prohibit greenhouse use cannot be used in greenhouses or high tunnels regardless of the crops or pests/diseases listed on the label.

Angular Leaf Spot (Pseudomonas syringae pv. lachrymans)

The symptoms of angular leaf spot appear as small, angular brown spots with a yellow halo on the foliage. Leaf spots eventually dry out and fall through leaving holes in the leaves. Spots are typically confined to the veins of the leaves, giving infected plants the characteristic angular spots. On fruit, lesions are small, tan, and appear water-soaked. Fruit is later affected by soft rot that can consume the entire fruit as the disease progresses. Avoid working in the fields when the foliage is wet. Plow crop residue under promptly after harvest to aid decomposition. Rotate out of cucurbits for 2 years. Plant resistant varieties when possible. Use pathogen-free seed or treat with hot-water to kill the bacterium in the seed. Sprays may not be effective if applied too late or if environmental conditions are conducive to spread of the disease.

copper hydroxide (Kocide 3000^OG): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.
mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.

Anthracnose (Colletotrichum), Alternaria Leaf Spot, and Black Rot (Didymella)

Anthracnose symptoms appear on cucurbits as circular, water-soaked leaf spots. These eventually turn yellow/tan and can become brown and necrotic. Alternaria symptoms first appear on older leaves near the crown. Lesions are small, yellow-brown, and have a characteristic yellow halo around the infected spots. Black rot symptoms usually appear after harvest as small dark watery lesions on the fruit surface. Black fruiting bodies from the fungus can typically be seen on the fruit and appear as black specks. Plant only certified disease-free seed. Rotate out of cucurbits for at least 2 years. Control all weeds, especially volunteer cucurbits. Collect and burn or plow down deeply all infected crop debris after harvest. Grow cultivars with resistance if available. Avoid wounding fruit during harvesting. Immerse fruit in clean and fresh water containing a post-harvest sanitizer. Chemical control can be obtained through a regular spray program of targeted and protective fungicides. Coverage of leaf undersides and fruit is crucial to success.

azoxystrobin (Quadris): 11.0 to 15.5 fl oz/A; PHI 1d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.
azoxystrobin plus chlorothalonil (Quadris Opti): 3.2 pt/A; PHI 1d, REI 12h, Groups 11 & M05. See label for tank mix precautions.
azoxystrobin plus difenoconazole (Quadris Top): 10.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.
boscalid (Endura): 6.5 oz/A; PHI 0d, REI 12h, Group 7. Black rot and Alternaria only.
chlorothalonil (Bravo Weather Stik): 1.5 to 3.0 pt/A; PHI 0d, REI 12h, Group M05. Bravo WS can cause injury to watermelon fruit; see label.
copper hydroxide (Kocide 3000^OG): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette.
cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 1d, REI 12h, Groups 9 & 12.
difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Groups 3 & 9. Apply in sufficient volume to achieve thorough coverage.
famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Tank mix with an appropriate contact fungicide with a different mode of action. Anthracnose and Alternaria only.
fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 14d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides. Alternaria only.
fluopyram plus tebuconazole (Luna Experience): 6.0 to 17.0 fl oz/A; PHI 7d, REI 12h, Groups 7 & 3. Watermelon only.
mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03. Some cantaloupe varieties are sensitive.
mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.
penthiopyrad (Fontelis): 12.0 to 16.0 fl oz/A; PHI 1d, REI 12h, Group 7. Black rot and Alternaria only.
polyoxin D (OSO 5%SC^OG): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.
potassium bicarbonate (MilStop^OG): 2.0 to 5.0 lb/100 gal/A; PHI 0d, REI 1h, Group NC. See label for small volume application rates.
pyraclostrobin (Cabrio EG): 12.0 to 16.0 oz/A; PHI 0d, REI 12h, Group 11.
pyraclostrobin plus boscalid (Pristine): 12.5 to 18.5 oz/A; PHI 0d, REI 12h, Groups 11 &7. Do not make more than 1 application before alternating with a non-Group 11 fungicide.
thiophanate methyl (Topsin M 70WP): 0.5 lb/A; PHI 1d, REI 24h, Group 1. Repeated exclusive use may lead to buildup of resistant strains of fungi and loss of disease control. Anthracnose and black rot only.

Bacterial Wilt (Erwinia tracheiphila)

Bacterial wilt is transmitted by cucumber beetles. Symptoms of this disease cause foliage to become a dull green and wilt during the day, recovering at night. As the disease progresses, leaves eventually turn yellow and brown at the margins and die back. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. Seedlings at the cotyledon and 1- to 3-leaf stage are more susceptible to infection with bacterial wilt than older plants. Thus, it is especially important to keep beetle numbers low before the 5-leaf stage. Cucumber beetles must be controlled by appropriate insecticide programs. Please refer to the information on cucumber beetle for management recommendations. Use crop rotation to reduce beetle numbers. Because this bacterium is transmitted systemically by cucumber beetles, bactericide sprays are not effective.

Cucumber Mosaic Virus (CMV)

Many different strains of this virus occur and the host range includes plants in more than 31 different families. Many weed species also serve as hosts and the virus is seedborne in chickweed. Symptoms of infection include stunting, yellow leaf spots, vein yellowing, malformation of leaves, and a mosaic pattern of light and dark green on leaves. On fruit, the viral symptoms appear as ring-spots or line patterns. The virus is spread by more than 40 species of aphids and 2 beetles. Seed transmission is possible but unlikely in commercial cucumber seed. The abundance of other host plants, their proximity to crops, and the presence of vectors govern the incidence and severity of disease. The use of resistant varieties is the most effective means of control. Reduce weeds, especially chickweed, pokeweed and milkweed, as much as practical. Practice rotation and plant away from previously contaminated fields. Insecticides are not effective.

Downy Mildew (Pseudoperonospora cubensis)

Pseudoperonospora cubensis only infects members of the cucurbit family and is an obligate parasite. Its survival depends on the presence of living cucurbit hosts, either in climates that permit their growth year round or in greenhouse culture. The source of primary inoculum in cold climates is windblown sporangia from areas where plants survive the cold season. Generally, downy mildew of cucurbits does not arrive in southern New England until August. However, in some seasons it can move up the eastern seaboard early and arrive in July. The progress of downy mildew is tracked by the North American Plant Disease Forecast Center (http://cdm.ipmpipe.org/). Symptoms of downy mildew include small angular lesions on the leaves which stay confined to the veins. These lesions later develop into darker necrotic spots and usually develop grey fuzzy fungal growth under leaves. Physiological specialization occurs in P. cubensis and at least 5 pathotypes have been described. Cucumber and melon are susceptible to all pathotypes, while squash and pumpkin cultivars vary in their reactions. Spread of downy mildew can occur over long distances by air currents and moves within a field via wind-dispersed sporangia. The main means of control are fungicide applications, the use of resistant cultivars, and cultural practices. Maximum control can be achieved only with a combination of these measures.

Some commercial cultivars of cucumber have good levels of resistance to downy mildew. Watermelon and melon cultivars are available with low levels of resistance. Squash and pumpkin cultivars are resistant to some pathotypes and outbreaks of non-resistant pathotypes do not usually occur in New ENgland until very late in the season, typically causing minimal yield losses.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40.
azoxystrobin plus chlorothalonil (Quadris Opti): 3.2 pt/A; PHI 1d, REI 12h, Groups 11 & M05. See label for tank mix precautions.
Bacillus amyloliquefaciens strain D747 (DoubleNickel^OG): 0.25 to 3.0 lb/A; PHI 0d, REI 4h, Group BM02. Disease suppression only. For improved control, mix or rotate with a chemical fungicide.
chlorothalonil (Bravo Weather Stik): 1.5 to 2.0 pt/A; PHI 0d, REI 12h, Group M05.
copper hydroxide (Kocide 3000^OG): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH of less than 6.5 or tank mix with Aliette.
cyazofamid (Ranman 400 SC): 2.1 to 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Alternate sprays of Ranman with a fungicide with a different mode of action.
cymoxanil (Curzate 60 DF): 3.2 to 5.0 oz/A; PHI 3d, REI 12h, Group 27. Use only in combination of a labeled rate of a protectant fungicide (copper, chlorothalonil, mancozeb).
dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Apply only in combination with a labeled rate of another non-Group 40 fungicide. Do not make more than 2 sequential applications of Forum before alternating to a fungicide with a different mode of action.
ethaboxam (Elumin): 8.0 fl oz/A; PHI 2d, REI 12h, Group 22. See label for restrictions.
famoxadone plus cymoxanil (Tanos): 8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Tank mix with an appropriate contact fungicide with a different mode of action.
fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 14d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides.
fluazinam (Omega 500F): 12.0 to 24.0 fl oz/A; PHI 7d and 30d (see label), REI 12h, Group 29. See label for restrictions.
fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. A tank mix with another labeled fungicide with a different mode of action must be used for resistance management.
fosetyl-Al (Aliette WDG): 2.0 to 5.0 lb/A; PHI 12d, REI 24h, Group P7. Do not tank mix with copper products or apply in a spray solution with a pH less than 6.0.
mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03.
mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.
mancozeb plus zoxamide (Gavel 75DF): 1.5 to 2.0 lb/A; PHI 5d, REI 48h, Groups M03 & 22. Apply preventively. Do not tank mix with other fungicides if downy mildew is the only target pest.
oxathiapiprolin (Orondis Ultra): 5.5 to 8.0 fl.oz/A; PHI 0d, REI 4h, Groups 49 & 40. Begin foliar application prior to disease development. Use higher rate when disease is present.
phosphorous acid (Fosphite): 1.0 to 3.0 qt/20.0 gal (foliar); PHI 0d, REI 4h, Group P07. Do not apply to plants that are heat- or moisture-stressed. Do not apply directly plants treated with copper within 20-day interval to avoid plant injury. See label for other application methods and additional restrictions.
propamocarb HCl (Previcur Flex): 1.2 pt/A; PHI 2d, REI 12h, Group 28. Alternate with a contact fungicide (copper, chlorothalonil, sulfur).
Reynoutria sachalinensis extract (Regalia^OG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application methods and restrictions.
zoxamide + chlorothalonil (Zing!): 30.0 to 36.0 fl oz/A; PHI 0d, REI 12h, Groups 22 & M05.

Phytophthora Blight and Fruit Rot (Phytophthora capsici)

Symptoms of this disease can occur at any stage of development. In seedlings symptoms are characteristic of damping off. On vines it appears as water-soaked lesions that become dark and later girdle the stems causing collapse and foliage death. On the foliage, symptoms include chlorosis, water-soaked lesions, and leaf death. Lesions will usually begin as small spots and quickly become necrotic with an olive green border around the spots. P. capsici cannot be managed by fungicide applications alone; successful disease control is achieved only by a season-long effort to manage water and other cultural practices. The single most effective way to control this disease is to prevent its movement into clean fields by equipment, humans, or infested water. Plant susceptible crops (tomatoes, peppers, eggplant, all cucurbit species, and beans) in fields that have no history of this disease and are well-drained. Plant non-vining crops on raised beds, avoid planting in low areas where water puddles, and improve drainage by sub-soiling. Promptly disk under small areas where the disease appears, along with a border of healthy-appearing plants. Avoid working in wet fields and minimize compaction.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 & 40.
cyazofamid (Ranman 400 SC): 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Addition of a surfactant improves effectiveness when disease pressure is severe. Alternate sprays of Ranman with a fungicide with a different mode of action. Observe a 30-day plant back interval for crops not on label.
dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Apply only in combination with a labeled rate of another non-Group 40 fungicide. Do not make more than 2 sequential applications before alternating to a fungicide with a different mode of action.
famoxadone plus cymoxanil (Tanos): 8.0 to 10.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Suppression only. Foliar or fruit phase only. Tank mix with an appropriate contact fungicide. Do not alternate with other Group 11 fungicides.
fluazinam (Omega 500F): 12.0 to 24.0 fl oz/A; PHI 7d & 30d (see label), REI 12h, Group 29. See label for restrictions.
fluopicolide (Presidio 4SC): 3.0 to 4.0 fl oz/A; PHI 2d, REI 12h, Group 43. A tank mix with another labeled fungicide with a different mode of action is required.
fosetyl Al (Aliette WDG): 2.0 to 5.0 lb/A; PHI 12d, REI 24h, Group P7. Do not tank mix with copper compounds. Mixing Aliette with surfactants or foliar fertilizers is not recommended. Use the high rate when Phytophthora blight is active.
oxathiapiprolin (Orondis Ultra): 5.5 to 8.0 fl.oz/A; PHI 0d, REI 4h, Groups 49 & 40. Begin foliar application prior to disease development.
phosphorous acid (Fosphite): 1.0 to 3.0 qt/20.0 gal (foliar); PHI 0d, REI 4h, Group P7. Do not apply to plants that are heat- or moisture-stressed. Do not apply directly to plants treated with copper within 20-day interval to avoid plant injury. See label for other application methods and additional restrictions.
Reynoutria sachalinensis extract (Regalia^OG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group P5. Apply to ensure thorough coverage. See label for specific application methods and restrictions.

Powdery Mildew (Podosphaera xanthii)

Powdery mildew infections are very characteristic to its name. Symptoms of this disease first appear as pale yellow leaf spots. As the disease progresses these spots develop into powdery, white patches across the bottom and top of the leaf surface. Unlike downy mildew, the symptoms of this disease are not confined to the veins of the foliage and can spread over any part of the plant. Older plants are typically affected first. Fungicides should be applied at the first sign of disease (or earlier with some products). Begin scouting for powdery mildew at fruit initiation. On cucurbits, powdery mildew fungi attack both the top and bottom of the leaf, and this makes the disease more difficult to control with non-systemic fungicides. However, powdery mildew fungi tend to become resistant to systemic fungicides such as Topsin-M (Group 1) and Cabrio, Flint Extra, Quadris, and Sovran (Group 11). Resistance to Group 1 and Group 11 fungicides have resulted in the removal of these classes of fungicides from recommendations, with the exception of Pristine which is a combination product. Resistance to the DMI fungicides (Group 3, e.g. Rally, Procure) is also widespread; use these products at the high labeled rate only. The most effective contact fungicides are sulfur, mineral oil, and chlorothalonil. Begin applying fungicides when powdery mildew is at a low level (less than 1 of 50 old leaves with symptoms on either leaf surface); do not begin using mobile fungicides when disease is widespread. A 7-day interval is recommended once disease is observed.

Bacillus amyloliquefaciens strain D747 (DoubleNickel^OG): 0.25 to 3.0 lb/A; PHI 0d, REI 4h, Group BM02. Disease suppression only. For improved control, mix or rotate with a chemical fungicide.
boscalid (Endura): 6.5 oz/A; PHI 0d, REI 12h, Group 7. Suppression only.
botanical extract (Ecoswing^OG): 1.5 to 5.0 pt/A; PHI 0d, REI 4h, Group BM01.
chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 pt/A; PHI 0d, REI 12h, Group M05. Use caution when applying to watermelon. See label for restrictions.
copper hydroxide (Kocide 3000^OG): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.
cyprodinil plus fludioxonil (Switch 62.55 WG): 11.0 to 14.0 oz/A; PHI 1d, REI 12h, Groups 9 & 12.
cyflufenamid (Torino): 1.7 to 3.4 oz/A; PHI 0d, REI 4h, Group U6.
difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Groups 3 & 9.
fluopyram plus tebuconazole (Luna Experience): 6.0 to 17.0 fl oz/A; PHI 7d, REI 12h, Groups 7 & 3. Watermelon only.
flutriafol (Rhyme 2.08 SC): 5.0 to 7.0 fl oz/A; PHI 0d, REI 12h, Group 3.
mineral oil (JMS Stylet-oil^OG): 3.0 to 6.0 qt/100.0 gal; PHI 0d, REI 4h, Group NC.
metrafenone (Vivando): 10.3 to 15.4 fl oz/A; PHI 0d, REI 12h, Group 50.
potasium dihydrogen phosphate (Nutrol): 10.0 to 20.0 lb/A; PHI 0d, REI 4h, Group P7.
myclobutanil (Rally 40 WSP): 2.5 to 5.0 oz/A; PHI 0d, REI 24h, Group 3.
penthiopyrad (Fontelis): 12.0 to 16.0 fl oz/A; PHI 1d, REI 12h, Group 7.
polyoxin D (OSO 5%SC^OG): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.
potassium bicarbonate (Kaligreen^OG): 2.5 to 5.0 lb/A; PHI 1d, REI 4h, Group NC. Not labeled for muskmelon. See label.
quinoxyfen (Quintec): 4.0 to 6.0 fl oz/A; PHI 3d, REI 12h, Group 13. Melon only. Alternate with other effective fungicides at their recommended rates and spray intervals.
sulfur (Microthiol Disperss^OG): 2.0 to 4.0 lb/A; PHI 0d, REI 24h, Group M02. Sulfur can injure plants, especially at temperatures above 90° F. Do not apply to sulfur-sensitive varieties.
triflumizole (Procure 480SC): 4.0 to 8.0 oz/A; PHI 0d, REI 12h, Group 3. Alternate with a protectant fungicide (copper, chlorothalonil, mancozeb, sulfur).
triflumizole (Trionic 4 SC): 4.0 to 8.0 fl oz/100 gal.; PHI 1d, REI 12, Group 3. Apply only as foliar spray. See label for surfactant recommendation. Labeled for greenhouse use.

Scab (Cladosporium cucumerinum)

Scab is a significant problem for summer and winter squash, pumpkin, melon, and watermelon. Symptoms of this disease appear on both the foliage and fruit. On foliage, symptoms are greyish-brown lesions with a yellow halo. Depending on the severity of infection, the disease can also cause leaf deformation. Fruit symptoms appear small at first and can grow into larger, dark pockmarks. As the disease progresses, lesions on fruit can grow together and become entry points for secondary infections. Resistant cultivars of cucumber are widely available. The pathogen can live on infected crop debris on or in the soil and may be seedborne. Rotate with non-cucurbit crops for 2-3 years. Select sites with well-drained soil and good air movement for rapid drying of foliage and fruit. Avoid overhead irrigation and dense plant canopies. Fungicide sprays may not be effective during extended cool, wet weather due to the short disease cycle of this pathogen.

acibenzolar-S-methyl (Actigard 50 WG): 0.5 to 2.0 oz/A; PHI 0d, REI 12h, Group P1. For surpression only.
chlorothalonil (Bravo Weather Stik): 2.0 to 3.0 lb/A; PHI 0d, REI 12h, Group M05. Use caution when applying to watermelon. See label for restrictions.
mancozeb (Dithane F45): 1.6 to 2.4 qt/A; PHI 5d, REI 24h, Group M03.
mancozeb plus copper hydroxide (ManKocide): 2.0 to 3.0 lb/A; PHI 5d, REI 48h, Groups M03 & M01.
polyoxin D (OSO 5%SC^OG): 6.5 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

Seed Decay

Buy fungicide-treated seed. Do not use treated seed for food, feed or oil purposes.

Bacillus amyloliquefaciens strain D747 (DoubleNickel^OG): 0.01 to 0.4 fl oz/100,000 seeds; PHI 0d, REI 4h, Group BM02.
fludioxonil (Maxim 4 FS): 0.08 to 0.16 fl oz/100 lb seed; REI 12h, Group 12. For protection against seed and soil-borne fungi.
mefenoxam (Apron XL SC): 0.085 to 0.64 fl oz/lb seed; REI 48h, Group 4. For Pythium damping-off protection.
thiram (Thiram SC): 4.5 fl oz/100 lb seed; REI 24h, Group M03.

Watermelon Mosaic Virus (WMV) and Papaya Ringspot Virus (PRSV-W)

Several aphid species transmit these 2 viruses. PRSV-W is only known to occur in the cucurbit family but WMV has been reported from alfalfa, vetch, crimson clover, sour clover, snow-on-the-mountain, and mallow. Seed transmission is considered a possibility but remains unproven. Symptoms of this virus include stunted growth, leaf malformation, mottling and marginal chlorosis. On fruit, symptoms appear as mottling and bumpy warts or blister-like areas.

Zucchini Yellow Mosaic Virus (ZYMV)

ZYMV was first discovered in the United States in the early 1980s. Two strains, Connecticut and Florida, are currently recognized. The Connecticut strain produces more severe symptoms than the Florida strain. Symptoms include severe malformation, blisters, necrosis, and severe plant stunting. On the fruit, the virus causes knobby areas and prominent deformation. The virus is transmitted in a non-persistent manner by aphids. At this time, no weed hosts have been identified. Resistant varieties are now available.

Disease Control

Cucumber, Muskmelon and Watermelon Insect Control

Cucumber & Melon - General Cucumber & Melon Disease Control Cucumber & Melon Weed Control

NOTES: For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (AI) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same AI. Please see Table 27 and Insecticides Alphabetically Listed by Trade Name for more information on these insecticides.

The designation (Bee: L, M, or H) indicates a bee toxicity rating of low, moderate, or high. See the Protecting Honeybees and Native Pollinators section for more details.

The symbol * indicates a product is a restricted use pesticide. See Pesticide Safety and Use for more details.

The symbol ^OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.

Caution: Insecticides should not be applied when bees are active in the field. Avoid products with high or moderate bee toxicity during bloom. If application of an insecticide is necessary while the crop is blooming, select products with low bee toxicity or with short residual period; apply in the evening after the bees have left the field. See Protecting Honeybees and Native Pollinators in the Insect Management section for more suggestions on how to avoid harmful effects on pollinators.

Aphids, Green Peach (Myzus persicae) and Melon (Aphis gossypii)

Aphids found in cucurbits include green peach aphid and melon aphid. See Peppers for more information about green peach aphids. The melon aphid has a wide host range; vegetable crops attacked include cucurbits, asparagus, pepper, eggplant, and okra. Among cucurbits, it is more serious on cucumber, muskmelon, and watermelon than in squash and pumpkins. Varieties differ in susceptibility. Melon aphids overwinter in the north on woody plants, including catalpa and rose of Sharon; more southerly (and in high tunnels with winter production), adults survive on cold tolerant plants, including spinach and dock. The life cycle is similar to the green peach aphid; winged females colonize crops in early summer, and wingless females produce live young for about 15 days (70-80 offspring per female), resulting in multiple generations.

The time from birth to reproductive adult can be 1 week. Wingless females are 1-2 mm long. Color varies from light green mottled with dark green (most common) to white, yellowish, or dark green. The cornicles at the tip of the abdomen are always black, a key diagnostic feature. Melon aphid outbreaks are more common in hot, dry weather.

Infestations occur on the undersides of leaves where aphids extract plant sap with their piecing-sucking mouthparts. Feeding causes yellowing, puckering, leaf curling, and leaf death at high numbers, along with shiny honeydew deposits and the buildup of sooty mold. Viruses transmitted by melon aphids include cucumber mosaic virus, watermelon mosaic virus, and zucchini yellow mosaic virus. Because transmission occurs within 15 seconds of feeding, insecticides may not prevent initial virus infection but may reduce its spread in the crop. Oils may reduce virus transmission but test for phytotoxicity.

Using reflective mulch or row covers may prevent early infestation and virus transmission. Reflective mulch confuses aphid orientation and reduces their ability to locate and infest plants. Direct-seeding is recommended in reflective mulch for maximum effectiveness. When using row cover, apply immediately after setting transplants or seeding, and be sure transplants were not infested while in the greenhouse. Cultivars differ in susceptibility to aphid buildup and to viruses; plant resistant varieties, if available. Separate early and late plantings.

Scout for aphids beginning in mid-June by searching the undersides of leaves on runners. Treatment may be needed if 20% of runners or more have live aphids. Good coverage of the undersides of leaves is needed with materials that require direct contact with the pests; translaminar products help to reach aphid feeding sites. Use selective insecticides for other pests to conserve natural enemies.

acetamiprid (Assail 30 SG): 2.5 to 4 oz/A; PHI 0d, REI 12h, Bee: M, Group 4A.
afidopyropen (Sefina): 3 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D.
alpha-cypermethrin (Fastac* CS): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
azadirachtin (Azatin O^OG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L, Group UN. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.
cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. For best performance, use with an effective adjuvant.
cyantraniliprole (Verimark): 6.75 to 13.5 oz/A cotton/melon aphid and 10 to 13.5 oz/A green peach aphid at planting, 6.75 to 10 oz/A cotton/melon aphid and 10 oz/A greean peach aphid chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applicationes at planting, or drip chemigation during first half of crop growing cycle.
cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28. For best results, use with an effective adjuvant. Melon aphid only.
dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A for watermelon; 1 pt/A for other melons; PHI 3d, REI 48h, Bee: H, Group 1B. Melons only.
dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. Cucumber and melon transplants only, while in greenhouse. Not for use on field or greenhouse grown crops.
dinotefuran (Venom): 1 to 4 dry oz/A foliar or 5 to 7.5 dry oz/A soil; PHI 1d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Soil application may be as a band during bedding, in-furrow at seeding, as a transplant or post-seeding drench, as a sidedress, or through drip. Do not apply to vegetables grown for seed. Suppression only.
flonicamid (Beleaf 50SG): 2 to 2.8 oz/A, 2.8 to 4.28 oz/A or 0.065 to 0.1 oz/1000 sq ft for greenhouse cucumbers; PHI 0d, REI 12h, Bee: L, Group 9C.
flupyradifurone (Sivanto): 7 to 12 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 4h, Bee: L, Group 4D.
gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
imidacloprid (Admire Pro): 7 to 10.5 oz/A soil; 0.44 fl oz/10,000 plants on seedling transplants in greenhouse; PHI 21d, REI 12h, Bee: H, Group 4A. Greenhouse applications only provide short-term protection. An additional field application must be made within 2 weeks following transplanting to provide continuous protection. Not for foliar applications.
insecticidal soap (M-Pede^OG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Apply with a labeled companion insecticide on green peach aphids. On other aphids, use of a companion insecticide is recommended for enhanced and residual control.
lambda-cyhalothrin (Warrior* II): 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 24h cucumber, 12h melons, Bee: H, Group 1B. Do not apply unless plants are dry.
methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d for 1.5 pt/A; PHI 3d for over 1.5 pt/A, REI 48h, Bee: H, Group 1A. Melon aphid only.
oxamyl (Vydate* L): 2 to 4 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A.
petroleum oil (Suffoil X^OG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L.
pymetrozine (Fulfill): 2.75 oz/A; PHI 0d, REI 12h, Bee: L, Group 9A. Selective control of aphids including melon and green peach aphid. Translaminar. Apply before populations build up.
pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur, or oils.
thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.
thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. Do not apply as a foliar spray.
tolfenpyrad (Torac): 17 to 21 fl oz/A; PHI 1d, REI 12h, Bee: H, Group 21A.

Cucumber Beetle, Striped (Acalymma vittatum) and Spotted (Diabrotica undecimpunctata)

The striped cucumber beetle is a key pest of all cucurbit crops in New England, one that requires cultural and often chemical controls to prevent direct feeding damage and transmission of bacterial wilt. Adult beetles are 7 mm long, are yellow with 3 black stripes that reach the end of the forewings, and have a yellow thorax and black head. Adults overwinter primarily in field edges near last year's crop, with a small proportion remaining in the field. With the onset of warm days (> 50°F), beetles feed on pollen in early-blooming wild plants. High tunnel and greenhouse cucumbers draw beetles first, followed by early field crops. After mating, eggs are laid in soil at the base of the stem, and larvae feed on roots. After pupation in the soil, 'summer adults' emerge, generally in late July and August. Summer adults feed until early fall when they move to overwintering sites. Some may produce a second generation, which emerges in the fall. There is one generation per year in northern New England and a partial second generation in southern New England.

Beetles can colonize a field very rapidly. Adults cause direct feeding damage to cotyledons (often as gouges on the underside), leaves (ragged holes), and the base of the stem (wounds and scars). Wounds on the stem allow entry of soil-borne pathogens. Once flowering begins, beetles congregate in flowers. Adults may feed directly on fruit in high numbers, causing pits and scars. Larval root feeding, hidden but important, reduces plant vigor and yield. The striped cucumber beetle also vectors Erwinia tracheiphila, the causal agent of bacterial wilt. The pathogen overwinters in the beetle gut and is transmitted through fecal material deposited in feeding wounds. The bacteria then invade the vascular system of the plant. Non-infected beetles can become infected by feeding on infected plants. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. Seedlings at the cotyledon and 1- to 3-leaf stage are more susceptible to infection with bacterial wilt than older plants. Thus, keeping beetle numbers low before the 5-leaf stage is especially important.

Use crop rotation, moving spring crops from last year’s fields and overwintering areas as far as possible. Exclude beetles using row covers supported by hoops to prevent abrasion; remove at flowering to allow pollination. Use transplants so that plants reach at least the 3- to 4-leaf stage before beetles arrive. Some repellents or systemic insecticides may be applied to transplants outside the greenhouse before setting in the field, and some may be applied through drip irrigation. See cucumber beetle in the insect control section of Pumpkin, Squash, and Gourds for information on using trap crops to protect a main crop of cucumbers and melons from beetle damage.

Scout twice per week from emergence to 3-leaf stage, then weekly. Count beetles per plant and note damage to leaves and stems. The economic threshold depends on the crop. To prevent bacterial wilt in highly susceptible crops such as cucumber, muskmelons, summer squash, and zucchini, treat when there is 1 beetle for every 2 plants. Less wilt-susceptible crops (butternut, watermelon, most pumpkins) will tolerate 1 or 2 beetles per plant without yield losses. Spray within 24 hours after the threshold is reached. Timely and effective early control will prevent the need for sprays during flowering when bees are active in the crop. There are minimal options for bee-friendly insecticides to use during flowering; if sprays are needed, apply in the evening after bees have stopped foraging.

Spotted cucumber beetle does not overwinter here but disperses from more southern areas, reaching New England in mid to late summer. Also known as southern corn rootworm, it feeds on a very wide range of crops and weeds and is often found in flowers. Adults are yellowish green with 12 black spots and a black head. Immature stages are in the soil. This pest rarely builds up to damaging levels in New England.

acetamiprid (Assail 30 SG): 2.5 to 5.3 oz/A; PHI 0d, REI 12h, Bee: H, Group 4A.
alpha-cypermethrin (Fastac* CS): 3.0 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Adults only.
beta-cyfluthrin (Baythroid* XL): 2.4 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.
bifenthrin (Brigade* 2 EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
carbaryl (Sevin XLR Plus): 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A. Do not apply when foliage is wet. Do not apply to crops or weeds in bloom.
cryolite (Prokil Cryolite): 8 to 16 lb/A; PHI 14d, REI 12h, Bee: L, Group UN. Melons only.
cyclaniliprole (Harvanta): 10.9 to 16.4 fl oz/A; PHI 1d, REI 4h, Bee: H, Group 28. Striped cucumber beetle only.
deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
dinotefuran (Venom): 1 to 4 oz/A foliar; PHI 1d, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed.
esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Adults only.
fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24h, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant. May be combined with Belay (see label for rates and increased PHI). Do not apply during bloom or if bees are actively foraging.
gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adults only.
imidacloprid (Admire Pro): 7 to 10.5 oz/A; PHI 21d, REI 12h, Bee: H, Group 4A. Soil applications only.
kaolin (Surround WP^OG): 25 to 50 lb/A or 0.25 to 0.5 lb/gal for backpack sprayer; PHI 0d, REI 4h, Bee: L. Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. Product residue may need to be washed off if applied after fruit set. White residue may be minimized if applications stop when fruit is 25% of its expected harvest size. Follow label instructions for mixing. Generally compatible as a tank mix with other insecticides.
lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Adults only.
malathion (Malathion 57 EC): 2 pt/A watermelons, 1.6 pt/A all other melons; PHI 1d, REI 12h, Bee: H, Group 1B. Melons only.
methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 1d for 1.5 pt/A, PHI 3d for over 1.5 pt/A, REI 48h, Bee: H, Group 1A.
permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A. Adults only.
pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
thiamethoxam (Actara): 3 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4. Suppression only.
thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. Do not apply as a foliar spray. Suppression only.
zeta-cypermethrin (Mustang*): 2.8 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A. Adults only.

Cutworms

See cutworms in the Pepper and Tomato (Outdoor) sections for more information on black and variegated cutworms.

alpha-cypermethrin (Fastac* CS): 1.4 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
Bacillus thuringiensis aizawai (XenTari^OG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L, Group 11. Must be ingested. Apply in evening before larvae are actively feeding. Adherence and weather-fastness will improve with use of an approved spreader-sticker. Use high rate at cool temperatures.
beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.
bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
deltamethrin (Delta Gold*): 1 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A. Seedling spray only.
gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
methomyl (Lannate* LV): 1.5 pt/A; PHI 1d, REI 48h, Bee: H, Group 1A. For variegated cutworm.
permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.
spinosad (Seduce^OG): 20 to 44 lb/A or 0.5 to1 lb/1000 sq ft; PHI 1d cucumber, 3d melons, REI 4h, Bee: M, Group 5. Spread bait on soil around plants. Reapply after heavy rain or at least every 2-4 weeks but not more than 3 times per 30 days.
zeta-cypermethrin (Mustang*): 1.28 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Seedcorn Maggot (Delia platura)

See seedcorn maggot in the Beans insect control section for more information.

cyantraniliprole (Verimark): 10 to 13.5 oz/A soil; PHI 1d, REI 4h, Bee: H, Group 28. Apply as in-furrow spray or transplant tray drench no earlier than 72 hours prior to planting in field, or as transplant water treatment, hill drench, or surface band.
dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A watermelon; 1 pt/A other melons; PHI 3d, REI 48h, Bee: H, Group 1B. Melons only.

Squash Bug (Anasa tristis)

See squash bugs in the insect control section of Pumpkin, Squash, and Gourds for more on life cycle, monitoring, and management.

acetamiprid (Assail 30 SG): 5.3 oz/A; PHI 0d, REI 12h, Bee: M, Group 4A. Most effective on newly laid eggs and nymphs.
alpha-cypermethrin (Fastac* CS): 3.0 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.
azadirachtin (Azatin O^OG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L, Group UN. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
bifenthrin (Brigade* 2EC): 2.6 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
carbaryl (Sevin XLR Plus): 1 qt/A; PHI 3d, REI 12h, Bee: H, Group 1A. Do not apply when foliage is wet. Apply sufficient spray volume for thorough coverage. Time sprays for early morning or late afternoon. Repeated application may cause plant injury.
dinotefuran (Venom): 1 to 4 dry oz/A foliar or 5 to 7.5 dry oz/A soil; PHI 1d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed.
esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24h, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant. May be combined with Belay (see label for rates and increased PHI). Do not apply during bloom or if bees are actively foraging.
flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar; PHI 1d, REI 4h, Bee: L, Group 4D. Foliar applications only.
gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A.
permethrin (Pounce* 25WP): 12.8 oz/A; PHI 0d, REI 12h, Bee: H, Group 3A.
pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
zeta-cypermethrin (Mustang*): 2.8 to 4 oz/A; PHI 1d, REI 12h, Bee: H, Group 3A.

Two-spotted Spider Mite (Tetranychus urticae)

Also known as red spider mite. Two-spotted spider mite (TSSM) outbreaks are often caused by the use of broad-spectrum insecticides that kill beneficial insects that normally keep populations in check, especially in field production. Watch for white speckling on the upper surface of leaves or webbing on the undersurface around leaf veins. Avoid early-season, broad-spectrum insecticide applications for other pests. Use selective products whenever possible. With most miticides (not bifenazate), use 2 applications, approximately 5-7 days apart, to help control immature mites that were in the egg stage and protected during the first application. TSSM are prone to developing pesticide resistance, so be sure to alternate between products after 2 applications to help prevent or delay resistance. For more information on TSSM, see the Eggplant section.

abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 7d, REI 12h, Bee: H, Group 6. Must be mixed with a non-ionic wetting, spreading, and/or penetrating spray adjuvant. Do not use binder or sticker type adjuvant.
bifenazate (Acramite 50WS): 0.75 to 1 lb/A; PHI 3d, REI 12h, Bee: L, Group 25.
bifenthrin (Brigade* 2 EC): 5.1 to 6.4 oz/A; PHI 3d, REI 12h, Bee: H, Group 3A.
etoxazole (Zeal): 2 to 3 oz/A; PHI 7d, REI 12h, Bee: L, Group 10B. Do not apply more than once per season.
fenpropathrin (Danitol* 2.4EC): 10.66 to 16 oz/A; PHI 7d, REI 24h, Bee: H, Group 3. Control may be improved by the addition of a non-ionic surfactant.
fenpyroximate (Portal XLO): 2 pt/A; PHI 1d cucumber, 3d melons, REI 12h, Bee: L, Group 21A. A selective contact miticide.
gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.
insecticidal soap (M-Pede^OG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Use of a companion labeled insecticide is recommended for enhanced and residual control.
malathion (Malathion 57 EC): 1.5 pt/A; PHI 1d, REI 12h, Bee: H, Group 1B. Melons only.
Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal (drench), 8 to 64 oz/A (foliar); PHI 0d, REI 4h, Bee: , Group UN.
neem oil (Trilogy^OG): 1 to 2% solution in 25 to 100 gal water/A; PHI 0d, REI 4h, Bee: M, Group 18. Avoid midday applications and ensure good coverage.
petroleum oil (Suffoil X^OG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L.
sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur, or oils.
spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 23. Complete coverage is necessary. An adjuvant may be used to improve coverage and control. Effective against egg and immature stages.

Whiteflies

See whiteflies in insect control section of Tomato for more information.

afidopyropen (Sefina): 14 fl oz/A; PHI 0d, REI 12h, Bee: L, Group 9D.
Chenopodium extract (Requiem EC): 2 to 4 qt/A; PHI 0d, REI 4h, Bee: L. Apply before pests reach damaging levels.
Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M, Group UN.
cyantraniliprole (Exirel): 13.5 to 20.5 oz/A; PHI 1d, REI 12h, Bee: H, Group 28. For best performance, use with an effective adjuvant.
cyantraniliprole (Verimark): 6.75 to 13.5 oz/A at planting, 10 oz/A chemigation; PHI 1d, REI 4h, Bee: H, Group 28. For soil applications at planting or drip chemigation during first half of crop growing cycle. Allow 1-3 days for control to be translocated into the aerial portions and to fully protect transplants following an at-plant application. Allow 2-5 days following chemigation.
dinotefuran (Safari 20SG): 0.16 to 0.32 oz/1,000 sq ft; 3.5 to 7 oz/100 gal; 7 to 14 oz/A; REI 12h, Bee: H, Group 4. Cucumber and melon transplants only, while in greenhouse. Not for use on field or greenhouse grown crops.
dinotefuran (Venom): 1 to 4 oz/A foliar or 5 to 7.5 oz/A soil; PHI 1d foliar, 21d soil, REI 12h, Bee: H, Group 4A. Do not apply to vegetables grown for seed.
fenpyroximate (Portal XLO): 2 pt/A; PHI 1d cucumber, 3d melons, REI 12h, Bee: L, Group 21A. Suppression only.
flonicamid (Beleaf 50SG): 2.8 dry oz/A, 4.28 oz/A or 0.1 oz/1000 sq ft for greenhouse cucumbers; PHI 0d, REI 12h, Bee: L, Group 9C. Suppression of greenhouse whitefly only.
flupyradifurone (Sivanto): 10.5 to 14 oz/A foliar, 21 to 28 oz/A soil; PHI 1d foliar, PHI 21d soil, REI 4h, Bee: L, Group 4D.
gamma-cyhalothrin (Declare*): 1.54 oz/A; PHI 1d, REI 24h, Bee: H, Group 3A. Suppression only.
imidacloprid (Admire Pro): 7 to 10.5 oz/A soil; 0.44 fl oz/10,000 plants on seedling transplants in greenhouse; PHI 21d, REI 12h, Bee: H, Group 4A. Greenhouse applications only provide short-term protection. An additional field application must be made within 2 weeks following transplanting to provide continuous protection. Not for foliar applications.
insecticidal soap (M-Pede^OG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Spray to wet all infested plant surfaces. May require repeated applications. Use of a companion labeled insecticide is recommended for enhanced and residual control.
Metarhizium anisopliae Strain F52 (Met 52 EC): 40 to 80 oz/100 gal (drench), 8 to 64 oz/A (foliar); PHI 0d, REI 4h, Bee: L, Group UN.
petroleum oil (Suffoil X^OG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L.
pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M, Group 3A.
pyriproxyfen (Knack): 8 to 10 oz/A; PHI 7d, REI 12h, Bee: L, Group 7. Does not control adults. Apply when whiteflies reach economic threshold. Higher water volumes may provide improved control.
sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal; REI 12h, Bee: L, Group 25. Do not apply in midday sun or mix with copper, sulfur, or oils.
spiromesifen (Oberon 2SC): 7 to 8.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 23. Complete coverage is necessary; an adjuvant may be used to improve coverage and control. Effective against egg and nymphal stages.
thiamethoxam (Actara): 3 to 5.5 oz/A; PHI 0d, REI 12h, Bee: H, Group 4.
thiamethoxam (Platinum): 5 to 11 oz/A; PHI 30d, REI 12h, Bee: H, Group 4. Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting or shanked into root zone after transplanting or establishment. Do not apply as a foliar spray.

Insect Control

Cucumber, Muskmelon and Watermelon Weed Control

Cucumber & Melon - General Cucumber & Melon Disease Control Cucumber & Melon Insect Control

NOTES: For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using.

Growing on Plastic Mulch

Many growers choose to grow cucumber, muskmelon, and/or watermelon on plastic mulch. Herbicides can be applied before laying down plastic to help control weeds that may grow underneath the plastic or in planting holes. Herbicides can also be used between beds of plastic. Some herbicides cannot be used under plastic, even if they are registered for use in the crop. Read labels carefully! See notes on specific herbicides in the following section for more information on use and timing.

Labeled for preemergence weed control under plastic:

bensulide (Prefar)
halosulfuron (Sandea) (cucumber and watermelon only)

Labeled for preemergence weed control between plastic beds(directed and shielded band applications):

bensulide (Prefar)
clomazone (Command)
ethalfluralin (Curbit)
halosulfuron (Sandea) (cucumber and watermelon only)
pendamthalin (Prowl) (melons only)

Labeled for postemergence application between plastic beds:

halosulfuron (Sandea) (cucumber and watermelon only)
paraquat (Gramoxone SL 2.0*)
clethodim (Select Max)
sethoxydim (Poast)

Stale Seedbed

See Stale Seedbed Technique for information on the use of these herbicides or flaming.

carfentrazone (Aim EC): PHI 0d, REI 12h, Group 14.
glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9.
paraquat (Gramoxone SL 2.0*): REI 12h or 24h, Group 22. May be fatal if swallowed or inhaled. *Restricted use: Applicators must complete an EPA-approved paraquat training every 3 years: https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0.

Preemergent Herbicides (before weeds germinate)

bensulide (Prefar 4E): REI 12h, Group 0. May be used under plastic. Apply 5-6 qts/A per application. Can be applied to flat planted or bedded crops. Incorporate 1-2” into the soil within 36 hours by shallow cultivation or with water through irrigation or rainfall. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control.
clomazone (Command 3ME): PHI 30d cucumbers, REI 12h, Group 13. For melons, apply 6.4-10.7 oz/A per application, only 1 application per year. For cucumbers, apply 6.4-16.2 oz/A per application, only 1 application per year. For all cucurbits can be applied after seeding but before emergence or before transplanting. Be sure to place the roots of transplants below the treated soil. Apply in a minimum of 10 gal/A of spray. Use the lower rate on sandy soils and the higher rate on silt and clay soils.
ethalfluralin (Curbit EC): REI 24h, Group 3. Apply 3-4.5 pt/A per application, only 1 application per year. Has not been tested on all varieties; crop tolerance should be verified before treating the entire field. Can be applied up to 2 days after seeding but before the crop emerges, or as a banded spray between rows after crop emergence. Activate with a minimum of 0.5" of water through irrigation (within 2 days after application) or rainfall (within 5 days of application) or a shallow cultivation. Rate based on soil texture. Do not use during cold, wet weather or crop injury or stunting may occur.
pendimethalin (Prowl H2O): PHI 35d, REI 24h, Group 3. Melon only. Apply up to 2.1 pt/A per application, up to 2 applications allowed per year, a minimum of 21 days apart. Do not exceed 4.2 pts/A per year. Can be applied as a shielded application between rows with 6” on either side of row middles (before melon transplanting or before a seeded crop has emerged), or between beds covered with plastic mulch (before holes are punched in plastic for melon planting). Avoid spray contact with melon foliage or running vines because crop injury will occur. If applying a 2nd time, maintain a minimum of 6” on either side of stem or vines or apply before melon vine running.
s-metolachlor (Dual Magnum): REI 24h, Group 15. MA and NH only. Make sure the label for your state is available for download before using this product. This is a restricted label available only to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge. All label instructions will be supplied after the application for use is completed.
sulfentrazone (Aquesta 4F): REI 12h, Group 14. Apply 3-8 oz/A per application, only 1 application per year. Rate based on soil texture, percent organic matter, and soil pH. Citron melon, muskmelon, and watermelon only. Apply from 48 hours before planting up to just before seedling emergence. If seedlings are close to soil surface or have emerged, do not apply solution directly to melons. Do not use on soils that contain less than 1% organic matter.

Pre- and Postemergent Herbicides

halosulfuron (Sandea): PHI 14d cucumber, 57d watermelon REI 12h, Group 2. Apply 0.5-1 oz/A per application, up to 2 application allowed per year, a minimum of 21 days apart. Do not exceed 2 oz/A per year. Apply in a minimum of 15 gal/A of spray or 20 gal/A of spray for watermelon. Use the lower rate on sandy soils and the higher rate on silt and clay soils.

Can be applied after planting seeds but prior to soil cracking, or before transplanting. Transplant into treated area no sooner than 7 days after application and take care to limit movement of treated soil. If using with plastic mulch, apply after the final bed shaping but before plastic installation. Crop may be seeded or planted no sooner than 7 days after application. Can also apply to row middles.

Can also be applied after the crop has reached at least 3-5 true leaves but before 1st female flowers appear and at least 14 days after transplanting crops if applicable. May be applied as an over-the-top application, or a directed spray application with shields to minimize contact of the herbicide with the crop. Can be applied to row middles of direct-seeded or transplanted. If plastic is used on the planted row, adjust equipment to keep the application off the plastic (over-the-top applications not allowed on plastic mulch).

Split applications will help with control of nutsedge (although not allowed in watermelon). Either apply before the crop emerges and gain after the crop emerges, or twice after the crop emerges. Use a spot treatment to target emerged nutsedge and do not exceed 1.0 oz per treated acre.

Can cause temporary stunting. Heavy rains following application or organophosphate use will increase the potential for crop injury.

Postemergent Herbicides (after weeds germinate)

carfentrazone (Aim EC): PHI 0d, REI 12h, Group 14. Apply 0.5-2 oz/A per application, multiple applications allowed per year. Do not exceed 6.1 oz/A per year. Apply to row middles of emerged crops with hooded sprayers to control emerged weeds, including crops grown on mulch or plastic. Prevent any spray from contacting the crop, or injury will occur. Can also be applied as a preplant burndown no later than 7 days before seeding with 15-30 gal/A of spray with a methylated seed oil. For best results, make application to actively growing weeds up to 4” tall and rosettes less than 3” across.
clethodim (Select Max): PHI 14d, REI 24h, Group 1. Apply 9-16 oz/A per application, up to 4 applications allowed per year, a minimum of 14 days apart. Do not exceed 64 oz/A per year. Apply to actively growing grasses. Add 0.25% v:v nonionic surfactant (1 qt/100 gal of spray). Can also be applied as a spot-spray by mixing 0.33-0.66% (0.44-0.85 oz/gal) Select Max and 0.25% v:v nonionic surfactant (0.33 oz/gal). Spray to wet, but do not allow runoff of spray solution.
glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9. Apply 10 oz to 3.1 qts/A per application, multiple applications allowed per year. Do not exceed 5 qts/A per year. Rate based on target weed species. Can be applied during fallow intervals, prior to planting or transplanting, at planting, or before crop has emerged. Allow a minimum of 3 days between application and seeding and do not apply after seeding for many varieties. Could cause injury when applied prior to transplanting or direct-seeding into plastic mulch. Remove residual product from plastic mulch with a 0.5” of water through irrigation or rainfall prior to planting.
paraquat (Gramoxone SL 2.0*): REI 12h or 24h, Group 22. Apply 2-4 pts/A per application, up to 3 applications allowed per year, a minimum of 7 days apart. Do not exceed 8 pts/A per year. May be fatal if swallowed or inhaled. *Restricted use: Applicators must complete an EPA-approved paraquat training every 3 years: https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators.
pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0. Apply a 3-10% solution (3-10 gal/100 gal of spray). Apply in 75-200 gal/A of spray. Can use preplant, or as a directed and shielded spray during crop growth. Avoid contact with foliage or crop damage may occur. Spray to wet, but do not allow runoff of spray solution.
sethoxydim (Poast): PHI 3d cucumber and muskmelon, 14d other melons, REI 12h, Group 1. Apply up to 1.5 pt/A per application, multiple applications allowed per year, a minimum of 14 days apart. Do not exceed 3 pts/A per year. Apply to actively growing grasses. Apply with crop oil concentrate (2 pt/A) or methylated seed oil (1.5 pt/A). Crop oil can cause injury under hot and humid conditions. Can also be applied as a spot-spray by mixing 1-1.5% (1.3-1.9 oz/gal) Poast and 1% v:v crop oil concentrate (1.3 oz/gal). Spray to wet, but do not allow runoff of spray solution.
trifluralin (Treflan HFP): PHI 60d watermelon, 30d cucumber and muskmelon, REI 12h, Group 3. Apply up 1-2 pt/A per application, only 1 application per year. Rate based on soil texture and rainfall. Apply after crop has emerged when plants have 3-4 true leaves as a directed spray between the rows avoiding contact with foliage or crop injury may occur.

Weed Control