Follow Cucurbit Quality Cues to Manage Insect, Disease Damage

Dupont Verimark Shoot in Donna, TX 5-18-12

In cucurbits, protecting quality and yield by preventing aphid and whitefly damage is a season-long challenge. With carryover populations, silverleaf disorder and poor squash coloration triggered by immature whiteflies are a concern for fall plantings.

Direct-seeded crops can be protected with a two-phase foliar application of DuPont™ Exirel® once true leaves form, about three to five weeks after planting.

Exirel® is recommended to prevent damage from whiteflies, major worm species (beet armyworm, western yellowstriped armyworm, melonworm, pickleworm), aphids (cotton/melon aphid, green peach aphid) and cabbage looper, plus suppression of foliage-feeding thrips and flea beetle.

Exirel® should be applied at 13.5 to 20.5 ounces per acre to help suppress and slow virus transmission carried by whiteflies, including cucurbit yellow stunting disorder virus.

For best results when controlling aphids and whiteflies, Exirel® should be used with an effective adjuvant. The tank-mixing and use of adjuvant sections of the label can be consulted for additional directions.

Defeating Disease

Many diseases are spread by wind-driven rains that move pathogenic organisms from infected plant debris or soil to new plants. Bacterial speck and bacterial spot are two examples that can remain viable on plant debris for a year or more. Controlling the risk calls for field sanitation.

Growers can handle the unexpected and prevent disease losses in cucurbits by applying a fungicide such as DuPont™ Fontelis® fungicide (FRAC Group 7) every five to 14 days, beginning before disease development.

Fontelis® provides preventive and curative activity with a single active ingredient for maximum flexibility. It helps control Alternaria leaf spot (Alternaria spp.), gray mold (Botrytis cinerea), gummy stem blight (Didymelia bryoniae), powdery mildew (Sphaerotheca fuliginea and Erysiphe cichoracearum) and sclerotinia stem rot (Sclerotinia sclerotiorum).

No more than two sequential Fontelis® applications should be made before switching to another mode of action to help prevent resistance development.


The information provided on this website is for reference only. Always refer to the product labels for complete details and directions for use.

DuPont™ Exirel® and Fontelis® are not available in all states. See your local DuPont sales representative or retailer for details on availability.