1. Integrated Pest Management in Watermelon Camilla B. Yandoc

2. Watermelon Pests Insects & Mites Weeds Diseases Nematodes

3. Common Insect Pests Aphids RindwormsSweetpotato whitefly Cutworms

4. Aphids & Whiteflies Downward curling & crumpling of leaves (aphids) Honeydew excreted by both insects attracts sooty molds Both are efficient vectors of plant viruses

5. Cutworms & Rindworms Cutworms: reduce young watermelon stands May feed on leaves of young seedlings Rindworms: general term for worms that feed on rind (fall armyworms, corn earworm, cutwroms and loopers Foliage & stem damage Eat away irregular patterns of the rind

6. Occasional Insect Pests Cucumber beetle Mites Mole crickets Wireworms White-fringed beetle Leafminers Thrips

7. Occasional Insect Pests Root maggots Flea beetles & fleahoppers Leafhoppers Plant bugs Grasshoppers Melonworms & pickleworms

8. Insect Damage Foliar damage (holes) Stem damage Root damage (wilting, stunting & death of plant) Fruit damage Drying up of leaves (sucking insects) Leaf spots, mottling or discoloration

9. Insect & Mite Management Sampling Establish ETL Recognize & identify beneficials Important Practices:

10. Aphid Control Biocontrol lady beetles, syphrid fly larvae,lacewings & tiny wasps cultural control reflective plastic mulch Stylet oil sprays (interferes with virus transmission)

11. Sweetpotato Whitefly Control Monitoring use of traps Cultural control planting location & sanitation Weed control control alternate hosts Chemical control alternate different classes of insecticides

12. Cutworm & Rindworm Control Mechanical control (cutworm): thorough soil prep Chemical control (cutworm): broadcast application of approved insecticides before planting Chemical control (rindworm): spray before worms > 1/2 in length, spray all of exposed fruit

13. Control of Other Insect Pests Chemical control insecticide sprays for flea beetles, leafminers, mites, mole crickets,wireworms, fleahoppers,leafhoppers, plant bugs,grasshoppers, melon worms and pickleworms

14. Control of Other Insect Pests Cultural control avoidance (white-fringed beetles), plowing & deep turning of crop litter before planting (root maggots), overhead irrigation (mites)

15. Insect & Mite Management Reflective mulch Planting location/timing Sanitation Weed control Overhead irrigation Plowing & turning in crop debris Cultural Practices

16. Diseases Reduce crop yield & quality Poor disease control due to delayed accurate diagnosis & delayed implementation of control measures Disease control consists of a sequence of properly timed control measures (cultural, mechanical & chemical)

17. Root & Stem Diseases Anthracnose Damping-off Fusarium wilt Gummy stem blight Fusarium rot

18. Root & Stem Disease Management Gummy stem blight postharvest plow- down of debris, crop rotation, fungicidal sprays, use fungicide treated seeds Anthracnose resistant varieties, fungicidal sprays, clean seeds,sanitation Fusarium wilt resistant var.,healthy transplants,crop rotation, soil fumigation, delayed thinning

19. Foliar Diseases Anthracnose Downy mildew Cercospora leaf spot

20. Other Foliar Diseases Alternaria leaf spot Bacterial leaf spot Watermelon mosaic

21. Foliar Disease Management Cercospora leaf spot sanitation (removal of crop debris, diseased vines & weed hosts), crop rotation, fungicide sprays Downy mildew fungicide application, resistant var., avoid irrigation, reduce canopy density

22. Foliar Disease Management Alternaria leaf spot protectant fungicides Bacterial leaf spot avoid overhead irrigation, sanitation, protective sprays (copper sprays)

23. Foliar Disease Management Watermelon mosaic stylet oil application to interfere with virus transmission & insecticides to control aphid (vector)population

24. Fruit Diseases Bacterial fruit blotch Anthracnose Bacterial rind necrosis

25. Other Fruit Diseases Bacterial leaf spot Blossom-end rot Speckle Watermelon mosaic

26. Fruit Disease Management Bacterial fruit blotch plowing infested soil, elimination of inoculum sources, field rotated out for 3 years or more, copper sprays (Kocide DF Kocide 2000), use of high quality transplants

27. Fruit Disease Management Anthracnose resistant varieties, fungicides, use clean seeds Bacterial rind necrosis use less susceptible cultivars

28. Fruit Disease Management Blossom end-rot soil testing & liming, irrigation during fruit development (preventive), foliar Calcium application (curative)

29. Disease Management Sanitation Healthy transplants Resistant varieties Crop rotation Weed/Insect vector control Liming & irrigation Cultural Practices

30. Disease Management Fungicide sprays Soil fumigation Fungicide seed treatment Chemical Control

31. Weeds Compete with the crop for nutrients, sunlight, water and space Serve as alternate hosts of nematodes, viruses and insect pests

32. Weed Management Polyethylene mulch Cultivation Soil fumigant Hoeing & disking Herbicides Cultural, Mechanical & Chemical Control

33. Economically Important Nematodes Root-knot nematodes (Meloidogyne spp.) Sting nematode (Belonolaimus longicaudatus) Reniform nematode (Rotylenchus sp.)

34. Nematode Damage Root galls interfere with normal water & nutrient uptake Reduced size of root system limits availability of water & nutrients Aboveground damage: stunting, wilting & chlorosis Roots attacked by nematodes are predisposed to secondary invasion by root rotting plant pathogens

35. Nematode Management Planting location Resistant varieties Crop rotation Land preparation Use of clean & healthy transplants Cultural Practices

36. Nematode Management Fumigants Non-fumigants Chemigation Chemical Control

37. A Grower’s Pest Management Tactics: Insect control: chemical insecticides Weed control: mechanical control (cultivation) Disease control: resistant varieties & chemical fungicides, removal & destruction of diseased seedlings

38. What Growers Do in the Field… Scout for presence of insects and diseases (major pest problem) Watch the weather and spray accordingly (follow recommendations) Some spray protective fungicides even when weather is dry (for insurance)

39. What Growers Do in the Field.. May spray 1 or 2x a season for aphid control, some never spray because insect problem is minor Follow recommendations for tillage & crop rotation Plant in soils without RKN problems

40. What Growers do in the Field Fusarium Wilt control: crop rotation, use of resistant varieties, scouting for diseased transplants and removal of infected transplants Gummy stem blight & Downy mildew control: fungicide sprays based on weather(likelihood of disease occurrence) or presence of spots

41. References Zitter, A.T., D.L. Hopkins, and C.E. Thomas (eds.). 1996. Compendium of Cucurbits Diseases. APS Press. Maynard, D. N. (ed.). 1992. Watermelon Production Guide for Florida. Florida Cooperative Extension Service & IFAS Mr. Melvin Poole (Gainesville watermelon grower) Mr. Gerry Brinen (County Extension Office)