The document discusses the implementation and effectiveness of large-scale net houses for vegetable production in Alabama, highlighting their role in pest management and challenges faced, particularly for organic farmers. It presents past research demonstrating the efficacy of net houses in reducing insect pest populations and the associated reduction in insecticide use. Additionally, it outlines the construction and initial outcomes of a net house in Baldwin County, Alabama, while identifying future research needs related to heat stress, disease management, and pest control strategies.

1. Large-scale Net House for Vegetable Production: Pest Management Successes & ChallengesAyanava MajumdarExtension Entomologist (Peanuts, Vegetables)State SARE Coordinator (Auburn U)Alabama Cooperative Extension System&Mike PowellAmerican Farm Systems (PolyProductos de Guatemala)

2. Vegetable Production in Alabama50 vegetables produced2006: 5700 acres >> 2008: 5,950 acres100% fresh market produceValue: ~$17 millionTomato: ~1300 acres = $12 million6 organic producers

3. Need for net house researchInsect pest pressures in southeast U.S. are very high (struggle for organic producers)Vegetable production is insecticide dependentBlocking insects by physical exclusion reduces insecticide use (nothing new!)Net house is a closed crop production system that excludes insect pests via a physical barrier.Could be of interest to organic farmers…

4. Past research on insect nettingMartin et al. (2006): Africa, cabbage production, 25-mesh, reduction in caterpillars - Spodopteralittoralis66%, Trichoplusiani97%, Hellulaundalis88%, Plutellaxylostella (moths) 78%, no change in aphids (6% infestation), net return $247, 3-10x spray reductionFang-Cheng et al. (2010): China, tomato seedlings, 50-mesh, whitefly reduction 98%, 5x spray reduction, small structureHarmanto (2006), Mutwiwa & Tantau (2009): Germany, greenhouse + netting (50-mesh), 40% reduction in air velocity, thrips & whitefly reduction on tomatoesMovable net house (Africa)Low net house (Malaysia)

5. Past research on large net housesTalekar et al. (2003): Taiwan, 15 crop cycles of leafy greens, 2 m or 6.5 ft structure, 32-mesh netKaur et al. (2004): India, egg plant production, doubled plant yield in net house, mesh size??Anonymous (2010): Malaysia, okra & tomatoAnonymous (2008): Vietnam, cost $186Guatemala, Israel: commercial tomato & bell pepper in net housesLarge net house (India)Large net house (Vietnam)

6. Large net house vegetable production (Guatemala)Large commercial scale net housePhotos:Polyproductos de GuatemalaTop Greenhouses Ltd., Israel

7. Commercial net houses in the U.S.Top Greenhouse Ltd., Israel: flat net houses on 280,000 m2 (~70 acres) in CA; bell pepper, tomato, chili production.Commercial citrus production, FL

8. First net house in Alabama (2010)Location: Baldwin County, AL Dimensions: 150 ft x 46 ftEntrance: Double door50-mesh fabric (any between above 16- to 50-mesh is fine)Mesh size depends on target insect & costHeight provides air movement…fans can also be installedCrops, 2010: Celebrity tomatoes, California Wonder peppers

9. The making of a net house… April 2010: Setting up the polesApril 2010: Sewing the long net pieces 17-ft14-ftApril 2010: Stretching the support cablesMay 2010: Fabric on cable with S-hooks

10. Soil preparation before sealing side-wallsMid-May, 201010 ft17 ft14 ft

11. Crops grown with partial success (Year 1)40% black shade cloth for cooling the interior!TomatoesBell peppers

12. Temperature and humidity challenge**Year 2010 was an unusually dry and hot year in Alabama: increased disease pressure and shocked the plantsAWIS = Alabama Weather Information System

13. Does net house block insect pests?Pheromone trap catches (moths)Trapping method: Sticky wing trap with replaceable bottom were used for season long monitoring of moths. Traps were serviced every 10 days.

14. Does net house block insect pests?Caterpillar counts: Net house vs. conventional vegetablesSampling method: Number of caterpillars in 10 plants every 10 ft of row. Plants sampled from 4 locations each row (4 replications). Sampling done in July 2010.

15. Insects in a net houseCotton aphid (Aphis gossypii) and potato aphid (Macrosiphumeuphorbiae) outbreaks in July.

16. Managed with one spray of Fulfill 50WDG (selective feeding blocker)

17. Armyworm moths lay eggs on fabric near joints