Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

___________________________________________________________________________________Major Agronomic PracticesFruits can be snapped from the plant, but less damage usually occurs if they are clipped with a sharpknife or scissors. A short piece of stem is left attached to the fruit. Handle the fruit carefully to avoiddamage, wipe it to give a clean, bright appearance.Staking of plants may be necessary to prevent branches touching the ground later in the season as thenumber and size of the fruits increase. Rain, wind and irrigation can cause the branches to break ordroop. Fruit touching the ground may spoil.Eggplant fruits loose water and quality quickly at warm temperature after harvest. Ideal would be to storefruits in a cool space (7 to 13 o C and a relative humidity of 90-95%).In some (western) countries, eggplant fruits are wrapped in plastic shrink film to reduce weight loss andmaintain firmness, due to the high relative humidity. However, wrapped fruits decay rapidly if the film isnot perforated. It is obvious that this practice is very expensive and is only worth it if high prices arefetched in the market.Related exercises from CABI Bioscience/FAO Vegetable IPM Exercise Manual:2-C.10. Assessment of harvest time2-C.11. Harvesting practices and crop residue management3.17 Crop rotationCrop rotation is necessary to:1. Avoid build up of large populations of certain pest insects and pathogens.Some of the more common serious pests and diseases which live in the soil attack a range of plantswithin the same botanical family - but no others. If the sorts of plants they attack are continually grown inthe soil, the pest and diseases can build up to serious populations. Once a soil-borne disease such asbacterial wilt (Ralstonia solanacearum) or fungal wilt (Fusarium oxysporum, Verticillium sp.) has entereda field it is very difficult to eliminate. If there is a break of several seasons or even several years in whichother crops (of a different crop family) are grown, their numbers will diminish and they will eventuallydisappear. This is the main reason for rotating crops.2. Avoid nutrient deficiency and degradation of soil fertility.Another reason for crop rotation is that it reduces loss of fertility and nutrient deficiency. When the samecrop is planted in the same field every season, there will be a continuous consumption of the samenutrients from the soil. Adding chemical fertilizers will supply only part of the nutrients that are consumed,mostly N, P and K. Adding chemical fertilizers containing the deficient nutrients will not solve theproblem. It is necessary to introduce crop rotation and supply organic matter to the soil. Rotating withgreen manure crop (see section 3.8.3.2) and adding legumes (supplying nitrogen) to the rotationschedule is therefore recommended.Nutrient consumption is quite different for each crop. In general, nutrient consumption can be rankedfrom low to high consumption:1. legumes2. root crops (e.g. carrot, radish)3. leaf crops (e.g. cabbage, lettuce)4. fruit crops (e.g. eggplant, tomato, cucumber)5. cereals (e.g. rice, barley)45Eggplant Ecological Guide