Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

__________________________________________________________________________________Major Eggplant Insect Pests• Sanitation practices such as cleaning the soil of the field to remove FSB pupae, normally found ondead and fallen leaves (pers. comm. P.Kumar, 2001).• A study in Bangladesh demonstrated the potential for using net houses to protect eggplants againstFSB infestation. Details in box below.Net houses: keeping the pest away from the plant!In a field study in Bangladesh, a net house was made out of bamboo sticks, nylon nets and tied togetherwith clips and rope. Height of the net house was about 2m. The net house was covering a number ofeggplants. The soil under the net house was carefully checked for pupae and other potential pestinsects which were removed. Insects from outside, e.g. FSB adults, could not reach the plants andinfestation of insect pests was lower as compared to the control plot, where no net house was placed.Pollination of eggplant flower was not impaired as over 90% of the flowers is self-pollinated.If a net house lasts for about two or three seasons, the investment in net house materials may be paidback by better fruit quality through less FSB damage. However, in this study, the investment was notpaid back because the net house was stolen from the field… Try it and find out if it works for you!• Fertilization can have an effect on occurrence of pests: in trials in India (Haryana, 1987), an increasein the doses of nitrogen and phosphorus applied to the eggplant crop resulted in heavier infestationby both jassids (leafhoppers) and FSB, but increased doses of potassium resulted in lighterinfestation. Only the interactions between nitrogen and phosphorus, nitrogen and potassium, orphosphorus and potassium (and not those between all 3 elements together) were found to contributepositively towards a marketable yield without infestation of fruit by FSB (Chaudhary, 1987). A similarfield study was carried out in India, testing the effects of nitrogen, phosphorus and potash fertilizerson FSB infesting eggplant. The minimum levels of fruit and shoot infestation (12.60 and 7.73%,respectively) were observed after treatment with potash at 100 kg/ha, closely followed by phosphorus;treatment with nitrogen resulted in the highest levels of infestation by the pest (Mehto, 1981). Set upan experiment to test the effect of different fertilizer doses on pest occurrence and yield in your field!• Intercropping with herbs: A study from Bihar, India, reports that lower fruit and shoot borer infestationwas recorded when three rows of nigella (Nigella sativa) were planted as an intercrop between rowsof eggplant, compared to an eggplant monocrop. Intercropping with fennel (Foeniculum vulgare) alsoreduced the pest infestation (Gupta, 1999). Other sources mention coriander (Coriandrum sativum)sown in a single line to be effective in reducing FSB injury to fruits as compared to eggplant plantingalone (Khorsheduzzaman, 1997). Community approachFor proper reduction of FSB populations, it is important that farmers of an area cooperate. This isbecause FSB can easily fly from one field to the next. If a farmer does not properly control FSB, hisfield becomes a source of infection for other eggplant fields. Once FSB is present in the field:• Sanitation: remove infested shoots, fruits and fallen leaves and destroy or burn them. This helpsreduce populations considerably as shown in several field studies (e.g. Sasikala, 1999; FFS NegrosOccidental, pers.comm. Carlito Indencia, 2001).• Flooding the field: during a Farmers’ Field School in Negros Occidentale (1998/1999), the Philippines,flooding the eggplant field weekly during the dry season (for irrigation) killed large numbers of FSBpupae present in the soil and on dried leaves. This was discovered by farmer participants who foundthe dead pupae in the soil 2 days after irrigation (pers.comm. Carlito Indencia, 2001).74Eggplant Ecological Guide