Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

__________________________________________________________________________________Major Eggplant Insect PestsHow to recognize a parasitized pupa of FSB:unparasitized. Trathala sp. Cotesia sp.FSB adult large hole small exit holeemerges, towards endopening at top(pers. comm. P. Kumar, 1999)Management and control practicesPrevention activities:• Tolerant and resistant eggplant varieties have been reported, mainly from India. See table in section3.2.2 for variety names. However, none of the tested varieties is 100% resistant to FSB, but there areremarkable differences in the percentage infestation. The degree of resistance varies with localconditions. For example, in a field test in Bihar, India, the variety Long purple was rated as resistantwith 7,7 % infestation of shoots and 6.7% infestation of fruits (Mehto, 1981). In addition, wild eggplantvarieties such as Solanum indicum and Solanum macrocarpon are highly resistant to FSB (Behera,1999a; Kumar, 1996). AVRDC found that a landrace of eggplant, EG058, proved to be resistantagainst FSB in India, Sri Lanka and Thailand, but not in Bangladesh (ref. www36). These genotypesmay be interesting for breeding purposes. The best way to find out if a variety is resistant to certainpests is to set up a field trial to compare susceptibilities of different varieties under local conditions.Eggplant resistance to fruit and shoot borer: an example of research findings.In a field study in Bhubaneswar, India, 174 eggplant varieties were screened for resistance to fruit andshoot borer. None of the eggplant varieties was immune (=zero infestation) to larval attack of shoots andfruits but there was a remarkable difference in the percentage attack.The mean percentage of shoot infestation varied from 1.6 to 44.1% and fruit damage varied from 8.5 to100%. Maximum shoot damage was recorded 75 DAT (days after transplanting), with maximum fruitdamage recorded at 76-121 DAT and 99-114 DAT in susceptible and resistant cultivars, respectively.Thus, early fruiting varieties are more liable to fruit attack by fruit and shoot borer.Leaf hair density and number of shoots/plant played a role in restricting shoot damage. A tight calyx andlong fruits increased the resistance of the fruits. L. orbonalis attack of fruits was also restricted by tightlypacked seeds inside the fruit, low percentages of moisture, nitrogen and potassium, and a highphosphorus content. It is suggested that in order to minimize the incidence of fruit and shoot borer,resistant cultivars such as Pitala Local 1 and Sambalpur Local should be grown (Panda, 1999).• Breaking the clods of the soil before transplanting also helps reducing populations. Rough soils favorpupation of FSB (pers. comm. P.Kumar, 2001).• Avoid planting over-aged seedlings (pers. comm. P.Kumar, 2001). When seedlings remain in thenursery too long, they form stretched, weaker seedlings due to competition for space, light, andnutrients. Crowded nurseries can form good breeding ground for FSB.73Eggplant Ecological Guide