Files
Abstract
Leafhopper infestation in the field followed the same pattern as that observed during the 1998 dry season trial. Adult and nymph populations peaked at 60 days after transplanting (DA T). More leafhoppers infested the 5th leaf from the growing tip. Based on over-all counts, the varieties Jackpot and Bulakena were most preferred by both adults and nymphs; variety IPB GS1 was least preferred. Overall damage rating showed that the variety SRO2 had the least yellowing and cupping symptoms. Among the varieties tested, Bulakena and Jackpot were susceptible at 60 DAT. Dumaguete Long Purple and Abar were the tallest varieties at vegetative and reproductive stages, respectively. Abar had the longest leaf while IPB GSl, the smallest. Both varieties were tolerant but whether these plant characters can affect leafhopper preference has not been established. Variety SRO2 had the highest number of trichomes per 40 sq. mm while Abar had the longest trichomes. This suggests that the dense trichomes in SRO2 could have deterred leafhopper feeding and oviposition. IPB GSI yielded the healthiest fruits. The yield of Jackpot and Dumaguete Long Purple was comparable to IPB GSI. Bulakena had the lowest number of healthy fruits. Damaged fruits due to borer infestation were counted and expressed as percentage of the total number of healthy and damaged fruits. During the four harvest periods, Abar had the highest percentage of damaged fruits while IPB GSI had the lowest percent infestation. SRO2 was resistant to leafhopper at vegetative and reproductive stages while Abar was tolerant to leafhopper until the last harvesting period. Jackpot was tolerant and yielded high despite the high leaf yellowing rating. Bulakena was the most susceptible variety showing distinct leaf cupping before the yellowing symptoms of leafhopper damage.