Evaluation of peanut germplasm for insect resistance

Uniform Insect Nursery Test No.1: This trial was repeated from the 1989 rainy trial. Twenty six lines of peanut were used. Three major insects found moderately in this season were leaf miner, leafhopper and thrips. At the crop of 65 days old, the number of damaged leaves caused by leaf miners, leafhopper and thrips ranged from 181-241, 7-84 and 4-45 leaves per row, respectively. Number of damaged pods from soil insects ranged from 0-8 pods per ten plants. Seed yields were higher than the rainy season. There was one line that gave better yield than Tainan 9. It was Mani Pinter[Robut 33-1*NC 2232]. International Germplasm Tes: Twenty-one lines from International Germplasm. Test were evaluated for resistance to leaf miners, leafhopper, thrips and soil insects under natural infestation at Khon Kaen University in the rainy season of 1990. Tainan No.9 gave the highest seed yield. The leaves infested by leaf miners and leafhopper showed no difference among the peanut lines tested. Thrips showed different preference on peanut lines. The highest score of leaf damages was on Tainan No.9 while the lowest score was on GP-NC 343*NC5. Experiments during October 1990 to February 1991: There were three trials in the late rainy season of 1990. Twenty eight peanut lines from leafhopper F6 test, thirty two lines from ICRISAT germplasm test and thirty nine from uniform insect nursery test No.2. Pod damages were recorded at harvest. Leafhopper F6 test: At the crop of 50 days old, leaf damages caused by leaf miner, leafhopper and thrips. Pod damages reached 61.5 % in Lampang*GP-NC 343 and Tainan 9*NC 302. It showed that Tainan 9*NC 10272 gave the highest pod yield of 2.47 kg/ha. ICRISAT Germplasm Test: Leaf damages caused by leaf miners, leafhopper, and thrips when the crop was 50 days old. Pod damages caused by soil insects. The tested lines showed resistance to the complex of insects. Mani Pintar[Robut 33-1*NCAc 2232] gave the highest yield (4.38 t/ha). Uniform Insect Nursery Test No.2: Leaf damages caused by leaf miner, leafhopper and thrips when the crop was 50 days old. Pod damages caused by soil insects. NC 7*NC 10272 gave the highest pod yield(2.81 t/ha).