COMPARATIVE PLANT RESISTANCE IN FIFTY-FIVE TEA ACCESSIONS, CAMELLIA SINENSIS L., IN IBADAN, SOUTH WEST, NIGERIA

Abstract

Fifty five accessions comprising both local and exotic clones were assessed for their resistance to field pest at Abarakata farm, CRIN. The accessions derived from Mambilla plateau, CRIN out-station, Taraba State were screened for resistance to infestation by leaf defoliators. Results revealed that there were significant differences among the accessions in terms of the number of holes on the leaf and plant damage both in the dry and raining season. On NGC15, NGC17, NGC19, C235, C357 tea clones recorded less number of holes and total damage of leaves and thus considered highly resistant to field insect pests. Based on the rating, clones NGC 8, NGC12, NGC14, NGC24, NGC27, NGC40, NGC41, NGC42,NGC49, NGC50,NGC51, C68, C270,C318, C359, C377 were significantly resistant to the insect infestations, while NGC18, NGC22, NGC23,NGC25, NGC26, NGC29, NGC35,NGC47, NGC48, NGC53, NGC54, NGC55, C61, C136, C143, C228, C236, C327, C353, C354, C369, C370 were moderately resistant. NGC13, NGC32, NGC37, NGC38, NGC45, NGC46, C56, C74, C108, C363, C367 and C368 were the most susceptible with the highest damage indices values (P<0.05). The range of each of the resistance indices measured in the susceptible clones in both dry and wet season were number of leaf damage (43-51)(37-46), number of leaf holes (18-19)(16-20).