LONG-TERM PERFORMANCE OF A FEW INDIAN AND EXOTIC CLONES OF HEVEA BRASILIENSIS IN LARGE SCALE TRIALS IN INDIA

摘要

Growth and yield of certain Indian and imported clones of Hevea brasiliensis in large scale trials were studies over 15 years of tapping in the traditional rubber growing zone of India.Data on yield and secondary characters like tapping panel dryness and diseases were also collected.In Trial-I,only RRII 105 recorded significantly higher yield (54.5 g/t/t) in BO1 panel while,in panel BO 2,RRII 105,RRII 101,RRII 116 and RRII 103 recorded significantly higher yield than the control clone Tjirl.In terms of mean yield over 15 years of tapping,clones RRII 105,RRII 101,RRII 116 and RRII 103 were significantly superior to the control.At the age of 23 years girth of clones RRII 114 (112.5 cm) and RRII 116 (107.9 cm) was significantly higher than that of the control Tjir 1 (95.5cm).In Trial-II,RRIC 100 with the yield of 49.3 g/t/t was significantly superior to the control GT 1 (41.4 g/t/t).At the age of 21 years,clones RRIC 104 (114.0 cm),RRIC 52 (107.8cm) and RRIC 100 (96.5 cm) showed significandy higher girth.In Trial-1 clone RRII 105 and in Trial-II RRIC 100 showed overall superiority.