Long term performance of a few RRII clones in large scale trial
Mercykutty V C
Long term performance of a few RRII clones in large scale trial - Journal of Plantation Crops 1995 - 84-88
Performance of nine clones of Hevea brasiliensis (Willd. ex Adr. de Juss) Mull Arg. evolved at the Rubber Research Institute of India, over a period of 24 years (8 years before tapping and 16 years of tapping) was evaluated in a large scale trial in the central part of Kerala state. Among these nine clones, four were hybrid clones (RRII 108, RRII 112, RRII 115, RRII 119) and the rest ortet clones. (RRII 1, RRII 2, RRII 19, RRII 20, RRII 21). An old popular clone Tjir 1, of Indonesian origin, was used as the control. The trial was laid out in randomised block design with three replications. Yield performance over a period of 16 years, summer yield depression, mean girth at 24th year, girth increment before tapping and on tapping, bark thickness, number of latex vessel rows in eight year renewed bark, percentage incidence of tapping panel dryness, wind damage and diseases like powdery mildew and abnormal leaf fall have been observed. The data showed that all the clones were on par with the control clone Tjir 1 for yield. The clone RRII 108 recorded highest yield (55.38 g tree -1 tap -1) over 16 years of tapping which was followed by RRII 119 (54.28 g tree -1 tap -1), whereas the control clone Tjir 1 recorded 48.59 g tree -1 tap -1. There were significant differences between clones for summer yield depression. RRII 1 showed the lowest yield depression during summer over other clones tried.
Long term performance of a few RRII clones in large scale trial - Journal of Plantation Crops 1995 - 84-88
Performance of nine clones of Hevea brasiliensis (Willd. ex Adr. de Juss) Mull Arg. evolved at the Rubber Research Institute of India, over a period of 24 years (8 years before tapping and 16 years of tapping) was evaluated in a large scale trial in the central part of Kerala state. Among these nine clones, four were hybrid clones (RRII 108, RRII 112, RRII 115, RRII 119) and the rest ortet clones. (RRII 1, RRII 2, RRII 19, RRII 20, RRII 21). An old popular clone Tjir 1, of Indonesian origin, was used as the control. The trial was laid out in randomised block design with three replications. Yield performance over a period of 16 years, summer yield depression, mean girth at 24th year, girth increment before tapping and on tapping, bark thickness, number of latex vessel rows in eight year renewed bark, percentage incidence of tapping panel dryness, wind damage and diseases like powdery mildew and abnormal leaf fall have been observed. The data showed that all the clones were on par with the control clone Tjir 1 for yield. The clone RRII 108 recorded highest yield (55.38 g tree -1 tap -1) over 16 years of tapping which was followed by RRII 119 (54.28 g tree -1 tap -1), whereas the control clone Tjir 1 recorded 48.59 g tree -1 tap -1. There were significant differences between clones for summer yield depression. RRII 1 showed the lowest yield depression during summer over other clones tried.