Estimate of repeatability for selection in mature seedlings of rubber tree

Abstract

The present study was carried out to determine the number of annual means of tapping required to select mature seedlings of superior genotypes of rubber trees (Hevea spp). Coefficients of repeatability (p) were estimated by using analysis of variance for anual mean of two, three, four, five and six tappings. An average repeatability value ( 0.815) was obtained, and the highest repeatability estimated was 5= 0.983, value obtained for five-year tappings. These results showed that the genetic variance between plants was higher when compared with the environmental variance. The largest progress in the selection was obtained utilizing two, five and six-year tappings with of 31.03%, 33.24% and 31.93%, respectively. Based on the results, it was concluded that two-year repeatability with a high percentual of genetic gain for two years tapping showed a better progress in the selection