Optimum number of trees in tapping experiments on Hevea brasiliensis II. Tapping systems with different lengths of cut and frequencies of tapping
Narayanan, R.; P' ng, T.C.; Ng, E.K.
Journal of the Rubber Research Institute of Malaya 23(3): 178-192
1972
Document Number: 257605
The daily variation in yield of 3 clones was examined under tapping systems with different lengths of cut and frequencies of tapping. The yield variation had no consistent seasonal pattern, but was higher with full-spiral tapping. The minimum number of trees necessary to estimate treatment means accurately and to distinguish between treatments was about 50. The variation between trees was more pronounced than that between days of the month, thus enabling an accurate estimate of monthly treatment means to be made from only one or two days' yield recording in each month. The grain in accuracy in estimating annual treatment means from two, rather than one, 12-day cycles of recording per month was quite small. [For part I see HcA 38, 8703.].