(Rubber Research Institute. Agalawatta, 1991) Dissanayake, D.M.A.P.; Dissanayake, T.; Gunasekera, R.; Jayasekera, S.
Genotypic variability in utilization of rock phosphates including the local source Eppawale was evaluated using Hevea clones during the early immature phase. All the clones responded to P fertilization, and the responces were related to the source of fertilizers and other soil characteristics. Plants of clone RR1C 121 utilized Eppawala rock phosphate efficiently, both in Matale and Boralu soil. But, plants of clone RR1C 110 were able to use both rock phosphate sources only in Matale soils. However, responce to rock phosphate from plants of 100 was comparatively low in relation to P uptake and dry matter production. The necessity of testing these clones for the locally available phosphate source in the field scale is also discussed
