[Studies on the physiological behavior of Pinus merkusii Jungh. and Pinus massoniana Lamb].

The formation and the function of the resin channels result from processes in the history of development; differences between various pine varieties must be traced to differentiation processes in the history of development. Longer flowing duration, higher reformation speed and reduced crystallization are properties which make Pinus merkusii especially suited for systematic resin production. Pinus merkusii does not react to treatment with weak acids or biologically effective stimulants, like yeast extract solution, which can be used to increase the yield of Pinus massoniana up to 30%. This means specific stimulants for Pinus merkusii still have to be found.