EFFECT OF NUTRIENT APPLICATION ON LEAF LONGEVITY IN TREE SEEDLINGS: AN EXPERIMENTAL TRIAL

Abstract

Leaf longevities of Quercus leucotrichophora and Pinus roxburghii seedlings were compared at five levels of nutrient application. Seedlings of both species were grown in polyethylene bags each containing 1 kg mixture of sieved forest soil and fine sand in 1:3 ratio. Seedlings were grown both in pure (intra specific) and mixed (inter specific) culture. Nutrient application treatments were 0, 144, 264, 384 and 504 mg of 12:32:16 NPK fertilizer per bag. Percentage leaf drop increased significantly with increasing level of nutrient application in both species. However, the values were always higher for Q. leucotrichophora than for P. roxburghii. In mixed culture, leaf longevity of P.roxburghii increased while the reverse was true for Q. leucotrichophora. In both species percentage leaf drop showed significant positive correlation with soil nutrients, nitrogen concentration in mature leaves and height of seedling.