龙眼叶片营养诊断的研究

1979～1982年对我省乌龙岭、福眼等龙眼主栽品种营养诊断方法进行了探讨。根据龙眼的生物学特性、叶片营养组分的年周期变化及其与产量的相关性,提出龙眼叶片分析以1月份采摘夏梢营养枝顶端第3片复叶的中部小叶为宜。文中初步提出龙眼丰产的叶片营养的适量范围(1月份):氮以1.70%(按干物质计)以上,磷0.12～0.20%,镁0.20～0.30%为宜;钾、钙含量与产量虽无相关性,但高产者叶片含钾量多为0.60～0.80%,合钙量多为1.50～2.50%。

AN INVESTIGATION ON THE LEAF NUTRITIONAL DIAGNOSIS CRITERIA OF LONGAN(DIMOCARPUS LONGAN LOUR.)

The criteria of nutritional diagnosis on the major longan cultivars such as “Wulongling”,“Fuyan”were investigated in Putian and Quanzhou in 1979-82.According to the correlation between longan biological characteris- tics and yearly periodic changes of nutritional composition of longan leaves and longan yields,we suggested that the sampling of the middle leaflets on the third compound leaf which were originated from Jan.to become summer growth shoot were preferable for longan nutritional diagnosis.Through a series of experiments we found the range of longan leaf nutritional contents for high fruit yields were as follwos:nitrogen, higher than 1.70%,phos- phorus,0.12-0.20%,magnesium,0.20-0.30%.The contents of potassium and calcium were not well correlated with longan fruit yields.However, high fruit yield variefies usually maintained the levels of 0.60-0.80% for potassium and 1.52-2.50% for calcium.