光皮木瓜苗期生长节律研究

摘要

In the nursery field of Xinyang Forestry Science Institute,the growth height and ground diameter of two-year-old and stumping Chaenomeles sinensis seedlings were investigated weekly to analyze the growth rhythm,and the growth process was simulated by Logistic curve.The results showed that the regression of simulating growth process by Logistic curve were very significant.The division of growth period for seedling height and ground diameter by the inflection point of day increment change rate curve derived from the equation were in line with the routine observation.The growth rhythms of seedling height and ground diameter were basically the same,and both had obvious fast-growing period.And the beginning of ground diameter fast-growing period of two-year-old seedlings were about 14 days later.The net growth of height and ground diameter of stumping seedlings were higher than those of two-year-old seedlings with modest amplification,but significantly higher than those of one-year-old seedlings.Combining the fitted value and observing value,the growth process could be divided into 3 periods,growth prophase,fast-growing period and later growth period,and the corresponding measures for seedlings were put forward according to the growth characteristic of each period.%在信阳市林业科学研究所苗圃内,按周(7 d)对光皮木瓜2年生苗苗高、地径和平茬苗木苗高、地径的生长量进行调查,分析生长节律,并利用Logistic曲线拟合生长过程.结果表明:用Logistic方程拟合生长过程其回归性均达到极显著水平,导出的连日生长量变化速率曲线的拐点对苗高、地径生长时期的划分与定期观察结果基本相符;苗高、地径的生长节律基本一致,均存在着明显的速生期,但2年生苗地径的速生期起始时间要晚14 d左右;平茬苗木苗高和地径的净生长量高于2年生苗,增幅不大,但明显高于1年生苗的苗高和地径;根据拟合值与实际观测值相结合,可以将苗木的生长过程划分为生长前期、速生期和生长后期3个时期,并根据不同阶段的生长特性提出相应的育苗措施.