林木营养与虫害——杨树不同栽培措施的抗虫效应

本文探讨了杨树与刺槐混交、间种绿肥、施土杂基肥和追施化肥等不同栽培措施后的抗害虫效应,并探讨了不同栽培措施后其抗性不同的机理。主要结果如下:(1)混交或间种明显降低了青杨枝天牛和杨扇舟蛾的数量及对杨树的为害;(2)用混交林杨叶喂饲柳毒蛾或用间种绿肥的杨树叶喂饲杨扇舟蛾,幼虫生长不利,蛹及成虫的雌雄比、怀卵量与对照组相比显著下降;(3)混交和间种后的杨叶所含总蛋白质、总游离氨基酸、粗纤维、灰分及含水量均高于对照组,但总糖、碳氮比、游离胱氨酸明显低于对照组,而且缺乏游离蛋氨酸和组氨酸。我们的资料表明,上述混交和间种措施提高了杨树对上述害虫的抗性。

THE RELATIONSHIP BETWEEN TREE NUTRITION ANDPESTS——HOW DIFFERENT CULTIVATION MEASURES AFFECTPOPLARS RESISTANCE TO PESTS

This paper deals with the resistance of poplars to pests.The poplars were subjected to different cultivation measures including intercropping the poplars with locusts,the poplars with legumes for green manure, using organic fertilizers and chemical fertilizers. A study was also made of the reasons why the resistance of the poplars varied with the different measures. The main results are as follows (a) Intercropping the poplars with the locusts or with the legumes not only significantly decreased the number of Saperda populnea and Clostera anachoreta,but also affected the growth of the poplars, (b) Growing larvae of Leucoma Candida were fed the leaves of the poplars intercropped with the locusts or growing larvae of Clostera anachoreta were fed the leaves cf the poplars intercropped with the legumes.The larvae grew relatively slowly, compared to the control larvae fed on the leaves of the poplars grown on their own. The ratio of female to male of the pupas and adults, and the egg number in the female pupas' bodies also decreased. (c)The amount of total protein, total free aminoacid, raw cellulose, ash and liquid in leaves of the intercropping poplars was higher, but the amount of total sugar, the ratio of nitrogen to carbon and the free cystine was lower than that of the control trees. In addition, the fee methionine and histidine in the leaves of the intercropping poplars was deficient. Our data show that intercropping measures raise the resistance of the poplars to pests.