農藥對橫山梨樹落葉、開花與結實之效果

Effects of Insecticides and Fungicides on the Leaf-drop, Blossoming and Fruit Set of Heng Shan Pear

本試驗使用五氯酚、石灰硫黃合劑、夏油及飛邦4種農藥，各分2種濃度，探求不同濃度處理對調節橫山梨樹落葉、開花及結實之效果，以五氯酚2,500PPm.及5,000PPm.，與石灰硫黃合劑l25,000PPm.3種處理，對橫山梨樹落葉及開花期之調節效果較為顯著，但對果實產量之影響，則有待進一步試驗。

Heng Shan is the main commercial variety of pears growing in the low altitude area in Taiwan. Owing to the lack of low temperature during winter, the leaves persisted on the twigs deiayed the time of blossoming and fruit setting. Several kind of insecticides and fungicides were used in this experiment, in order to determine their effects on leaf-drop, blossoming and fruit setting. It was found that 2,500ppm. and 5,000ppm. of Sodium salt of pentachlorophenol monohydrate (P. C. P.) and 125,000ppm. of Lime-sulfur are more effective.