柑桔枯枝處理與黑點病之發生

Effect of Citrus Dead Twig Treatments on Melanose Incidence

根據室內藥劑試驗，以免賴得及依滅列可以有效減低黑點病保菌枝孢子角形成率，鋅錳乃浦及腈硫醌之抑制效果不佳。於田間柑桔修剪枝條藥劑處理結果與室內試驗相符，以免賴得及依滅列噴佈修剪枝條，皆可有效減低接種源形成；另以腈硫醌、巴拉刈處理者亦可減少枯枝上孢子角及子囊殼產生量。且剛修剪的新鮮枝條馬上予以處理較諸延後處理者，對於抑制接種源產生之效果為佳。移去樹冠內及其周圍地面枯枝，對於本病的防治效果並不顯著；柑園之枯枝予以藥劑處理，亦無顯著防治效果。可知佐以枯枝處理之餘，柑桔果實的化學藥劑防治仍是最主要的防治方法。

According to laboratory test, the inoculum twigs treated with two fungicides, Benomyl and Imazalil, resulted in decreased spore horn formation. The prunings of fresh twig sprayed with four pesticides, Benomyl, Imazalil, Delan and Paraquat, produced lower amount of inoculum. It is the time to spray chemical to twigs just after it was pruned. But, field experiment has shown that melanose could not be controlled completely by removing out all dead wood in winter once a year. Treatment of the prunings with Benomyl and Parapuat was not the effective control method for citrus melanose without other chemical control.