Field efficacy evaluation of Acibenzolar-S-methyl for induction of resistance in mango (Mangifera indica L.) to anthracnose (Colletotrichum gloeosporiodes Penz.)

The study was conducted from December 1999 to May 2001. The first experimental set up was conducted in a mango orchard at Brgy. [village] Palangue III, Naic, Cavite [Philippines] from December 1999 to May 2000 while the second experiment was conducted in a mango orchard at Brgy. Calumpang, Lejos, Indang, Cavite from December 2000 to May 2001. The experiment was set up RCBD [randomized complete block design] with 4 replications. The rest chemicals was applied five times after flower induction at 12, 22, 38, 55 and 101 days after flower induction (DAFI). The study was conducted to evaluate the efficacy of Acibenzolar-S-methyl for induction of resistance in mango (Mangifera indica L.) to anthracnose (Colletotrichum gloeosporioides Penz.) Acibenzolar-S-methyl showed no phytotoxic effects on mango leaves, flowers and fruits during the trials. In both trials mango trees sprayed with Acibenzolar-S-methyl have lower percent disease severity compared to the untreated control. The performance of Acibenzolar-S-methyl was more than 80%. At medium rates the product performance was comparable to the standards. At lower rates, the efficacy of Acibenzolar-S-methyl was not as effective as the standards, benomyl and Difenoconazole but performed better than mancozeb. Percent anthracnose infection on fruits (6 days after harvest) obtained from Acibenzolar-S-methyl treated fruits was significantly lower than the standard, mancozeb and untreated control. The product performance was comparable to the given at lower and medium rates and at higher rates the test chemical was superior to the standards. Percent control provided by Acibenzolar-S-methyl at higher rates was more than 90%. Fruit set at 45 and fruit retention count at 60 and 75 DAFI showed that Acibenzolar-S-methyl treated trees have a significantly higher fruit set and retention count than the untreated control and were comparable to the standard mancozeb. Highest fruit retention count at 75 DAFI was obtained from Acibenzolar-S-methyl treated trees produced significantly more marketable fruits than the untreated control. At 2.50 and 5.0 ml a.i./100 li., the product's performance was comparable to the standards, mancozeb. At lower rate the product performance was comparable to the standard fungicide, mancozeb.