Efficacy of different dose of fungicide Mancozeb against purple blotch complex (Alternaria porri) of Shallot

Abstract

Shallot (Allium ascalonicum L) is subjected to attack by a number of diseases caused by fungi, bacteria, and viruses which are the major constraints for higher production. Among the several diseases which attacked shallot, purple blotch disease of shallot caused by Alternaria porri (Ellis) Cif, is one of the most destructive disease; causing accountable losses of about 57 percent. Present study was aimed to determine the efficacies of different doses of fungicide (Mancozeb) against Alternaria leaf blight in shallot. A field experiment for the evaluation of different doses of mancozeb was conducted at Subang, West Java. The research used randomized complete block design (RCBD), with 6 treatments and 5 replications. The treatments were six doses of mancozeb (3 g/L; 2.25 g/L; 1.5 g/L; 0.75 g/L; 0.5 g/L and 0 g/L of water) were applied after 7 days intervals. All Mancozeb doses reduce the disease severity compared to untreated control. Among the different treatments, minimum disease intensity (13.33 %) was observed when the plots were sprayed with mancozeb 3 g/L followed by mancozeb 2.25 g/L (20.27%), mancozeb 1.5 g/l (20.53%), mancozeb 0.75 g/L (21.07%) and mancozeb 0.50 g/L of water respectively.