Efektivitas Fungisida Propineb dan Klorotalonil dalam Pengendalian Penyakit Bercak Ungu (Alternaria porri) pada Tanaman Bawang Merah (Allium ascalonicum L.) di Dolok Sanggul

Abstract

Shallots are widely used in daily life, including as a cooking spice and traditional medicine. One of the causes of low shallot production is the disturbance of purple blotch disease caused by the pathogenic fungus Alternaria porri. This study aims to determine the effectiveness of combining different concentrations and application intervals of fungicides with active ingredients Propineb and Chlorothalonil in controlling purple blotch disease in shallot plants.. The study was conducted in Purba Dolok, Dolok Sanggul, Humbang Hasundutan Regency, North Sumatra Province, at an altitude of ± 1400 meters above sea level. The research was carried out from April to June 2024. The experiment used a factorial randomized block design (RBD) with three factors and three replications. The first factor was fungicide treatment with three levels: F0 = no treatment (control); F1 = Propineb; F2 = Chlorothalonil. The second factor was fungicide concentration with three levels: K1 = 1 g/L; K2 = 2 g/L; K3 = 3 g/L. The third factor was application interval with three levels: A1 = 5-day interval; A2 = 10-day interval; A3 = 15-day interval. The results revealed that the treatment F1K3A1 (Propineb at 3 g/L with a 5-day application interval) exhibited the lowest disease severity of purple blotch, with a percentage of 1.09% at 7 weeks after planting.