Growth and response of several shallot varieties to its important diseases in Lembang highlands

Abstract

Abstract Disease attacks on shallots (Allium cepa L. var. aggregatum) are one of the main constraints on increasing shallot production. Important diseases that often appear in shallots are purple blotch disease (Alternaria porri), leaf blight (Stemphylium vesicarium), and downy mildew (Peronospora destructor). The diversity of existing varieties is wealth as a substitution for seed sources. The aim of this study was to determine the growth and disease resistance of several shallot varieties grown in Lembang highlands. The research was conducted at the Margahayu Experiment Field of the Indonesian Vegetable Research Institute Lembang, from March to July 2021. The Randomized Block Design (RBD) was used in this study with a treatment consisting of 11 varieties of shallots (Violetta 1 Agrihorti, Violetta 2 Agrihorti, Violetta 3 Agrihorti, Ambassador 1 Agrihorti, Ambassador 2 Agrihorti, Ambassador 3 Agrihorti, Ambassador 4 Agrihorti, Maja Cipanas, Pancasona, Kramat 1, and Sembrani), with 3 replications. The results showed that the growth performance varied between varieties. The Violetta 3 Agrihorti was the highest for plant height, the highest number of tillers was in the Pancasona, and the highest number of leaves was in the Ambassador 3 Agrihorti. Among the eleven shallot varieties tested at high altitudes, none were resistant to the diseases of Alternaria porri, Stemphylium vesicarium, and Peronospora destructor, except for the Pancasona variety which was classified as tolerant (resistance category included in the susceptible category, but has high yield). Meanwhile, for disease resistance, the Violetta 1 Agrihorti is relatively resistant to purple blotch disease, leaf blight, and downy mildew.