Management of Chili leaf curl disease (ChiLCD) through resistant germplasm and Nutrients in relation to Environmental Factors

Abstract

Chili (Capsicum annuum L.) is an important commercial spicy crop grown in many regions across the world. Six chili varieties such as Zinia F1, Desi (Jalalpuri), Desi (Jalalpuri 2), Wonder Hot, Summer Queen F1, and Faisalabad Selection was evaluated against the most devastating and catastrophic Chili’s leaf curl disease caused by Begomovirus Chili leaf curl virus (ChiLCV). Out of all six varieties, Wonder Hot and Summer Queen F₁ showed moderately resistant (MR) response whereas three varieties including Zinia F₁, Desi (Jalalpuri) and Desi (Jalalpuri 2) had a moderately susceptible (MS) response, and only one variety namely Faisalabad Selection, expressed resistant (R) response. Four varieties; Desi (Jalalpuri), Desi (Jalalpuri 2), Zinia F1, and Wonder Hot, were used for management purposes with four micronutrients in combinations, namely T₁ (ZnSO₄ + CuSO₄), T₂ (MnSO₄ + CuSO₄), T₃ (Boric Acid + CuSO₄) and T₄ (ZnSO₄ + CuSO₄ + MnSO₄ + Boric Acid). When compared to control (58.14%), only T₄ demonstrated minimum disease severity (11.63%). In the case of disease incidence, T₄ gave the best results with minimum disease incidence (35.65%) as compared to control (92.59%). Treatments were able to decrease the disease progression even in the existing of favorable environmental factors.There was significant (p˂0.05) but positive correlation between wind speed and disease severity. Wind speed was highly correlated with the disease severity of variety Wonder Hot (r=0.91). We concluded that the application of micronutrient activate the plant defense system and at the same time suppress the vector populations.