Organic management of white rust of mustard in Sikkim Himalaya

Abstract

White rust caused by Albugo candida (Pers. ex Fr.) Kuntze is one of the important diseases in mustard. The effect of different dates of sowing, botanicals, biocontrol agent and organically approved fungicide was evaluated against white rust. It was seen that the incidence of white rust was maximum in November and December sown crop and minimum in October sown crop. Findings of the field experiment study revealed that the severity of white rust was significantly lower in copper oxychloride spray @ 0.25% + Trichoderma viride treated seed and soil application with lower per cent disease index (13.5 PDI) and per cent stag head (1.1%). The seed yield was also highest in plots treated with copper oxychloride 0.25% + Trichoderma viride compared with other treatments. Among the botanicals, lowest disease severity (27.4) and highest yield (886 kg/ha) was recorded in aqueous extract of garlic @ 5% as compared to control. Early sowing in the month of October and T. viride seed treatment and soil application along with copper oxychloride and also garlic extract were found as suitable alternative for the systemic fungicides for managing white rust especially in organic mustard production.