Variability of Albugo candida causing white rust in rapeseed and mustard under Manipur conditions

An intensive survey was carried out at the farmer's field level to understand natural prevalance of white rust of rapeseed and mustard at seven valley areas of Manipur and it ranged from 2.22–16.70 per cent. Maximum disease intensity (16.70%) was found in Vajing of Churachandpur district, and minimum (2.22%) at Kakching of Thoubal district. Studies on morphological variability of sporangia of all isolates of A. candida revealed that the size of sporangia varied in different isolates and which ranged from 154.54 – 297.59μm. The germination percentage of sporangia among isolates ranged between 58–80% after 7hrs. of incubation at 10°C. All isolates of Albugo candida showed creamy white pustules, however the size of the pustules in all isolates ranged from 1-5mm in diameter. The present study showed the prevalence and presence of variability of A. candida in Manipur.