Botanicals to control soft rot bacteria of potato.

ABSTRACT

Extracts from eleven different plant species such as jute (Corchorus capsularis L.), cheerota (Swertia chiraita Ham.), chatim (Alstonia scholaris L.), mander (Erythrina variegata), bael (Aegle marmelos L.), marigold (Tagetes erecta), onion (Allium cepa), garlic (Allium sativum L.), neem (Azadiracta indica), lime (Citrus aurantifolia), and turmeric (Curcuma longa L.) were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc) P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments.