Plant Disease Research

Pomegranate (Punica granatum L.) is becoming very popular fruit crop all over Himachal Pradesh. During last decade, pomegranate crop has witnessed a tremendous growth potential in mid hill zone of Kullu and Mandi districts. Cultivation of this fruit crop is adversely affected by various foliar (leaf spots), fruit (spots and rots) and soil borne (wilt) diseases resulting in huge losses to the growers. The extensive cultivation in different agro-ecological situations under mid hill zone with introduction of new varieties directly by the growers from other States is further adding to the pathogenic fauna. Therefore, a survey of pomegranate growing areas conducted during June to September 2011 revealed that the biggest threat to pomegranate cultivation is posed by wilt disease caused by Ceratocystis fimbriata and Fusarium oxysporum with their incidence varying from 1.03 to 15.3 and 0.1 to 7.3 percent, respectively. This disease was more pronounced in areas having heavy soils. Incidence of leaf and fruit spots were caused mainly by Cercospora punicae (Pseudocercospora punicae) and Alternaria alternate showing incidence of 1.1 to 17.3%t. Similarly, fruit rot was caused by Coniella granati (1.0 to 14.8%), Phomopsis aucubicola (1.0 to 14.7%) and Phytophthora sp. (1.4 to 13.6%). The incidence of anthracnose (7.3%) caused by Colletotrichum gleosporoides was recorded only at one location (village Samtana) in Hamirpur district. A bacterial pathogen Xanthomonas axonopodis was found causing leaf and fruit spots and subsequent fruit rotting ranging from 1.2 to 7.5 percent. Stem and twig canker to the tune of 1.1 to 39.5 percent was recoded only at two locations (Hathithan in Kullu district and Shilligad of Mandi district) on Mridula and Sindhuri varieties directly introduced from Maharashtra by the farmers.