Occurrence of wheat stripe rust in Kashmir

摘要

Stripe rust of wheat (Triticum aestivum L.) caused by Puccinia striiformis Westend f. sp. tritici is an important disease in India. It occurs regularly in severe form on susceptible varieties in North Western Plain Zone (NWPZ) covering states of Punjab, Haryana, Rajasthan, western Uttar Pradesh and Northern Hill Zone (NHZ) covering Himachal Pradesh, Jammu and Kashmir and Nilgiri Hills in Tamil Nadu in Southern Zone (SZ). In NHZ, the stripe rust has recently been observed to damage wheat crop in Kashmir division of Jammu and Kashmir state. Stripe rust thrives well under cool and moist field conditions and appears before the on set of leaf rust in these zones. The disease first appears on leaves of susceptible cultivars and gradually spread to other plant parts like awns and sheath. When such a large scale spread of stripe rust occurs, it leads to heavy losses to wheat crop. Deployment of diverse resistances in crop population helps in reducing the intensity and frequency of rust epiphytotics throughpreventing the spread to a large area (Sawhney, 1998). The occurrence of virulences for Yr9 (Nayar et al, 1996) and for Yr21 (Prashar et al, 2007) have posed a serious threat for rust management in India. Wide spread cultivation of varieties like PBW343 (India), and Inquilab 91 (Pakistan), having 7r27 based protection is therefore, under threat of stripe rust epidemic in their respective areas and has led to large inoculum build up in these zones.