Impact of planting time on grain yield and neck blast incidence in tall and semi dwarf genotypes of basmatirice (Oryza sativa)

摘要

Haryana state is well known for cultivation and export of basmati rice which gets a premium price in the market for its excellent aroma, cooking quality and palatability. basmati rice varieties are occupying about 65% of the total area under rice in the state. Time of planting is one of the most important management factors which have a significant bearing on the crop yield. Blast continues to be an economically important disease in all the rice ecosystems of the country (Muralidharan, 2006), which is known to affect different parts of the rice plant viz. leaf, node, neck and the collar region of leaf and stem. Of these, neck blast caused by Pyricularia grisea Sacc. {Magnaporthe grisea (Hebert) Barr) has become a major constraint in realizing the potential yield of basmati rice varieties grown for export purpose in the state (Ram Singh et al" 2004). Although the effect of planting time on grain yield and neck blast incidence has been studied in traditional tall and photo-sensitive basmati rice variety Taraori Basmati (Dodan and Ram Singh, 1995) but no such information is available on semi-dwarf (photo-insensitive) varieties as well as on other tall and promising (photo-sensitive) genotypes of basmati rice. Keeping above facts in view, present study was carried out to determine the optimum time of transplanting for different basmati rice genotypes in order to minimize neck blast incidence and to obtain maximum grain yield.