Light interception and radiation use efficiency of wheat varieties as influenced by number of irrigations

Abstract

An experiment was conducted during rabi seasons of 2002-03 and 2003-04 to quantify the light interception and radiation use efficiency for three wheat varieties as affected by variable number of irrigations with the combination of three wheat varieties viz., HUW-234, HD-2285 and PBW-154. The light interception increased successively till 90 days after sowing (DAS) and thereafter a gradual decrease was observed till maturity of the crop. Four irrigations given at CRI, late tillering, late jointing and ear head formation stages showed highest radiation interception followed by three and two irrigations, however, the lowest radiation interception was observed for wheat crop receiving one irrigation only. On an average, 19.08 % and 12.79 % increase in radiation interception was found for wheat crop irrigated four and three times respectively as compared to singly irrigated crop. Highest radiation interception was recorded with HUW 234 followed by HD 2285 at all the growth stages except 15, 30, 45 DAS. More light interception reflected in significantly superior yield and yield attributes in the order of I4>I3>I2>I1. Subsequently, radiation useefficiency (RUE) also followed the similar trend showing highest and lowest RUE with four and one irrigation respectively. Among the different varieties, HUW-234 recorded highest radiation use efficiency followed by HD-2285. The average RUE during the entire growing period for HUW-234 and HD-2285 was found to be 1.68 g MJ-1 and 1.63 g MJ-1 respectively, which was 4.83 and 1.95 % higher than PBW-154.