RESPONSE OF WHEAT TO EXOGENOUS BORON SUPPLY AT VARIOUS GROWTH STAGES

A field experiment to identify the most suitable growth stage for boron application was conducted at Agronomic Research Area, Bahauddin Zakariya University, Multan, Pakistan during, 2009. The boron application times included control, at tillering, jointing, booting and anthesis stage and the treatments were compared in randomized complete block design. The diverse response of plant growth parameters in the given study suggested the active involvement of boron in plant metabolism. The results revealed that boron application time has least significant effect on vegetative growth than reproductive ones. Therefore, the mean values obtained against boron application time for plant height, number of tillers and straw yield did not differed significantly over control. Whereas, boron application was potential contributor to total grains mass by improving the spike length, number of spikelets and grains spike^-1, 1000-grain weight, grain yield and harvest index over control and it ranged from 14.87 to 17.40 (cm), 18.33 to 21.67, 44.00 to 51.33, 31.33 to 38.38 (g), 2.88 to 3.56 (t ha^-1) and 38.50 to 47.16, respectively. It is concluded from the study that boron application in wheat is crucial for improving seed set and its application at booting and anthesis stage seems to be superior among the tested growth stages for enhancement of grains production and better economic returns.