Impact of foliar application of boron on growth and yield of maize under drought conditions

An experiment was conducted at Agronomic Research Area, University of Agriculture Faisalabad, during spring 2010 to study the interactive effect of drought and foliar applied boron on growth, yield and quality of hybrid maize. Experiment was laid out in randomized complete block design with split plot arrangement. Three irrigation regimes viz. I1= no stress (irrigation at 10 days interval), I2= drought at knee height (30 Days after sowing) and I3=drought at anthesis (60 days after sowing) and four levels of foliar applied boron B0=0%, B1= 0.1%, B2= 0.2% and B3= 0.3% boric acid (17% boron) solution (B) were tested on maize hybrid FH-793. Experiment was replicated thrice with a net plot size of 5 mx2.25 m. The crop was harvested on June 15, 2010. Mainly data regarding growth and grain yield was recorded as indicator of drought mitigation by application of boron. Data regarding growth, yield and quality parameters were recorded using standard procedures and were statistically analyzed by Fisher's analysis of variance technique. Treatments means were compared by using least significant difference (LSD) test at 5% level of probability. All the growth and yield parameters increased with boron application. However, mean values showed by B3 were statistically at par with respect to B2. Maximum grain yield (6.92 t per ha) was recorded where boron was applied @ 0.3% B (B3) under no stress (I1) which was statistically at par with boron application B2 @ 0.2% B at same level of stress. Minimum grain yield (2.32 t per ha) was noted with no spray of boron (B0) from drought (I2) at 30 DAS. Foliar spray @ 0.2% B enhanced grain yield under no stress (I1), drought (I2) at 30 DAS and drought (I3) at 60 DAS. Drought at both vegetative and reproductive stages hampered the growth and yield of maize but more severely at vegetative stage in this experiment. 0.2% foliar spray of boric acid solution (B2) helped to ameliorate the drought effects by decreasing the frequency of kernal abortion which is the main consequence of drought. Boron application did not affect the seed oil content but the seed starch content was significantly affected by boron application and drought. Leaf B content increased with increasing concentration of the solution but even the maximum level was found to be non-toxic.