Effect of boron on growth and yield parameters of sunflower in acid soil

Sunflower (Helianthus annus L.) is an exotic North American plant but its commercialization as a crop started in Russia and now widespread across the globe. Boron has a synergistic effect on nitrogen uptake, which is directly linked with amino acids, RNA, and protein synthesis thereby enhancing the relative growth rate and absolute growth rate. Although numerous studies emphasized the positive effects of boron application on growth, yield and oil content of sunflower, limited information is available on the influence of boron nutrient in sunflower crop cultivated in acid laterite soils. The experiment was laid out in factorial completely randomised block design in Sunflower (Helianthus annus L.) in laterite Soil during Zadi, in 2018 at AICRP on Micronutrients, department Soil science and Agricultural chemistry, OUAT, Bhubaneswar, with two factors (5 Soil types and 5 boron doses of 0kg boron/ha, 0.5kg boron/ha, 1.0kg boron/ha, 1.5kg boron/ha and 2kg boron/ha.) with 25 treatments replicated twice. All the yield parameters showed positive and significant correlation with the soil boron application in all soil types except in soil type 2 and soil type 3 where the growth declined after 1.5 kg/ha and 1 kg/ha respectively. The maximum head diameter (6.33cm at 75 days after sowing) and head dry weight (20.64g) was in Soil type 1 with boron dose 2 kg/ha. Soil type 1 with boron dose 2 kg/ha was also recorded the highest of number of filled seeds per head(183) and seed weight (6.15g),maximum oil content(29.105 %). In Soil type 3 boron dose 2 kg/ha maximum total boron concentration (120.2ppm) and maximum the seed concentration of boron (24.79ppm) was observed. Harvest Index was observed to be maximum in Soil type 1 boron dose 2 kg/ ha it was maximum (16.70%).