Effect of source and level of sulphur on yield and sulphur content of plant parts of sunflower (Helianthus annuus)

Abstract

A field experiment was carried out on Vertisol to find out the dry-matter yields of different plant parts (stems,leaves, flower-heads, stalks and buds) at various stages of growth and to understand the pattern of distribution of sulphur in these parts of sunflower (Helianthus annuus L.) genotypes ('Morden', 'APSH 11' and 'EC 68414'). Highest yield, S content and uptake were observed in 'EC 68414', followed by 'APSH II'and 'Morden', irrespective of the plant part tested when S was applied as anunonium sulphate followed by gypsum. Sulphur content in leaves at bud and flowering stages and in seeds at maturity was highest; it - decreased with advancement in crop age. Though there was decrease in dry-matter yleld at 60 kg S/ha, the S uptake increased with the increase in S level from 0 to 60 kg/ha. It was concluded that to achieve optimum production, sunflower plant requires presence of high sulphur content in leaves at bud and flowering stages.