PARTITIONING OF BIOMASS, N AND S IN SUNFLOWER (HELIANTHUS-ANNUUS L) BY NITROGEN AND SULFUR NUTRITION

Response of sunflower (Heliathus annuus L.) to sulphur applied ca. 0, 30, 90 and 150 mg kg(-1) and nitrogen applied ca. 0, 100 and 200 mg kg (-1) soil were studied on a Typic Camborthids in greenhouse. Nitrogen and S application had a significant (P < 0.01) main and interactive ef fect on seed yield and dry weight of leaves and stem. Cumulative N and S contents of sunflower seeds, stem and leaves were significantly (P < 0.01) affected by N and S application. Sulphur transport and accumul ation in sunflower seeds was increased with S application. There were significant (P < 0.01) correlations between seed yield and N and S con tent of sunflower plants. Critical S concentration (%) in 60 days old plants was 0.36 for 95% relative yield of the maximum. Application of 90 mg S kg(-1) with 200 mg N kg(-1) resulted in the highest seed yield and maximum total S and N contents in sunflower leaves, stem and seed s. Relative increase in sunflower seeds yield at higher levels of N an d S was more than that of dry weight of stem and leaves.