Nutritional Management Studies on Spring Planted Sunflower (Helianthus Annuus L.).

Nutritional management studies on sunflower comprised of two field experiments were carried out during 2004 and 2005. First experiment was conducted to assess the response of sunflower to nitrogen application in various splits. Nitrogen was applied at 100 kg ha-1, full at sowing, full at first irrigation, full at flowering, 1/2 at sowing + 1/2 at first irrigation, 1/2 at sowing + 1/2 at flowering, 1/2 at first irrigation + 1/2 at flowering, 1/3 at sowing + 1/3 at first irrigation + 1/3 at flowering, 1/3 at sowing + 1/3 at first irrigation + 1/3 at seed formation, 1/3 at sowing + 1/3 at flowering + 1/3 at seed formation stage. The highest achene yields of 2446 kg ha-1 and 2370 kg ha-1 were obtained in 2004 and 2005, respectively from plots where nitrogen was applied in three equal splits; at sowing, at first irrigation and at flowering. The second experiment was conducted to assess the maximum yield potential of sunflower in response to integration of crop manuring and nitrogen application. The integration of organic and chemical fertilizers comprised of treatments; control (no fertilizer), farm yard manure at 20 t ha-1, poultry manure at 8 t ha-1, 100 - 75 - 50 NPK ha-1, farm yard manure (20 t ha-1) + 25 - 75 - 50 NPK kg ha-1, farm yard manure (20 t ha-1) + 50 - 75 - 50 NPK by kg ha-1, farm yard manure (20 t ha-1) + 7575 - 50 NPK kg ha-1, farm yard manure (20 t ha-1) +100 - 75 - 50 NPK kg ha-1, poultry manure (8 t ha-1) + 25 - 75 - 50 NPK kg ha-1, poultry manure (8 t ha-1) + 50 - 75 - 50 NPK kg ha-1, poultry manure (8 t ha-1) + 75 - 75 - 50 NPK kg ha-1, poultry manure (8 t ha-1) + 100 - 75 - 50 NPK kg ha-1. The maximum achene yields of 2895 kg ha-I and 2792 kg ha-1 were recorded in the treatment of 50-75-50 NPK kg ha-1 + PM at 8 t ha-1 during both years, respectively. Chemical fertilizers (100-75-50 NPK kg ha-1) produced relatively more achene yield than organic manures (FYM at 20 t ha-1 and PM at 8 t ha-1) and the poultry manure alongwith chemical fertilizers gave higher yield than farm yard manure alongwith chemical fertilizers. The treatments which produced the maximum achene yields in both experiments, also gave significantly highest values of all physiological traits such as harvest index, leaf area index, mean crop growth rate and net assimilation rate and quality traits like protein contents (%) and linoleic acid (%). All the parameters had a positive correlation with the achene yield except achene oil content (%) and oleic acid % in oil of sunflower. Application of nitrogen at 100 kg ha-I in three equal splits at sowing, at first irrigation and at flowering and application of chemical fertilizers at 50-75-50 NPK kg ha-1 alongwith poultry manure at 8 t ha-1 in the first and second experiment, respectively appeared to be the most appropriate, economical and suitable nutritional management practices to obtain maximum yield of sunflower. Download Full Thesis