PHENOLOGY AND YIELD OF SUNFLOWER (HELIANTHUS ANNUUS L) HYBRIDS AS AFFECTED BY VARYING PLANT SPACING AND NITROGEN LEVELS UNDER SEMI ARID CONDITIONS OF SARGODHA, PUNJAB.

Abstract

The field experiment was conducted to study the effect of different plant spacing andnitrogen rates on phenology, and yield of sunflower hybrids at research area of University College ofAgriculture, Sargodha, during spring season, 2010.The treatments include two hybrids (Hysun-33 andS-278) at three plant spacing (20, 25and 30 cm) with three levels of nitrogen (100, 125 and 150 kg Nha-1). The trial was conducted in split split plot design and the data collected were statisticallyanalyzed by employing the Fisher’s analysis of variance technique and treatments means werecompared using least significant difference (LSD) test at 0.05 level of probability. The obtained resultsrevealed that there was a significant difference for days taken to flowering (DF), achene’s formation(DAF) & physiological maturity (DPM) and yield in both of the hybrids except, number of days togermination (DG.). The hybrid S-278 started reproductive stages and matured earlier and gave higherachene’s yield (3.34 t ha-1) than hybrid Hysun-33 (2.73 t ha-1). Increasing plant density decreased thedays taken to flowering (DF), achene’s formation (DAF) and physiological maturity (DPM) whileincreases the achene, s yield (AY) in sunflower. By contrast, with increasing nitrogen applicationphonological duration and achene’s yield was increased. There was an interaction between hybrids andplanting densities (HxD), hybrids and nitrogen (HxN) for days taken to flowering, achene’s formation,physiological maturity, achene’s yield ha-1 while no interaction for number of days to germination.The highest achene’s yield (3.75 t ha-) was produced by sunflower hybrid S-278 sown with 20 cmplant spacing (H2D1). Similarly Hybrid S-278 gave highest achene yield (3.57 t ha-1) with theapplication of 125 kg N ha-1 (H2N2). In the interaction of density and nitrogen, highest achene’s yield(3.72 t ha-) was in D1N3 treatment which was statistically similar with D1N2 treatment and wasfollowed by D2N2 and D2N3 treatment.