TITLE:
Differential Growth and Development Response of Sunflower Hybrid in Contrasting Irrigation Regimes
AUTHORS:
Amjed Ali, Ijaz Rasool Noorka
KEYWORDS:
Growth; Irrigation; Leaf Area Index; Yield
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.5,
May
29,
2013
ABSTRACT: Water is the most important factor limiting crop productivity
at different growth stages of crop growth and development. The study was
conducted to investigate the effect of irrigation scheduling on sunflower
hybrid (Hysun-38) at vegetative versus reproductive stages during spring season
2010. The trial was laid out in randomized complete block design (factorial
arrangement), replicated thrice, having net plot size of 3.5 m × 9 m. The
treatments comprised of irrigation application of 75 mm each, at different
growth and development stages. viz., I1 =
irrigation at plant establishment, I2 =
irrigation at plant establishment and irrigation at vegetative phase, I3 = irrigation
at plant establishment, irrigation at button stage and irrigation at flowering,
and I4 = irrigation at plant establishment, irrigation at
vegetative phase, irrigation at button stage and irrigation at achene’s
formation. Days taken to 50% flowering was highest in I2, where
irrigation was applied at plant establishment and vegetative phase, and in I4 treatment , where irrigation was given at seedling establishment,
irrigation at vegetative phase, irrigation at button stage and irrigation at
achene’s formation. Leaf area index at different growth intervals was
significantly affected by irrigation levels. Crop growth rate was highest for
treatment I4. Plant height (PH), stem girth (SG) head diameter (HD),
1000-achene’s weight (AW) and achene’s yield (AY) were significantly affected
by different irrigation levels at various growth stages. Maximum AY (2415.68 kg·ha-1) was obtained in I4 treatment while,
minimum AY (1275.35 kg·ha-1) was
obtained in case of those plots which were irrigated only at plant
establishment stage. Sunflower productivity was affected with irrigation regime
at different growth stages with the strongest responses seen at early growth
stages which ultimately affected the final achene yield adversely.