Effect of sulphur and different irrigation regimes on par distribution, canopy temperature, yield and water use efficiency of groundnut (Arachis hypogaea L.)

A field experiment was conducted to study the effect of different levels of irrigation and sulphur on leaf area index, on distribution pattern of photosynthetically active radiation, consumptive use, water use efficiency, Canopy-Air Temperature Difference as well as yield attributes and yield of summer groundnut (Arachis hypogaea) during two consecutive years (2009 and 2010) at the ‘C’ block farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal during pre-kharif season in a sandy loam soil with 24 treatment combinations (eight irrigation level in main plot and three level of sulphur in sub-plot) in a split plot design replicated thrice. The study revealed that both the levels of irrigation and sulphur significantly influenced all the yield attributing characters and the kernel yield. The highest values of yield attributing characters and kernel yield were recorded when sulphur applied @ 15 kg ha⁻¹. The highest consumptive use, and water use efficiency were recorded under three irrigations applied at flowering, pegging and pod filling stage followed by two irrigations at pegging and pod filling stage. No irrigation treatment recorded lower photosynthetically active radiation absorption percentage value but higher photosynthetically active radiation extinction coefficient and Canopy-Air Temperature Difference value as compare to irrigation treatments, respectively.

Irrigation applied at flowering, pegging and pod filling stage (I8) along with sulphur applied @ 15 kg ha⁻¹ (S2) gave the best result with maximum crop water-use efficiency and no irrigation treatment (I1) resulted lower PAR absorption percentage but comparatively higher PAR extinction coefficient.

The canopy air temperature difference could indicate extreme stress as evident from higher CATD value recorded from no irrigation treatment as compared to other irrigation treatments.