Effect of light and soil moisture on yield, yield components, and abortion of reproductive structures of chickpea (Cicerarietinum), in Canterbury, New Zealand

Abstract

An experiment was conducted in 1994–95 to test the effects of soil moisture (two levels, nil and fully irrigated) and shade (two levels, full light and 40% shaded) on the abortion of reproductive structures, yield, and yield components in chickpea (Cicer arietinum L.). Shade and soil moisture interacted significantly, and the highest dry matter (DM) production of 838 g/m2 was produced by unshaded irrigated plants. This was about twice the DM produced by shaded unirrigated plants. Total DM production was highly correlated with radiation interception, where c. 2.1 g DM were produced per MJ of intercepted photosynthetically active radiation (PAR). Functional growth analysis showed that the crop growth rates were 14 and 27 g/m2 per day for shaded and unshaded plants respectively. The two factors again interacted on seed yield. Highest yields were produced from plants that were unshaded and irrigated (389 g/m2), whereas shaded irrigated plants produced only 139 g/m2. Reduced seed yield was accompanied by a large drop in harvest index (HI) in shaded irrigated plants. This drop in HI was because of a limited assimilate supply in shaded plants and increased reproductive abortion in shaded and irrigated plants.