Ideal plant characters for maximizing yield under rainfed conditions in castor (Ricinus communis L.)

A study was conducted with an objective of identifying the growth characters which influence yield potential under rainfed situations thereby defining an ideal plant type for rainfed situations. Seventy genotypes with distinct morphological characters were studied during rainy season from 1995–96 to 1998–99. Observations on different growth characters viz., plant height, number of branches, number of leaves, petiole length, node number, length of different order branches, leaf area, days to flowering, dry matter production, yield and yield components were recorded. The genotypes were categorized into different groups for each ofthese characters. Depending on nature of curve, suitable regression equations were worked out. Based on that, the ideal characters of castor for rainfed situations are proposed. These include dwarf to medium height (50–60) cm, short to medium durtion (120–150 days), 2–3 secondary and tertiary order branches with better orientation of leaves and branches for efficient light utilization, medium sized leaves of 35–40 with LAI of 3–3.5, long productive spikes with bold capsules and seeds, better harvest index (30–40%) with pest and disease resistance.