Early assessment of sweet sorghum as an agro-industrial crop. 2. Maturity factors

Abstract

Two experiments were carried out at Ayr, north Queensland, to examine maturity factors on sweet sorghum (Sorghum bicolor) juice characteristics and yields. In experiment 1, four commercially available forage cultivars were harvested at anthesis, milk dough and mature grain stage, and 10 days after maturity. Sucrose and soluble solids concentration and yields in stems were highest at or near grain maturity. In experiment 2, harvests of the cv. Rio were taken at milk dough or mature grain stages on plants that had been left intact, had the panicle removed at anthesis, or had the panicle and subsequent shoots removed. Induced barrenness resulted in a higher concentration of soluble solids and sucrose in the stem over that in intact plants. The sucrose yield of stems of barren plants (up to 3.2 t ha-1) equalled the carbohydrate yield as stem sucrose and grain starch in intact plants. In barren plants, leaves remained greener for longer and stems were less prone to lodging.