Contractile Growth of the Hypocotyl of Lotononis bainesii Seedlings in Relation to Some Environmental Factors

Lotononis bainesii seeds were sown in a glasshouse at 0, 10, 20 or 30 mm depth, covered with 0, 70, 140, or 210 g m litter and grown under shades giving 24, 47, 77 and 100% light transmission. Light negatively influenced the extension of the hypocotyl above ground level and positively increased the contractile growth of the hypocotyl to produce a buried crown. Emergence from 10 and 20 mm depth and the absence of litter also favoured development of a buried crown. In the field the extension of the hypocotyl of seedlings was negatively related to the light received by the seedlings, as varied by companion Digitaria decumbens growth. A buried crown did not develop in the absence of grazing. Maintenance of grazing pressure following seedling regeneration favours increased L. bainesii density in mixed pastures. -from Authors