Effect of Sowing Season, Age and Height of Cutting of the Primary Crop of Sorghum bicolor cv. ‘Abu Sabeen’ on Growth and Forage Yield of the Secondary Crop

Abstract

A field experiment was conducted for two consecutive seasons
at the Gezira Research Farm to study the effect of growing season, age
and height of cutting of the primary crop of ‘Abu Sabeen’, on the
regrowth yield. The first experiment was sown on 4th of September 2005
and the second was on 7th of June 2006.The treatments comprised cutting
the primary crop at 5 ages i.e. 6, 7, 8, 9 and 10 weeks from sowing and 4
cutting heights i.e. 5, 10, 15 and 20 cm above ground. The 20 treatments
were allotted to a randomized complete block design with 3 replications.
Data were collected on weather conditions, forage yield, plant height, and
culm density of the first regrowth. The growing season was crucial for
multiple -cut crop of ‘Abu Sabeen’; long days and high temperature being
more conducive for high dry matter yield of the regrowth mainly through
the increase in plant height, and shorter days and relatively lower
temperature being conducive for high culm density and retarded growth.
Taller plants were determinant of the regrowth yield than the increase in
the culm density. Highest dry matter yields of the regrowth were
associated with June sowing and cutting the primary crop at the age of 7
weeks and cutting height of 15 or 20 cm above ground.