Sorghum Yield Estimation (T.Ha-1.Season-1) Based On SmithS (1994) Climatic Criteria

Sorghum is indigenous to Africa. In comparison with maize, it is grown in relatively warm areas. Sorghum is planted mainly between mid-October to mid-December, depending on weather patterns of the particular season (NDA, 2005). Cultivated in rainfall regimes ranging from 300 - 1 200 mm in the growing season, its optimal rainfall for this period is around 600 mm/a. It is killed by frost and is grown ideally where relative humidities are < 60 percent. Using Smith`s (1998) climatic criteria, yields of sorghum are estimated using the effective rainfall for October to March and heat units (base 10 degree Celsius) for the same period, with modifications to yield made for soil properties and management levels. Rainfall values were derived from the 1 arc minute (1` x 1` latitude x longitude) median monthly rainfalls generated for South Africa by Lynch (2004).