Effects of planting dates on stalk yield and agronomic characters of sweet sorghum (Sorghum bicolor (L.) Moench)

Abstract

Sweet sorghum has been proven that it had very high potential for using as an additional raw material for commercial ethanol production. The trials on identification of suitable planting date were studied at Khon Kaen University Farm. The trials were conducted from 1 February to 1 October, 2009 with 15 days interval of planting dates. The results from planting date revealed that days to 50% flowering average from 61 to 75 days, stalk yield average from 3.33 to 8.24 tons/rai, sugar content average from 17 to 20 obrix, plant height average from 166 to 319 cm., stalk size average from 10.9 to 18.6 mm., seed yield average from 104 to 191 kg/rai., and the relative juice quantity average from 696 to 2,620 l/rai. The results also revealed that the early planting in February gave lower yield (5.0 to 5.1 tons/rai) than the planting date from March to late July (5.9 to 8.24 tons/rai). Whereas the late planting from August to October tended to reduce yield (3.33 to 5.83 tons/rai). It was concluded that the farmers can grow sweet sorghum from February to August and the suitable growing period are from March to July which will give higher yield than that of growing in February and August. This information can be utilized to ensure continuous supply of raw material with proper planting date sequence.