CROP : SORGHUM (Sorghum bicolor)
PlantCharacteristics
Sorghum is a member of the grass family and a native wild plant of Africa. Summer annual, coarse, erect with much variability in growth characteristics; culms solid or sometimes with spaces in pith, 0.6-5 m tall, depending on variety and growing conditions, 5 to over 30 mm in diameter, either dry at maturity or with sweet insipid juice; leaves broad and coarse, similar in shape to those of corn but shorter and wider; blades glabrous and waxy; sheaths encircle culm and have overlapping margins; panicle erect, sometimes recurved, usually compact in most grain sorghums and more open in forage types; seed covered by glumes that may or may not be removed by threshing; prop roots may grow from culm nodes; bud at each node from which a tiller may grow; seeds white, yellow, red, or brown; panicle with up to 6,000 spikelets. Seeds 25,000 to 61,740/kg.
Sorghum is a plant of hot and warm localities. The optimum temperature for growth is 300C and it needs about 250-400 mm rainfall. Excess moisture and prolonged drought are harmful. It is fairly tolerant to alkalinity and salinity.Soils with clay loam or loam texture, having good water retension capacity are best suited for sorghum cultivation.
Selection Criteria For Planting Materials
Always use certified seeds. Seed treatment with Thiram @ 3g per kg seed is recommended.. In the case of hybrids, use new hybrid seeds every year.
Seasons
Rainfed crop: May-August
Irrigated crop: January-April
Varieties
Varieties of sorghum are classified into 4 groups: grain sorghums, grass sorghums, sweet sorghums, and broom corn. Broom corn is grown for the branches of the seed cluster, which are used to make brooms. Sweet sorghums have sweet juicy stems and are grown to be made into sorghum syrup. The syrup is made by pressing the juice out of the stems and boiling it down to the proper thickness. Sweet sorghums can also be made into animal feed or silage. Grass sorghums are grown for green feed and hay but can also be weeds. Two types of grass sorghums that grow in Kansas are Sudan grass, an annual grown for feed and hay, and Johnsongrass, a perennial weed.
Varieties
Co.1, Co-10, Co-12, Co-17, K-1, K-2
Hybrids - CSH-1 to CSH-4, Co-11, Co-1
Seeds And Cultivation
Seed rate and sowing
Seeds are sown at the rate of 12-15 kg/ha. Dibble two seeds/hole, at a spacing of 45 x 15 cm
WaterManagement
Usually sorghum is grown as a rainfed crop. At the time of flowering and grain filling stages the crop requires more water. At no stage plant should be allowed to wilt.
NutrientManagement
For both irrigated and rainfed crops FYM / compost may be applied @ 5 t/ha.
Fertilizers may be applied as follows
Nutrients / ha Irrigated Crop Rainfed Crop
N 90 kg 45 kg
P2O5 45 kg 25 kg
K2O 45 kg 25 kg
Apply FYM and entire quantity of P2O5 and K2O as basal dose. Apply N in two equal splits, half as basal and the rest 30 days after sowing.
WeedManagement
Thinning, weeding and hoeing may be done on the 20th day after sowing
Plant Protection
Apply carbofuran @ 1.5 kg ai/ha on the 25th day after germination against stem borer. Apply carbaryl or methyl parathion at milky stages for the control of earhead bugs. Spray zineb @ 2g/l/ha on 30th and 45th day after germination for the control of foliar diseases.
Harvesting
Sorghum takes about 100-115 days to mature.The right time to harvest is when the grains have become hard having less than 25% moisture. Do not wait for stalks and leaves to dry. In the areas where there is chances of rain at the time of harvesting, the mature earheads should be harvested first and plants cut and heaped later on.
Processing
Threshed grain should be cleaned and dried in sun for 6-7 days to bring the moisture content below 13%.
AverageYield
5 tons/ha grain and 10 tons/ha of dry stover under irrigated condition.
2.5-3 tons/ha grain and 8-10 tons/ha of dry stover under rainfed condition