Introduction-
Sorghum is an important cereal crop grown for food, feed, and fodder n mostly dryland ecosystems of the country. In India, Kharif sorghum is grown in an area of 28.92 lakhs hectare and rabi sorghum in 46.39 Lakhs ha. Maharashtra (54%), Karnataka(18%), RajasthBn (8%), Madhya Pradesh (6%) and Andhra Pradesh (4%) are the major sorghum growing states.
Scientific name-Sorghum bicolor.
Land preparation for growing sorghum
• Deep ploughing once in summer followed by 2-3 harrowings
• 8-10 tons of farmyard manure (FYM) per ha
• Soil application of Thiram @ 4.5 kg/ha
Sowing time
- 3rd week of June to 1st week of July with on-set of monsoon.
Seed rate of Sorghum
- 7-8 kg seeds per ha (3 kg/acre)
Row spacing
- Row to row 45 cm and plant to plant distance 12 to 15 cm.
- Maintain plant population as 1,80,000 plants per ha (72,000 plants per acre)
Seed treatment
- Treat the seed with 14 ml imidacloprid (Gaucho)+ 2 g carbendazim (Bavistin) for one kg seed, or thiamethoxam (Cruser) 3g/kg seed.
Sorghum fertilizer requirements
- For light soils and low rainfall areas: 60 kg Nitrogen, 30 kg P2O5 and 20 kg K2O per ha. AppLy 30 kg nitrogen, and totaL phosphorus and potash at sowing and remaining 30 kg nitrogen at 30-35 days after sowing (DAS).
- For medium-deep soils and moderate to high rainfall areas: 80kg nitrogen, 40 kg P2O5 and 40 kg K2O per ha. Apply half nitrogen+ full P2O5 and K2O at sowing and remaining nitrogen at 30 DAS.
Weed control and inter cultivation
- Keep the crop free from weeds for about initial 35 days.
- Spray atrazine @ 0.5 kg a.i./ha immediately after sowing.
- Striga is controlled by hand pulling when population is less, otherwise, spray 2,4-D sodium salt @ 1.0 kg a.i./ha
- Two times inter cultivation with blade hoe at 3 and five weeks of germination.
Insect Pests Management
1.Shoot Fly-
Nature of damage
- Infestation occurs during seedling stage up to 1 month. Maggots cut the growing point and feed on the decaying tissues.
- The infestation results in withering and drying of the central leaf, giving a typicaL “dead heart” symptom.
Control measures
- Early sowing within 7 to 10 days of the onset of monsoon.
- High seed rate @ 10 to 12 kg/ha.
- Intercropping of sorghum + red gram in 2:1 or 2:2 ratio.
- Seed treatment with imidacloprid @14 ml/kg seed or thiamethoxam 70 WS @ 3 g/kg seed or furan/carbofuran 50SP@100 g/kg of seed may also be used.
- Soil application of carbofuran 3G granules @20kg/ha in furrows at the time of sowing.
2.Stem Borer-
Nature of damage
- It attacks the crop from 2 weeks after germination until crop harvest.
- Irregular-shaped holes on the leaves, caused by the early instar larvae feeding in the whorl.
- Drying of central shoot giving “dead heart” look.
- Extensive stem tunneling.
- After panicle emergence, peduncle tunneling results in their breaking or result in complete or partial chaffy panicles.
Control measure - Uprooting and burning of stubbles and chopping off stems of an earlier crop to prevent its carryover.
- Need-based application of carbofuran 3G, carbaryl 3G, or furadan 3G @ 8-12 kg/ha at 20 and 35 days after emergence inside the Leaf whorls.
- Intercropping of sorghum with cowpea.
3.Grain Mold-
Symptoms
- Grains show symptoms of fungal infection and develop fugal bloom of various colors (black, white or pink) depending on fungus.
- The infected grains are soft, powdery, low in nutritional quality, poor germination, and acceptability for human consumption.
Control measures
- Harvesting of genotypes at physiological maturity and drying.
- Spray of Tilt 25% EC @ 0.2% starting from flowering and another spray after ten days interval.
4.Downey Mildew-
Symptoms
- The most conspicuous symptom is the appearance of vivid green and white stripes on the leaves and white patches of oospores.
- Whole leaves may become chlorotic at advanced stage and plants usually fail to exert panicles. Even if panicles are exerted, they are small, compact or club-shaped and have Little or no seed set.
Control Measures
- Deep ploughing before planting to reduce oospores.
- Seed dressing with metataxyl/ ridomil25@ ig a.i./kg.seed followed by spray with ridomyl-MZ @ 3g/liter water.
Intercropping
- Intercropping sorghum with legumes not only produces higher yields per unit area and time but also provides nutritional security, economic benefits and improves soil health.
- Sorghum+ pigeon pea (2:1) and sorghum+ soybean (3:6) are the two most common sorghum – based intercropping systems in the country.
- Sorghum + fodder cowpea (2:2) provides nutritive green fodder, helps to improve soil fertility and checks weed growth.
- Medium duration sorghum genotype like CSH 16, CSH 18, CSH 23, CSV 15 and CSV 20 are most suitabLe for intercropping
Sequence cropping
- Sorghum (Kharif)-chick pea, safflower and mustard (rabi) are the most suitable cropping sequences under limited irrigation conditions.
- These cropping sequences are more profitable in areas receiving annual rainfall above 700 mm and in medium to deep soils having high water retention capacity.
- In irrigated situations, a sorghum-wheat sequence is also followed in some parts of Northern and Central India.
The area under sorghum is reduced drastically from 17.37 m ha in 1970-71 to 7.67 m ha in 2009-10. However, due to concerted efforts made by the scientists, extension workers, developmental; agencies and farmers, average productivity has now reached to >1000 kg/ha during 2009-10.
Latest sorghum cultivars (CSH 23, CSV 20, CSV 23, CSV 17 and CSV 15) demonstrated under frontline demonstrations (FLDS) gave up to 67% higher grain yield and up to 64% higher stover yield than the local cultivars during Kharif 2009 (Fig. 2). On an average, the demonstrated cultivars gave 56% more net profit (Rs.17,955/-per ha), than the Local cultivars (Rs. 11,494/-per ha).
Source-Directorate of Sorghum Research.
