1. Origin:
Cluster bean (Cyamopsis tetragonoloba), popularly known as Guar, is believed to have its origin in Africa. It was introduced and domesticated in the Indian subcontinent several centuries ago. Historically, it has played a crucial role in the traditional farming systems of arid and semi-arid regions. Its ability to withstand drought has made it a preferred crop among farmers in rainfed regions.
2. Geographical Distribution in India:
In India, Cluster bean is majorly cultivated in the north-western belt. Rajasthan leads the production with more than 70% share, followed by Gujarat, Haryana, Punjab, Madhya Pradesh, and parts of Uttar Pradesh and Maharashtra. The crop has found a niche in areas with low rainfall and sandy soils where other crops struggle to thrive.
3. Economic Importance:
Guar holds significant commercial value due to the extraction of guar gum from its seeds. This gum is widely used in industries like oil drilling (as a thickening agent in hydraulic fracturing), textiles (as a sizing agent), paper (for improving sheet formation), food (as a stabilizer and emulsifier), and pharmaceuticals (as a binder and laxative). Apart from industrial uses, the green pods are consumed as vegetables, especially in Rajasthan. Guar also serves as an excellent fodder crop and enhances soil fertility through nitrogen fixation.
4. Soil and Climatic Requirements:
Guar is best suited to well-drained sandy loam soils with neutral to slightly alkaline pH (7.0–8.5). It is highly tolerant to salinity and drought, making it suitable for arid zones. Ideal temperatures for growth are between 25°C to 35°C, and the crop requires 400–600 mm of well-distributed rainfall during its growing period. High humidity during pod maturity should be avoided to prevent fungal diseases.
5. Land Preparation:
Land should be ploughed 2–3 times to remove weeds and create a fine seedbed. One or two harrowings followed by planking will ensure good soil tilth. Incorporation of well-decomposed Farm Yard Manure (FYM) at 10–15 tonnes/ha is recommended during the final ploughing to enhance soil health and moisture retention.
6. Varieties Developed in India:
- HG-563: High gum content and good grain yield.
- HG-365: Drought tolerant and suitable for semi-arid regions.
- RGC-936: Resistant to common pests and diseases.
- RGC-1003, RGC-1038, RGC-1066: Improved varieties with better performance under rainfed conditions and higher gum yield.
7. Seed Requirement:
For grain production, a seed rate of 18–20 kg/ha is sufficient. For fodder purposes, 12–15 kg/ha is adequate. Seeds should be treated with Rhizobium and PSB (Phosphate Solubilizing Bacteria) cultures to enhance nitrogen fixation and phosphorus availability. This ensures early establishment and better productivity.
8. Sowing Time:
Cluster bean is generally sown during the Kharif season (June–July) with the onset of monsoon. In areas with irrigation facilities, summer sowing is possible from February to March. Timely sowing ensures better yield and disease escape.
9. Cropping Systems:
Guar is grown as a sole crop as well as in intercropping systems. Common intercrops include pearl millet (bajra), sesame, and groundnut. It is often rotated with wheat, mustard, or chickpea to maintain soil fertility and break pest and disease cycles.
10. Fertilizer Requirements:
- Basal Dose: 20 kg N and 40 kg P2O5 per hectare.
- Though guar fixes atmospheric nitrogen, application of starter nitrogen helps in early growth.
- Micronutrients like Zinc and Sulphur may be added in deficient soils.
- Use of biofertilizers (Rhizobium + PSB) significantly enhances yield and soil fertility.
11. Water Requirements:
Being drought-resistant, cluster bean requires minimal irrigation. Under rainfed conditions, irrigation may not be necessary. In dry conditions, 2–4 irrigations are optimal. Critical stages include flowering and pod development. Excess irrigation or waterlogging must be strictly avoided.
12. Weed Management:
Weeding is important during early crop growth. Manual weeding should be done at 20–25 and 40–45 days after sowing. Pre-emergence application of Pendimethalin @ 0.75–1.0 kg a.i./ha effectively controls most annual weeds. Mulching and inter-row cultivation are also beneficial in reducing weed pressure.
13. Diseases and Insect Pests & Their Management:
Diseases:
- Powdery Mildew: Appears as white powdery patches on leaves; controlled by Sulphur dust or wettable sulphur (0.2%).
- Bacterial Blight: Managed by seed treatment with Streptocycline (0.01%) and use of resistant varieties.
Insect Pests:
- Aphids & Jassids: Control with Imidacloprid 0.3 ml/litre water or Neem oil spray.
- Pod Borer: Managed by Quinalphos 2 ml/litre or Chlorpyriphos 2.5 ml/litre at ETL.
14. Harvesting & Threshing:
The crop is ready for harvesting in 90–120 days depending on the variety and season. Signs of maturity include leaf drying and browning of pods. Plants are uprooted or cut at the base, sun-dried for a few days, and then threshed manually or with threshers. Timely harvesting is crucial to prevent seed shattering and pest attack.
15. Yield of Crop:
Under good agronomic practices:
- Grain Yield: 10–15 quintals/ha
- Fodder Yield: 100–150 quintals/ha
Improved varieties and good rainfall can boost yields further.
16. Post-Harvest Operations:
After threshing, seeds should be cleaned and dried to a safe moisture content (10–12%) to prevent spoilage. Proper grading and packing in jute or moisture-proof bags is essential for storage and marketing. Store in a cool, dry place, and use neem leaves or pest repellents to prevent storage pests like bruchids.