Sugarcane Cyst Nematode

📖 Description

Sugarcane Cyst Nematode (Heterodera sacchari), also called Sugarcane Cyst Nematode, is an important soil-borne microscopic nematode pest of sugarcane across the Indian subcontinent, particularly severe in the major sugarcane-growing belts of Uttar Pradesh (Meerut, Muzaffarnagar, Bijnor, Saharanpur, Bareilly, Lakhimpur Kheri — India’s largest sugarcane-producing state with over 50% of national area), Maharashtra (Kolhapur, Sangli, Satara, Solapur, Pune, Ahmednagar), Karnataka (Belgaum, Bagalkot, Mandya, Bidar), Tamil Nadu (Tirunelveli, Cuddalore, Villupuram, Erode, Karur), Andhra Pradesh (Krishna, Guntur, East Godavari, West Godavari, Srikakulam), Telangana (Nizamabad, Medak, Karimnagar), Punjab (Jalandhar, Ludhiana, Amritsar, Gurdaspur), Haryana (Karnal, Yamunanagar, Kurukshetra), Bihar (West Champaran, East Champaran, Gopalganj) and Gujarat (Surat, Navsari, Bharuch, Valsad) where India is the world’s 2nd largest producer of sugarcane (over 5 million hectares cultivated, producing over 400 million tonnes annually — sugarcane is a critical cash crop for smallholders and large farmers alike, supporting over 50 million livelihoods and contributing significantly to India’s agricultural economy and sugar exports). The pest is unusual among sugarcane pests because (a) it is a cyst nematode — adult females swell up, die and form protective cysts that contain 200-400 eggs and can survive in soil for 5-8 years without a host — making this one of the most difficult soil pests to control, (b) the cysts are spread primarily in soil on equipment, footwear and irrigation water — making sanitation between fields essential, (c) the pest has a relatively narrow host range (sugarcane, rice in upland conditions, sorghum, maize, pearl millet and some grasses) — meaning that crop rotation with non-host pulses and oilseeds can effectively suppress populations over 1-2 years, (d) the pest is essentially invisible (microscopic juveniles and adult females inside roots) until severe damage is done — by the time patchy stunting is visible the nematode population is already well-established, (e) the pest has a relatively long life cycle (45-60 days) — only 2-3 generations per crop season — but populations build up over multiple seasons and especially in ratoon crops, (f) the pest is most severe in continuous sugarcane cropping (especially ratoon crops — where the same root system is reused for 2-3 years), in light sandy soils (heavy clay soils suppress nematode movement), and in fields with poor water management, and (g) the cysts protect eggs from nematicides and natural enemies — only systemic nematicides or soil fumigation are effective, and even these provide only partial control. IPM with soil testing for nematode presence before planting (most critical preventive measure), resistant sugarcane varieties (Co 86032, Co 94012, Co 0238 show tolerance), 1-2 year crop rotation with non-host pulses and oilseeds (cysts survive 5-8 years so short rotations are only partially effective), marigold intercropping or rotation (roots release alpha-terthienyl toxic to nematodes), biological control (Pochonia chlamydosporia and Paecilomyces lilacinus egg-parasitic fungi destroy eggs inside cysts), organic amendments (neem cake, mustard cake, farmyard manure), and need-based nematicide rotation provides effective and sustainable control. The pest is a particular concern for Indian sugarcane growers because the long survival of cysts (5-8 years) and the buildup in ratoon crops mean that once a field is infested it requires multi-year management to bring the population below damaging levels — making prevention through soil testing and sanitation absolutely critical. The pest is most severe in light sandy soils of Punjab, Haryana and western Uttar Pradesh sugarcane belts where continuous sugarcane cropping with 2-3 ratoons has allowed populations to build up to damaging levels. Climate change with warmer winters is allowing the pest to expand its range and severity in northern India.