Chickpea dry root rot (Rhizoctonia bataticola / Macrophomina phaseolina)

Dry root rot (DRR) of chickpea is caused by Rhizoctonia bataticola (Taub.) Butler — the asexual stage of Macrophomina phaseolina (Tassi) Goid. It is the principal terminal-drought disease of chickpea in central and peninsular India and is emerging as the most damaging chickpea disease in the warming, drier climate of Madhya Pradesh, Maharashtra, Karnataka, Andhra Pradesh and Telangana. ICAR-IIPR Kanpur and ICRISAT estimate average national losses of 5-35%, rising to 50-80% in drought years.

Pathogen and identification

R. bataticola/M. phaseolina is a soil-borne necrotrophic fungus that produces black, pin-head microsclerotia on infected roots. Disease develops late in the season under combined heat and moisture stress (above 30 deg C with depleted profile moisture during pod-fill). Diagnostic symptoms:

Sudden wilting of plants at flowering to pod-fill, without preceding yellowing
Dry, brittle root system: roots strip cleanly when pulled, with the bark separating from the stele
Black microsclerotia in the root cortex and lower stem pith — visible as black dots under a hand lens; this is the key distinguishing sign from fusarium wilt
No xylem discoloration (unlike fusarium wilt, where xylem is dark brown)
Field pattern: patches of dead plants in the driest, shallowest soils, expanding during rain-free pod-fill periods

Lab confirmation by isolation on PDA shows characteristic dark mycelium with abundant microsclerotia after 7-10 days.

Hosts and lifecycle

M. phaseolina has an exceptionally wide host range — over 500 plants, including chickpea, pigeonpea, soybean, groundnut, sorghum, maize, cotton, sunflower and many vegetables — making rotation alone an unreliable management tactic. Microsclerotia survive 5-15 years in soil and infect through roots and at the soil line. Disease is favoured by soil temperatures above 30 deg C and soil moisture below 60% field capacity at flowering/pod-fill. Late-sown chickpea (after mid-November) is at much higher risk because pod-fill coincides with heating and drying.

Damage and economic impact

DRR has overtaken fusarium wilt as the leading chickpea disease in many southern and central Indian tracts since 2010, driven by warmer winters and shorter rainy seasons. Susceptible cultivars in Kurnool, Anantapur, Vikarabad, Vijayapura and Latur regularly lose 30-60% stand in years with February-March heat spikes. Because DRR strikes at pod-fill, it produces shrivelled grain with reduced 100-seed weight, further depressing market value below FAQ for NAFED procurement.

Management

Resistant/tolerant varieties: ICCV 10, ICCV 92944 (Super Annigeri), JG-11 (moderate tolerance), JG-130, Vihar, Vijay, JAKI 9218, JG-16; for kabuli — JGK 2, JGK 5
Timely sowing: complete sowing by 30 October in central India and by 15 October in peninsular zones to escape terminal heat
Soil moisture management: pre-sowing irrigation in residual-moisture fields; one protective irrigation at pod-fill (60-70 DAS) reduces DRR by 40-60%; raised-bed/BBF on sloping land conserves moisture
Seed treatment: Trichoderma viride or T. harzianum at 4-6 g/kg seed, followed by Pseudomonas fluorescens at 10 g/kg; chemical option carbendazim 1 g + thiram 2 g per kg seed
Soil amendment: FYM at 5 t/ha or vermicompost enriched with Trichoderma; incorporate cereal residue to build microbial competition
Avoid stress predisposition: balanced NPK; avoid excessive urea which causes lush growth and worsens stress at pod-fill
No effective rescue chemistry once DRR appears — the entire emphasis is preventive

The recommended package combines a tolerant variety, early sowing, Trichoderma seed treatment and a protective pod-fill irrigation.

Sources

Dry root rot of chickpea. ICAR-Indian Institute of Pulses Research, Kanpur.
Dry root rot — terminal-drought disease. ICRISAT, Patancheru.
Macrophomina phaseolina factsheet. CABI Plantwise.