Pigeon pea Diseases and Management Practices
Pigeon pea (Cajanus cajan) is an essential food legume crop mostly cultivated in tropical and subtropical regions. It is a significant source of protein and other nutrients for millions of people. However, pigeon pea is susceptible to a number of diseases, which can cause significant yield losses.
Most Important Diseases of Pigeon Pea
The following are some of the most common diseases of pigeon peas:
Fusarium wilt (Fusarium udum)
This disease is caused by the fungus Fusarium oxysporum f. sp. cajani and is considered one of the most important ones for the crop. It can infect pigeon pea plants at all crop growth stages but is most destructive to young plants. Symptoms of fusarium wilt include wilting and yellowing of leaves, followed by the death of the plant.
Control measures :
- Select a field with no previous wilt record (disease history) for at least 3 years.
- Pigeon pea can be grown as intercrop or mixed-crop with another more resistant (or non-host) crop species.
- Rotate pigeon peas with Sorghum, Tobacco, or Castor crops every 3 years.
- The uprooting of wilted plants.
- Solarize the field in summer to help reduce the inoculum, decreasing the problem for next year.
- Seed treatment with talc formulation of T. viride @ 4g or P. fluorescens @ 10 g/kg Carbendazim or Thiram @ 2 g/kg
- Basal soil application of neem cake @ 150 Kg/ ha
- Soil application of P. fluorescens or T. viride @ 2.5 Kg/ha + 50 Kg of well-decomposed FYM or sand 30 days after sowing.
- Spot drenching with Carbendazim 1 gm/liter could be helpful.
Dry root rot
The disease is caused by Macrophomina phaseolina (Rhizoctonia bataticola). This is both soil and seed-borne disease.
Symptoms: This disease occurs both in young seedlings and mature plants. The lower leaves show yellowing, dropping, and premature defoliation. The discolored area later turns black, and the death of plants occurs. The infected plants can be easily pulled out due to the rotting of the roots. Minute dark sclerotia (like mustard seeds) are seen in the shredded bark or at the collar region and root. A large number of brown dots on the stem portion represent the Pycnidial stage caused by Macrophomina phaseolina. Prolong dry weather or drought followed by irrigation or rain favors this disease build-up.
Control Measures:
- Seed treatment with talc formulation of Trichoderma viride @ 4g or Pseudomonas fluorescens @ 1g/kg seed (or) Carbendazim or Thiram @ 2g/kg Neem cake @150 kg/ha
- Soil application of P. fluorescens or T. viride @ 2.5 kg/ha + 50 kg of well-decomposed FYM at 30 days after sowing.
- Spot drenching with Carbendazium @ 1gm/liter.
Alternaria leaf spot/Alternaria leaf blight
Symptoms: This disease is caused by Alternaria alternata. Typical symptoms of infected leaves initially show small necrotic spots on the leaves, and these gradually increase in and form characteristic lesions with dark and light brown concentric rings with a wavy purple margin. As the infection progresses, the lesions coalesce and cause blighting of leaves, including pods. Severe defoliation and drying of infected branches. This disease appears more commonly in older leaves of adult plants but may infect new leaves of young plants, particularly in the post-rainy season.
Control measures:
- Spraying with an active ingredient, the Mancozeb@ 1kg/ha or Carbendazim 50 WP @1g/liter of water
- Cultivation of pigeon peas on ridges with a proper drainage system and avoiding the soing in heavy soil is helpful in disease management.
- Cultivating resistant varieties of pigeon peas is recommended according to the location/region.
Powdery mildew
Symptoms: this disease is caused by Leveillula taurica. The affected leaves show powdery patches on the lower surface, corresponding with yellowing on the upper surface. Usually, older leaves show symptoms first. There will be premature defoliation of affected leaves. The disease is airborne.
Control measures:
- Spraying with Neem Seed Kernel Extract (NSKE) 5 % or Neem oil 3% twice @ 10 days intervals from the initial disease appearance.
- Spray Carbendazium 1g/liter or Wettable sulphur 2.5g/liter.
Sterility Mosaic Disease (SMD): Pigeon pea Sterility Mosaic virus
Symptoms: This pathogenic virus is spread by the vector Aceria cajani. The infected plants have a bushy and stunted appearance due to a reduction in the size of the leaves and the proliferation of the branches. Infected leaves of younger plants will have light and dark green mosaic patterns. The infected plants may suffer from partial or complete sterility, resulting in reduced or no flowering and podding (yield). Only some parts of the plant may show disease symptoms when the infection occurs 45 days after emergence or later, while the rest of the plant appears healthy. Diseased plants are usually in groups.
Control measures:
- Rouging out infected plants up to 40 days after sowing
- Spraying with Fenazaquin 1 ml/liter soon after the appearance of the disease; if necessary, repeat after 15 days.
Mungbean Yellow Mosaic Virus/ Yellow Mosaic/Redgram yellow Mosaic virus
Symptoms: This is a virus disease, and the virus is transmitted through White fly Bemisia tabaci. The first symptoms of the disease are the yellow, diffused spots scattered on the leaf lamina. Such spots slowly expand, and as the disease progresses, yellow patches alternate with green patches developed on the leaves. Younger leaves completely turn yellow, and infected plants are stunted and produce only a few pods.
Control measures:
- Roughing out the infected plants up to 40 days
- Remove weed hosts periodically.
- Spray Methyldemeton @ 500 ml/ha
- Integrated disease management practices such as deep summer plowing.
- Application of FYM @ 12.5 K/ha along with 2.5 kg or Trichoderma viride or Pseudomonas flurescensSeed treatment with Talc formulation of Trichoderma viride @ 4g or Pseudomonas fluorescens @ 10 g/kg Carbendazim or Thiram @ 2g/kg
- Spot drenching with Carbendazim 1 g/litre of water to control root rot and wilt diseases
- Avoid water stress during the flowering period to control root rot.
- Rogue out virus-infected plants up to 40 days after sowing for managing sterility mosaic and yellow mosaic diseases.
References:
- V. Reddy, T.N. Raju, S.B. Sharma, Y.L. Nene, and D. McDonald, 1993. Handbook of Pigeonpea Diseases. Information Bulletin no. 42. International Crops Research Institute for the Semi-Arid Tropics.
- Pigeonpea Botany and Production Practices, Compiled by Faujdar Singh and D.L. Oswalt. International Crops Research Institute for the Semi-Arid Tropics.
- Gupta, Prince & Kaur, Manpreet & Roy, Bishal & Joshi, Sarthak & Kumar, Abhishek & Singh, Prabhas Shankar. (2022). Pigeon pea Diseases and their Recent Approaches for Sustainable Management in India: Current Status and Future Prospective.
- https://agritech.tnau.ac.in/crop_protection/crop_prot_crop%20diseases_pulses_redgram.html
- Srivastava, J.N., & Singh, A.K. (Eds.). (2020). Diseases of Field Crops Diagnosis and Management: Volume 2: Pulses, Oil Seeds, Narcotics, and Sugar Crops (1st ed.). Apple Academic Press. https://doi.org/10.1201/9780429321962
Further reading
Pigeon pea: Plant information, History, and Nutrition
Principles of selecting the best varieties and hybrids for Pigeon pea cultivation
Pigeon pea Soil requirement, Soil preparation and Plant density
Irrigation requirement for Pigeon pea Cultivation
Fertilization requirement for Pigeon Pea
Weed Management in Pigeon Pea Farming
Pigeon pea Diseases and Management Practices
