Common Pulse Diseases
| COMMON DISEASES | CAUSAL ORGANISM |
| Dry root rot | Macrophomina phaseolina |
| Leaf spot | Cercospora canescens |
| Powdery mildew | Erysiphe polygoni |
| Rust | Uromyces phaseoli-typica |
| Anthracnose | Colletotrichum lindemuthianum |
| Bacterial blight | Xanthomonas phaseoli |
| Yellow mosaic | Yellow mosaic virus |
| Leaf crinkle | Leaf crinkle virus |
| RED GRAM / PIEGON PEA | |
| Wilt | Fusarium oxysporum f.sp. udum |
| Stem blight | Phytophthora drechsleri f.sp. cajani |
| Sterility mosaic virus | Red gram sterility mosaic virus |
| CHICK PEA / BENGAL GRAM | |
| Wilt | Fusarium oxysporum f.sp. ciceri |
| Blight | Ascochyta rabiei |
| Stunt | Chick pea stunt virus |
| BLACK GRAM AND GREEN GRAM | |
| Leaf curl | Tomato spotted wilt virus [TSWV ] |
| SOYABEAN | |
| Downy mildew | Peronospora manshrica |
| Soyabean mosaic | Soybean mosaic virus |
| COWPEA | |
| Cowpea aphid borne mosaic | Cowpea aphid borne mosaic virus |
1. DRY ROOT ROT – Macrophomina phaseolina
Symptoms
The disease occurs both in young seedlings and grown up plant. Infected seedlings shows reddish brown discolouration at collar region. The lower leaves show yellowing, dropping and premature defoliation. The root rot affected plants suddenly wilt and die. The affected roots are brittle and break when touched. Numerous, minute, black “pycnidia” are seen on the hypocotyls and lower portions of the stems. The lesion coalesce and cause the branches or hole plant to dry up and die.
Mode of Spread
Seed borne and air borne pycnidiospores primarily spread the disease. Secondary spread is through soil borne sclerotia carried by irrigation water and implements
Survival
The pathogen survives as sclerotia in soil and dead plant debris
Epidemiology
Prolonged drought followed by irrigation and high temperature favour the disease
Management
- Field sanitation
- Crop rotation with cumbu or sorghum
- Seed treatment with captan or thiram or T.viride @ 4 g/kg or carbendazim at 2 g/kg of seed
- Application of farm yard manure and green leaf manure like Gliricidia maculata @ 10 tons / ha or neem cake @ 250 kg/ha
2. LEAF SPOT – Cercospora canescens
Symptoms
Initially small light brown coloured spots appear on under surface of the leaves, later become dark brown and the infected portion drop off leaving shot hole symptoms.
Mode of Spread and Survival
The spreads through air borne conidia and survives in the infected plant debris
Epidemiology
Cool temperature and humid weather favour the disease
Management
- Field sanitation
- Spray mancozeb 1 kg/ha or carbendazim 500 g/ha
- Grow resistant lines like UC 2515/2, 796/1, 2113/1, 2568/1.
3. POWDERY MILDEW – Erysiphe polygoni
Symptoms
White powdery growth appears on the upper surface of the leaves. Later the leaves turn yellow, wilt and defoliate. Infection after the pod setting may have only slight effect on yield.
Mode of Spread and Survival
The fungus is an obligate parasite. Primary infection is usually by ascospores from cleistothecia and secondary spread by air borne conidia and rain splashes. Tha pathogen survives in the infected plant debris
Epidemiology
The disease is severe, generally during late kharif and rabi season. Dry weather, a temperature range of 22-26oC and relative humidity 80-88 % favour the disease.
Management
- Field sanitation
- Spray with wettable sulphur 1.5 kg/ha or carbendazim 500 g/ha at fortnightly intervals
4. RUST – Uromyces phaseoli-typica
Symptoms
Dark reddish – brown pustules (uredosori) appear on both surfaces of the leaves and the pustules may be surrounded by yellow halo. Finally the leaves defoliate and drop off.
Mode of Spread and Survival
The pathogen is an autocious rust which spreads through wind borne uredospores and survives in the infected plant debris.
Epidemiology
Cloudy humid weather favour the disease development
Management
- Removal and destruction of infected plant debris
- Spray with mancozeb 1 kg/ha
5. ANTHRACNOSE –Colletotrichum lindemuthianum
Symptoms
The fungus attacks young as well as old seedlings. Small, round to oblong, brown spots appear on leaves, stem and pods. Black lesions develop on stem which spreads to leaf petiole and leaves. Numerous acervuli can be seen scattered on the stem.
Mode of Spread
Primary spread is through seed and soil-borne conidia and secondary spread is through air borne conidia
Survival
The pathogen survives in the infected plant debris and seeds [Acervuli-asexual fruiting body]
Epidemiology
Cool rainy weather and High RH above 90 % favour the disease
Management
- Seed treatment
- Spray with mancozeb @ 1 kg/ha or Carbendazim @ 500 g/ha
- Grow resistant varieties
6. BACTERIAL BLIGHT –Xanthomonas phaseoli
Symptoms
Brown, circular to irregular and distinctly raised spots appear on the diseased leaves. The infected young plants show stunting, chlorosis and defoliation
Mode of Spread and Survival
The primary spread is through seed borne bacteria and it survives in the infected plants and crop residues
Epidemiology
Cool, rainy weather favours the disease development
Management
- Use disease free seeds
- Protective spray with Streptocline at 100 ppm
7. YELLOW MOSAIC –Yellow mosaic virus
Symptoms
On the leaves irregular, yellow and green patches alternating each other appears. Infected plants are stunted, mature later and produce very few flowers and pods. The leaf size is generally not much altered, but sometimes the green areas are slightly raised and the leaves show slight puckering and reduction in size. The leaves become papery white and thin.
Vector
The disease is transmitted by white fly –Bemisia tabaci
Epidemiology
Summer temperature (30-350 C) favours multiplication of vectors and the disease spread.
Management
- Infected plant should be removed up to 40 DAS.
- Grow barrier crop – sorghum / maize / cumbu.
- Spray with Monocrotophos @ 500 ml/ha to control vectors.
- Grow resistant varieties – black gram ___ VBN 1, 2.
8. LEAF CRINKLE – Leaf crinkle virus
Symptoms
Enlargement in size followed by crinkled surfaces of laminae were the characteristics symptoms of the affected trifoliates. The affected plants are stunted, appear bushy, remain green and do not die till harvest. In severe infection, all the leaves are curved downwards.
Vector
The insect vectors white fly — Bemisia tabaci and Aphid – Aphis craccivora and A.gossypii transmit the disease
Epidemiology
High temperature during summer period favours the disease spread.
Management
- Field sanitation and remove the weed host.
- Spray with Monocrotophos or Methyl demeton @ 500 ml/ha to control vectors.
