| Sign of Attack/ Symptom |
Control |
| Insect-pests |
|
| Hairy caterpillar : They first of all feed on leaves in clusters and later on disperse in the field. Often skeletonize the plant completely. Appear in epidemic form at the onset of monsoon. |
1. Collect and destroy the young gregarious caterpillars.
2. Give spot treatment by dusting 5% malathion at 35-40 kg/ha against gregarious caterpillars.Spray1250mlendosulfan (Thiodan/Endocel 35 EC) or 625 ml dichlorvos (Nuvan 100) in 625 L water/ha for advance staged larvae.
|
| Blister beetle : Adults feed voraciously on flowers and tender terminals. |
Spray 1250 ml endosulfan (Thiodan/ Endocel 35 EC) or 625 ml methyl parathion (Metacid 50 EC) in 625 L water/ ha at the pre-bloom and flowering stages. |
| Bean bug : Both nymphs and adults such sap from foliage and lower the vitality of the plant. Small whitish or yellowish spots on the upper leaf surface confirm the damage by the pest. |
Spray625mlmonocil/Milphos36SL (Monocrotophos) in 625 L water/ha in addition to the chemicals recommended for blister beetle. |
Diseases
|
(A) Mash and Mung
Bacterial stalk rot : Cercospora leaf spot : Brown or black, circular to angular spots are formed on leaves. During humidweather,thespotsbecomeso numberous that they merge with each other to form large irregular spots. At this stage the leaves wither, die prematurely and fall. |
Spray the crop with Indofil M-45 (0.25%) or Bavistin (0.05%) at fortnightly interval starting after 45 days of sowing or when the first symptoms of the disease appear. 2-3 sprays give better and economical control. |
| Ascochyta leaf spot : Dark coloured, circular lesions with concentric rings are present on leaves. In severe cases, shot holes surrounded by remanants of concentric rings are formed. |
As above |
| Colletotrichum leaf spot : Crescent-shaped, dark brown lesions are formed on leaves. In severe cases, the lesions may coalesce resulting in brunt appearance. |
As above |
| Head smut : Powdery mildew : A white powdery growth occurs on the leaves spreading to cover the stem and other plant parts. The disease is more severe when the plants are in flowering stage and persists until harvest. |
Dust the crop with sulphur @ 20 kg/ha. If the crop has been sprayed with Bavistin, there is no need to sulphur dustring. |
| Yellow mosaic : The leaves show yellow patches alternating with green areas which also turn yellow and gradually change to whitish shade and finally become necrotic. Affected plants are dwarfed. Flowering and seed setting is very poor. |
1.Obtain seed from disease free crop or from disease free areas such as higher hills.
2. Rogue out diseased plants in early stages.
3. Control insect vectors with sprays of Metasystox/ Dime cron/Rogor @ 1 ml/L water. |
(B) Rajmash
Anthracnose : All plant parts above ground level and at any stage of plant growth are attacked. The most prominent symptom is a characteristic spotting on the pods. Water soaked lesions appear on the pods which become brown and enlarge to form circular spots of varying sizes. The spots are usually depressed with dark centres and bright red, yellow or orange margins. In moist weather, pink masses of spores are present on the spots. |
1. Obtain seed from disease free locations.
2. Treat seed with Bavistin @ 2.5 g/kg seed.
|
| Angular leaf spot : Numberous small, angular, brown spots appear on foliage and on pods, dark brown to black, circular spots are formed. Some times pods are deformed. |
1. Use healthy seed.
2. Treat seed with Bavistin @ 2.5 g/kg
3. Spray the crop with Bavistin (0.1%) at fortnightly intervals starting from flowering or when the first symptoms of the disease appear. 2-3 sprays should be done which are economical. |
| Floury leaf spot : White powdery growth resembling flour appears on lower surface of leaves when the crop is in flowering stage. The diseased leaves are shed prematurely. |
As above |
| Bacterial/Fuscous blight : The disease appears early in the season. Transluscent water-soaked spots are formed on leaves which turn yellow and die. Lesions of various shapes and sizes are visible on dead leaves. Small spots also appear on pods. |
1. Obtain seed from disease free area.
2. Follow crop rotation of 3 years |
(C) Arhar
Floury leaf spot : Sterility mosaic : In the beginning, plants look pale, there is reduced and bushy plant growth as a result of profuse branching. Mild motting appears on leaflets. The plants may be partially or wholly sterile. |
1. Collect seed from healthy crop.
2. Repeated cultivation in the same field should be avoided. |