Integrated Pest Management

Alternaria leaf spot

Causal Organism

Alternaria tenuissima (Kunze ex Pers.)

Damage

• Seed become small and shriveled. Dark, irregular, spreading sunken areas occur on the seed.

• Appearance of brown, necrotic spots with concentric rings on foliage, which coalesce and form large nacrotic areas.
• Infected leaves later in the season dry out and drop prematurely.

Survival & Favourable Conditions

• The pathogen survives in crop residues.

• Disease is favoured by high humidity and high temperature, more severe in high rainfall areas.

Cultural Control

• Use healthy/certified seeds
• Use tolerant varieties.
• Use of balanced fertilizer.

Mechanical Control

• Destroy crop residues from fields.

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.
• Use Mancozeb or copper fungicide at 3gm/l or carbendazim 1-1.5 g/l.

Anthracnose/pod blight

Causal Organism

Colletotrichum truncatum (Schw.) Andrus & W.D. Moore

Damage

• Infected seeds become shriveled, mouldy and brown.

• Symptoms on cotyledons appear as dark brown sunken cankers.
• In early stage, irregular brown lesions appear on leaves, stems and pods.
• In advanced stages, the infected tissues are covered with black fruiting bodies of fungus.
• Under high humidity, symptoms on leaves are veinal necrosis, leaf rolling, cankers on petioles premature defoliation.

Survival & Favourable Conditions

• The fungus survives in infected seed and plant debris and spreads through air borne conidia.

• Warm humid climate favours disease incidence.

Cultural Control

• Use resistant varieties.
• Use healthy or certified seeds.
• Rotate soybean with cereals.
• Do not cultivate when the foliage is wet.

Mechanical Control

• Completely remove plant residue by clean ploughing the field soon after harvest.
• Destroy last years infected stubble.
• Maintain well drained field.

Chemical Control

• Seed treatment with thiram or captan or carbendazim 3 g/kg and
• Use mancozeb @ 3g/l as spray or carbendazim 1-1.5 g/L.

Bacterial blight

Causal Organism

Pseudomonas syringae pv. glycinea (Coerper.) Young Dye & Wilkie

Damage

• Seeds may develop raised or sunken lesions and become shriveled and discolored.
• Small, angular, translucent, water-soaked, yellow to light brown spots appear on leaves.
• Young leaves are most infected and are destroyed, stunted and chlorotic.
• Angular lesions enlarge and merge to produce large, irregular dead areas.
• Early defoliation of lower leaves may occur.
• Large, black lesions develop on stems and petioles.

Survival & Favourable Conditions

• The pathogen survives in seed and crop debris.

• Spreads during windy rainstorms and cultivation while the foliage is wet.

Cultural Control

• Deep summer poughing.
• Use resistant or tolerant varieties.
• Use healthy/certified seeds.

Mechanical Control

• Destroy infected crop debris

Chemical Control

• Seed treatment with streptocyclin @ 250 ppm (2.5 g/10 kg seeds).
• Application of any copper fungicides @ 2 gm/lit along with streptocyclin at the rate of 250 ppm (2.5 g/10 lit water).

Bacterial pustule

Causal Organism

Xanthomonas axonopodis pv. glycines Syn.

Damage

• Minute, pale green spots with elevated centres on either or both leaf surfaces are seen.
• Later a small, raised, light coloured pustule appears in its centre.
• Severe infection results in some defoliation.
• Small, reddish brown, slightly raised spots may also develop on pods.

Survival & Favourable Conditions

• The pathogen survives in seeds, in surface crop debris, in the rhizosphere of wheat roots and on
  weeds.

• It develops during warm and wet weather.

• The disease spreads rapidly in rainy conditions.

Cultural Control

• Deep summer poughing.
• Use resistant or tolerant varieties.
• Use healthy/certified seeds.

Mechanical Control

• Completely cover plant residue by clean ploughing the field soon after harvest.
• Destroy last years infected stubble.

Chemical Control

• Seed treatment with streptocyclin @ 250 ppm (2.5 g/10 kg seeds).
• Application of any copper fungicides @ 2 gm/lit along with streptocyclin at the rate of 250 ppm (2.5 g/10 lit water).

Bud blight

Causal Organism

Peanut bud necrosis virus in India.
Tobacco ring spot virus (TRSV)

Damage

• Infected young plants are stunted.

• The main symptom is the curving of terminal bud to form a hook.

• Later, other buds on the plant become brown, necrotic and brittle.

• Pith of stems and branches may show a brown discoloration.

• Petioles, leaflets and pods are also infected by this disease.

Survival & Favourable Conditions

• TRSV is seed and sap transmissible and have host range of wide variety of plants.

• Disease is more severe at the temperatures below 25^o C and under water stress conditions

Cultural Control

• Virus-free soybean seeds should be used.
• Keep the field free from weed.
• No resistant varieties are available

Chemical Control

• No suitable chemical control is available.
• Seed treatment with Imidacloprid @ 5 g/kg and spray of monocrotophos @ 0.01% or metasystox @ 0.01% or other systemic insecticides reduces severity of the disease.

Cercospora leaf blight, leaf spot and Purple seed stain

Causal Organism

Cercospa kikuchii

Damage

• Infected leaves appear leathery, dark, reddish purple.
• Severe infection cause rapid chlorosis and necrosis of leaf tissues, resulting in defoliation.
• Lesions on petioles and stems are slightly sunken, reddish purple; severe cause defoliation.
• Later, blighting of young, upper leaves over large areas, even entire fields occur.

Survival & Favourable Conditions

• The pathogen survives in seed and crop debris.

• High humidity and warm (23-27 C) weather especially during flowering and maturing stage.

Cultural Control

• Use healthy/certified seeds.
• Use tolerant varieties.
• Use of balanced fertilizerved.

Mechanical Control

• Previous crop debris should be removed.

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.
• Use Mancozeb or copper oxychloride at 3gm/l or carbendazim 1-1.5 g/l.

Charcoal rot, ashy or stem blight or dry root rot

Causal Organism

Macrophomina phaseolina (Tassi) Goid.

Damage

• This disease occurs when the plants are under moisture stress or under nematode attack or through soil compaction or may be through nutrient deficiencies.

• It is a most common basal stem and root disease of the soybean plant.

• Lower leaves become chlorotic and wilting and drying is apparent.

• The diseased tissues generally develop grayish  discolouration.

• The sclerotia look like black powdery mass hence the disease is known as charcoal rot.

• Blacking and cracking of roots is the most common symptom.

Survival & Favourable Conditions

• The fungus survives in soil and crop debris in dry conditions.

• Dry conditions, relatively low soil moisture and nutrient and temperature ranging from 25^o C to
  35^o C are favourable for the disease.

Cultural Control

• Deep ploughing in summer.
• Use resistant varieties.
• Use healthy or certified seeds.
• Ensure balanced fertilization of the crop.
• Rotate soybean with cereals.

Mechanical Control

• Maintain well drained field
• Destroy last years infected stubble.

Biological Control

• Seed treatment with Trichoderma harzianum or T. viride @ 5 g/kg seed.
  

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.

Collar rot / Sclerotial blight

Causal Organism

Sclerotium rolfsii Sacc.

Damage

• Infection usually occurs at or just below the soil surface.

• Sudden yellowing or wilting of plants is the first symptom.

• Light brown lesions, which quickly darken, enlarge until the hypocotyl or stem is girdled.

• Leaves turn brown, dry and often cling to dead stem.

• Numerous tan to brown, spherical sclerotia form on infected plant material.

Survival & Favourable Conditions

• The pathogen survives mainly in soil.

• Disease occurs in hot (25-35^o C) and humid weather, sandy soil, sandy loam soil, high soil moisture, high plant population, dense canopy and presence of un decomposed organic matter.

Cultural Control

• Deep ploughing in summer.
• Use resistant varieties.
• Ensure balanced fertilization of the crop.
• Crop rotation with maize or sorghum.

Mechanical Control

• Maintain well drained field
• Destroy last years infected stubble.

Biological Control

• Seed treatment with Trichoderma harzianum or T. viride @ 5 g/kg seed fallowed by soil application of @ 5 kg/ha 30 days after sowing.
  

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.

Frog eye leaf spot

Causal Organism

Cercospora sojina Hara

Damage

• Light to dark gray or brown areas varying from specks to large blotches appear on seeds.

• The disease primarily affect foliage, but, stems, pods and seeds may also be infected.

• Leaf lesions are circular or angular, at first brown then light brown to ash grey with dark margins.

• The leaf spot may coalesce to form larger spots.

• When lesions are numerous the leaves wither and drop prematurely.

• Lesions on pods are circular to elongate, light sunken and reddish brown.

Survival & Favourable Conditions

• Fungus survives in infected seeds and in debris.

• Warm, humid weather favour disease incidence

Cultural Control

• Use resistant varieties.
• Use healthy or certified seeds.
• Rotate soybean with cereals.

Mechanical Control

• Completely remove plant residue by clean ploughing the field soon after harvest.
• Destroy last years infected stubble.

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.
• Spray Mancozeb @ 3g/L or Carbenzadium (0.05%).

Myrothecium leaf spot

Causal Organism

Myrothecium roridum Tode ex Fries

Damage

• Disease is visible around 30-35 days after planting.
• The symptoms appears on the other aerial parts, such as stem, petiole, pods.
• Small round or oval, brown, spots develop with dark brown or purple margin on leaves in the infected plants.
• Translucent areas develop around these spots which appear as concentric rings.
• Later on white sporodochia develop in these areas.
• The spots may merge to form irregular shape and leaves become dry.

Survival & Favourable Conditions

• The pathogen survives in seed and crop debris

• The disease spreads rapidly under rainy conditions, it is more severe during warm and wet weather.

Cultural Control

• Deep summer ploughing
• Use tolerant cultivars like JS 335, JS 71 -05, JS 93-05.
• Use healthy/certified seeds
• Rotate soybean with cereals

Mechanical Control

• Completely remove plant debris.

Chemical Control

• Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.
• Use Mancozeb or copper fungicide at 3gm/l or carbendazim 1-1.5 g/l.

No Podding/ Bud proliferation

Causal Organism

MLO's, Rhabditis, Pratylenchus, Heterodera,

Damage

• Symptoms appear at the time of flowering.
• Intensive proliferation of buds occur and flowers are not formed.
• The pods are either not formed or pods get deformed.
• Senescence is delayed.

Cultural Control

• Field sanitation.
• Deep summer ploughing.
• Use of healthy certified seeds.
• Follow crop rotation.

Chemical Control

• Application of any of the following pesticides at flowering stage and second spray after 15 days of first effectively controlled the malady.
  Triazosphos 40 EC at 0.8 l/ha
  OR
  Chlorphyriphos 20 EC at 1.5/l/ha
  OR
  Methoyml at 2.0l/ha
  OR
  Ethion 50 EC at 1.5 l/ha.
  OR
  Quinolphos 25 Ec at 1.5 l/ha.
• Soil application of Phorate 10 G @1 kg a.i./ha at the time of planting

Powdery Mildew

Causal Organism

Microsphaera diffusa Cke.& Pk.

Damage

• White powdery patches/lesions are formed on leaves, stem and pods.
• In severe conditions, all above ground parts are covered with white powdery mass.

Survival & Favourable Conditions

• The pathogen survives through plant debris.

• Warm condition develop disease development.

Cultural Control

• Deep summer poughing.
• Use resistant or tolerant varieties.

Mechanical Control

• Removal of infected plant debris

Chemical Control

• Spray Karathene (0.08%) or Carbendazim @ 0.1% at the appearance of the disease.

Rhizoctonia aerial blight / Web blight

Causal Organism

Rhizoctonia solani Kuhn.,

Damage

• Infected seeds have irregularly shaped tan or light brown sunken lesions.
• Infected leaves appears as water soaked at first instance. They soon take on a greenish brown to reddish brown appearance.
• The infected portion later turns tan brown or black in colour.
• Under high rainfall or high humid conditions, a web like mycelial growth of fungus forms on the leaves.
• Dark brown sclerotia are formed on leaves and petioles.

Survival & Favourable Conditions

• The pathogen survives as sclerotia in soil.

• Humid and cool (24-32^o C) are favourable weather condition.

Cultural Control

• * Use healthy/cerified seeds.
  * Use resistant varieties.
  * Avoid dense planting.
  * Timely sowing.

Mechanical Control

• * Completely cover plant residue by clean ploughing the field soon
  after harvest.
  * Destroy last years infected stubble.

Chemical Control

• * Seed treatment with thiram + carbendazium (2:1) @ 3g/kg seed.
  * Use Mancozeb or copper fungicide at 3gm/l or carbendazim 1-1.5 g/l.

Rust

Causal Organism

Phakopsora pachyrhizi Syd. & P. Syd.

Damage

• The disease begins with small water soaked lesions which gradually increase in size, turning from grey to tan or brown.

• Tan to dark brown or reddish brown lesions are appear on the underside of leaflets.

• Lesion may also appear on petioles, pods and stems.

• In severe case leaf necrosis and complete death of infected areas may result.

Survival & Favourable Conditions

• The pathogen survives through collateral host.

• Mean daily temperature 22-27 C accompanied 80-90% RH and long periods of leaf wetness
  occurring throughout the growing season.

Cultural Control

• Deep summer ploughing
• Do not cultivate soybean in rabi season
• Use tolerant cultivars like Ankur, JS 80-21, PK 1024, PK 1029.

Mechanical Control

• Destroy last crops infected stubble.

Chemical Control

• Spray schedule has to be initiated before symptoms appear.
• Use Mancozeb at 3gm/l
• Spray Hexaconazole or Propoconazole 1 ml/l.

Soybean mosaic

Causal Organism

Soybean mosaic virus (SMV) belongs to poty virus

Damage

• Infected seeds gets mottled.
• Diseased plants are usually stunted with
  distorted (puckered, crinkled, ruffled, stunted, narrow) leaves.
• The parts are often stunted.
• Flattened or curved and contain fewer and smaller seed.
• Infected seeds fail to germinate or they produce diseased seedlings.

Survival & Favourable Conditions

• Soybean mosaic virus is seed borne.

• The SMV can be transmitted through sap, 32 aphid species and seed.

• Cool (around 18^o C) and humid are favourable.

Cultural Control

• Deep summer ploughing.
• Use resistant or tolerant varieties.
• Use healthy/certified seeds.
• Keep the field free from weeds.

Mechanical Control

• Rogue out infected plants and burn them

Chemical Control

• Pre-sowing soil application of phorate @ 10 kg/ha.
• Two foliar sprays of thiamethoxam 25 WG @ 100 g/ha or methyl demeton 800 ml/ha at 30 and 45 days after sowing.

Target leaf spot

Causal Organism

Corynespora cassicola (Berk. & Curt.) Wei.

Damage

• Target spot affects leaves, stems, pods, hypocotyls and roots.
• Leaf lesions are round to irregular and reddish brown and vary from specks to mature spots.
• Lesions are surrounded by dull green to yellowish green halos.
• Infected areas on petioles and stems are dark brown and range from specks to elongated, spindle-shaped lesions.
• Pod spots are circular and about 1 mm in diameter with slightly depressed, purple black centres and brown margins.

Survival & Favourable Conditions

• Pathogen survive in diseased stems, roots and seeds and can survive in fallow soil for 2 years.

• Prefer most temperature 28 C with RH about 80% or more

• Soil temperature of 15-18 C is optimal for infestation and disease development.

Cultural Control

• Use resistant varieties like JS 335, JS 93-05, JS 72-44, PK 1024 and Pb 1.
• Use healthy certified seeds.

Mechanical Control

• Burning of infested plant parts.

Chemical Control

• Treat the seed with Thiram or Captan @ 3-4 g/kg seeds.
• Spray Mancozeb @ 2.5 kg/ha in 1000 litre of water at 10-14 days intervals. 2-3 sprays are enough for controlling the disease
  OR
• Spray carbenzadium or thiophanate methyl(0.05%).

Yellow mosaic

Causal Organism

Mung bean yellow mosaic virus (MBYMV)

Damage

• Characteristic symptom is conspicuous systemic bright yellow mottling of leaves.
• The yellow area are scattered or occur in indefinite bands along the major veins.
• Rusty necrotic spots appear in the yellow areas as the leaves mature.

Survival & Favourable Conditions

• This virus has a wide host range and is not sap or seed transmissible.

• Insect vector for MBYMV is whitefly. (Bemisia tabaci).

• Early infection may cause severe losses.

Cultural Control

• Grow resistant/tolerant varieties/early maturing varieties.
• Timely sowing.
• Maintain weed free fields.

Mechanical Control

• Rogue out infected plants and burn them.

Chemical Control

• Pre-sowing soil application of phorate @ 10 kg/ha.
• Foliar sprays of thiamethoxam 25 WG @ 100 g/ha or methyl dematon 25EC @ 800 ml/ha or ethofenoprox 110EC @ 1 lit/ha at 10 days after sowing.