Integrated Pest Management

Alternaria blight

Causal Organism

Alternaria alternata

Damage

• The disease occurs during the flowering stage of the crop.
• Leaves are infected most.
• Shedding of lower leaves generally occurs in the infected plant.
• The lesions are seen on leaflets as water soaked, small, circular and purple in colour.
• Infected pods turn blackish in colour.
• Infected seeds get shriveled.

Survival & Favourable Conditions

• This is a soil and seed borne disease of gram.
• Temperature around 20 to 25^o and excessive humidity favours the disease.

Cultural Control

• The plants should be planted distantly.
• Avoid excessive vegetative growth.
• Intercrop with linseed.
• Avoid excessive irrigation.
• Use compact varieties.

Chemical Control

• Use mancozeb at the rate of 3g/l
  OR
• Use Carbendazim at 1.5g/l.

Ascochyta blight

Causal Organism

Ascochyta rabiei

Damage

• All plant parts are affected.
• Symptoms appear on leaves as water soaked lesions.
• Symptoms include smaller circular brown spots on leaves.
• Under favorable conditions, these spots enlarge rapidly and coalesce, blighting the leaves and buds.
• In case of severe infection, the entire plant dries up suddenly.
• The lesions are also developed on stems and petioles.
• Late infections result in shriveled and infected seed.

Survival & Favourable Conditions

• The disease is seed borne in nature.
• Left over debris in the fields serve as a source.
• Wet and warm weather, and dense crop canopy are conducive to the spread of the disease

Cultural Control

• Sow disease-free seed.
• Sow late
• Follow rotation crop.
• Sow deep (15 cm or deeper)
• Intercrop with wheat, barley, mustard
• Use resistant varieties

Mechanical Control

• Remove and destroy dead plant debris.
• Bury diseased debris 10 cm or deeper.

Chemical Control

• Seed treatment with carbendazim @ 3g/kg of seed. or
• Hot water seed treatment (52 C for 10 min) to lower the infestation.
• Spray the crop with mancozeb @ 3g/l if noticed during the growth period.
  OR
• Spray wettable sulphur at the rate of 2.3g/litre of water.

Botrytis gray mold

Causal Organism

Botrytis cineria

Damage

• Lack of pod setting is the first indication.
• Under favourable conditions, foliage shows symptoms and plants often die in patches.
• Shedding of flowers and leaves, covered with spore mass can be seen.
• Lesions on stem are 10-30 mm long and girdle the stem fully.
• Tender branches break off at the point where the gray mold has caused rotting.
• Affected flowers turn in to a rotting mass.
• Lesions on the pod are water-soaked and irregular.
• On infected plants, the pods contain either small, shriveled seeds or no seeds at all.

Survival & Favourable Conditions

• A seedborne disease.
• It survives on infected chickpea debris and remain infective up to 8 months.
• Excessive vegetative growth due to irrigation or rain, close spacing and varieties that have
  spreading habit favour the disease development

Cultural Control

• Avoid excessive vegetative growth.
• Intercrop with linseed.
• Avoid excessive irrigation.
• Use compact varieties.
• Deep summer ploughing
• Reduce plant density and increase in air passage between the plants.

Mechanical Control

• Use Trichoderma spp. as a bio-control agents

Chemical Control

• Seed treatment with Carbendazim + Thiram (1:1) @ 3g/kg of seed is recommended.
  OR
• Spray the crop with captan 5 - 6 kg/ha at 15 days interval.
  OR
• Spray of Carbendazim @ 1.5g/l of water is recommended.
  OR
• Spray mancozeb @3 g/litre of water.

Collar rot

Causal Organism

Sclerotium rolfsii

Damage

• It comes in the early stages i.e up to six weeks from sowing.
• Drying plants whose foliage turns slightly yellow before death, scattered in the field is an indication of the disease.
• Seedling become chlorotic.
• The joint of stem & root turns soft slightly contracts and begins to decay.
• Infected parts turn brown white.
• Black dots, like mustard in shape known as sclerotia are seen appearing on the white infected plant parts.

Survival & Favourable Conditions

• High soil moisture, low soil pH and high temperature are favourable.
• The presence of un decomposed organic matter on the soil surface and high moisture at the time
  of sowing and at the seedling stage favour disease development.
• Disease incidence is higher when sown after rice or early sown crop.

Cultural Control

• Deep pluoghing in summer.
• Avoid high moisture at the sowing time.
• Seedlings should be protected from excessive moisture.

Mechanical Control

• Destroy the residues of last crop and weed before sowing and after harvest.
• All un decomposed matter should be removed from the field before land preparation.

Chemical Control

• Treat the seeds with a mixture of Carbendazim 1.5g and Thiram 1.5g per kg of seed.

Dry root rot

Causal Organism

Rhizoctonia bataticola/Macrophomina phaseolina

Damage

• The disease appears from flowering to podding stage as scattered dried plants.
• The leaves and stem are become straw colored.
• Affected plants wither and spread across the entire field.
• The roots of infected plants become brittle and dry.

Survival & Favourable Conditions

• Maximum temperatures above 30 degree and dry soil conditions and moisture stress promote
  disease development.

Cultural Control

• Deep ploughing in summer
• Grow cultivars resistant to dry root rot.
• Drought should be avoided.
• Sowing should always be done on the recommended time.
• Germinating and young seedlings should be saved from high temperatures.

Chemical Control

• Seed treatment with a mixture of Carbendazim 1.5 g and Thiram 1.5 g per kg of seed.
  OR
• Seed treatment with Trichoderma viride formulation + 3 g thiram per kg seed can reduce the disease incidence.

Fusarium wilt

Causal Organism

Fusarium oxysporum f.sp.ciceri

Damage

• The disease can affect the crop at any stage.
• The field symptoms of wilt are dead seedlings or adult plants, usually in patches.
• At seedling stage, 3-5 weeks after sowing, whole seedlings collapse and lie flat on the ground with dull green leaves and shrunken stem.
• Dark drown or dark discoloration of the internal stem tissues is visible.
• At adult stage, drooping of petioles, rachis and leaflets and finally entire plant occurs.

Survival & Favourable Conditions

• The fungus is seed and soil borne.
• Warmer and drier climates (>25^o C) favor disease and also when crop rotations are not practiced.

Cultural Control

• Deep summer ploughing
• Grow cultivars resistant to wilt
• Practice soil solarization
• In fields with a history of Fusarium do not grow gram for 3 years.
• Follow crop rotation measures continuously.
• Always use disease free seeds.
• Avoid sowing when temperatures are high.
• Follow 6-year crop rotations with sorghum
• Apply FYM 10-15 cart load/ha.

Biological Control

• Apply Trichoderma viride @ 4 g/kg seed reduces disease incidence.
   

Chemical Control

• Seed treatment with Carbendazin at the rate of 2.5g/kg of seed.
  OR
• Seed treatment with Thiram + Carbandizm @ 1g+2g per kg of seed.
  OR
• Carboxin + thiram 1:2 at the rate of 3g/kg of seed.

Powdery mildew

Causal Organism

Oidiopsis taurica

Damage

• Crop plants of all the age group are affected.
• With the onset of the disease white powdery mass appear on the leaves.
• Small patches of white powder coating initially develop on both surfaces of older leaves.
• Affected leaves turn purple and then die.
• When infection is severe, stems, young leaves, and pods are also covered with the powdery coating.

Survival & Favourable Conditions

• Cool and dry weather favours disease growth.
• The disease is more prominent during the flowering stage of the crop.

Cultural Control

• Field and crop sanitation.
• Timely sowing of the crop.
• Sowing of tolerant and resistant varieties.
• Crop rotation should be practiced in disease endemic areas.

Chemical Control

• Application of sulphur at 25kg/ha.
  OR
• Dithane M-45 at 2.5 g/l should be sprayed.

Rust

Causal Organism

Uromyces cicer-arietini

Damage

• The leaves generally become crowded with small, round and oval, light brown to dark brown pustules.
• These pustules tend to coalesce and form bigger pustules.
• Pustules are formed on both the leaf surfaces, sometimes on stems also.
• The affected leaves dry up and fall prematurely.
• Severely infected crop looks rusty.

Survival & Favourable Conditions

• The disease generally occurs at the end of February.
• Cool and moist weather favours the disease build-up.

Cultural Control

• Plant resistant varieties if available.
• Burn the remains of previous crops.
• Use crop rotation or 2 - 3years.

Chemical Control

• Seed treatment with vitavax @ 2 - 3 gm/kg of seed.
• Spray mancozeb at the rate of 3g/litre at 10 days interval with the appearance of the disease.
  OR
• Spray Hexaconazole 1 ml/L.
  OR
• Spray Propoconazole 1 ml/L.

Sclerotinia stem rot

Causal Organism

Sclerotinia sclerotiorum

Damage

• It affect the crop at any stage.
• The disease is characterized by the appearance of chlorotic or drying branches or whole plants scattered in the field.
• Rotting of the stems at the basal region or lesion on the stem occurs.
• The leaves of affected plants/ branches turn yellow or droop while remaining green, dry up and turn straw colored.
• Whitish or brownish irregular shaped sclerotia can be seen on branches or inside the stem.

Survival & Favourable Conditions

• Excessive vegetative growth, high soil moisture and cool weather (20 C) favour disease growth.

Cultural Control

• Deep summer ploughing.
• Avoid excessive vegetative growth.
• Avoid excessive irrigation.

Mechanical Control

• Removal of infected plant debris from the field.

Stemphylium blight

Causal Organism

Stemphylium sarciniforme

Damage

• It infects the crop during the flowering stage.
• Defoliation or lower plant parts is common in infected plant.
• Lesions include ovoid spots which are dark brown in centre and have a grey border.
• Minute, dark brown, elongated spots also developed on the stems.
• The entire plant becomes black.

Survival & Favourable Conditions

• Excessive vegetative growth, high humidity, and cool weather (15-200^o C) favor disease
  development.
• Usually affects the crop from the flowering stage onwards

Cultural Control

• The crop should get maximum aeration and sunlight.
• Planting should be done distantly.
• Rouge out the infected plants.
• Gram should be intercropped with linseed.

Chemical Control

• Spray of mancozeb at 3g/l or Carbendazim 1-1.5 g/L.

Stunt

Causal Organism

Pea leaf roll virus

Damage

• The affected plants are easily identified by their yellow, orange or brown discoloration and stunted growth.
• The stems and leaves become discolored and stiffer and thicker than normal.
• Phloem browning at the collar region occurs.
• Many plants dry up prematurely.
• No flowering and fruiting occurs.

Survival & Favourable Conditions

• The disease is not seedborne.
• Early sowing and wider spacing favour stunt incidence.
• The aphid vector activity favour disease occur.

Cultural Control

• Avoid close spacing.
• Sow when aphid vector activity is low.