Thrips are minute and slender insects, appear in the nursery as well as the main field and affect the
crop through out its life period. Both adults and nymphs damage the crop and lacerate the leaf tissue
and suck the sap. Tender shoots, buds, and flowers are attacked. As a result, they become twisted and deformed, upward curling of leaves is seen· Pest infestation increases at high temperature.
Occurs mainly in dry, cloudy, cold and humid weather conditions during February –April while heavy rains wash away the aphid colonies. Aphids are small, succulent, pear-shaped insects that vary in color from yellow to green to black. Appear on them tender shoots and the lower surface of the leaves. Suck the sap and reduce the vigour of the plants. Secrete sweet substances which attract ants and develops sooty mold.
Tobacco caterpillar adult is brown. The larvae of second and third instar enter chilli pods by making a hole near calyx and feed on chilli seed. The affected seeds drop off or develop white colour on drying. It is nocturnal in habit but can be seen during day time as well.
The insect is very active in post – rainy season, (October to March) which coincides with reproductive phase of chilli crop. Larvae damages by boring into fruits and feeds on inner contents of the pods. On bell pepper, fruits are attacked during April-June period.
Damping off is severe in warm and moist wet soils having poor drainage. Seed may rot before emergence, or the seedlings may be toppled before they emerge from the ground. Young seedlings die in patches due to the decay of tissues in the collar
2.Cercospora Leaf spot
Appears as brown, circular spots with small light grey centres and dark brown margins. Severely infected leaves may drop off prematurely resulting in reduced yield.
3.Die-back & Anthracnose
The spots on fruits are usually circular, water-soaked and sunken with black margins. As the disease advances the spots spread, forming concentric markings with dark fructifications. The fruits with many spots drop off prematurely resulting in heavy loss of yield. The fungus may also attack the fruit stalk and spread along the stem causing dieback symptoms.
The disease is most likely to occur in poorly drained soils and is characterised by yellowing, upward and inward rolling of the leaves and wilting of the plant. Initially, wilt appears in patches in water stagnating / low lying areas and quickly spreads through irrigation along the water channel. By the time above – ground symptoms are evident, the vascular system of the plant is discoloured, particularly in the lower stem and roots.
It is more common in hot pepper. It occurs during warm periods under both dry and humid weather conditions. Initially, chlorotic blotches or spots appear on the upper leaf and surface with white to gray powdery growth on the corresponding lower surface. It proceeds from the older to younger leaves and shedding of foliage is very prominent.
Leaves are greatly reduced in size and plant gives a stunted look due to leaf curl infection caused by a begomo virus. In advanced stages, the whole plant appears bushy, with stunted growth and fewer flowers. Small sized fruits are produced with deformed seeds In case of severe infection; complete crop failure is not uncommon.
It spreads during November. Nymphs and adults suck sap from leaves. Affected leaves curl downward along the margins of the leaf and attain an inverted boat shape. Leaf petioles get elongated and small leaves are serrated giving the bunchy appearance. Leaves turn a dark grey with reduced leaf sheath, plants stop flowering and result in considerable yield reduction.
It is a physiological disorder of bell pepper and fruits facing direct sun rays are affected more by sun scald. Symptoms include a whitish necrotic area on the side of the fruit exposed to a fierce, usually afternoon, the sun. The flesh becomes light, dry and papery in areas that had direct sunlight on them. Poor foliage cover allows the defect to occur.
Validated Integrated Pest Management Interventions for Hot Pepper / Bell pepper Crop
- Prepare raised nursery beds about 10 cm above ground level for good drainage to avoid damping off etc.
- Cover the beds with polythene sheet of 45 gauge (0.45 mm) thickness for three weeks for soil solarization for soil borne pests. Sufficient moisture should be present in the soil for solarization.
- Mix 50 g of effective strain of Trichoderma from reliable source in 3 kg of FYM and leave for 7-14 days for
enrichment followed by mixing of Trichoderma enriched FYM in the soil of a 3 m2 bed.
- Seed treatment with an effective strain of Trichoderma from reliable source @ 10 g / kg and imidacloprid 70 WS @ 10 g / kg seed to manage damping off and sucking pests in the initial stage in direct seeded chilli 1 WP.
- Pseudomonas fluorescens (TNAU Strain, ITCC BE 0005 @ 10 g / kg seed or Trichoderma viride (TNAU Strain ITCC 6914 @ 4g / kg seed can also be used as a seed treatment.
- Need based soil drenching with captan 75 WP @ 0.25 % or captan 75 WS @ 0.2-0.3 % or mancozeb 75 WP @ 0.3 % or metalaxyl + mancozeb @ 0.3 % to manage damping off / rots
- Erect Khaskhas shading/support on one side of nursery beds of bell pepper to avoid the exposure to cold/frost during winter (December-January). Cover the beds with polythene sheets at nights to avoid frost injury. However, remove the sheets during day time to expose them to the sun.
- At the time of planting, dip the seedlings in Pseudomonas fluorescens solution @ 5 ml/litre for ten minutes.
- Erect bird perches @ 10 / acre for facilitating visits of predatory birds.
- Install delta traps @ 2 / acre for hoppers, aphids and white fly, etc.
- Spray with P fluorescens @10 g / l twice (at the vegetative and flowering stage) at evening time for overall health and growth of plants.
- A spray of neem products / NSKE 5% against aphids, thrips, hoppers and white fly. Spray NSKE 5% 2-3 times against thrips at 15-20 days after transplanting (DAT) when the rating is between 1-2. If the population of thrips & white fly is still high, then spray fenpropathrin 30 EC @ 250 -340 ml / ha in 750-1000 lit water or pyriproxyfen 10 EC @ 500 ml or spinosad 45 SC @ 160 g / ha in 500 lit water (thrips) or fipronil 5 SC @ 800-1000ml / ha in 1000 lit water (thrips only).
- If both thrips & mites are seen together, spray of fenpropathrin 30 EC @ 250 -340 ml / ha in 750 – 1000 lit water or ethion 50 EC @ 1.5 -2.0 litre / ha in 500-1000 lit water is very useful.
- Rouging out and destroying of leaf-curl disease/mosaic complex affected plants periodically.
- Erection of pheromone traps @ 5 / ha for H. armigera / S. litura for monitoring of adults for egg laying.
- Periodic releases of egg parasitoid, Trichogramma sp @ 1.5 lakh / ha for fruit borer (H. armigera)
- 2-3 sprays of HaNPV / SlNPV (250 LE / ha) (2 x 109 POB) / ha in initial stages or as and when needed.
- Only need based spray of insecticides viz; spinosad 45 SC @ 160 ml or emmamectin benzoate 5 SG @ 200 or indoxacarb 14.5 SC @ 333-400 ml/ha in 500 lit water during initiation of flowering & fruiting stage for fruit borer, H. armigera is highly effective. Apply these pesticides preferably during evenings.
- Periodic removal and destruction of damaged fruits due to borer.
- Protective spray with mancozeb 75 WP or zineb 75 WP @ 1.5-2.0 kg / ha in 750-1000 lit water or propineb 70 WP @ 0.5 % and need based application of difenconazole @ 0.05 % or myclobutanil 10 WP @ 0.04 %, or captan 70 % + hexaconazole 5 WP @ 500-1000 g / ha in 500 lit water to manage fruit rot and die back.
- Spray sulphur 52 SC @ 2 lit / ha in 400 lit water or sulphur 80 WP @ 3.13 kg / ha in 750-1000 lit water and need based application of flusilazole 40 EC @ 100-150 ml / ha in 500 lit water against powdery mildew.
- Need based spray of either hexaconazole 2 SC @ 3 lit / ha or tebucunazole 25.9 % m / m EC @ 500-750 ml or tebucunazole 10 WP + sulphur 65 WG @ 1250 ml / ha in 500 lit water or azoxystrobin 11 % + tebucunazole 18.3 % SC W / W @ 600-700 ml / ha in 500-700 lit water, against powdery mildew and fruit rot.
- At the time of planting, apply effective strain of Trichoderma from reliable source @ 5 kg/ha along with well rotten FYM to manage fungal wilts.
- Crop rotation is followed if wilt occurs regularly every year.
Conservation of natural enemies
The commonly seen natural enemies of pests in bell pepper cropping system should be protected from unwanted and excessive sprays of chemical pesticides.
- ICAR-National Research Centre for Integrated Pest Management.