Bell peppers, also known as capsicum, are among the most widely grown vegetable crops because of their high market demand and nutritional value. But along with their popularity comes a major challenge—these plants are highly susceptible to a variety of pests and diseases, which can cause significant damage to plants, lowering yield and fruit quality.
For growers, early recognition of these problems and timely management is the key to saving the crop. This guide serves as a complete handbook on capsicum pests and diseases, covering their symptoms, causes, and effective management practices. By following these strategies, growers can ensure healthier plants and a more productive harvest.
Diseases attack on Capsicum:
| Disease | Cause | Symptoms | Comments | Management |
| Anthracnose (Colletotrichum spp.) | Fungus | Circular lesions on fruit with tan–orange–black concentric rings; may enlarge to cover most of fruit; irregular gray spots on leaves/stems | Found worldwide, can cause heavy yield losses | Use disease-free/hot-water treated seed; crop rotation (3 yrs); bury crop residue; remove debris |
| Cercospora Leaf Spot (C. capsici) | Fungus | Small circular spots with white–brown centers and dark/purple border; brittle, cracked mature lesions | Common in tropics/subtropics; minor in peppers | Remove crop debris; crop rotation; fungicide if severe |
| Damping-off (Pythium spp., Rhizoctonia solani) | Fungus | Seeds fail to germinate; seedlings collapse; dark shriveled stems near soil line; water-soaked roots | Spread in infected soil/water; worsens with overcrowding, excess nitrogen | Use well-drained raised beds; high-quality seed; fungicide seed treatment |
| Fusarium Wilt (Fusarium oxysporum) | Fungus | Yellowing, wilting leaves; vascular tissue turns red-brown; plant death | Favors high soil moisture | Plant in well-drained soil; avoid waterlogging |
| Gray Leaf Spot (Stemphylium spp.) | Fungus | Small red-brown leaf spots that expand to gray centers; high infections cause yellowing & leaf drop | Common in cool-season peppers; also attacks tomatoes | Keep nursery beds clean/ventilated; remove debris; rotate away from solanaceous crops; fungicides if severe |
| Powdery Mildew (Leveillula taurica) | Fungus | White powdery patches under leaves; yellow-brown upper surface; leaf curling & drop | Spreads in both dry & humid conditions; worse on older leaves | Apply fungicides if severe |
| Southern Blight (Sclerotium rolfsii) | Fungus | Sudden wilting, yellowing; brown stem near soil line; white mycelial mat & sclerotia on stem/soil | Survives in soil; thrives in warm, humid, acidic soils | Remove infected plants; crop rotation; deep plowing; wrap lower stems with foil |
| Verticillium Wilt (Verticillium spp.) | Fungus | Stunted growth; lower leaves yellow & drop; day wilting, night recovery; vascular browning | Found in US/Europe/Canada; severity varies | No cure once present; rotate crops (3–4 yrs); soil fumigation/solarization |
Insect / Pest attack on Capsicum
| Pest | Symptoms | Cause | Comments | Management |
| Aphids (Myzus persicae) | Small soft-bodied insects (green, yellow, pink, brown, red, or black) on undersides of leaves; leaves may yellow, curl, or show necrotic spots; stunted shoots; sticky honeydew leads to sooty mold. | Insect | Have cornicles (tubular structures) on body; move slowly when disturbed. | Prune infested shoots; inspect transplants; use tolerant varieties; silver mulches deter feeding; strong water jet to knock off; insecticidal soaps or neem/canola oil effective if severe. |
| Beet Armyworm (Spodoptera exigua) | Circular/irregular holes in leaves; skeletonized foliage; shallow fruit wounds; egg clusters (50–150 eggs, cottony/fuzzy appearance); young larvae pale green/yellow, older ones dark green with stripes. | Insect | 3–5 generations per year. | Use biological control/natural enemies; Bacillus thuringiensis effective; chemical sprays limited for home gardens. |
| Colorado Potato Beetle (Leptinotarsa decemlineata) | Heavy leaf feeding → defoliation; adults are black-yellow striped beetles; larvae red/pink with black spots. | Insect | Adults emerge in spring; female lays 500+ eggs in 4–5 weeks. | Early-maturing varieties escape damage; handpick adults/larvae; Bt effective for larvae; spinosad works against adults. |
| Flea Beetles (Various spp.) | Tiny shot-like holes in leaves; seedlings most vulnerable; severe cases stunt or kill plants; beetles are small (1.5–3 mm), shiny/metallic, and jump when disturbed. | Insect | Overwinter in weeds, debris, soil; 2–3 generations/year. | Use row covers; early planting; trap crops (crucifers); mulching; neem oil or diatomaceous earth; chemicals like carbaryl/spinosad/bifenthrin effective for short-term. |
| Leafminers (Lyriomyza spp.) | White winding trails in leaves; heavy mining → white blotches & leaf drop; reduced yield; small black-yellow flies lay eggs inside leaves. | Insect | Lifecycle 2 weeks in warm weather; 7–10 generations/year. | Inspect transplants; remove plants after harvest; avoid unnecessary insecticide to protect natural enemies. |
| Leafroller (Platynota stultana) | Rolled/tied leaves with silk; feeding damage; defoliation; silk on fruits causing scars; larvae wriggle/drop on silk thread. | Insect | Adult is a moth; hosts include alfalfa & sugar beet. | Regular monitoring; remove weeds; avoid planting near sugar beet/alfalfa; use Bt or Entrust SC sprays. |
| Pepper Weevil (Anthonomus eugenii) | Damage to foliage, buds, and young fruits; larvae feed inside pods; fruits misshapen/discolored; fruit drop; adult = small black beetle | Insect | Multiple generations/year; prefers peppers but feeds on other nightshades. | Remove nightshade weeds; clear dropped fruits; rotate crops; pyrethrin sprays acceptable; destroy crop residue after harvest. |
| Thrips (Frankliniella occidentalis, Thrips tabaci, etc.) | Distorted buds/leaves; silvered leaves with black feces; flower damage; spreads Tomato Spotted Wilt Virus (TSWV); adults pale yellow–brown, tiny (1.5 mm). | Insect | Retain TSWV transmission for life. | Avoid planting near onions/garlic/cereals; reflective mulches deter; apply insecticide if heavy infestation. |
| Tomato Fruit Worm (Helicoverpa zea) | Larvae bore into fruit near stem; cause decay & premature fruit drop; young larvae cream with black head; older vary (yellow-green to black); eggs laid singly, white → brown ring → dark before hatch. | Insect | Adult = pale green/tan moth; overwinters in soil; also called corn earworm. | Early control needed before larvae enter fruits; monitor eggs/young larvae; Bt or Entrust SC for organic; chemicals for commercial farms. |
| Spider Mites (Tetranychus urticae) | Yellow stippling on leaves; bronzed leaves with webbing; mites visible as tiny dots; severe cases → yellowing & leaf drop. | Arachnid (Mite) | Thrive in dusty & water-stressed plants. | Spray with strong water jet; apply insecticidal soap; avoid chemicals that kill natural enemies (they worsen mite outbreaks). |
Conclusion
In capsicum cultivation, pests and diseases are inevitable—but losses are not. Success lies in early detection, smart prevention, and guided management. From fungal blights to hidden insect attacks, every challenge can be turned into an opportunity with the right strategy. For greenhouse growers, precision and consistency are the key to higher yields and premium quality. With the dedicated support of the Pioneer Agritech in-house agronomy team, you get not just solutions but a partner committed to protecting your crop and ensuring your farming journey stays profitable and sustainable.
Reach out today, for tailored crop protection strategies and hands-on support.