Fungal diseases of vegetables -chili

Fungal diseases of vegetables-Chilli

1. Fungal diseases of vegetables- Chili Vaishali S.Patil Professor, Department of Botany Shri Shivaji College of Arts, Commerce & Science Akola

2. 1.Anthracnose caused by Colletotrichum gloeosporioides , Colletotrichum capsici , Glomerella cingulata , Colletotrichum coccodes Symptoms - are seen on leaf, stem and fruit.Small , circular spots on the skin of the fruit and expanded in the direction of long axis of the fruit. The fruits with many spots drop off prematurely.Fungus may also attack the fruit stalk and spread along the stem causing dieback. Control- Fungicides,disease -free chilli seed. The field should have good drainage & be free from infected debris.

3. 2.Cercospora (frogeye) leaf spot caused by Cercospora capsici Symptoms - small brownish spots on the leaves and gradually develops into the big circular grayish spots with whitish center . Later they form into large lesions due to coalescing of the spots. Infection on fruit stalk and calyx on severity. Control- rotation, use pathogen-free seed, inspect transplants and discard diseased plants, use drip, destroy diseased plants, fungicides.  

4. 3.Charcoal rot caused by Macrophomina phaseolina Symptoms - slightly smaller leaflets, reduced vigor , leaflets yellow, then wilt and turn brown. The brown leaves remain attached to the petioles (leaf stems). A light gray of silver discoloration will be visible in the taproot and lower stem when plants are split open. Black specs ( microsclerotia ) will be visible in this tissue of the stem and tap root. Outer tissues will have black, dusty microsclerotia .   Control- Resistance varieties, rotation 

5. 4.Choanephora blight (wet rot) caused by Choanephora cucurbitarum Symptoms - water-soaked areas develop on leaves, and apical growing points become blighted. It grows rapidly downward, causing dieback. Dark gray fungal growth can be seen on some lesions. Close inspection will reveal silvery, spine-like fungal structures and dark spores. A black soft rot can also develop in fruit. Control- fungicide

6. 5.Damping-off and root rot caused by Rhizoctonia solani , Phytophthora  spp., Fusarium  spp. Pythium  spp . Symptoms - Seeds may rot before germinating or seedlings may die prior to emergence. Young seedlings develop a rot at the crown. Later, the tissue becomes soft and constricted, and the plants wilt and fall over. Dark-brown to black, water-soaked lesions that rapidly spread over the entire seedling. Brown, water-soaked lesions that start on the roots and later extend up the hypocotyl characterize post-emergence. The lesions girdle the hypocotyl , causing seedlings to wilt and die. The root cortex becomes macerated and easily sloughs off. Control- Improving drainage and moisture regulation, fungicide, seed treatments, crops rotation, soil fumigation or solarization , use pasteurized soil mixes.

7. 6.Downy mildew caused by Peronospora tabacina Symptoms - Initial symptoms include large, angular or blocky, yellow areas visible on the upper surface. As lesions mature, they expand rapidly and turn brown. The under surface of infected leaves appears water soaked. Upon closer inspection, a purple-brown mold becomes apparent. Small spores shaped like footballs can be observed among the mold . Control- planting early season varieties, fungicides, drip system, and improve air circulation.  

8. 7.Fusarium stem rot caused by Fusarium solani Symptoms - Soft, dark brown or black cankers are formed on the stem, usually at nodes or wound sites. These may girdle the stem in later stages of disease development. There is a dark brown discolouration of the internal portion of the stem that may extend a considerable distance. The lesions may eventually develop cinnamon or light orange-coloured, very small, flask-shaped fruiting structures known as perithecia , which are the fruiting bodies of the fungus. White cottony mycelium may also be present on the surface of stem cankers in late stages of disease development. Stem cankers restrict the upward flow of water resulting in wilting and death of the plant. Control- Avoid dripping fertilizer solution at the stem base, good ventilation and drainage, sanitization,

9. 8.Fusarium wilt caused by Fusarium oxysporum f.sp . Capsici Symptoms -On the young seedlings initially, water soaked areas developed at the collar region and a brown sunken lesion which soon appeared as girdled resulting in seedling collapse. On adult plant initially, slight drooping of leaves which led to drying of leaves starting from lower ones extended from root to stem region and plants exhibited wilting symptom. Control- Use certified seeds, Seed treatment with fungicide, Reduce the nitrogen fertilizers, Apply  Trichoderma viride  to the soil, Collect and burn any infected plants, maintain the pH level of the soil

10. 9.Gray leaf spot caused by Stemphylium solani , Stemphylium lycopersici Symptoms - Spots appear as minute, circular to oblong, brownish black specks on lower leaves. Lesion are randomly scattered across leaves, and enlarge with age. Spots occasionally coalesce and kill large areas of the leaf. Spots later dry out and develop cracks before the entire leaf turns yellow. The infected leaf dies quickly and drops from the plant. Gray leaf spot does not affect fruit, but defoliation reduces fruit yield and grade. Control- crop rotation, eliminate crop debris, avoiding overhead irrigation and dense plantings, resistant varieties, fungicide

11. 10.Gray mold caused by Botrytis cinerea Symptoms - a dark, water-soaked, slimy lesion and then the affected areas turn tan to light-brown before turning brownish-gray and powdery-looking as spores develop. Petioles, stems, and fruit can develop lesions. Green or ripe fruit infections cause a soft, brown-to-gray rot that can eventually encompass the entire fruit. Plants can die from stem infections. Control- Crop rotation, avoid over-fertilization with nitrogen, limit irrigation during and after bloom, fungicides, biological control.

12. 11.Phytophthora blight caused by Phytophthora capsici Symptoms - attack the roots, stems, leaves, and fruit,  sudden wilting and death occur as plants reach the fruiting stage. Stems discolor internally, collapse, and may become woody in time. Lesions may girdle the stem, leading to wilt above the lesion, or plants may wilt and die because the fungus has invaded the top branches before the stem lesions are severe enough to cause collapse. Leaves first show small dark green spots that enlarge and become bleached, as though scalded. If the plant stems are infected, an irreversible wilt of the foliage occurs. Infected fruits initially develop dark, water-soaked patches that become coated with white mold and spores of the fungus. Fruits wither but remain attached to the plant. Seeds will be shriveled and infested.  Control- crop rotation, Avoid poorly drained fields, sufficient drainage of field, fungicide.

13. 12.Powdery mildew caused by Oidiopsis sicula , Oidiopsis taurica , Leveillula taurica Symptoms - A powdery-white fungal growth on the undersides of leaves with light-green to yellow blotches on the upper leaf surfaces. These areas turn brown with time, and the affected areas coalesce, causing a general yellowing of the entire leaf. The outer edges of leaves may curl upward. The older leaves lower in the canopy are usually infected first and show symptoms before the younger leaves. Infected leaves drop from the plant prematurely. This loss of photosynthetic leaf area slows plant growth and fruit development. The defoliation also exposes fruit to direct sunlight, which can lead to sunscalding of the fruit Control- well-drained soils and good air circulation, and light penetration into the canopy. Avoid excessive fertilization, fungicides.

14. 13.Southern blight caused by Sclerotium rolfsii , Athelia rolfsii Symptoms - A small, brown lesion on the stem. A cottony, white growth around the stem near the ground is also seen. Yellowing on the leaves, which will eventually turn brown. Control- keeping plants dry, spacing them out to allow airflow, and having well-drained soil,crop rotation, fungicide, Clean out plant debris, solarization ,

15. 14.Verticillium wilt caused by Verticillium albo-atrum , Verticillium dahliae Symptoms - Stunting and a slight yellowing of the lower foliage takes place. As the disease progresses, excessive yellowing and shedding of leaves may occur. The fungus invades the xylem elements and disrupts water transport. As the disease develops, varying degrees of vascular discoloration may occur, and the plant begins to wilt as a result of water stress.  Control- Crop rotations, Soil fumigants, Soil solarization

16. 15.White mold caused by Sclerotinia sclerotiorum Symptoms -It is a soft, watery rot. Diseased tissues eventually bleach white. Sclerotia that are black on the surface and white inside, associated with this bleached tissue, are diagnostic. Control- Avoid planting adjacent to a field area affected the previous season with white mold , crop rotation, encourage maximum air movement between plants, fungicides.