Thyroid Physiology_Dr.E. Muralinath_ Associate Professor
Fungal diseases of vegetables -chili
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.
