23 Questions
What is the characteristic shape of the sunken spots that appear on the skin of infected fruits?
Elliptical
What is the primary source of infection for anthracnose and ripe fruit rot?
Infected seeds in external seeds borne plants and crop debris
What is the optimal temperature range for the growth of anthracnose and ripe fruit rot?
17-28°C
What is the effect of frequent rainfall on the disease intensity of anthracnose and ripe fruit rot?
It increases the disease intensity
What is the purpose of collecting and destroying infected plant parts in the management of anthracnose and ripe fruit rot?
To reduce disease spread
Which of the following is a bioagent used in the biological control of anthracnose and ripe fruit rot?
Bacillus subtilis
What is the characteristic symptom of leaf decay in Phytophthora capsici infection?
Leaf decay progressing downwards
What is the appearance of the mould on decaying fruits in moist conditions?
Whitish mould
What is the region of the plant where waterlogged patches accompanied by a white mass are observed?
Collar region
What is the role of sporangia in the infection process?
Dissemination of infection to nearby fruits and foliage
What is the effect of Phytophthora capsici infection on the fruit?
Fruit becomes softer
What is the characteristic symptom of powdery mildew on the upper surface of infected leaves?
Yellow patches
What happens to severely infected leaves?
They dry out and shed
What is the effect of powdery mildew on infected fruits?
They do not grow further and may drop down
What is the ideal temperature for conidia germination?
25-30°C
What is the purpose of using sprinkler irrigation in managing powdery mildew?
To reduce humidity and prevent conidia germination
What is the function of cleistothecium in powdery mildew?
It survives in dormant mycelium
What is the direction in which the small, circular, yellowish to pinkish spots on the skin of the fruits spread?
In the direction of long axis of fruit
What is the consequence of the infection reaching the pedicel and branch tips?
Flower loss may occur
What is the characteristic of the affected fruits in the severe stages of the disease?
They lose their pungency
What is the mode of survival of the disease?
Infected seeds and plant debris
What is the colour of the affected plant branches in the severe stages of the disease?
Straw-like
What is the consequence of necrosis of tender twigs?
Wilting of branches or even the entire plant
Study Notes
Anthracnose and Ripe Fruit Rot
- Fully mature green and red ripe fruits exhibit symptoms of anthracnose and ripe fruit rot.
- Small, circular, yellowish to pinkish, sunken spots appear on the skin of the fruits, spreading in the direction of the fruit's long axis, and eventually turning brownish to black as the fruit matures.
- Severely infected fruits display a straw or pale white color, lose their pungency, and develop numerous dots in concentric rings, which are actually acervuli.
- The disease causes the crop to produce rusty, discolored seeds covered with a mycelial mat.
- Infected fruits suddenly fall from trees.
Mode of Survival and Spread
- The disease survives on infected fruit and plant debris, such as infected twigs, stems, and fruits.
- The primary spread of infection occurs through infected seeds in external seed-borne plants and crop debris.
- The secondary source of infection is conidia dispersed by wind.
Epidemiology
- The disease thrives in humidity ranging from 92-97% and temperatures between 17-28°C.
- Disease intensity increases with the age of plants.
- Frequent rainfall leading to humid weather and wet periods lasting 12 hours or longer contribute to the spread of the disease.
Management
Cultural Control
- Collect and destroy infected plant parts.
- Use healthy planting material.
- Remove solanaceous weeds and practice clean cultivation.
- Use resistant varieties of chilli, such as Anthracnose, Bengal Green, $20-1, H-4, H-6, Lorai, G3, G4, B61, Surekkh, Chemthor, Hisar Shakti, Hisar Vijay, and TNAU Chilli Hybrid Co 1.
Biological Control
- Use bio agents like P. fluorescens, Bacillus subtilis, and T. viride.
- Apply essential oil – Nigella sativa – which has antimicrobial activity.
Chemical Control
- Treat seeds with captan or Thiram fungicide @ 3-4g/kg seeds.
- Spray fungicides, such as Captan @ 1.5%, Mancozeb @ 0.25%, at the time of flowering.
- Use Copper oxychloride @ 0.25%, Thiophanate methyl @ 0.1%, and Propoconazole @ 0.1%.
- Dip fruits in IAA/NAA @ 200mg/lt for 30 minutes or Carbendazim @ 1000mg/ml for 10 minutes.
Identify the symptoms of anthracnose and ripe fruit rot disease, including its effects on fruit appearance and quality. Learn about the characteristic spots, color changes, and impact on seeds.
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