Anthracnose of tomato
|Anthracnose of tomato|
| Anthracnose of tomato
Anthracnose of tomato is primarily a disease of ripe and over-ripe tomato fruit. If left unchecked, the disease can cause serious losses in yield and marketability. The disease is widespread and common in areas where moisture conditions promote disease development and also affects aubergine, pepper, and potato.
Symptoms are first noticeable on ripe fruit, although green fruit is also infected and these latent infections can become a serious post-harvest problem. Tiny lesions may also occur on leaves and stems, are usually overlooked, but can serve as an initial source of inoculum for fruit. Small, circular, sunken spots appear on ripe fruit and are characterized by numerous submerged, black microsclerotia often in concentric rings. Spots can coalesce and involve large areas of the fruit. Under humid conditions, spots darken due to the production of hairs (setae) on the fruiting bodies of the pathogen and pink, gelatinous masses of conidia may ooze from lesions. Lesions may crack and become invaded by secondary soft-rotting organisms.
- Azoxystrobin (Quadris): 5to 6.2 fl oz/A (0 dh, REI 4 hr, Group 11).
Apply at the first sign of disease and rotate with chlorothalonil, maneb, or cupric hydroxide after 7 to 14 days if necessary. Do not rotate with other strobilurins (Cabrio, Flint).
- Boscalid (Endura): 2.5-3.5 oz/A. (0 dh, REI 12h, Group 7.
- Chlorothalonil (Bravo Ultrex 82 WDG): 1.3 to 1.8 lb/A (0 dh, REI 12 hr, Group M5).
Apply every 7-10 days. Use the higher rate and shorter interval when disease pressure is high.
- Cupric hydroxide (Kocide 3000): 0.75-1.75 lb /A (0 dh, REI 24 hr, Group M1).
Apply on a 7-10 day interval as soon as disease appears.
- Famoxadone plus cymoxanil (Tanos); 8 oz/A. (3 dh, REI 12h, Groups 11 & 27).
Must be tank mixed with an appropriate contact fungicide and alternated with a fungicide with a different mode of action after one application..
- Mancozeb (Penncozeb, Manzate, Dithane): Rates very with formulation (5 dh, REI 24 hr, Group M3).
- Mancozeb plus zoxamide (Gavel 75DF): 1.5-2.o lb/A. (5 dh, REI 48 h, Groups M3 & 22).
Add surfactants to improve performance.
- Mandipropamid plus difenconazole(Revus Top):5.5-7.0 fl oz/A. (1 dh, REI 12, Groups 40 & 3).
Addition of a spreading/sticking agent is recommended.
- Pyraclostrobin (Cabrio EG): 8 to 12 oz/A (0 dh, REI 12 hr, Group 11).
Apply at the first sign of disease and alternate with chlorothalonil, maneb, or cupric hydroxide after 7-14 days if necessary. Do not rotate with other strobilurins (Quadris, Flint).
Start with certified, disease-free seed. Use fungicide treated seed or treat seed with hot water 50°C (122°F) for 25 minutes. Rotate with non-solanaceous crops for at least one year. Keep fields free from weeds. Avoid excess overhead irrigation. Staking and mulching can reduce losses to anthracnose. Fungicide sprays provide acceptable control if applied on a regular schedule from first fruit set to harvest. Use weather based disease forecast model to schedule sprays.