TOMATO - DISORDERS
LOW TEMPERATURE, PHOSPHORUS DEFICIENCY
Aetiology: low temperature, phosphorus deficiency
Importance: The leaves of plants, young ones in particular, turn purple when the temperature and/or the substrate is too wet.
Symptoms: Both leaves and stems get a reddish to purple tinge, particularly pronounced on the underside of leaves. If the unfavourable conditions persist, plants turn yellow and eventually may even die. These symptoms must not be confused with the initial symptoms of the stolbur disease, which usually appears much later in the field.
Treatment:
- increase temperature,
- use substrate with better structure and provide balanced nutrition.
LEAF CURL |
Importance: Leaf curl is quite common in indeterminate varieties when lateral shoots are removed, but it has little if any impact on the yield.
Symptoms: Leaflets, especially at the base of plants, roll upward and inward around the main vein. The more vigorous the plants grow, the more intensive the curling may be. The most intensive symptoms can be observed when the top shoot is removed. Intensive sunshine may burn the underside of leaves.
1. Figure Leaf curl
Source: project number: HU/02/B/F/PP-136012
Treatment: There is no suitable solution.
CATFACES
Aetiology: low or very high temperatures during flowering and the early development of fruits
Importance: This disorder is relatively frequent especially at the beginning of the season. Fruits with more locules are more susceptible. Affected fruits are not marketable.
Symptoms: The irregular necrotic spots are found mainly on the apical part of the fruit, extending towards the basal part. The spots may be invaded by sooty mould in wet weather, but the mould does not cause them. Do not confuse these symptoms with those of calcium deficiency - see below.
2. Figure Cat faces
Source: project number HU/02/B/F/PP-136012
Treatment:
- cannot be controlled under field conditions
- select less susceptible varieties
CALCIUM DEFICIENCY
Aetiology: Blossom and root
3. Figure Blossom end rot
Source: project number HU/02/B/F/PP-136012
Slight calcium deficiency causes only light symptoms. In this case, the apical part of the fruit appears to be injured.
4. Figure Blossom end rot
Source: project number HU/02/B/F/PP-136012
In the case of severe calcium deficiency, cells in the apex of the fruit collapse resulting in necrosis. Sometimes this necrosis is only visible inside the fruit. Necrotic spots may be invaded by sooty mould in wet weather. Plum-shaped fruits are more susceptible. As leaves and fruits compete for calcium, the fruits of more vigorously growing varieties may suffer more damage.
5. Figure Blossom end rot
Source: project number: HU/02/B/F/PP-136012
Blossom end rot only affects the apex and its vicinity. Necrotic spots are usually round and slightly sunken. Catface may also appear on the apical parts, but its symptoms are usually not restricted to that zone only. The spots caused by catface are of irregular shape and extend to the upper parts of the fruit; their edges appear to be torn.
Sooty mould, though thriving on these spots, does not cause the disorder.
These symptoms must not be confused with those of catface.
Treatment
Liming does not always solve the problem. Instead, the conditions of calcium uptake should be improved:
- balanced irrigation (avoid water surplus or water stress),
- balanced fertilization (avoid excess nitrogen and other elements),
- application of foliar fertilisers containing calcium.
RUSSETING
Aetiology: low temperatures during fruit development, phytotoxicity of some pesticides.
Occurrence and importance: Russeting commonly occurs at the beginning or at the end of the season when temperatures are lower.
Symptoms:
6. Figure Russeting
Source: project number: HU/02/B/F/PP-136012
The skin of the fruit is rough and corky, with small cracks.
Do not confuse these symptoms with the cracking of fruits caused by erratic watering conditions. In the latter case, the cracks run very deep and do not affect the skin of the fruit only.
Treatment: It cannot be controlled under field conditions.
POTASSIUM DEFICIENCY - YELLOW TOP
Aetiology: excessively low or high temperatures or great differences between day and night temperatures during fruit development, especially around maturation.
Importance: Yellow top is a very frequent disorder, but the impacted fruits often remain marketable, because consumers usually do not recognize the damage.
Symptoms:
7. Figure Yellow top
Source: project number: HU/02/B/F/PP-136012
The maturation of the upper part (around the calyx) is delayed and remains green or yellow even when the apical part is already quite ripe. Sometimes this symptom is only visible when the fruit is cut. The flavour of the damaged part is inferior.
8. Figure Yellow top
Source: project number: HU/02/B/F/PP-136012
The picture illustrates the internal symptoms in the fruit.
Treatment
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SUNSCALD
Aetiology: sudden exposition to direct sunshine
Importance: Sunscald on leaves occurs relatively frequently after transplanting. Fruits are damaged much less frequently. Fruit damage usually occurs when the leaves covering fruits are removed by the grower or destroyed by some disease and the weather is sunny afterwards. Damaged fruits are unmarketable, though damaged leaves are soon replaced by new ones.
Symptoms:
9. Figure Suncald
Source: project number: HU/02/B/F/PP-136012
Relatively large, almost white spots appear on the fruit, usually on the upper parts. Their surface is firm and leathery.
10. Figure Suncald
Source: project number: HU/02/B/F/PP-136012
Spots on the leaves are whitish and have a papery appearance. Both on fruits and leaves, the spots have very sharp edges. The spots may be invaded by sooty mould in wet weather, but the ty mould, does not cause the spots.
Treatment:
- proper hardening of transplants before planting,
- control of foliar diseases,
- do not remove the leaves if sunny weather is expected.
Listo of Viruses:
- TOMATO LEAF CURL NEW DELHI VIRUS (ToLCNDV)
- PEPINO MOSAIC VIRUS (PepMV)
- TOMATO TORRADO VIRUS (ToTV)
- TOMATO CHLOROSIS VIRUS (ToCV)
- TOMATO INFECTIOUS CHLOROSIS VIRUS (TICV)
- TOMATO BROWN RUGOSE FRUIT VIRUS (ToBRFV)
- TOMATO STOLBUR PHYTOPLASMA
- BACTERICAL CANKER
- BACTERIAL SPECK AND BACTERIAL SPOT
- BACTERIAL WILT
- LATE BLIGHT
- EARLY BLIGHT
- DAMPING OFF
- LEAF SPOT OF TOMATO
- GREY MOLD
- FUSARIUM WILT OF TOMATO
- VERTICILLIUM WILT
- LOW TEMPERATURE, PHOSPHORUS DEFICIENCY
- LEAF CURL
- CATFACES
- CALCIUM DEFICIENCY
- RUSSETING
- POTASSIUM DEFICIENCY - YELLOW TOP
- SUNSCALD
- TOMATO LEAF MINER
- SOUTHERN GREEN STINKBUG
- RED TOMATO SPIDER MITE
- THRIPS
- COTTON BOLLWORM
- GREENHOUSE WHITEFLY, SILVERLEAF WHITEFLY
- TWO-SPOTTED SPIDER MITE
- COLORADO POTATO BEETLE
- ROOT-KNOT NEMATODES
- POTATO CYST NEMATODE