Tomato leaf problem

I don't think you have the below but though I would send this information if it does turn out to be lead mould.

I think you have either over water or it maybe down to feed. Just take the leaves off and see what happens. I have had a few leaf problems with my large beef steak tomatoes but it has been after I have fed them. I have taken the leaves off and they are doing ok. I alway stip my tomato plants of excess leaves and use grow bags but with tomato rings in them as this gives a better yield.

Tomato leaf mould (Cladosporium fulvum)

Symptoms

Patches of pale greyish-brown mould develop on the underside of leaves of tomatoes growing in the greenhouse. A yellowish blotch is usually seen on the corresponding upper surface. Lower leaves are usually infected first, and dead leaves wither but do not fall. When infection is severe the mould may develop on both leaf surfaces, and occasionally even flowers and fruit are affected. Infection of plants growing outdoors is rare.

Cause

The mould growth contains huge numbers of spores of the causal fungus. The first symptoms may develop in April or May, but the disease is usually most troublesome from June or July onwards. During warm, moist conditions the disease can develop very rapidly.

How does the disease affect a tomato crop?
Because the vigour of the plants is reduced, the yield will also be reduced. In addition, if the disease is not controlled it can carry over to infect next year's crop.

Spread

Spores are carried on air currents and insects, and also on your clothing as you brush against infected plants. The spores can survive over winter on plant debris and on the greenhouse structure.

Prevention

Good ventilation and a maximum temperature of 21oC (70oF) may help to prevent the disease. Try to avoid wetting the foliage when watering - this is particularly important in the evening, as the leaves may then stay wet all night. Spacing the plants more widely apart than usual will also help. Good hygiene is very important, so remove affected foliage as soon as it is seen, and dispose of all infected plants at the end of each season (do not compost). Then, once the greenhouse is clear, disinfect it with Jeyes Fluid or Armillatox.

Resistant cultivars

‘Shirley’, ‘Dombello’, ‘Estrella’, ‘Eurocross BB’, ‘Grenadier’, ‘Shirley’ and ‘Cumulus’ are all resistant, but check the seed catalogues for others.

Chemical control

Best reagrds

Debs

Once the disease has appeared the plants should be sprayed with mancozeb (Bio Dithane 945). Copper fungicides (Bordeaux Mixture, Murphy Traditional Copper Fungicide) can also be used, but tend to harden the foliage and are best applied later in the season. Neither mancozeb nor copper is labelled for leaf mould control, but both are labelled for control of tomato blight, and if used as directed for this disease should give some control.

The plant requires more water,sunlight,minerals for minerals instead of ground water pour mineral water morning sunlight is required water the plants in the evening as the evaporation losses are the minimum.