Question

tomato plant on fruiti   QUESTION: New Tomato leaves are discoloring not growing to full size. Do you have any idea of what could cause this? and what do we do to overcome this problem.

ANSWER: Khurram:

Mostly likely the issue would have its origin in the root/soil interface.  There maybe a nutrient imbalance in the soil.  If the older leaves are yellowing, a lack of Nitrogen may be the source.  A soil test may be called for.  How are the other vegetables in the garden appearing?

Also suggest carefully digging up a symptomatic plant, washing the soil off and looking at the roots for any "bumps" on them.  This may be nematodes, a parasitic worm.  It can cause yellowing and stunting if the population is high enough.  Check out the color of the roots also.  They should be whitish/cream color to be healthy.

If plants were subjected to a sudden change in temperature this may cause a temporary slowing of growth and even some foliar damage if temperatures dropped significantly.

Regards
Steve

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old plant  

new plant   QUESTION: thanks for your reply, contents noted. you are correct that there is a severe temperature change during the days and night, in the evening temperature sore upto 38 degs and at night it cools down to 23-25 deg. this problem is in the whole area that spreads to 2000 acres.

Please see the below images. this is a TYLCV resistant plant, in one of the images there is a leaf curling upside and in the other one new leaves are changing its color.

Answer
Khurram:

Growing disease resistant varieties is one of the best ways to deal with infectious diseases.  Viruses, in particular are difficult to impossible to diagnose based on symptoms alone.  An ELISA test is an effective way to confirm this pathogen.

Environmental extremes can often mimic infectious diseases.  Lab tests should be considered if there is any doubt.

Steve