These symptoms has been seen in all of the plants.
please notice this important point that these symptoms first appeared on older (lower) leaves. i will appreciate if someone tell me what the cuse of this disease on the plants is?
Are you sure, the symptoms first appeared on older leaves? Symptoms looks like Tomato Mosaic Disease. Check if there is internal browning on the fruit wall.
In other hand, it may be due to Magnesium deficiency which also causes interveinal chlorosis.
The earliest symptoms of Tomato Mosaic Disease are yellow patches on the leaves, that are sharply demarcated. But various light flecks indicate a lack of the necessary elements of nutrition or a reaction to toxins.
I agree with Oadi Matny - it may be reaction on some toxin.
OR
There is white venation on the older leaves. Obvious patches indicated problem with carbon dioxid methabolism.
There is a problem. the farmer said to me these symptoms first did not appear on the upper leaves but after a while it has been seen. so i think it couldn't be due to treating with any solution.
Yes, I also agree with Somnath Koley and Qadi Matny. Maybe your plant nutrient deficiency or poisoning. Try to do fertilizing back and see the results. Plants that are infected by the virus, will not be back to normal.