questions: asking about prophylactic spraying of fungicides in tomato 
 answers: depending upon weather conditions particularly on cloudy weather mancozeb/pradhan 75 wp (2 g/l) should be sprayed as prophylactic measure. alternatively, dithane z-78 @  (2.5 g in 1 lit of water) can be used. if disease appears, spraying should be done at an interval of 7 to 10 days depending upon weather condition.while spraying care should be taken to cover the lower sides of the leaves.