Question
hi i am from india and have gerbera plants in my garden.
some day before , their leaves started to develop some white powder on them , so i treated them with a fungicide (carbendazim + mancozeb) 2 times a week.Also i removed the infected leaves completely.
Now the problem is that though the white powder is not visible now(not sure whether it is completely gone), but there is brown color infection on small  buds and then the bud diminishes in size becoming black and disappears completely.

i take care not to water the leaves , rather i water at base , also they receive 1-2 hours of good sunlight , temperature here is less at night(10 - 15 deg celsius) and at day(25-30 deg celsius)

is this brown bud disease related to white mildew that may still be out there .Whatever may be the case i want to eradicate them completely and want excellent flowers.Please suggest something.

Answer
Hi Deepak,
Sorry for the delay in responding.  Here in the Midwestern part of the USA we are climbing out of 25 cm+ of snow and this morning's temperature is -18C.  Very cold for us and we are not used to these conditions although it is far from "tropical" in Kansas in the winter.

It sounds like the white mildew may have attacked the buds of your plants.  It may also be botrytis which is a fungal blight that can be controlled by the following chemicals:

chlorothalonil, copper hydroxide, copper sulfate pentahydrate, and mancozeb, are generally more effective against B. cinerea.

I try to stay away from chemicals if at all possible and of course if you are growing organically, these chemicals are unacceptable.  To reduce chances for blight make sure you don't get water on the leaves, make sure the plants aren't crowded.  The plants do not do well in areas of high humidity.  Remove diseased buds and leaves and burn them or send them to the landfill don't compost them.  If the plants are seriously diseased, pull them up and dispose of them.  I hope this helps.
Tom