questions: asking about application of organic pesticides in cabbage. 
 answers: treat the seed with trichoderma viridie @5gm/100gm seed before sowing. mix the seed properly and keep for 30 min folowed by sowing.

neem products like neemacin and neemacide can be used as insecticide.
take 2-5ml/l water and spray during insect/pest infestation.