HI SIddharth,
1. Generally there is no any recommondation for taking intercrops in banana as there is always humid climate in banana orchard.
2. There is limited air and sunlight between banana plants.
3. Banana is heavy feeder crop. It is having shallow root system. It requires regular application of fertilizers both organic and inorganic.
4. Possibility of disease spread is more under humid conditions hence most of farmers donot prefer any intercrop in banana.
5. Onion for seed production is found suitable intercrop in banana at verious locations.
6. Cultivation of intercrops found beneficial after cutting of bunch from the plan.
&. After the bunch is removed you can inter crop with radish, yam, spinach.
REgards
Ashiwni S