Distinct kinds of crops possess distinct needs to grow well. Some of the plants like to grow in the humid and hot environment, while the others grow well in winter. Some of the crops strictly need monsoon for their development, on the other hand, some get destructed in the presence of rainfall.
The crops like rice grow well in humid and hot climate, thus they are grown in a monsoon at the time when the humidity is at its maximum with plenty of rainfall. On the other hand, in the case of wheat, dry and clean climate with less temperature is needed.