The concept of multiple cropping index was proposed by: (RJ AARO Agronomy 2014)

✅Explanation:
Dalrymple is widely recognized in agricultural studies for his work on multiple cropping indices.
Multiple cropping is the practice of growing two or more crops in the same piece of land during a single growing season. It helps to harvest as much as possible from the limited land resources provided other resources required for crop production are effectively utilized.  

🔴Additional information::
-Single crop: This refers to growing the same type of crop on the same land year after year.
-Intercropping: This involves growing two or more crops simultaneously on the same land, but it doesn't necessarily involve sequential planning in succession or changing the crops year after year.
-Mixed farming: This refers to integrating livestock raising with crop production on the same farm.