If safe storage is to be ensured, the moisture content of foodgrains at the time of harvesting should not be higher than

Safe long-term storage of foodgrains requires low moisture to limit insect and fungal activity; practical guidance and safe-storage charts place the desirable harvest moisture around the mid-teens or lower. A simple field test and guidance note imply that moisture below about 15% is considered dry for storage handling [1]. Safe-storage tables demonstrate markedly longer allowable storage when moisture is reduced from 17% to 15% (e.g., corn safe storage days rising from 88 to 275 at the same temperature), showing the importance of keeping moisture near or below mid-teens for safe storage [2]. Crop-specific guidance (e.g., field peas) recommends safe storage between 12–16% moisture, supporting 14% as an appropriate upper limit for general foodgrains.

Sources

1. [1] https://www.fao.org/4/i2433e/i2433e10.pdf
2. [2] https://www.uaex.uada.edu/publications/pdf/FSA1058.pdf