Some indicators like moisture content and black layer are used but the precision seems a problem. If someone has a good information; the same may please be shared.
Thank you dears Samota and Ferdinand. Dear Ferdinand; did you mean the direction of panicle of rice towards ground or lodging or some thing else? Please give some detail.
Because of the heaviness of the panicle the plant cant stand erect, when see this farmers used to say the paddy is ready to harvest . If will get more information and give you after two days.
Physiological maturity is attained a few days earlier than the crop ready for harvesting when plant stops to continue its physiological processes. Is there any analysis or process to judge the same?.
In the case of wheat, the lost of the greenes by the spike and peduncle is the visual indicator. This can easily be evaluated by the human eye, The most important point is to calibrate your eye to be accurated.