The irrigation planning and Management either at field, water course, sub-canal or main canal level requires the information of crop evapotranspiration. The estimation of the crop water requirement or crop evapotranspirations requires the information of reference evapotranspiration (ET0) and crop coefficient (KC) for different stages of crops. The sizable research has been done to determine the crop evapotranspiration (ETC) and crop coefficient (KC) using the Lysimeter instrument. However, a few attempts have been done in world on the ETC and KC measurement using the Canopy Chamber. An attempt was done to collect the past work relevant to ET0, ETC, Lysimeter and KC. From these reviews, it can be said that the Penman- Monteith (PM) equation reveales the most accurate one. Therefore,in this research work the well proved Penman-Monteith equation has been used as standard method to compare the different empirical methods. The Weighing type Lysimeters has been developed for measurement of

crop evapotranspiration. However, there are some limitations in using the Lysimeter. The higher initial cost, regular maintenance and complex construction of the instrument restricts its use on field-scale. It can be used for only single crop in one season. For avoiding such problems, canopy chamber method has been developed for measuring crop evapotranspiration. However, very few studies have been conducted on development of automatic closed canopy chamber for evapotranspiration measurements. Crop coefficient of some important crops is not given in FAO-56 guideline; therefore, it is very necessary to develop region specific stage-wise crop coefficient of field crops. The main objective of the paper is to provide an overview of recent research in development of closed canopy chamber for evapotranspiration measurement. The study done in the areas during the last few years has been reviewed from the national and international research works. The application of artificial intelligence in development of automatic closed canopy chamber has been also taken into account 

Highlights

• Accurate estimation of crop evapotranspiration (ETC) is essential for effective irrigation planning and management at various levels (field, water course, sub-canal, or main canal). This requires data on reference evapotranspiration (ET0) and crop coefficients (KC).
• The Penman-Monteith (PM) equation has been identified as the most accurate method for estimating crop evapotranspiration and crop coefficients, and it is used as a standard for comparing empirical methods.