Yield components:

Components which finally make up or control yield of any crop. For example, yield components of cereal grain yield are grain weight per grain number/ear, ear number/plant and plant number/unit area.

Yield evaluation:

Yield evaluation is the estimation of yield per hectare of principal crops. It is conducted by the Bureau of Economics and Statistics in collaboration with the state departments of agriculture. The process of yield evaluation is through a systematic survey. Yield is estimated by harvesting threshing, cleaning and weighing a measured sample area. The size of the sample area depends on the uniformity of the stand of the crop. If it is quite uniform, the field is divided into 4 quadrants. A sample of 1 metre is then taken per quadrants. A sample of 1*1 metre is then taken per quadrant as also from the central section of the field. Sometimes, the harvested crop from all 5 areas of the field is mixed together, the yield is then estimated from this sample. If the stand is uneven then two samples of 1 m * 1 are taken from each class. Two from the good patch, two from the moderate patch and two from the poor patch. The yield is then estimated from the sample.

Yield potential :

Full production capacity of crop.

Yield stability :

The maintenance of yield at desired level over a period of time. Its index is measured by inverse of coefficient of variation, regression between yield and environmental index and disaster level estimated by probability of a system.