The accumulated growing degree days (GDD) were also workout for phenological stages in three dates of sowing under irrigated and unirrigated conditions. It was found the growing degree days (GDD) were higher in irrigated condition as compare to unirrigated condition in all the three dates of sowing. This is because the duration of the crop under irrigated condition was higher than in unirrigated condition. The average maximum temperature under D1 in the germination to grand growth stage is higher in the first date of sowing. However, later on that is from grand growth to bud formation the maximum temperature is higher in D1 as compare to D2 and D3 both in field as well as observatory data.

The average minimum temperature in the first date of sowing varied from 21.6 0C to 11.5 0C under different phenological stages based on observatory data. While in the field data it varied from 21.0 0C to 10.8 0C during different growth stages. In the second date of sowing the minimum temperature based on observatory and field data varied from 24.1 0C to 9.9 0C and 16.5 0C to 9.4 0C in different growth stages. In the third date of sowing the minimum temperature varied from 10.7 0C to 17.2 0C and 10.3 0C to 16.30C in different growth stages based on both observatory as well as field data.

Correlation coefficient between different weather parameters based on field as well as observatory data revealed that the temperatures in the field data and observatory data are highly correlated but the relative humidity between field and observatory is not well correlated. This shows higher moisture status in the field as compared to observatory.

The accumulated growing degree days (GDD) for different sowing environment conditions varied considerably from sowing to maturity. The highest growing degree days (GDD) were found from pod development to physiological maturity. As per the observatory data, the growing degree days (GDD) in the stage varied from 527 to 691 degree days under irrigated condition. Under unirrigated condition the growing degree days (GDD) varied from 456 degree days in the first date of sowing to 522 degree days in second date of sowing. While in third date of sowing the growing degree days (GDD) under unirrigated condition were 424 degree days. Thus, the GDD during pod formation stage were less under unirrigated condition than in irrigated condition. This is because of faster physiological maturity at all the dates of sowing under unirrigated condition. Similarly for 50% flowering to pod development stage also the growing degree days (GDD) were less under unirrigated condition in the first date of sowing. In other dates of sowing the growing degree days (GDD) under irrigated condition were higher than unirrigated condition.

Same pattern was observed in case of field data also. The total growing degree days (GDD) under irrigated condition based on field data varied from 4080 degree days under D1, 3062 degree days under D2 and 3086 degree days under D3 conditions. In the same pattern the total degree days under unirrigated condition were from 1139 under D1, 1246 degree days under D2 and 1069 degree days under D3 conditions.

The total number of helio thermal units (HTU) varied from 10466 under D1 to 10100 under D2 conditions. In case of D3 the value of helio thermal units (HTU) was highest (11376). In case of unirrigated conditions the helio thermal units (HTU) values were 9164 under D1, 9334 under D2 and 8048 under D3 conditions. Similarly in the third date of sowing the total helio thermal units (HTU) were 10057.