Modeling the effect of transplanting on yield and water use of cotton under Gorgan condition

In order to simulate transplantation, the parameters related to cotton seedling growth are firstly measured in a factorial experiment in a randomized complete block design at Gorgan University of agricultural sciences and natural resources within 2018. The parameters are then utilized in SSM-iCrop2 Model. In the simulation section, four seedling size based on the leaf area (namely 17, 22, 27, and 37 cm-2 per plant) are evaluated in 4 planting dates (15 June, 1 July, 15 July, and 30 July). Results show that in early planting date, seedling transplantation rushes the process of crop maturation for 43 to 49 days. However, this has had no significant effect on yield values (from 453 to 461 g/m2) and net water requirement (312 to 316 mm). The usual sowing date causes the crop to mature between 27 and 38 days (earlier vacant land), whereas seed sowing at this planting date impairs the subsequent crop cultivation. At this planting date, as in early planting, transplanting has no strong effect on the yield (from 444 to 452 g/m2) and water requirement (299 to 308 mm). In a late planting date, seedling transplanting with four seedling sizes between 1 and 5 days results in premature seed germination, even though seed cultivation impairs subsequent planting. At this planting date, transplanting has a noticeable effect on the yield (361 to 441 g/m2), but the amount of pure irrigation (271 to 300 mm) remains unaffected by transplanting.