Effect of heat stress during anthesis on the Summer Maize grain formation: Using integrated modelling and multi-criteria GIS-based method

Dealing with high temperatures during the anthesis stage is an important factor that can affect summer maize. Here, the possibility of heat stress injury (HSI) in the summer maize-grown fields of Golestan province was investigated. A multi-criteria weighted overlay procedure was used to determine the suitability of arable land for maize cultivation. Using the CERES-Maize model and long-term meteorological data, the map of the days with Tmax > 35 degrees C from three days before to seven days after anthesis was provided. The results showed that the irrigated corn fields in the study area have suitable degrees for corn cultivation and different conditions in the field of HSI experience around pollination. Although most of the fields were located in highly suitable areas, probable HSI (as described by PDT35) affected the final suitability. Also, more reliable sowing dates were introduced. The results revealed that on 18th of June, maize could be sown at all suitable areas except in some arable lands of Kalaleh where the PDT35 was more than 40%. The results showed that HSI should also be considered around the pollination stage to obtain reliable results from land suitability.