Investigating and matching the stages of plant growth with growth degree day index (GDD) based on the native phenology information of Wheat, fodder Corn and Sugar beet in water requirement system (NIAZAB)
Subject Areas : Crop Production Researchآرش تافته 1 * , Niyaz Ali EbrahimiPak 2
1 - موسسه تحقیقات خاک و آب
2 - Faculty members of Irrigation Department, Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran.
Keywords: Growth day degree (GDD), Growth stages, Phenology period, Temperature, Wheat,
Abstract :
The growth degree day (GDD) plant index is one of the most important plant models in determining plant growth periods; Therefore, extensive research is done in this field. This parameter is a climatic-plant characteristic. The relationship between plant growth and temperature is very important for calculating GDD. In this study, according to the creation of the local phenology database plants, it was loaded into the water requirement system. Using climatic data and the latest methods for determining GDD, which were presented in 2008, GDD values for wheat were calculated and its sub-system was completed and loaded into the system after verification. The results showed that the data of GDD and native growth periods have a good compatibility with each other and the values are completely different and unique for each region. Also, very good relationships were obtained between the plant coefficient and the water requirement of different plants with the GDD index, some of which were mentioned in this report. For example, the GDD index with the Kc coefficient in the evaluation showed that this model has performed very well for wheat, fodder corn and sugar beet with the model efficiency index of 78, 78 and 95% respectively and with an error of about 8, 9 and 6% respectively. It has an acceptable performance; Therefore, by using this index in stations without sufficient data, this index can be used to estimate the transpiration evaporation coefficient of plants. Also, the results of the water requirement investigation showed that the model for wheat, fodder corn and sugar beet plants has an efficiency of 98, 98 and 99%, respectively, and the cumulative water requirement can be calculated with an error of 2, 5 and 4%.