Investigation and prediction of maize water requirements in four growth stages under the influence of natural factors (Case study: Qazvin plain, Iran)

Abstract

Since maize water requirement is different at different growth stages, so prediction and extraction of association rules related to water requirements of the plant were performed separately at initial, development, mid, and late season growth stages. Accordingly, information on water requirement of maize during 20 years (2000–2019) in Qazvin plain was used. First, the results of C5.0, CART, CHAID, and QUIST algorithms related to corn water demand forecast were evaluated. According to the results, CART algorithm at the initial growth stage and C5.0 algorithm at the development, mid and late season stages of growth, had the best performance in predicting water requirements of maize. The factors of air humidity and precipitation were the most important factors in predicting water requirements of maize at the initial stage of growth by CART tree algorithm. Also, according to the results of C5.0 algorithm, it was found that at the development and mid-season growth stages, precipitation and air temperature were the most important, while at the late season stage of growth, the two factors of sunny (sunshine) hours and wind speed were most important in predicting plant water requirements. Finally, using Apriori algorithm, association rules between water requirements and the factors affecting it were extracted at four growth stages of maize. The results of association rules were evaluated by indicators of confidence, support, and lift. According to the results of Apriori algorithm, precipitation at the initial and development growth stages as well as air temperature and wind speed factors at the mid and late season stages of growth, respectively, had the greatest relationship with water requirements of maize.