The effect of some of growth stimulants and different amounts of chemical fertilizer on yield and yield components of maize

In order to evaluate the effect of different plant growth stimulants and different amounts of chemical fertilizer on yield and yield components of corn, a field experiment with factorial arrangement of treatments based on randomized complete block design with three replications and 21 treatments was conducted at research field of Soil and Water Research Institute (SWRI), Karaj, Iran, during 2019. The studied factors included different amounts of fertilizer (application of 100% fertilizer required by the plant, application of 75% fertilizer required by the plant, and no fertilizer (control)) and different growth stimulants (foliar application of amino acid, foliar application of seaweed, humic acid irrigation fertilizer acid, foliar application of fulvic acid, foliar application of humic acid, humic acid irrigation fertilizer + Foliar application of seaweed + amino acid, and no growth stimulants (control)). Treatments of 100% application of chemical fertilizer and humic acid irrigation fertilizer, 100% chemical fertilizer application with a combination application of humic acid irrigation fertilizer + seaweed foliar + amino acid foliar, and 75% chemical fertilizer application with seaweed foliar application, respectively 27.57, 24.60, and 23.83% produced higher grain yield than the control. According to the results of this experiment, the use of seaweed not only improved the yield but also reduced the use of chemical fertilizers required by 25% without reducing the yield of the plant. Therefore, the use of seaweed foliar application is recommended.