Evaluation of glycine betaine and methanol on maize (Zea mays L.) yield and nutritive value in different planting dates

Appropriate planting dates are one of the most important factors in determining the yield potential of crops, and the use of methanol and glycine betaine increased plant growth, especially in delayed cultivation. For this purpose, a factorial research was carried out in the form of a completely randomized block design with three replications in two years (2020–2021) in Sari, Mazandaran, Iran, on maize as a second planting after rice harvest. Treatments included glycine betaine at three levels [0 (control), 1, and 2 ppm], methanol at three levels [0 (control), 10, and 20% v/v], and three planting dates: [August 6, 16, and 26]. The results illustrated that the application of methanol and glycine, as well as increasing the concentration of methanol (20% v/v) and glycine betaine (2 ppm), improved the yield and forage quality of maize. The delay in maize cultivation (August 26) decreased the yield and forage quality of maize. The best planting date for corn cultivation was August 6. Foliar spraying of methanol and glycine reduced the negative effects of delayed planting dates compared to the control. Methanol 20% v/v + glycine betaine 2 ppm on the planting date of August 6 raised dry matter yield (655%), WSC (190.75%), DMD (21%), ADF (50.32%), and NDF (39%) compared to the control of methanol and glycine on August 26. Overall, in order to achieve maximum yield and forage quality of maize, foliar spraying of methanol 20% v/v along with glycine 2 ppm on the August 6 planting date is recommended.