Effects of sowing date on the growth and yield of maize cultivars (Zea mays L.) and the growth temperature requirements
A field experiment was conducted to analyze the relationship between growing degree days, yield and yield components of maize cultivars. Five maize cultivars (SC 108, SC 301, SC 604, SC 704 and TVG) were sown on four different dates during summer in a randomized complete block design with split plot arrangements with three replications. Maize cultivars exhibited significant differences on yield, weight of 100 seeds, biological yield and harvest index. The best hybrid SC 704 accumulated growing degree days (GDD) and was the highest for seed yield and all yield components. The plant sown on 5th August, accumulated suitable GDD and produced the highest seed yield, biological yield and harvest index. Generally, 5th August plantation accumulated more suitable GDD in comparison with the other sowing dates (6th July, 21st July and 20th August), as such, it exhibited higher seed yield, biological yield and harvest index. The results show that SC 704 had the highest biological yield, seed yield and harvest index. This hybrid received the highest quantity of GDD as compared to other cultivars thus, suggesting the use of SC 704 and sowing on the 5th of August in Sistan region.
Keywords: Growing degree days, harvest index, seed and biological yield, sowing date