Sowing Date and Hybrid Choice Matters Production of Maize–Maize System

Abstract

Maize can be sown in spring and fall seasons in Pakistan under maize–maize cropping system. Due to seasonal variability in meteorological parameters, optimization of planting time for maize hybrids is vital to harvest improved productivity in maize-maize system. This study was designed to explore the effect of diverse sowing dates on phenology, growing degree days (GDDs), photo-thermal-units (PTUs) and helio-thermal-units (HTUs), and its impact on radiation-use-efficiency (RUE) and grain yield (GY) in different maize hybrids under maize-maize cropping system. Two-year experiments were conducted to optimize planting dates for hybrids during 2016 and 2017. In spring, three hybrids were sown on Jan 15, Feb 5, Feb 25, Mar 15 and Apr 05. During fall, three hybrids were planted on Jun 15, Jul 05, Jul 25, Aug 15 and Sept 05. Results showed that spring early (Jan 15), while fall late (Jul 25) sowing took more days to complete 50% tasseling, silking and maturity. However, maize sown on Feb 05 and Jul 25 accumulated more GDDs to attain 50% tasseling, silking and maturity. Maize sown on Feb 05 and Jul 25 had more leaf area index (LAI), crop growth rate (CGR), RUE and GY, which was linked with higher accrual of GDDs, PTUs and HTUs. Likewise, hybrids P-33M15 and P-30R50, during spring and fall observed higher values of all above cited traits. Moreover, positive-correlation was witnessed among days taken to complete different phenophases, LAI, CGR and 1000-grain weight, total biomass, GY and RUE. However, higher GY and RUE was obtained in spring than fall. In conclusion, maize sown on Feb 05 and Jul 25 using hybrids P-33M15 and P-30R50, during spring and fall crops, respectively produced more GY and higher RUE due to more accumulation of GDDs, PTUs and HTUs. Thus the spring season seemed more productive than fall season under maize-maize cropping system.