Manipulating maize genetics and agronomy for improved yield and reliability in northern NSW – Gurley 2017/18

Abstract

Key findings •Early planting into a soil temperature of 10 °C, which is lower than the recommended 12° C at this site in this season, did not affect plant establishment. Further research is needed to validate these results and allow for consideration of the affects in different seasons when frosts can occur around sowing. •Harvest index (HI) was highest from the earliest sowing date (SD) – the beginning of August. •There was little effect from hybrid or plant population on harvest index at SD1 (2 August) or SD2 (22 August). In contrast, differences in HI resulted from varying plant populations at SD3 (17 October), with the results varying between hybrids. •There was an interaction between plant population and SD for yield. •The earliest SD produced the highest yields. Two of the hybrids, Pioneer® P1467and Pioneer® P1756 were unresponsive to varying plant population. In contrast, PAC 606IT produced the highest yields when its population was 44,000 plants/ha. •The third SD suffered from heat stress during the critical growth stages of pollination and grain fill, producing the lowest yields.