Transformational agronomy by growing summer crops in winter: northern NSW

Abstract

Grain sorghum yield is often reduced by heat and water stress during critical growth stages around anthesis when planted in the traditional sowing window. Sorghum sown during late winter or early spring can flower before these stresses develop, though reduced plant establishments due to sub optimal soil temperatures and the likelihood of frost damage need to be managed. Two years of experiments at Mungindi, Moree and the Liverpool Plains in Northern NSW compared sowing time effect on plant establishment, date of anthesis and grain yield. Sorghum can be established in sub-optimal temperatures (<16°C) if seedbed moisture is available but losses of 10-30% need to be factored into sowing rates. The overlap between flowering and heat stress was minimised by ‘winter’ or early spring sowing. Grain yield was maintained or improved by planting earlier compared to traditional sowing times.