Improving flowering of sugarcane for breeding progress and prospects

Flowering of parental germplasm at BSES Meringa is variable and moderate. Consequently, genetic improvement of the Australian sugar industry cannot be fully effective. This paper summarizes field and photoperiod facility (PF) research conducted to resolve this problem. Regulated field irrigation improved flowering, but under high temperature conditions adequate soil moisture was not a sufficient condition for flowering. Research failed to explain two aberrant flowering effects. Initial PF research produced variable results suggesting uncontrolled variables in photoperiodic regimes and/or plant management. A far-red canopy treatment· at the beginning of the dark period, or imposition of a dark break during the day, failed to increase flowering. Recent PF research yielded excellent induction levels, particularly during cooler periods. Misting to maintain canopy temperature <30°C produced poor and variable induction. Staged exposure of plants to temperatures >35 °C during induction suggested photoinduction sensitivity. Duplication of PF facilities to produce a majority of required panicles is dependent upon verification of research results. Operating PFs twice yearly will reduce output costs, but a timing offset from natural induction may be necessary until high-temperature inhibition of photoinduction is fully understood and management strategies developed.