South African Sugarcane Research Institute, P/Bag X02, Mount Edgecombe, South Africa
Van Heerden, P.D.R., South African Sugarcane Research Institute, P/Bag X02, Mount Edgecombe, South Africa
Information from Brazil and Australia indicates that trinexapac-ethyl (Moddus®) is an excellent new sugarcane ripener. However, there is no information on the response of South African varieties to this chemical. The objective of this investigation was to establish the ripening potential of this chemical in local varieties and to compare responses with the current industry standards, Ethephon® and Fusilade Forte®. Evaluation was conducted in drip irrigated plant crops of N27 and N32 at Heatonville and Pongola respectively. Each trial was laid out in a complete randomised replicated design. Ripener treatments comprised (a) untreated control, (b) Ethephon® applied 84 days before harvest (DBH), (c) Fusilade Forte® applied 43 DBH, (d) Moddus® applied at two rates 70 DBH, (e) Ethephon® and Fusilade Forte® applied as a combination treatment, and (f) Moddus® (at two rates) and Fusilade Forte® applied as combination treatments. At Pongola the various treatments improved estimated recoverable crystal (ERC) yields in N32 by between 1.0-4.3 t/ha compared with the control. Best results were achieved in the combination treatments. However, the two Moddus® -Fusilade Forte® combination treatments outperformed the standard Ethephon®-Fusilade Forte® combination treatment by 1.0 t ERC/ha. At Heatonville ripener responses in N27 were smaller with improvements ranging between 0.5-1.0 t ERC/ha and without clear treatment differences. These preliminary results indicate that Moddus® is an effective ripener and that a Moddus® -Fusilade Forte® combination treatment could increase ERC yields considerably more than current industry standards. Results will be verified in the first ratoon crops at both locations.