Herbicides Roundup (Glyphosate) and Paraquat (Gramoxone) as chemical ripeners for sugarcane variety SP70-1143 (A case study at Debel Khozaie Agro-Industrial Co.)

Abstract

In the Khuzestan province of Iran, sugarcane harvesting is normally carried out between the early November and March periods, when rain and frost risks occur. This results in delayed harvesting and reduced profitability due to cane deterioration and a reduction in cane sucrose content. Management strategies such as the application of chemical ripeners were hypothesized to tackle such challenges by harvesting the crop earlier when the natural ripening condition was poor. Consequently, paraquat and roundup herbicides were applied as chemical ripeners to investigate the effect of their application time and rate on accelerating the ripening quality of the sugar cane variety SP70-1143 using a split-plot design. The treatments were control (unsprayed) [T0]; 1.0 Lha<sup>−1</sup> Paraquat (250 ppm) applied 8 weeks before harvesting (8WBH) [T1]; 0.8 Lha<sup>−1</sup> Roundup (200 ppm) applied 8WBH [T2]; 1.0 Lha<sup>−1</sup> Paraquat (250 ppm) applied 5 weeks before harvesting (5WBH) [T3], and 0.8 Lha<sup>−1</sup> Roundup (200 ppm) applied 5WBH [T4]. The results indicated that the glyphosate application treatments T2 and T4 induced a significant improvement in the sugarcane juice quality through an increase in Brix%, Pol%, %purity, and commercial cane sugar (CCS%) starting 1 week after their application. The results also confirmed the feasibility of an earlier harvesting operation on November 1st, one month before normal harvesting time in the study area, without significant loss of sucrose by application of 0.8 Lha<sup>−1</sup> Glyphosate (roundup), 8WBH.