Residue Content of Sugarcane Ripener Active Ingredients and Its Effect on Ratoon’s Growth in North Sumatera

The degree of sugarcane ripening is a vital parameter determined by measuring sucrose accumulation in sugarcane stalks. The constraints related to the degree of maturity that affect the quality of sugarcane in milled raw materials can be improved by applying sugarcane ripeners (SRs). However, some SRs are made from herbicides that could affect the subsequent ratoons. This study aimed to determine the effects of SRs on ratoon growth in sugarcane. The study was conducted in several plantations in North Sumatera. SRs were applied in December 2022, and the ratoons were observed in May 2023. The study used a split-split plot design with 3 treatment factors: variety (PS 881 and BZ 134), SRs application method (by drone and manual), SRs active ingredients (glyphosate, glyphosate plus Boron, and no spraying/control). The parameters observed were the number of shoots per row, the increase in gap, and the glyphosate residue in the subsequent ratoons. The results indicated a significant interaction between the application method, SRs’ active ingredients and the varieties and effects of SRs on the number of shoots per row. For PS 881, the drone and glyphosate application method showed the lowest number of shoots per row. The increase in the gap and fewer shoots per row was more common with drone spraying than manual spraying. Application of SRs using drones resulted in the highest residue in PS 881 compared to the other treatments.