SUGARCANE (SACCHARUM SPP. HYBRIDS) RESPONSE TO SIMULATED FALLOW FIELDRESIDUES OF METRIBUZIN AND SULFOMETURON

Sulfometuron at 17 g ai/ha in the planting furrow (13% of the anticipa ted fallow-field application rate) inhibited sugarcane emergence and d evelopment and ultimately reduced sugar yields in the initial producti on year by 13% when compared to a weed-free control that contained no herbicide in the planting furrow. Residual levels of metribuzin in the planting furrow representing 100% of the standard fallow-field applic ation rate of 1,680 g ai/ha had no adverse effect on sugarcane develop ment or sugar yield. When applied only to the soil surface immediately after planting, sulfometuron did not injure sugarcane, and sugar yiel ds were equivalent to standard, at-planting, preemergence (PRE) applic ations of either metribuzin at 2,020 g/ha or a mixture of pendimethali n plus atrazine each at 2,240 g ai/ha. To minimize sugarcane injury, s ulfometuron should be kept out of the germinating zone of lateral buds along planted sugarcane stalks.