Effects of maleic hydrazide and flumetralin on residues, yield, quality, and chemical content of Maryland tobacco
Various application rates of maleic hydrazide (MH) and flumetralin were investigated to determine the effects of these chemical treatments on yield and quality factors of Maryland tobacco, and to determine MH residue levels on the cured leaves. High-clearance sprayers were used to simulate farm practices. The recommended rate of MH (2.5 kg/ha) resulted in significantly lower MH residues than the double rate (5.0 kg/ha) or two applications of the recommended rate one week apart. The quality index (Q.I.) and value/ha of the tobacco from the plots treated with the recommended MH rate also were higher than for the double rate or two applications of the recommended rate. Treatments with flumetralin alone (2.5% solution) and a tank mix of flumetralin (1.25% solution) and MH (1.7 kg/ha) significantly reduced MH residues. However, these treatments produced significantly higher percentages of green (G) end greenish (V) colors in the cured leaves two out of the three years of this study.