MANAGEMENT OF AXILLARY SHOOT GROWTH AND MALEIC HYDRAZIDE RESIDUES WITH DIFLUFENZOPYR IN FLUE-CURED TOBACCO (NICOTIANA TABACUM)

Abstract Maleic hydrazide (MH) controls axillary shoot (sucker) growth in tobacco and is used on more than 90% of the tobacco acreage in North Carolina. Residues of MH on flue-cured tobacco often exceed residue limits set by foreign purchasers of U.S. leaf. Research was conducted at the Central Crop Research Station (CCRS) near Clayton, NC and the Border Belt Tobacco Research Station (BBTRS) near Whiteville, NC in 2003 and 2004 to evaluate diflufenzopyr, (2-(1-[([3,5-difluorophenylamino] carbonyl)-hydrazono}ethyl)-3-pyridinecarboxylic acid) (BAS 654 H and BASF 131) for the control of sucker growth. Diflufenzopyr was evaluated alone and in tank mixtures with the registered rate of flumetralin, and registered and reduced rates of MH. Treatments were arranged in a factorial design with MH at four rates (0, 0.6, 1.3, and 2.5 kg ai ha−1), flumetralin at two rates (0 and 0.7 kg ai ha−1), and diflufenzopyr at two rates (0 and 0.017 kg ai ha−1). All treatments were applied approximately ten days after the removal...