Conveyor use for suckercide application in North Carolina Burley tobacco production
In 2011, conveyors were introduced to the US market for use in chemical sucker control programs. Due to focused application and coarse droplet size, it was initially thought that conveyors might assist in reducing maleic hydrazide (MH) residues, reduce total solution output per hectare, and allow for material application in windy conditions. Research was conducted in 2011 and 2012 to quantify the effect of conveyor use with various combinations of MH and flumetralin in comparison to current practices used by many producers. Two rates of MH (1.68 kg a.i./ha and 2.25 kg a.i./ha) were tank-mixed with one rate of flumetralin (0.67 kg a.i./ha) and applied using a standard three-nozzle boom or a conveyor. In addition, two rates of MH (2.25 kg a.i./ha and 3.36 kg a.i./ha) served as comparison treatments for practices commonly used by many producers. Treatments were imposed at two locations in North Carolina in a randomized complete block design and replicated four times. In general, sucker control was consistently greater than 95% at all locations with all combinations of treatments. Therefore, sucker control was not improved beyond what is consistently achieved with the standard three-nozzle boom. In addition, MH residues do not appear to be influenced by application equipment, as residues were not different when equipment types were directly compared at the maximum labeled rate. Based upon this research, as well as similar results reported in flue-cured tobacco, it does not appear that conveyor use facilitates improvement in sucker control under ideal application and environmental conditions nor do the implements provide means to consistently reduce MH residues.