47th TWC, Tob. Work. Conf., 2016, abstr. 23

Comparison of sucker control methods for dark fire-cured tobacco

PITT W.D.; BAILEY W.A.; SIMS B.D.; WALKER E.R.
University of Tennessee, Springfield TN USA

Dark tobacco is known to be have more vigorous sucker growth than burley tobacco, and is also more prone to crooked stalks and lodging from wind damage, which makes chemical sucker control more difficult. Standard dark tobacco sucker control programs are still based on manual stalk rundown applications of contact fatty alcohols and local systemics made with drop line applicators or backpack sprayers. These manual application methods require between 15 and 20 man-hours of labor per acre depending on the condition of the tobacco. A major focus of dark tobacco sucker control research has been to find improved methods to mechanically apply suckercides to reduce these labor requirements, and also find best use practices for maleic hydrazide (MH) in dark tobacco. Unlike other types of tobacco grown in the U.S., dark tobacco sucker control programs do not rely on maleic hydrazide (MH). Although MH use has increased in dark tobacco in recent years, its use is still limited and it is a secondary component of dark tobacco sucker control programs. When MH is used close to topping as is standard in burley tobacco, excessive yellowing of upper leaves and potentially lighter colored cured leaf can result. Research has shown that if MH application is delayed until no sooner than 5 days after final topping, and a reduced rate of MH is applied at that time (1.88 lbs MH per acre for dark tobacco instead of the standard 2.25 lbs MH per acre used for burley tobacco), marketable leaves will show minimal or no effects of MH application. However, this delay in MH application requires that at least two applications of other suckercides still be made before MH is applied. This presentation will summarize 12 years of dark tobacco sucker control research that has been conducted in Kentucky and Tennessee. (Reprinted with permission)