Lower‐Leaf Removal and Nitrogen Application Programs for Flue‐Cured Tobacco Production

Abstract

Core Ideas Lower‐leaf removal will reduce cured leaf yield but can reduce the portion of lower‐demand stalk positionsNitrogen application after leaf removal is of limited value and is currently discouragedIf these programs are to find commercial success, a higher selling price should be offered by leaf purchasers With a current global over‐supply of flue‐cured tobacco (Nicotiana tabacum L.), tobacco producers in North Carolina have been encouraged to remove the lowermost leaves prior to harvest due to their low value in manufactured products. The objective of this research was to compare lower‐leaf removal programs. Research was conducted in 2016 and 2017 to quantify the agronomic effects of three lower‐leaf removal programs (0, 4, and 8 leaves plant−1) and the subsequent delivery of four N application rates (0, 5.6, 11.2, and 16.9 kg N ha−1 above base recommendation). All treatments combinations were applied during the early flowering stage of growth (8–10 wk after transplanting), when plants were approximately 120 cm tall. Programs absent of leaf removal generally produced the highest cured leaf yield. The addition of 16.9 kg N ha−1 increased yield when compared to lower N application rates within the 4‐leaf removal program. Nitrogen application did not affect yield in the 8‐leaf removal program. Cured leaf value was greatest in the 0‐leaf removal program (USD $10,131 ha−1) and was reduced in the 4‐ and 8‐leaf programs by $1611 and $2645 ha−1, respectively. Lower‐stalk positions were nearly eliminated in the 8‐leaf removal program, while the 4‐leaf removal program reduced their presence by more than 50%. Ultimately, if these programs are to be encouraged or required by industry, the removal of four leaves per plant proved to be more practical when paired with additional N, due to moderate yield reduction and lower‐stalk leaf production.

Climatic factors determine the yield and quality of Honghe flue-cured tobacco

“…In this study, the proportions of superior middle tobacco and superior tobacco were 91.18–95.83% and 62.19–73.29%, respectively, which is above the theoretical maximum proportion of superior tobacco (60%) 39 . A previous study demonstrated that the removal of four leaves per plant results in a moderate yield of flue-cured tobacco during the tobacco growing season 9 . In this study, the number of left leaves of K326 and the proportion of superior tobacco were higher, whereas the yield and economic value were lower, while the results of the Hongda cultivar were the opposite; this may indicate that the Hongda cultivar is more suited to the Honghe tobacco-planting area.…”

“…Finally, agronomic practices affect the yield and quality of flue-cured tobacco 5 , 9 , 23 , 44 , 51 . No special agronomic practices have been adopted at the flue-cured tobacco-planting sites sampled in this study.…”

“…Tobacco can adapt to a wide range of conditions but is very sensitive to the environment. The quality of tobacco is related to various factors, including the climate 4 , 5 , crop rotation patterns 6 , 7 , soil properties 8 , 9 , and soil microbes 10 , 11 . The natural environment is the ecological basis for the development of high-quality tobacco leaves.…”

Impacts of lower‐leaf removal timing, number, and nitrogen application to flue‐cured tobacco

“…Row spacing at the Lower Coastal Plain and Oxford Tobacco Research Stations was 44 and 48 in, respectively, and tobacco was transplanted to a density of 6,000 plants/ac. Tobacco was produced using recommendations from the North Carolina Cooperative Extension Service (Fisher, 2016), with the exception of treatments imposed.…”

“…Fisher, Vann, Inman, and Brown (2016) and Finch et al. (2019) suggested that the removal of eight leaves might be required to eliminate lug grades of flue‐cured tobacco.…”