Apart from the past use of non-flowering cultivars, there has been few reports on the use of low sucker growth varieties to help reducing the sucker control agent residues in flue-cured (FC) tobacco.

Among various FC cultivars and lines with no short photoperiod requirement, the upper stalk sucker growth propensity was investigated in a three steps approach, at Bergerac (France), in 2009 - 2014:

1. Defining the trait to be assessed,
2. Studying its variability among genotypes through different environments,
3. Testing sucker control strategies using “early” and “late” sucker producer genotypes, relative to floral growth.

Fatty alcohols may control suckers smaller in size than approximately 3 cm. Therefore, the size of the biggest sucker in a given plant was considered, rather than their number or weight. Sucker control treatment dates are based on the floral growth stage of the crop. Then, for a given plant and a given observation date, the biggest sucker size and floral growth stage were recorded.

Field trial data indicate that a significant genetic variability is available for the timing of sucker growth, relative to floral growth, in flue-cured tobacco. Plant population, stalk bent due to wind and CMV infections also have dramatic impact on upper stalk sucker growth.

Selected “late” and “early” sucker producer genotypes, relative to floral growth, were tested under a sucker control schedule based on fatty alcohols only. The “late” genotype was successfully controlled up to 14 days after topping, whereas the “early” was not.

Links between the “late sucker producer” trait, alkaloid content and plant shape are to be investigated, in particular to better estimate the possibility of designing aromatic flue-cured cultivars with this trait. (Reprinted with permission)