Apart from the past use of non-flowering cultivars, there have been few reports on the use of low sucker growth varieties to help reduce 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 (USG) propensity was investigated in a three step approach at Bergerac (France), from 2008-2014:

1. Defining the trait to be assessed,
2. Studying its variability among genotypes through different environments,
3. Testing sucker control strategies using « high » and « low » USG genotypes.

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 flowering stage of the crop. Then, for a given plant and a given observation date, the biggest sucker size and flowering stage were recorded.

Field trials data indicate that a significant genetic variability is available for USG in flue-cured tobacco. Filler flue-cured lines, with early leaf maturity, of “European” origin, tend to be “low” compared to later maturing lines. Plant population, stalk lodging and virus infections also have dramatic impact on upper stalk sucker growth.

Selected low and high USG genotypes were tested under a top sucker control schedule based on fatty alcohols only. The sucker control was significantly better with “low” genotypes.

In general, “low” genotypes display early leaf maturity, and high sugar content. However, some of them display a more desirable equilibrium for aromatic FC style tobacco production. Breeding efforts are underway to obtain lower USG cultivars adapted to aromatic FC production.