How plant allometry influences bud phenology and fruit yield in two Vaccinium species
Citation
Fournier, M.P., Paré, M.C., Buttò, V., Delagrange, S., Lafond, J., Deslauriers, A. (2021). How plant allometry influences bud phenology and fruit yield in two Vaccinium species. Annals of Botany (AOB), [online] 126(5), 825-835. http://dx.doi.org/10.1093/AOB/MCAA083
Plain language summary
In the blueberry fields of Saguenay–Lac-St-Jean, there are two species (Vaccinium) of wild lowbush blueberry, namely V. angustifolium Ait. and V. myrtilloides Michx. These species grow to different sizes and develop differently during the season. A project was carried out in a blueberry field, in which plants of both species were monitored for 2 years to study their characteristics and development. This study revealed that V. myrtilloides produced more stems and flowers than V. angustifolium, but that flowers appeared later in the spring in V. myrtilloides. The fruit yield potential appeared to be higher in V. myrtilloides, but V. angustifolium produced larger fruits, resulting in comparable productivity. The results allowed a better understanding of the behaviours of these two species in blueberry fields. However, since these species are not uniformly distributed in the fields, it is impossible to establish a specific management strategy for each one. By identifying the proportions of each species in the field, it may be possible to develop a more tailored management strategy.
Abstract
Background and Aims Understanding how plant allometry, plant architecture and phenology contribute to fruit production can identify those plant traits that maximize fruit yield. In this study, we compared these variables and fruit yield for two shrub species, Vaccinium angustifolium and Vaccinium myrtilloides, to test the hypothesis that phenology is linked to the plants' allometric traits, which are predictors of fruit production. • Methods We measured leaf and flower phenology and the above-ground biomass of both Vaccinium species in a commercial wild lowbush blueberry field (Quebec, Canada) over a 2-year crop cycle; 1 year of pruning followed by 1 year of harvest. Leaf and flower phenology were measured, and the allometric traits of shoots and buds were monitored over the crop cycle. We hand-collected the fruits of each plant to determine fruit attributes and biomass. • Key Results During the harvesting year, the leafing and flowering of V. angustifolium occurred earlier than that of V. myrtilloides. This difference was related to the allometric characteristics of the buds due to differences in carbon partitioning by the plants during the pruning year. Through structural equation modelling, we identified that the earlier leafing in V. angustifolium was related to a lower leaf bud number, while earlier flowering was linked to a lower number of flowers per bud. Despite differences in reproductive allometric traits, vegetative biomass still determined reproductive biomass in a log-log scale model. • Conclusions Growing buds are competing sinks for non-structural carbohydrates. Their differences in both number and characteristics (e.g. number of flowers per bud) influence levels of fruit production and explain some of the phenological differences observed between the two Vaccinium species. For similar above-ground biomass, both Vaccinium species had similar reproductive outputs in terms of fruit biomass, despite differences in reproductive traits such as fruit size and number.