Inflorescence temperature influences fruit set, phenology, and sink strength of Cabernet Sauvignon grape berries

Abstract

The temperature during the bloom period leading up to fruit set is a key determinant of reproductive success in plants and of harvest yield in crop plants. However, it is often unclear whether differences in yield components result from temperature effects on the whole plant or specifically on the flower or fruit sinks. We used a forced-convection, free-air cooling and heating system to manipulate the inflorescence temperature of field-grown Cabernet Sauvignon grapevines during the bloom period. Temperature regimes included cooling (ambient −7.5°C), heating (ambient +7.5°C), an ambient control, and a convective control. Cooling significantly retarded the time to fruit set and subsequent berry development, and heating shortened the time to fruit set and accelerated berry development relative to the two controls. Fruit set was decreased in cooled inflorescences, but although the cooling regime resulted in the lowest berry number per cluster, it also decreased seed and berry weight at harvest while not affecting seed number. Cooling inflorescences slightly decreased fruit soluble solids and pH, and increased titratable acidity, but did not affect color density. The inflorescence temperature did not impact leaf gas exchange and shoot growth, and shoot periderm formation occurred independently of the timing of fruit ripening. These results suggest that the temperature experienced by grape flowers during bloom time impacts fruit set and subsequent seed and berry development. Suboptimal temperatures not only reduce the proportion of flowers that set fruit but also limit the sink strength of the berries that do develop after fruit set. Shoot vigor and maturation, and leaf physiology, on the other hand, may be rather insensitive to temperature-induced changes in reproductive development.

Effects of histone methylation modification on low temperature seed germination and growth of maize

“…The growth and development of plants have high requirements on environmental temperature. As sessile organisms, plants have evolved various mechanisms to sense environmental temperature and adapt to natural 28,29 . Histone methylation also plays an important role in this [30][31][32] .…”

Optimizing Irrigation for Mechanized Concord Juice Grape Production

“…The low cluster numbers in 2012 might have been caused by low bud fruitfulness due to reduced inflorescence initiation during the cool 2011 summer or by the early soil water deficit in 2011 (Vasconcelos et al 2009, Levin et al 2020). In addition, there was about one week of unusually cool temperatures (T mean < 15°C) during bloom in 2012, which likely reduced fruit set (Keller et al 2022). In 2016, the decrease in clusters per vine under moderate preveraison deficit irrigation may have been a consequence of lower bud fruitfulness or lower shoot numbers resulting from longterm water stress (Williams et al 2010a, Levin et al 2020.…”

Berry shrivel in grapevine: a review considering multiple approaches

“…Berries of the same cluster ripen quite heterogeneously ( Coombe, 1992 ; Bigard et al , 2019 ; Hernández-Montes et al , 2021 ), and individual berries, rather than whole clusters, trigger enhanced phloem import as each berry begins to ripen over a period that can span >2 weeks ( Keller et al , 2015 ; Zhang and Keller, 2017 ). Many factors, including the timing of flowering and fruit set, berry growth, seed number, size, and content, contribute to asynchronous ripening ( Coombe, 1992 ; Gouthu and Deluc, 2015 ; Keller et al , 2022 ). Consequently, one factor for BS induction is still missing, as berries start ripening individually, but BS symptoms often appear across whole clusters simultaneously.…”