Impact of spring freeze on yield, vine performance and fruit quality of Vitis interspecific hybrid Marquette

- Grapevines cv. Marquette can produce significant yields even after severe spring freeze damages.
- The secondary bud of Marquette compound bud is fruitful, due to its Vitis riparia parentage.
- Clusters arising from secondary buds exhibits a slightly delayed phenology and ripening.
- At harvest, fruit on shoots from secondary buds has the same quality of fruit on shoot from primary bud.

In viticultural regions with spring freeze events, early budburst increases the risk of vine damages compromising industry long-term sustainability. Marquette is a cold hardy hybrid with Vitis riparia in its parentage, a source of cold hardiness and rapid budburst characteristics. In 2012 and 2013, the capacity of Marquette to rebound from significant bud mortality from a series of spring freeze events was quantified and the capacity of recovering the damages the following year, measuring vine yield and the effect on fruit quality. The compound bud on grapevine is actually three buds in one, with primary, secondary, and tertiary all present. Spring freeze events in 2012 killed over 80% of the shoots arising from primary buds (SPB) while secondary buds (SSB) were almost unaffected. By tracking the performance SPB and SSB, we were able to quantify vine response to spring freeze events. A comparative analysis of phenological and fruit quality characteristics of the SPB and SSB clusters showed different development and ripening of those of SBS. However, the differences disappeared at harvest, with no significant impact on yield or only partially on fruit composition. The results suggest that Marquette has the potential to generate significant yield from SSB with desirable fruit quality and could offer a solution to spring freeze losses. In 2013, year characterized by no spring freeze events, vines recovered full productivity, yielding 61% more fruit, due to an increased number of cluster per vine (+60%) with also better fruit quality at harvest.