Durif
Durif arose from a natural cross of Peloursin and Syrah in the 1860s in France. Vines have low to moderate vigor and moderate yield potential. Durif berries have high anthocyanin and tannin content, even when grown in warm climates. The berries are prone to sunburn and shrivel, and the clusters to bunch rot. However, these issues can be managed to some extent with appropriate cultural practices. Durif wines are typically dark-colored and full-bodied.
Figures
Figure 1 Durif cluster
Figure 2. A fasciated cluster of Durif.
Figure 3 Durif leaves
Origins and History
Durif resulted from a natural cross of Peloursin and Syrah that occurred in the experimental vineyard of Francois Durif, a French botanist and grape breeder (Robinson et al., 2012). Durif selected the vine in the 1860s, and it was soon noted to have some resistance to downy mildew. Charles McIver imported Durif to the USA in 1884 under the name Petite Sirah, and Meredith et al. (1999) confirmed that most California vines named Petite Sirah were genetically identical to Durif.
Vine Traits
Durif is fruitful at basal nodes, has low to moderate vigor, and a somewhat weeping habit. Leaves are circular and dark green, with five lobes. Petiolar sinuses are open and U-shaped. It is not uncommon to observe fasciated shoots and clusters. In the San Joaquin Valley, cordon-trained, spur-pruned vines averaged nearly 2 clusters/shoot (Table 1). Clusters were medium in size (0.28 kg), well filled to compact, with medium spherical to ovoid-shaped berries averaging 1.4 g. The compactness of the clusters makes them prone to rot.
Yield potential is moderate (Table 1), and the grapes are relatively late ripening. Durif grape berries are prone to sunburn, especially if the canopy provides insufficient shade from afternoon sun. Moreover, overripe fruit may shrivel and raisin, especially in warm climates.
In a San Joaquin Valley trial, Durif yield averaged 11 tons/acre due to moderate values for components of yield such as clusters/shoot, berry number and berry weight. Vine growth was moderate to low, resulting in a high yield:pruning ratio of 13.3. Even so, fruit composition was good with moderate titratable acidity (TA) and pH. Rot was high, as was shrivel in one particular year. Despite moderate to low yields by San Joaquin Valley standards, former UC Davis Viticulture Specialist James Wolpert recommended Durif due to its above average fruit and wine quality.
Vineyard Considerations
Because Durif has fruitful basal nodes it is commonly cordon-trained and spur-pruned. Leaf removal in the fruit zone can help reduce bunch rot, but leaves should not be removed from the south or west side of a canopy, or too late in the season, as excessive exposure increases the risk of sunburn. Overripe fruit can be difficult to remove with harvest machines. Therefore, for optimal yield and fruit quality, it is important to avoid subjecting Durif vines to excessive stress, especially water stress, and the grapes should be harvested promptly. In a San Joaquin Valley trial, vines planted at a 6’ x 10’ spacing yielded the equivalent of 11.2 tons/acre. If sunburn, shrivel, and bunch rot can be avoided, the fruit have good quality potential, particularly with respect to color and tannin, both of which are relatively high, even in warm climate regions.
Quality
Durif may produce wines that are well colored and tannic, even in warm and hot climate regions. Therefore, this variety may be of interest to growers looking for heat tolerant red wine varieties.
Tables
References
Robinson, J., J. Harding, J. Vouillamoz. 2012. Wine Grapes. HarperCollins, New York
