Cardinal 81

Cardinal, clone VCR 81, is a premium, internationally certified clonal selection of the famous table grape variety Cardinal, developed at the prestigious Italian institute Vivai Cooperativi Rauscedo, VCR. The variety was created by Elmer Snyder and Frederick Harmon in 1939. in Fresno, California, USA, through planned crossing of Flame Tokay and Alphonse Lavallée, and was released into wider production in 1946. The elite clone VCR 81 was selected primarily to reduce the variety’s natural tendency toward flower shatter and millerandage, to achieve significantly faster and more uniform berry coloration within the cluster, and to provide guaranteed healthy, virus-free, certified planting material. For decades, it has been an irreplaceable and by far the leading early black table grape variety throughout our entire region.

It is a fully self-fertile variety. The flower is morphologically hermaphroditic, properly developed and bisexual, with a high level of self-pollination and abundant pollen. However, fertilization may be significantly weaker if rainy, cold, and windy conditions occur during flowering, which in this variety leads to flower shatter, or coulure, and millerandage, with small green berries. For this reason, during this sensitive stage it requires proper agricultural practice and the application of micronutrients, especially boron and zinc. It flowers early.

The vine is exceptionally vigorous, with very strong, fast, and energetic growth, producing thick, long, and elastic shoots that carry very large, light green leaves. It requires the mandatory installation of a stable, strong, and high training structure, such as a trellis with multiple wire levels. It gives excellent and stable results both on low training forms and on high systems, such as cordons, pergolas, and arbors, where its large vegetative mass can be more easily distributed. It enters full bearing very early after planting grafted grapevines and produces regular, abundant, and extremely high yields per vine. It is especially important to emphasize that Cardinal naturally has highly fruitful basal buds on the shoot, which is why it requires exclusively short pruning to spurs, leaving 2 to a maximum of 4 fruiting buds. Long pruning to canes is strictly forbidden, as it leads to drastic overcropping, smaller berries, and a complete lack of red berry coloration.

It belongs to the group of very early table grape varieties. In our region and under continental climatic conditions, it ripens first, at the end of July and in early August, usually between July 25 and August 10, ripening about one month before Muscat Hamburg and opening the new summer grape season on the market.

Harvesting is carried out selectively and successively from the end of July to mid-August. Due to the pronounced ampelographic trait of uneven berry ripening within the same cluster, harvesting must be carried out carefully in several passes, removing from the vine only fully ripe and uniformly colored clusters. The fruit must be placed on the market within a short time after picking, because it does not tolerate long storage or remaining on the vine at the overripe stage.

Its fresh-storage ability is moderately short, which is standard for all very early summer table grape varieties. In cold storage, it can be successfully kept for only a few days, up to one week at most, and is primarily intended for quick consumption. Since it has thin skin and juicy flesh, it requires exceptional care during picking, sorting, and packing, because ripe berries are prone to cracking under rough pressure and easily detach from the pedicel. It is packed exclusively by hand in shallow crates in a single layer. It is the absolute ruler of the market at the beginning of the season, where, due to its early ripening and large berry size, it regularly achieves the highest price.

The cluster is large to very large, massive, luxurious, and heavy, with an average weight of 300 to 600 g, while on the elite VCR 81 clone individual clusters can easily reach weights of over 1 kg. It is cylindrical-conical in shape, often with one pronounced lateral wing, and is fairly loose to moderately compact on the vine. The berry is exceptionally large, weighing around 7–9 g, with a regular round to slightly oval shape. The skin is thin and smooth, red-violet at the beginning of harvest, while at full technological maturity it turns exceptionally attractive dark violet to deep burgundy-black, covered with a fine waxy bloom. The flesh is moderately firm, compact, fleshy, and exceptionally juicy. The taste is outstanding, refreshing, and very sweet, with a fine, discreet, and recognizable dessert aroma.

It belongs to the group of varieties more sensitive to phytopathological diseases and climatic fluctuations. It is highly susceptible to downy mildew, Plasmopara viticola, powdery mildew, Uncinula necator, and gray mold of the cluster, Botrytis cinerea. The greatest drawback of the variety is that in rainy August conditions the berry skin cracks massively and extremely easily due to excess moisture, immediately causing an explosive attack of Botrytis and crop loss, which is why it requires premium, intensive, and timely preventive chemical protection. It is also sensitive to low winter temperatures, with winter buds suffering permanent frost damage already at temperatures of -13°C to -15°C. Vineyards must therefore be established exclusively on warm, south-facing, elevated, and sheltered vineyard sites.

The root system is exceptionally strong, deep, and branched. It draws moisture and nutrients from deeper soil layers very well, tolerating prolonged summer droughts and heat without difficulty, but it requires deep, permeable, lighter, warm, and well-drained soils.

Our grafted grapevine plants are produced on highly compatible, certified rootstocks: Kober 5BB, Berlandieri x Riparia Kober 5BB, and its selected clones. This rootstock achieves a perfect and long-lasting anatomical graft union with Cardinal, ideally controls its great vigor, accelerates uniform ripening, and provides outstanding adaptability to calcareous and skeletal soils with a high content of active lime.