Mara Seedless

Main Characteristics

Mara Seedless is a new table grapevine variety obtained through controlled artificial pollination by American researcher Joseph Maranto. The breeding program was initiated in 1992 in the San Joaquin Valley (California), and the hybrid cross was made in 1993. The parental combination is represented by the seeded variety Red Globe as the female parent and the seedless variety Crimson as the male parent. The Mara Seedless grapevine variety is characterized by a mid-season ripening period; under the environmental conditions of Central California, the crop is ready for commercial harvesting and shipment in early to mid-October.

The variety under consideration demonstrates high productivity levels when managed with short spur pruning. The uniform yield consists of compact, conical shouldered clusters with an average weight ranging from 500 to 700 grams. The rose-pink berries reach an average weight of approximately 6 grams, featuring a relatively thick but very firm skin and a crisp, meaty internal texture with a pleasant sweet flavor. By the time of harvest in mid-autumn, the soluble solids accumulate to approximately 18% sugar, with an average titratable acidity level of 3.7 g/l and a juice pH of 3.81. The Mara Seedless grapevine variety possesses superior dessert dessert qualities, excellent shelf life, and high transportability.

Morphological Description of the Mara Seedless Grapevine Variety

• Vine and Cane: The mature trunk is relatively slender and covered with long split strips of bark. The bark color is brown, with a chicle sarouk-colored underbark. The mature one-year-old dormant cane has a medium length (within 1.5–1.8 m) and a substantially circular to slightly flattened cross-section measuring about 0.8 mm in diameter with longitudinal striations. The cane surface is smooth, and the shoot color is light green. The growing tip generally ascends straight up.
• Tendrils: Developed in moderate numbers, featuring a smooth texture and a bifurcated or trifurcated configuration. The average length of the tendrils ranges from 102 to 152 mm.
• Buds: The buds are distinguished by a pointed conical shape. The average length of a bud is approximately 6 mm, and the width is approximately 5 mm. Bud break commonly occurs at the end of March or early April.
• Leaves: The leaves are generally medium in size (average length of approximately 114 mm, width of approximately 120 mm) with a heavy density on the vine. The leaf blade is five-pointed, smooth, and glabrous on the ventral surface (lacking pubescence). The dorsal surface is green (cossack green), while the ventral surface is light green. The petiole sinus exhibits a U-shaped configuration, occasionally with overlapping margins. The midrib color is grape green. The leaf margins are serrate with irregular teeth, featuring approximately 10 to 12 teeth per lobe and a total of 50 to 60 teeth on the entire leaf blade. The petiole ranges from 84 to 123 mm in length and displays a holly green coloration.
• Flowers: The bloom date begins in early May, with the full bloom stage reached during the third week of May. The flowers are fertile, produced primarily at the second or third node from the base on a spur. The corolla consists of five petals that open from the bottom to the top. The five sepals are poorly developed. The androecium consists of six upright and diverging stamens producing abundant yellow pollen. A single pistil produces a liquid secretion to hold pollen for germination. The green filaments measure approximately 4 mm in length.
• Cluster and Berry: The cluster is characterized by a compact structure, a conical shouldered form, and a medium-to-large size (average length of 20.4 to 25.4 cm). The berries are uniform, ellipsoidal elongated in shape, with an average longitudinal length of 30 mm and a width of 18 mm. An average cluster contains approximately 100 to 120 berries. The skin is very firm, rose-pink in color, with no visible lenticels. The internal flesh is light green and completely seedless.

Vine Management and Viticultural Characteristics

The Mara Seedless grapevine variety exhibits high vigor that exceeds both of its parental varieties, Red Globe and Crimson. In commercial cultivation, this grapevine variety shows stable and high productivity with spur pruning. For asexual propagation, it has been successfully grafted onto mature Thompson Seedless rootstock. The berry skin is highly resistant to cracking, and no splitting tendencies have been encountered during observations to date. The berry capstem is strong, with long chalazas firmly attached to the vascular tissue of the fruit.

The variety shows a high level of environmental adaptability and resistance to climate stress factors. The grapevine exhibits a good ability to resist soil drought, strong winds, and extreme summer heat typical of Central California. The level of cold hardiness is rated as good; the vines successfully pass through the winter dormancy period. No visible disease problems, fungal infections, or bacterial symptoms have been encountered during observations to date. The commercial qualities of the harvested crop are excellent; the fruit is highly resistant to bruising and mechanical damage during handling and shipping. The Mara Seedless grapevine variety is highly suitable for long-term storage; after one month in cold storage, the fruit still displays its original appearance, flesh firmness, and flavor parameters.

* VINEYARD Note: The image published herein has been reconstructed from a printed version and may therefore contain inaccuracies in color reproduction.