Patent Application
20120030847
Latin name of the genus and species of the plant claimed: Vaccinium macrocarpon Ait.
Variety denomination: WI92-A-X15.
The present invention relates to a new and distinctive cranberry clonal variety having significantly higher yields, larger fruit size, more favorable bud set traits, tolerance to high levels of fertilizer, high red pigmentation and ability to produce excellent crops at an early age as compared to the leading commercial cultivar, ‘Stevens’.
The American cranberry, Vaccinium macrocarpon Ait., is a small fruit grown commercially in the temperate regions of North America and Chile. The United States is presently the major producer of cranberries, with the combined Wisconsin and Massachusetts harvests accounting for the majority of U.S. and world annual production. Currently Wisconsin produces over half of the U.S. crop.
The American cranberry is well known for its tart flavor and its red pigment. The importance of adequate pigment content (measured as total anthocyanins or Tacy, and expressed as mg per 100 grams fresh fruit) is recognized by most processors as they are known to give a reduced value to poorly colored fruit. Cranberry selections widely grown today have generally not experienced the extensive breeding as seen in other fruit-bearing species. Many selections were derived directly from native areas or from managed beds of mixed origin. For example, ‘Ben Lear’ (unpatented) is a cranberry selection taken directly from the wild in Wisconsin in the early 1880's, and is widely grown in short-seasonal areas due to its early fruit development and high color content. The U.S. Department of Agriculture undertook, in cooperation with state experimental stations, one generation of breeding in an attempt to improve U.S. cranberry cultivars. The breeding resulted in the introduction of the ‘Stevens’ (unpatented) variety in 1950. The ‘Stevens’ variety is today the most widely grown cultivar and is characterized by dependably good yields, but only moderate color development, especially in short-seasonal regions such as Wisconsin.
The present invention relates to a new and distinct cranberry variety. The variety is designated “WI92-A-X15” and was produced through controlled breeding performed in 1990 at the University of Wisconsin-Madison. Cranberry variety “W192-A-X15” is derived from a controlled cross of the ‘Stevens’ variety and a selection designated “Boone's BL8” (originally derived from an open-pollinated population of seedlings of ‘Ben Lear’).
“W192-A-X15” cranberry was initially selected based on large berry size in August of 1992 and was clonally propagated for field trials planted in 1994. “W192-A-X15” demonstrated continued production of large berries and favorable bud set traits, including both good fruit bud set in general and excellent bud set on fruiting stems (‘uprights’) specifically. “W192-A-X15” was compared to ‘Stevens’ both in plots within common beds (2004 and 2009 data presented in
“WI92-A-X15” exhibits significantly higher yields (up to approximately two times higher than variety ‘Stevens’), larger fruit size, more favorable bud set traits, tolerance to high levels of fertilizer, earlier and higher red pigmentation, and an ability to set excellent crops at an early age as compared to ‘Stevens’.
The distinctive characteristics of the new “WI92-A-X15” variety are shown in Tables 1 and 2 and described in detail below.
Visual analysis of “W192-A-X15” cranberry samples taken between early September and early October 2009 demonstrated fruit color development and fruit size exceeding that of parent cultivar ‘Stevens’. “W192-A-X15” fruit from the four-year-old, 0.66 acre bed and the three-year-old, 2 acre bed were harvested at the beginning of October and mid-October of 2009, respectively, and comparison ‘Stevens’ fruit was harvested over the course of several weeks in October. Yields from each “W192-A-X15” bed were compared to established beds of ‘Stevens’ over the whole farm and specific beds indicated in Table 1 (see Table 1 for harvest dates). Yield is expressed as barrels per acre or B/a, 1 barrel=100 lbs. As shown in Table 1, cranberries from the four-year-old “W192-A-X15” bed out-performed the established variety ‘Stevens’ by about two-fold, yielding 476 B/a versus a farm average of 243 B/a for 66 acres of ‘Stevens’. Examples of individual beds of ‘Stevens’ show a range from 217 to 278 B/a. The three-year-old “W192-A-X15” had a yield similar to that of established ‘Stevens’ with 242 B/a. In contrast, the yields produced from two beds of ‘Stevens’ planted in 1995, produced 153 and 156 B/a as three-year-olds, respectively, and 192 and 204 B/a as four-year-olds, respectively.
“W192-A-X15” was not only able to produce higher yields, but the fruit color was favorable when compared with ‘Stevens’. The 0.66 acre bed of “W192-A-X15” was harvested eight to fifteen days earlier than the ‘Stevens’ beds, yet had nearly equivalent fruit color (Table 1). The 2 acre area of “W192-A-X15” was harvested only a few days later than the ‘Stevens’ beds, yet had fruit color approximately 50% greater.
High rates of nitrogen can cause excessive vegetative growth, or “overgrowth”, resulting in numerous non-fruiting stolons growing over the top of the canopy. ‘Stevens’ is particularly susceptible to such nitrogen induced overgrowth, which can be associated with reduced yields. Unlike ‘Stevens’, “W192-A-X15” displays little overgrowth, no reduced yields, and no changes in berry size or upright average growth when treated with high levels of nitrogen; instead “W198-A-X15” displays an increase in flower bud set under high nitrogen fertilization. The tolerance of cranberry variety “W192-A-X15” to high levels of fertilizer can be seen in Table 2. The effects of increased fertilizer and the tolerance thereto displayed by “W192-A-X15” is also demonstrated in Table 1 as the yields shown for “W192-A-X15” were not adversely affected by the significantly higher units of nitrogen applied than what was used for ‘Stevens’.
In early October of 2009 the tolerance of “W192-A-X15” to increased nitrogen was evaluated at a testing site near Tomah, Wis. Plots of “W192-A-X15” were fertilized with nitrogen levels used throughout the bed or received additional fertilizer from three extra applications of ammonium sulfate as well as a slow release fertilizer. Table 2 shows the resulting effects of nitrogen treatment of five samples of “W192-A-X15”. In particular, the high nitrogen treated plot of “W192-A-X15” did not display overgrowth, reduced yields or differences in berry size or upright average growth; instead a slight increase in yield and a large increase in flower bud set was observed.
The red pigment of cranberry is located almost entirely in the epidermal layers of the fruit. One factor which can to contribute to high extractable fruit color in cranberry is small fruit size, due in part to the influence of surface area to weight ratio on the total pigment content for each fruit. A negative correlation between yield and fruit color has also been suggested. However, “WI92-A-X15” demonstrated better coloration in combination with increased fruit size and greater yield potential. Thus, “WI92-A-X15” appears to be able to produce high yields and large fruit size simultaneously with good fruit coloration (Table 1 and
Thus, “WI92-A-X15” appears to be able to develop high levels of extractable pigmentation simultaneously with increased fruit size and yield.
The combination of the above “WI92-A-X15” characteristics easily differentiates “WI92-A-X15” from both its parents. The above characteristics also provide the “WI92-A-X15” variety with benefits not recognized in other commercially grown and established varieties. For example, the increased yield and flower but set of “WI92-A-X15” provides the potential to increase both the current year's crop and the next year's crop through fertilizer regime. “WI92-A-X15” additionally provides beneficial and distinct aspects over other cranberry cultivars as evidenced by its high yields. For instance, the observed approximately two times greater yield than the most planted ‘Stevens’ cultivar demonstrates a great advantage of the “WI92-A-X15” variety.
