ARS | Publication request: NOTICE OF NAMING AND RELEASE OF MERLOT, A NEW, UPRIGHT, DISEASE RESISTANT SMALL-RED BEAN (PHASEOLUS VULGARIS L.) CULTIVAR

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 1, 2003
Publication Date: January 1, 2004
Citation: Hosfield, G.L., Kelly, J.D., Taylor, J., Varner, G.V. 2004. Notice of Naming and Release of Merlot, a New, Upright, Disease Resistant Small-red Bean (Phaseolus vulgaris L.) cultivar. Crop Science. 44(1):351-352.

Interpretive Summary: 'Merlot', a small-red, dry, edible bean was released cooperatively by the United States Department of Agriculture, Agricultural Research Service and Michigan State University. Merlot has an upright architecture with a strong stem to prevent lodging. Merlot also carries genes for resistance to bean common mosaic virus and bean rust. Merlot is the only commercial small-red cultivar resistant to bean rust. Merlot is a mid- to full- season bean with uniform dry down, and a desirable canning quality rating. Over 18 locations, Merlot out-yielded all of the check varieties from 1998-2002. The seed of Merlot is a nice garnet red that has a more intense red color than the check varieties. The seed of Merlot averages 39.2 grams per 100 seed. The seed is visually appealing due to the gently rounded apices and noticeable black hilum ring verses the more typical rhomboid shape of the check varieties. The desirable canning quality, disease resistance, and upright architecture of Merlot should promote an increased usage of beans of the small red market class.

Technical Abstract: 'Merlot', a new small-red dry bean (Phaseolus vulgaris, L.) cultivarA new small-red dry bean (Phaseolus vulgaris L.) cultivar was developed and jointly released by the USDA-ARS and Michigan State University. Merlot has a Type IIa growth habit, which is characterized by a plant with an erect architecture and a strong main stem and three to five branches acutely angled upward. This feature gives 'Merlot' excellent lodging resistance. 'Merlot' had an average yield of 2708 kg per hectare over 18 test sites from 1998-2002 and yielded 3,942 kg per hectare at Othello, WA in 2002. Seed of 'Merlot' are oval; plump at the surface tangential to the hilum with gently rounded at the apices and colored an attractive garnet with an intense red saturation and a noticeable black hilum ring. Seeds weigh approximately 40 grams per 100 seeds. 'Merlot' averages 47.0 cm in height at physiological maturity, blooms about 45 days after planting and matures between 87 to 100 days. Merlot has the bc-1**2 gene for resistance to bean common mosaic virus (BCMV), and the Ur-3 gene for resistance to Race 53 of bean rust disease caused by [Uromyces appendiculatus (Pers.:Pers.) Unger]. 'Merlot' is the only commercial small red cultivar resistant to bean rust disease. 'Merlot' has a desirable canning quality based on the judgments of sensory panelists who rated the cultivar on a seven-point hedonic scale where 7.0 is the most and 1.0 the least desirable perceptions for a trait. 'Merlot' had an average score of 5.0 for visual appeal, which is a function of the amount of clumping of beans in the can, degree of bean integrity (splitting); canning broth characteristics of viscosity, color, and exuded starch; and seed characteristics of color, size, and shape for the market class.