The greening indices presented below were developed at the request and with funding provided by the U.S. Potato Board.
Members of the research team included Laura Grunenfelder (Graduate Research Assistant), L.K. Hiller (Associate Professor) and R.E. Thornton (Professor), Dept. of Horticulture, WSU.
The objectives were to: 1) characterize the time course of greening/chlorophyll development for selected fresh market cultivars; 2) develop an objective scale of greening for each cultivar that can be used by growers, shippers, and retailers to subjectively sort tubers based on changes in visible color; and 3) evaluate the effects of light intensity, photoperiod, and packaging on the greening process of selected cultivars.
Color plates constituting the greening scales for each cultivar are presented below, along with time course graphs depicting the associated rates of greening at a light intensity equal to that in many retail potato displays.
The scales have been tested for sorting tubers selected randomly (with regard to the extent of greening) from retail outlets and were found to cover the range of greening normally encountered for each cultivar.
The scales, together with the derived time course of greening, provide a guide for quality control and estimating the remaining shelf life of potatoes in retail markets.
| White Rose | |
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| Yukon Gold | |
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| Norkotah | |
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| Dark Red Norland | |
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| Reba | |
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