Predictive Model for Onset and Development of Internal Heat Necrosis of 'Atlantic' Potato

Autor: M.R. Henninger, M. Lentner, S.B. Sterrett, G. S. Lee
Rok vydání: 1991
Předmět:
Zdroj: Journal of the American Society for Horticultural Science. 116:701-705
ISSN: 2327-9788
0003-1062
DOI: 10.21273/jashs.116.4.701
Popis: In 'Atlantic' potato (Solanum tuberosum L.) the onset and development of internal heat necrosis (IHN) varied with planting date and location in 1989. Symptoms of IHN (first trace) took fewer days to appear in the later plantings in Virginia and New Jersey. However, the interval from first trace to offgrade was extended in the later plantings. Data from successive harvests in these two locations over the past 4 years were used to develop a two-stage model to predict first trace and offgrade by stepwise regression techniques. The predictive model for first trace included rainfall and variables calculated from a heat-sum model that reflected maximum and minimum air temper- atures during tuber initiation and early enlargement. The addition of variables reflecting size distribution and rainfall events at first trace resulted in a strong predictive model for offgrade (R 2 = 0.98, Mallow's criterion = 2.97). These models indicate that onset and development of IHN are influenced by environmental stress during more than one stage of growth. A delay in the development of offgrade tubers would be expected in years with a cool, wet spring, fewer tubers >64 mm in diameter at first trace, and more rain events during the 10 days immediately after first trace. In the mid-Atlantic region, 'Atlantic' is the potato cultivar of choice for the potato chip industry. This cultivar combines high yields and high specific gravity with acceptable chip color (Webb et al., 1979). However, 'Atlantic' is susceptible to the disorder commercially referred to as IHN. The first visible symptoms of IHN are generally small, localized areas of necrotic tissue in the parenchyma inside the vascular ring. IHN occurs first toward the apical end of the larger tubers in the hill (Henninger et al., 1979). As IHN progresses, the area affected and the color in- tensity of the necrotic tissue increase (Sterrett et al., 1991). The USDA no. 1 grade potato standards specify that total defects may not exceed 8%, with internal defects not to exceed 5% by weight (U.S. Dept. of Agriculture, 1972). The occurrence of IHN in the largest tubers severely limits the percentage of tubers with IHN tolerated in a USDA no. 1 lot of potatoes. Several studies have associated the incidence of necrotic tis- sue with above normal temperature and below normal rainfall (Friedman, 1955; Larson and Albert, 1945; Wolcott and Ellis, 1959). Sterrett et al. (1991) found a complex relationship be- tween the progression of IHN, time (DAP), temperature, and rainfall.
Databáze: OpenAIRE
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