Several genotypes of Vactinium angustifolium were taken at random from 17 environmentally diverse sites in Michigan and transplanted to a common greenhouse environment. During the 2nd season of growth, genotypes from southern sites exhibited significantly greater numbers of inflorescence buds than northern sites. Genotypes from sites with low light levels exhibited greater numbers of inflorescence buds and flowers per bud than those from sites with high light levels. Genotypes from dry sites produced larger fruit than genotypes from wet sites. These data suggest that environments exist in which natural selection has favored horticulturally desirable traits.
Sixteen cultivars of blueberry (Vaccinium corymbosum L.) were field screened for resistance to the blueberry aphid Illinoia pepperi (McGillivary), the vector of blueberry shoestring virus. Significant differences were observed with ‘Bluejay’, ‘Northland’, ‘Bluetta’ and ‘Bluehaven’ supporting the lowest numbers, while ‘Spartan’, ‘Darrow’, ‘Lateblue’, ‘Coville’ and ‘Jersey’ carried the highest numbers. There was no significant correlation between aphid number and new shoot number, percentage of shoots with new growth, length of new growth, leaf length or leaf width. Half of the aphids were found in the lower 1/3 of the bushes.