Effects of Leaf Position and Sampling Date on Leaf Nutrient Composition of Eleven Highbush Blueberry Cultivars1

Abstract

Abstract Four types of leaf samples were taken in June and August 1966 from 11 early, mid-season, and late cultivars of highbush blueberry Vaccinium corymbosum L. The first three were the 1st, 2nd and 3rd mature leaves of current-season shoots subtending fruit clusters and the 4th was a composite collection of these leaves. Each sample was analysed for N, P, K, Ca, Mg, and Fe. Differences among cultivars were significant for all elements tested. Every cultivar had less Ca in June than in August, and most cultivars had lower Mg in June than in August. Most cultivars had similar N and Fe content in both months, but had higher P and K in June than in August. In June, K was lower in samples of young leaves than in composite samples. In August, young leaves were higher in Mg. In June, composite samples were higher in P than the second and third mature leaves. Cultivars, as well as sampling position and time will be important in evolving diagnostic criteria in highbush blueberry leaf analysis.