LEAF ELEMENTAL CONCENTRATIONS AS INFLUENCED BY GROWTH HABIT AND STRAINS OF DELICIOUS APPLES

Leaf elemental concentrations and leaf fresh and dry weights and their relationship with yield efficiency in twenty-eight strains of 'Delici ous' apple (Malus domestica Borkh.) with two types of growth habit (sp ur and standard) were evaluated over two years. Cluster analysis of le af elemental concentrations divided strains into groups approximately corresponding to growth habit. 'Starkspur Ultrared' and 'Wellspur,' wh ich are classified as spur types, tended to group with the standard ty pe strains on the basis of elemental concentration. Strains with a spu r type growth habit had more fluctuation in yield from year to year an d had higher leaf fresh and dry weights, leaf Ca, Mn, Zn, Mn, and Cu, but lower leaf K than standard type strains. 'Early Red One,' 'Starksp ur Supreme,' 'Starkspur Ultrared,' and 'Redchief' had higher concentra tions of leaf N, while 'Aomori,' 'Apex,' 'Classic Red,' 'Improved Ryan Spur,' and 'Red King Oregon Spur' had lower leaf K than many other st rains. 'Aomori' had a higher leaf K and lower leaf Ca but 'Hardi-Brite Spur' had lower K and higher leaf Ca than other strains. 'Imperial' a nd 'Improved Ryanred' were among strains with high leaf Fe and 'Improv ed Ryan Spur' and 'Ace' had low Fe. 'Silverspur' had the highest leaf Zn and Mn, making it desirable for areas with deficiencies of these el ements. 'Spured Royal' had a higher concentration of leaf Cu than most other strains.