Leaf Elemental Concentrations as Influenced by Growth Habit and Strains of 'Delicious' Apples

Abstract

Leaf elemental concentrations and leaf fresh and dry weights and their relationship with yield efficiency in twenty-eight strains of 'Delicious' apple ( Malus domesticaBorkh.) with two types of growth habit (spur and standard) were evaluated over two years. Cluster analysis of leaf elemental concentrations divided strains into groups approximately corresponding to growth habit. 'Starkspur Ultrared' and 'Wellspur,' which are classified as spur types, tended to group with the standard type strains on the basis of elemental concentration. Strains with a spur type growth habit had more fluctuation in yield from year to year and had higher leaf fresh and dry weights, leaf Ca, Mg, Zn, Mn, and Cu, but lower leaf K than standard type strains. 'Early Red One,' 'Starkspur Supreme,' 'Starkspur Ultrared,' and 'Redchief' had higher concentrations of leaf N, while 'Aomori,' 'Apex,' 'Classic Red,' 'Improved Ryan Spur' and 'Red King Oregon Spur' had lower leaf N than many other strains. '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' and 'Improved Ryanred' were among strains with high leaf Fe and 'Improved Ryan Spur' and 'Ace' had low Fe. 'Silyerspur' had the highest leaf Zn and Mn, making it desirable for areas with deficiencies of these elements. 'Spured Royal' had a higher concentration of leaf Cu than most other strains.