Submitted to: Acta Horticulturae
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/12/2002
Publication Date: 11/1/2002
Citation: OKIE, W.R., SCORZA, R. BREEDING PEACH FOR NARROW LEAF WIDTH. ACTA HORTICULTURAE. 2002. v.592. p.137-141. Interpretive Summary: Peaches with narrow, willow-like leaves may be useful in allowing more air and light into the tree, which could reduce disease and improve yield. Trees might also be easier to spray and pick. New peach selections with narrow leaves are close to commercial quality in terms of size, firmness and appearance. With these advanced selections, it will be possible to compare narrow-leaved to normal-leaved trees to test if the proposed advantages of the narrow leaf type are real. The narrowleaf trait is inherited but the number of genes involved is still not clear.
Technical Abstract: Mature peach leaves are typically about 4 x 16 cm, with a width/length ratio of about 25 percent. A narrow leaf seedling, selected by Wayne Sherman (Univ. of Florida, Gainesville), was hybridized at USDA-Byron with adapted commercial varieties. Early generation hybrids produced small, irregular-shaped fruit. After 5 generations, current selections are approaching commercial fruit standards in size, color, firmness, and attractiveness. Narrow-leaf trees are often noticeably more open than standard trees. This leaf type may be useful in standard- or high-density plantings to enhance spray penetration, to speed drying of wet foliage to reduce disease, to improve light penetration and photosynthetic efficiency for greater fruit size and red color, and to make the fruit more visible to speed picking. Inheritance studies indicate that the narrow-leaf character is at least partially dominant and is expressed in some F1 seedlings of crosses with wild-type parents. The exact inheritance remains unclear as the ratios obtained to date do not fit common inheritance patterns. Progeny vary in leaf width with ratios of width/length generally ranging from 10-25 percent. The most extreme seedling has leaves up to 28 cm long and 1 cm wide, and although it is not fruitful, it may have ornamental value.