Leaf measurements as a means of identification of peach varieties in nursery trees

• Main Author: Lapins, Karlis Otto
• Language: English
• Published: University of British Columbia 2012
• Subjects: Peach
• Online Access: http://hdl.handle.net/2429/40497

Ten different measurements or counts were made on peach leaf samples of 5 varieties in 6 locations in 3 years with the main objective being to test the possibility of identification of varieties in nursery trees. From the ten measurements, length of leaf blade, cm; width of leaf blade, expressed as percentage of length of leaf blade; base angle, measured at 1.5 cm from leaf base; maximum apex angle; and length of petiole, expressed as percentage of length of leaf blade, showed higher discriminative value than the other measurements under test. None of these measurements alone made it possible to distinguish between certain related varieties. Application of discriminant function analysis showed promise in identification of these varieties. Variation of the five characters which were used in construction of discriminant functions was found to be mainly in two dimensions and was expressed with two discriminant functions. The compound scores of two discriminant functions of the varieties could be simply plotted on two axes of a chart. Application of the discriminant functions is simple and consists in comparing the compound scores of an unknown sample to those of the average values of known varieties. The variety averages and corresponding compound scores of discriminant functions were calculated and used separately for three different growing regions of British Columbia. Large leaves from the middle portion of the central shoot of the one-year-old peach trees gave reliable samples. === Land and Food Systems, Faculty of === Graduate