Submitted to: Hortscience Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 21, 2000
Publication Date: N/A
Technical Abstract: Peach trees (Prunus persica L.) with diverse shoot growth habits have been developed but little is known about their root systems. Characterizing shoot and root systems can improve basic understanding of peach tree growth and be important in the development of rootstocks and own-rooted trees. This research determined shoot and root characteristics of four peach tree growth habits (compact, dwarf, pillar, and standard). Compact tree leaf number (1350/tree) was twice but leaf area (6 cm2/leaf) was half that of pillar and standard trees. The number of lateral branches in compact trees (34) was nearly 3-times more than in pillar and standard trees. The leaf area index (LAI) of pillar trees was greater than compact and standard trees (13 compared with 4 and 3, respectively) due to a narrower crown diameter. Dwarf tree shoots were distinct with few leaves (134 per tree) and a large LAI of 76. Compact trees grew more higher order lateral roots than pillar and standard trees. More second order lateral (SOL) roots were produced by compact than standard trees (1.2 vs. 0.8 SOL roots/cm first order lateral root). Pillar trees had higher shoot-to-root dry weight ratios (2.4) than compact and standard trees (1.7 for both) due to smaller root dry weights. Compact trees had more higher order lateral roots in roots originating near the root collar (i.e. more fibrous roots) and this correlated with more lateral branches in the canopy. Shoot weights were the same among pillar, compact, and standard trees but root weights were less in pillar trees, resulting in greater shoot-to-root dry weight ratios. These results indicate fundamental differences in root as well as shoot architecture among growth habits that can affect their use as scion or rootstock varieties.