architecture and cropping potential ( Bernad and Socias i Company, 1998 ). In almond, diverse tree architectures among cultivars are mainly the result of their genetically determined branching patterns rather than pruning practices because trees are usually
Claudia Negrón, Loreto Contador, Bruce D. Lampinen, Samuel G. Metcalf, Theodore M. DeJong, Yann Guédon, and Evelyne Costes
James N. Cummins
Rootstock influence on tree architecture may be seen in a variety of expressions. Above ground effects include canopy volume and shape, crotch angles, branch display angles, relative distribution of long shoots and spurs, internode length, relative distribution of fruit buds and spurs, and trunk taper. Below the graft union, effects include relative distribution of fine vs. coarse roots, total root mass, and numbers, nature and distribution of burrknots. Many of these phenomena are indirect effects that stare from induction of fruiting by the rootstock, e.g., early fruit production induced by the rootstock will result in reduced canopy volume, reduced aboveground total mass, flatter branch display angles, and reduced root mass. The rootstock also plays a major role in the duration of shoot extension growth; by influencing the production of growth regulators in the shoot tip, the rootstock indirectly influences the inhibit ion of lateral buds and therefore the production of feathers.
Ted M. DeJong, Romeo Favreau, Mitch Allen, and Przemyslaw Prusinkiewicz
Modeling source–sink interactions and carbohydrate partitioning in plants requires a detailed model of plant architectural development, in which growth and function of each organ is modeled individually and carbohydrate transport among organs is modeled dynamically. L-PEACH is an L-system-based graphical simulation model that combines supply/demand concepts of carbon partitioning with an L-system model of tree architecture to create a distributed supply/demand system of carbon allocation within a growing tree. The whole plant is modeled as a branching network of sources and sinks, connected by conductive elements. An analogy to an electric network is used to calculate the flow and partitioning of carbohydrates between the individual components. The model can simulate multiple years of tree growth and be used to demonstrate effects of irrigation, crop load, and pruning on architectural development, tree growth, and carbon partitioning. Qualitative model outputs are viewed graphically as the tree “grows” on the computer screen while quantitative output data can be evaluated individually for each organ or collectively for an organ type using the MatLab software.
Omar Carrillo-Mendoza, José X. Chaparro, and Jeffrey Williamson
Although growth forms in peach such as dwarf, pillar, weeping, and compact have been studied ( Scorza et al., 2006 ), little effort has been devoted to the study of tree architecture and branching. The standard peach tree has vigorous acropetal
Yiannis G. Ampatzidis and Matthew D. Whiting
purposes. There are issues with mechanical harvesting systems such as fruit and tree damage, difficulties in selective harvest, cost of machinery, and the need for specific tree architecture. Preliminary testing with a prototype mechanical harvester for
Gennaro Fazio, Yizhen Wan, Dariusz Kviklys, Leticia Romero, Richard Adams, David Strickland, and Terence Robinson
absorption, and interaction with soil biota) and the scion (fruit production, quality, storability, photosynthesis, tree architecture, disease and insect resistance, and climate stress tolerance). The benefits of selecting and using specific rootstocks for
David H. Byrne
Despite the hundreds of existing stone fruit (Prunus spp.) cultivars used for fresh market, there is a continuing need to develop new stone fruit cultivars as the requirements of the industry change. Over the last 20 years there has been a shift toward private breeding as the public sector decreases its support of these long-range programs. As a result there are fewer public breeding programs and many of those still operating protect their releases and partially fund their programs with royalty payments. Other trends that are shaping the development of new stone fruit cultivars are a need for smaller or more easily managed tree architecture, a trend toward the use of fewer agricultural chemicals, the expansion of production zones into the milder winter zones to allow year-round availability of stone fruit, a general diversification of fruit types being marketed, the increased awareness of the health benefits of fruit consumption, the need for better and more consistent quality, and given the global marketing of these fruit the increased need for enhanced postharvest qualities. The breeding programs of the world are responding to these trends and working toward developing the cultivars for the world markets of the future.
Dennis J. Werner and Jose X. Chaparro
Genetic interaction of the pillar (PI) and weeping (WE) growth habit genotypes was investigated in peach [Prunus persica (L.) Batsch]. Data from F2, BC1P1, and BC1P2 families showed that PI (brbr) was epistatic to the expression of WE (plpl). A unique growth habit not previously described in peach, and referred to as arching (AR), was recovered in the F2 family. Arching trees showed an upright phenotype similar to Brbr heterozygotes, but had a distinct curvature in the developing shoots. Progeny testing of AR trees revealed their genotype is Brbrplpl.
Omar Carrillo-Mendoza, Wayne B. Sherman, and José X. Chaparro
Most temperate fruit tree breeding programs pay major attention to fruit quality, chilling requirement, crop load, and tolerance to disease. In contrast, limited effort has been devoted to tree architecture and tree branching patterns ( Berthelemy
Dario J. Chavez, Thomas G. Beckman, and José X. Chaparro
. Nuclear genes. Single-copy genes associated with vernalization response (33), two major genes associated with tree architecture, and three genes expressing isozymes were included in this study. Hereafter, gene symbols will be used for these regions