ISHS Acta Horticulturae 557: VII International Symposium on Orchard and Plantation Systems
USING GRAFT TRANSMISSIBLE AGENTS IN Y-TRAINED PEACH SYSTEMS |
| Authors: | P.G. Gibson, G.L. Reighard, S.W. Scott, D.R. Ouellette |
| Keywords: | Apple Chlorotic Leaf Spot Virus, Dot Blot, Peach Latent Mosaic Viroid, Polymerase Chain Reaction, Prunus persica, ‘Ta Tao 5’, Y-trained |
| Abstract:
Physiological changes have been observed in peach trees grafted to ‘Ta Tao 5’ interstems. To investigate these effects, vegetative buds from ‘Ta Tao 5’ peach were grafted in August 1997 onto scaffold branches of two-year-old ‘Coronet’ peach trees planted in a high-density, Y-trained orchard system. Data were collected for 2 years and treated trees exhibited significant differences starting in the summer of 1998 with significantly increased light penetration. Light penetration also increased in summer 1999 in the ‘Ta Tao 5’ treated trees, and summer pruning was reduced significantly in 1998 and 1999. Autumn leaf defoliation occurred 6 days earlier in fall 1999 on the ‘Ta Tao 5’ treated trees. Bloom was delayed by 7 days in the second year (Spring 1999) after budding. Fruit maturity was also delayed in 1999. Yields were unaffected in 1998, but were significantly reduced in 1999 on treated trees, which averaged 16.1 kg/tree versus 17.8 kg/tree for the controls. Fruit quality was positively affected with increased firmness on the treated trees. ‘Ta Tao 5’ is known to be infected with Peach Latent Mosaic Viroid (PLMVd) and Apple Chlorotic Leaf Spot Virus (ACLSV), both of which are graft transmissible. Dot blots using cRNA probes confirmed the transmission of PLMVd from the ‘Ta Tao 5’ buds to the treated trees. Nested PCR was used to detect ACLSV in the treated trees. The presence of Asian Prunus Virus (also reported in ‘Ta Tao 5’) was not verified in the treatments. The application of ‘Ta Tao 5’ vegetative bud grafts resulted in the transmission of infective agents that caused physiological changes in ‘Coronet’ peach trees. This suggested that growers could utilize ‘Ta Tao 5’ to modify phenology and tree vigor in peach trees in high-density, Y-trained orchard systems. | |
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