Progress 10/01/12 to 09/30/17
Outputs
Target Audience:Peach growers in California and in other states. I have given presentations to peach growers and used the information that we have gained over the years from the field research and lab work on rootstocks to help them understand how dwarfing rootstocks function and thus how they can best be used in their orchards. Many growers are interested in decreasing the height of their orchards and are very interested in the potential of some of our new rootstocks to do that. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We have made presentations to local grower organizations and reported key scientific progress at international meetings of scientific organizations. What do you plan to do during the next reporting period to accomplish the goals?This project will be terminated because the PI has retired from the University.
Impacts
What was accomplished under these goals?
The final five year's of this project resulted in the culmination of 30+ years of peach rootstock research conducted by the PI of this project and numerous collaborators. As a result of 30+ years of research, 6 new size-controlling peach rootstocks were patented and released (Controller 5,6,7,8,9 and 9.5) and tested in numerous trials. In addition, more than 10 scientific publications were written that detail the performance characteristics of these rootstocks as well as providing documentation for the physiological mechanism involved in the size-controlling effects of the rootstocks on the scion. Two of the rootstocks (Controller 6 and 9) are rapidly becoming major rootstocks used in the commercial plantings of peach orchards in California.
Publications
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:Peach growers in California and in other states. I have given presentations to peach growers and used the information that we have gained over the years from the field research and lab work on rootstocks to help them understand how dwarfing rootstocks function and thus how they can best be used in their orchards. Many growers are interested in decreasing the height of their orchards and are very interested in the potential of some of our new rootstocks to do that. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We have made presentations to local grower organizations and reported key scientific progress at international meetings of scientific organizations. What do you plan to do during the next reporting period to accomplish the goals?We plan to focus research efforts on evaluating the one remaining promising new rootstock in the coming years. In addition, we will continue to develop a new research block that was planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed.
Impacts
What was accomplished under these goals?
The majority of the rootstock development part of this project is completed and the test plots have been removed. In 2013 we identified one additional rootstock in our 2007 planting that appears to have good tree size-controlling capacity, promote good fruit size on scions growing on it and may be quite low-chilling. We plan to focus research efforts on evaluating this rootstock further in the coming years. In addition, a new research block was planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed. This plot grew in 2016 and we will begin taking yield data on this trial in 2017.
Publications
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Peach growers in California and in other states. I have given presentations to peach growers and used the information that we have gained over the years from the field research and lab work on rootstocks to help them understand how dwarfing rootstocks function and thus how they can best be used in their orchards. Many growers are interested in decreasing the height of their orchards and are very interested in the potential of some of our new rootstocks to do that. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We have made presentations to local grower organizations and reported key scientific progress at international meetings of scientific organizations. What do you plan to do during the next reporting period to accomplish the goals?We plan to focus research efforts on evaluating the one remaining promising new rootstock in the coming years. In addition, we will continue to develop a new research block that was planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed.
Impacts
What was accomplished under these goals?
The majority of the rootstock development part of this project is completed and the test plots have been removed. In 2013 we identified one additional rootstock in our 2007 planting that appears to have good tree size-controlling capacity, promote good fruit size on scions growing on it and may be quite low-chilling. We plan to focus research efforts on evaluating this rootstock further in the coming years. In addition, a new research block was planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed.
Publications
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Peach growers in California and in other states. I have given presentations to peach growers and used the information that we have gained over the years from the field research and lab work on rootstocks to help them understand how dwarfing rootstocks function and thus how they can best be used in their orchards. Many growers are interested in decreasing the height of their orchards and are very interested in the potential of some of our new rootstocks to do that. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? We have made presentations to local grower organizations and reported key scientific progress at international meetings of scientific organizations. What do you plan to do during the next reporting period to accomplish the goals? We plan to focus research efforts on evaluating the one remaining promising new rootstock in the coming years. In addition, a new research block will be planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed.
Impacts
What was accomplished under these goals?
The majority of the rootstock development part of this project is completed and the test plots have been removed. In 2013 we identified one additional rootstock in our 2007 planting that appears to have good tree size-controlling capacity, promote good fruit size on scions growing on it and may be quite low-chilling. We plan to focus research efforts on evaluating this rootstock further in the coming years. In addition, a new research block will be planted in 2015 to test the best planting densities and pruning systems for deploying the new rootstocks that have been developed.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
T.M. DeJong, L. Grace, A. Almehdi, R.S. Johnson and K.R. Day. 2014. Performance and Physiology of the ControllerTM Series of Peach Rootstocks. Acta Hort 1058: 523-529.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Tombesi, S., K. R. Day, R. S. Johnson, R. Phene and T. M. DeJong. 2014.Vigour reduction in girdled peach trees is related to lower midday stem water potentials. Functional Plant Biology, 2014, 41, 1336 -1341
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Bruckner, C. H. and T. M. DeJong. 2014. Proposed pre-selection method for identification of dwarfing peach rootstocks based on rapid shoot xylem vessel analysis. Scientia Horticulturae 165:404-409.
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Peach growers in California and in other states. I have given presentations to peach growers and used the information that we have gained over the years from the field research and lab work on rootstocks to help them understand how dwarfing rootstocks function and thus how they can best be used in their orchards. Many growers are interested in decreasing the height of their orchards and are very interested in the potential of some of our new rootstocks to do that. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? We have made presentations to local grower organizations and reported key scientific progress at international meeting of scientific organization. What do you plan to do during the next reporting period to accomplish the goals? We pan to continue to focus our research on evaluation of processing peach cultivars growing on the new rootstocks and verify the production characteristics and chilling requirements of the recently discovered selection in the block of peach trees comprised of trees propagated on our most recently rootstock selections.
Impacts
What was accomplished under these goals?
In 2013, we removed most of the original fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center in 2003. We have focused on the four new rootstocks developed in this project. These four rootstocks are HBOK 10 , HBOK 27, HBOK 32 and HBOK 50. They have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These four rootstocks have root-knot nematode resistance and have been commercially released. Now that we have these size-controlling rootstocks available and know the mechanism behind their behavior we are focusing on understanding the horticultural characteristics of these rootstocks so that we can better advise the industry on their appropriate use. Funding for this project has been substantially curtailed due to decreased funding opportunities from the fresh market peach and nectarine industries. Our current focus is primarily on testing the suitability of these rootstocks for the processing peach industry. In 2013 we identified one additional rootstock in our 2007 planting that appears to have good tree size-controlling capacity, promote good fruit size on scions growing on it and be quite low-chilling. We plan to focus research efforts on evaluating this rootstock further in the coming years.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
DeJong, T.M., S. Tombesi, B. Basile and D. Da Silva. 2013. Beakbane and Thompson (1939, East Malling) Had It Right: Scion Vigour is Physiologically Linked to the Xylem Anatomy of the Rootstock.
Aspects of Applied Biology 119:51-58
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Tombesi, S., J. Marsal, B. Basile, A. Weibel, L. Solari, S. Johnson, K. Day and
T.M. DeJong. 2012. Peach Tree Vigor Is a Function of Rootstock Xylem Anatomy and Hydraulic Conductance Acta Horticulturae 932:483-489.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Almehdi A., T. DeJong, R. Duncan, J. Grant and M. McKenry. 2012. Evaluation of Rootstocks for Tolerance to Bacterial Canker, Orchard Replant Conditions and Size-Controlling in California. Acta Hort 962:435:441
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: In 2012, we removed most of the original fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center from 2003 through 2007 and focused on the four new rootstocks developed in this project. These four rootstocks are HBOK 10 , HBOK 27, HBOK 32 and HBOK 50. They have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These four rootstocks have root-knot nematode resistance and have been commercially released. Studies on the physiological mechanism involved with the size-controlling behavior of these rootstocks have been completed and published. Now that we have these size-controlling rootstocks available and know the mechanism behind their behavior we are focusing on understanding the horticultural characteristics of these rootstocks so that we can better advise the industry on their appropriate use. Funding for this project has been substantially curtailed due to decreased funding opportunities from the fresh market peach and nectarine industries. Our current focus is primarily on testing the suitability of these rootstocks for the processing peach industry. PARTICIPANTS: Dr. R. Scott Johnson (Cooperative Extension Specialist) and Mr. Kevin R. Day (UC Cooperative Extension Specialist) collaborated on this project. Ms. Rebecca Phene (Staff Research Associate) provided field assistance. TARGET AUDIENCES: The primary target audiences for this research are the peach and nectarine growers in California and the US. If the rootstocks are successful here they will likely also be used in other peach growing regions of the world. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project has culminated with the release of for commercial peach rootstocks that provide a range of size-controlling from ~60 - 90 percent the size of trees on the standard Nemaguard rootstock as well as substantial scientific evidence pertaining to the physiological mechanism involved in causing the size-controlling. There is currently much grower interest in these rootstocks because of their potential to be used in modified orchard systems that limit tree height to levels that make it possible to manage trees from the ground without ladders. If the rootstocks remain interesting in the initial grower plantings they have the potential for being used extensively in California and in other peach growing regions of the world. Knowledge of the mechanism involved in the size-controlling behavior of these rootstocks will likely make it easier to select for additional dwarfing rootstocks in the future.
Publications
- DeJong T.M., R.S. Johnson and K.R. Day. 2011. Controller 5, Controller 9 and Hiawatha peach rootstocks: their performance and physiology. Acta Hort. 903: 221-228.
- Weibel, A.M., G.L. Reighard, N.C. Rajapakse and T.M. DeJong. 2011. Dormant carbohydrate reserves of two peach cultivars grafted on different vigor rootstocks. Acta Hort 903:815-820.
- Tombesi, S., J. Marsal, B. Basile, A. Weibel, L. Solari, S. Johnson, K. Day and T.M. DeJong. 2012 Peach Tree Vigor Is a Function of Rootstock Xylem Anatomy and Hydraulic Conductance. Acta Horticulturae 932:483-489.
- Almehdi, A., T. DeJong, R. Duncan, J. Grant and M. McKenry. 2012. Evaluation of Rootstocks for Tolerance to Bacterial Canker, Orchard Replant Conditions and Size-Controlling in California. Acta Hort. 962:435:441
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: In 2011, we continued evaluation of fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center from 2003 through 2007. Three rootstocks currently recognized as HBOK 10 and HBOK 32 and HBOK 50 have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These three rootstocks have root-knot nematode resistance and were submitted for commercial release in 2010. An additional rootstock (HBOK 27) was submitted for release in 2011. This rootstock appears to have greater size-controlling capacity than those previously released. Studies on the physiological mechanism involved with the size-controlling behavior of these rootstocks was completed and published. Now that we have these size-controlling rootstocks available and know the mechanism behind their behavior we are focusing on understanding the horticultural characteristics of these rootstocks so that we can better advise the industry on their appropriate use. Funding for this project has been substantially curtailed due to decreased funding opportunities from the fresh market peach and nectarine industries. Our current focus is primarily on testing the suitability of these rootstocks for the processing peach industry. PARTICIPANTS: Dr. R. Scott Johnson (Cooperative Extension Specialist) and Mr. Kevin r. Day collaborated on this project. TARGET AUDIENCES: The primary target audiences for this research are the peach and nectarine growers in California and the US. If the rootstocks are successful here they will likely also be used in other peach growing regions of the world. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary outcome of this long-term project has been the development of 6 new peach rootstocks (two from earlier work and the four mentioned above) that have been, or are in the process of being released to growers for commercial use. In addition we have published knowledge of how these rootstocks work. It is too early to assess the impact of this project since four of the new rootstocks were just released for commercial propagation. However, it is highly likely that at least three of the four newest rootstocks eventually will be planted extensively by growers and one of the previously released rootstocks (Controller 9) is being planted by growers as fast as they are being propagated. There is currently much grower interest in these rootstocks because of their potential to be used in modified orchard systems that limit tree height to levels that make it possible to manage trees from the ground without ladders. If the rootstocks remain interesting in the initial grower plantings they have the potential for being used extensively in California and in other peach growing regions of the world. Knowledge of the mechanism involved in the size-controlling behavior of these rootstocks will likely make it easier to select for additional dwarfing rootstocks in the future.
Publications
- No publications reported this period
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: In 2010, we continued evaluation of fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center from 2003 through 2007. Three rootstocks currently recognized as HBOK 10 and HBOK 32 and HBOK 50 have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These three rootstocks have root-knot nematode resistance and have been submitted for commercial release. A fourth rootstock (HBOK27) has been identified in these trials and appears to have greater size-controlling capacity than those mentioned above. The productivity and fruit size characteristics of trees on all these rootstocks continued to be evaluated in 2010. Studies on the physiological mechanism involved with the size-controlling behavior of these rootstocks was completed and published. Knowing the physiological mechanism involved allowed us to attempt to simulate the size controlling behavior of peach rootstocks with our functional-structural model of peach tree development, growth and productivity. Now that we have these size-controlling rootstocks available and know the mechanism behind their behavior we are focusing on understanding the horticultural characteristics of these rootstocks so that we can better advise the industry on their appropriate use. PARTICIPANTS: Dr. R. Scott Johnson (Cooperative Extension Specialist) and Mr. Kevin R. Day collaborated on this project. This project also provided a training opportunity for one MS graduate student at UC Davis and a visiting PhD graduate student from Italy. TARGET AUDIENCES: The primary target audiences for this research are the peach and nectarine growers in California and the US. If the rootstocks are successful here they will likely also be used in other peach growing regions of the world. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary outcome of this long-term project has been the development of 6 new peach rootstocks (two from earlier work and the four mentioned above) that have been, or are in the process of being, released to growers for commercial use. In addition we have published knowledge of how these rootstocks work. It is too early to assess the impact of this project since three of the new rootstocks were just released for commercial propagation in 2010 and one more has yet to be submitted for release. However, it is highly likely that at least three of the four newest rootstocks eventually will be planted extensively by growers and one of the previously released rootstocks (Controller 9) is being planted by growers as fast as they are being propagated. There is currently much grower interest in these rootstocks because of their potential to be used in modified orchard systems that limit tree height to levels that make it possible to manage trees from the ground without ladders. If the rootstocks remain interesting in the initial grower plantings they have the potential for being used extensively in California and in other peach growing regions of the world. Knowledge of the mechanism involved in the size-controlling behavior of these rootstocks will likely make it easier to select for additional dwarfing rootstocks in the future.
Publications
- Tombesi, S., A.Almehdi, T.M. DeJong. 2011. Phenotyping vigour control capacity of new peach rootstocks by xylem vessel analysis. Scientia Horticulturae 127: 353-357
- Tombesi, S., R.S. Johnson, K.R. Day and T.M. DeJong. 2010. Relationships between xylem vessel characteristics, calculated axial hydraulic conductance and size-controlling capacity of peach rootstocks. Annals of Botany 105:327-331.
- Tombesi S., R.S. Johnson, K.R. Day, T.M DeJong. 2010. Interactions between rootstock, inter-stem and scion xylem vessel characteristics of peach trees growing on rootstocks with contrasting size-controlling characteristics. AoB PLANTS 2010: plq013,
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: In 2009, we continued evaluation of fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center from 2003 through 2007. Three rootstocks currently recognized as HBOK 10 and HBOK 32 and HBOK 50 have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These three rootstocks have root-knot nematode resistance and the paper-work has been submitted for commercial release. Several more new rootstocks that have the potential for size-controlling have been identified in these trials and are continuing to be evaluated. One strongly size-controlling rootstock that was previously developed from this project and was released jointly by UC Davis and USDA ARS as Controller 5 was recently found to have intermediate size-controlling capacity when use as an inter-stock between a vigorous scion cultivar and the standard Nemaguard rootstock. This discovery has interesting implications regarding the size-controlling mechanism involved in these rootstocks and also allows an alternative means for developing less vigorous trees while still using the standard Nemaguard rootstock. Now that we have these size-controlling rootstocks available we are focusing on the horticultural characteristics of these rootstocks so that we can better advise the industry on their appropriate use. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: The primary target audiences for this research are the peach and nectarine growers in California and the US. If they are successful here they will likely also be used in other peach growing regions of the world. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
It is too early to assess the impact of this project since the new rootstocks are being released for commercial planting in 2010. However, it is highly likely that at least two of the three new rootstocks that are being considered for release eventually will be planted extensively by growers. There is currently much grower interest in these rootstocks because of their potential to be used in modified orchard systems that limit tree height to levels that make it possible to manage trees from the ground without ladders. If the rootstocks remain interesting in the initial grower plantings they have the potential for being used extensively in California and in other peach growing regions of the world.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: In 2008, we continued evaluation of fifty different peach rootstocks planted in replicated trials at the UC Kearney Research and Extension Center from 2003 through 2007. Two rootstocks currently recognized as HBOK 10 and HBOK 32 have been tested over several years and have consistently exhibited moderate size-controlling capacity compared to the industry standard rootstock, Nemaguard. These two rootstocks both have root-knot nematode resistance and are currently being considered for commercial release. Another rootstock known as HBOK 50 has been identified as potentially having greater nematode resistance than Nemaguard and is also under consideration for commercial release even though it does not appear to have any size-controlling potential. Several more new rootstocks that have the potential for size-controlling have been identified in these trails and are continuing to be evaluated. One strongly size-controlling rootstock that was released jointly by UC Davis and USDA ARS as Controller 5 was found to have intermediate size-controlling capacity when use as an inter-stock between a vigorous scion cultivar and the standard Nemaguard rootstock. This discovery has interesting implications regarding the size-controlling mechanism involved in these rootstocks and also allows an alternative means for developing less vigorous trees while still using the standard Nemaguard rootstock. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
It is too early to assess the impact of this project since none of the new rootstocks that are being considered have been released for commercial planting. However, it is highly likely that at least two of the three new rootstocks that are being considered for release eventually will be planted extensively by growers. There is currently much grower interest in these rootstocks because of their potential to be used in modified orchard systems that limit tree height to levels that make it possible to manage trees from the ground without ladders. If the rootstocks remain interesting in the initial grower plantings they have the potential for being used extensively in California and in other peach growing regions of the world.
Publications
- No publications reported this period
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