ROOTSTOCKS, CULTIVARS, TRAINING AND CULTURE OF MULTI DENSITY DECIDUOUS FRUIT ORCHARDS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0174202
• Project Start Date: Oct 1, 2006
• Project End Date: Sep 30, 2011
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671

Performing Department
PLANT SCIENCES

Non Technical Summary
California is increasingly becoming non-competitive, even within the USA due to high production costs. Collectively these projects address several avenues of lowering tree fruit crops production costs in California's conditions through more efficient production methods; less fertilizer for stone fruits, better ability to predict when pistachios require dormancy breaking chemicals to increase crop, determining the salinity limits of pistachio establishment, mechanically harvesting olives, using temperature to eliminate prophylactic olive fly sprays, and developing the parameters of fresh fig production in California..

Animal Health Component

60%

Research Effort Categories

Basic

20%

Applied

60%

Developmental

20%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
203	1219	1060	20%
205	1099	1060	50%
205	1119	1060	10%
205	1219	1060	20%

Knowledge Area
205 - Plant Management Systems; 203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants;

Subject Of Investigation
1119 - Deciduous tree fruits, general/other; 1099 - Tropical/subtropical fruit, general/other; 1219 - Edible tree nuts, general/other;

Field Of Science
1060 - Biology (whole systems);

Keywords

stone fruits, nutrition

pistachios, chill accumulation

mechanical harvesting, salinity tolerance

olives, mechanical harvest, olive fly

figs, fresh, postharvest.

Goals / Objectives
Evaluate stone fruits, tree nut crops and the evergreen and deciduous subtropicals, olives and figs, for better production research efficiencies. Within stone fruits the focus was on determining nutrient baselines early in the spring as well as curves through the season. The pistachio projects are focusing on chill accumulation and when to apply dormant oil, evaluating mechanical harvesting, and determining the salinity tolerance of young orchards. For olives research focused on training for mechanical harvesting and controlling olive fly with ambient temperatures. For figs it focused on effect of preharvest factors on postharvest fruit quality and developing a phenology model.

Project Methods
The stone fruit nutrition study is a long term study using sand tank trials with frequent sampling to determine nutritional baselines and interactions through the season. The pistachio trials are being conducted in six production orchards, with different chill accumulations, in California. Dormancy breaking of males and females is being evaluated with and without oil applications. A phenology model was also started this year. The mechanical harvesting study is evaluating the effect of canopy tying, versus mechanical harvesting on tree harvest efficiency and yield. The salinity trial is evaluating the ability of young trees, on two different rootstocks, to establish under saline condtions. The olive study is employing temperature linked olive fly and olive fruit phenology models, and high temperature predictions, to determine when prophylactic olive fly sprays can be eliminated. The mechanical harvesting project is integrating mechanical harvester evaluations with abscission agent evaluation and processed fruit quality evaluations. Olive hedgerow plantings for better mechanical harvester efficiency are also being evaluated. For figs preharvest production practices, including growth regulators are being examined, as well as postharvest storage practices.

Progress 10/01/06 to 09/30/11

Outputs
OUTPUTS: From January 1 through December 31, 2011 the project to develop mechanical harvesting for California black ripe table olives and pistachios produced four major outcomes for the olive project and three major outcomes for the pistachios project. The first outcome was development of a prototype canopy contact olive harvester head. This harvester is smaller, more flexible and most importantly, can be fabricated more cheaply enabling smaller growers to purchase a fabricated unit or to purchase the head alone and mount on their own mobile unit and power supply. This head was evaluated in two olive orchards with split plot experimental designs, designed to evaluate the effect of mechanical pruning on mechanical harvester efficiency. The second major outcome was the determination of the modifications required to increase harvester efficiency in the next iteration being developed for 2012 testing. A fourth major outcome was the completion of sensory and consumer trials comparing hand and mechanically harvested olives that confirmed earlier results; neither sensory nor consumer panels could distinguish hand harvested olives from mechanically harvested olives. This is a significant finding because two major processors in California demanded confirmation of the viability of mechanical harvesting A fourth major output of this project was developing the research cooperation with Dr. Sergio Castro-Garcia in the Department of Rural Engineering at the University of Cordoba in Cordoba, Spain. A three month sabbatical there from September 1, 2011 through November 2011 resulted in identification, through evaluation, the best trunk shaking harvester for California's olive industry and development of a catch frame for the canopy contact harvester. The ongoing results from this project were disseminated the Glenn and Tulare County Olive Days, at two California Olive Research Subcommittee meetings, on the annual filmed online update on the project website, and in agricultural industry publications. The first major outcome of the pistachio harvester evaluation and development project was evaluating a new trunk shaking harvester technology for larger girth trees. The second major outcome was developing a prototype canopy contact harvester for pistachio trees too large for trunk shaking harvesters. The third major outcome was demonstrating the unharvested fruit left in the trees by both harvesters, and particularly the current commercial harvesters, was of marketable quality. Therefore there is a good reason to evaluate and increase harvester efficiency in addition to evaluating the effects of increasing trunk girth on harvester efficiency. These specific outcomes from both projects above were developed in late 2011 and will be disseminated in 2012 in research reports and annual commodity days for both crops. PARTICIPANTS: Both the olive and pistachio projects had a significant cooperator; Dr. Sergio Castro-Garcia from the Department of Rural Engineering, Rabanales, University of Cordoba, Spain. Dr. Castro Garcia provided analysis of trunk shakers we do not have in California, tested the Oxbo harvester d developed a catch from for this harvester. All improvements which benefitted our project. Additionally, their research results are confirming ours TARGET AUDIENCES: The target audience for the olive mechanical harvester development project is the 800 or less California live growers. They are primarily small, average 60 acres, diversified growers who are not likely to spend more money on olives. If hand harvest costs become prohibitive they will either abandon or remove the orchards. The industry is in decline. They have few early adapter so new information. The California pistachio industry is larger and growing, the average grower has over 200 acres and adapts new knowledge early. PROJECT MODIFICATIONS: The major change in the olive project is to move the focus from developing large harvesters for the large existing trees to developing smaller harvesters for hedgerow trained and mechanically pruned orchards. The major change in the pistachio project was to include canopy contact harvesters to harvest larger trees, thereby avoiding the need to increase trunk shaking force.

Impacts
The objective of this project was to develop mechanical harvesting for California black ripe processed olives. Developing harvesting for a processed product means the different components of achieving the final product, a marketable olive, must be evaluated simultaneously. As the harvester is developed and evaluated, the existing orchards, and how they need to be pruned, and new orchards and how they must be trained, and the effects of harvesting on long-term tree health must be considered. Finally, the effect of the harvesting on processed fruit quality must be considered. These are very long-term projects because the final goal is development of a reliable production practice. The development and testing of mechanical harvesters for the California black ripe olive industry within this project has not reached the point of producing olive harvesting technology that the California commercial harvester fabrication industry has agreed to produce for commercial sale. However, research thus far has had an impact on how existing orchards are being pruned and how new orchards are being developed. Our four of eight years of data demonstrating that mechanically hedged and topped orchards can produce as well as hand pruned orchards, with the added benefit of less alternate bearing, has resulted in one major grower now adopting mechanical pruning. Our demonstration that a moderate density hedgerow orchard initially trained on a wire trellis, and then mechanically pruned, yields as well as conventionally vase trained trees has convinced two major growers to plant hedgerow orchards; approximately 800 acres. In cooperation with Dr. Sergio Castro-Garcia we identified commercial harvesters in Spain that Mr. Dennis and Heath Burreson of Glenn County will be purchasing. The second major outcome of this project was to demonstrate, through use of sensory panels and consumer panels that mechanically harvested olives are commercially marketable. A third major impact has been to demonstrate that fruit removal force is not related to final harvester efficiency where as fruit weight is. This strongly suggests fruit weight is important in mechanical harvesting and that growers should chemically thin to achieve maximum harvest efficiency. In summary, the major outcomes/impacts of this project have been first, how to train future orchards for mechanical harvesting and how to mechanically prune current orchards for adaptation for mechanically harvest. The second impact was to demonstrate mechanically harvested olives are commercially viable and the third was to demonstrate final harvester efficiency is a function of fruit weight more than fruit removal force. The project to evaluate mechanical harvesting technologies for large girth pistachio trees has produced two impacts. First, growers now realize they do not know the final harvest efficiencies of the harvesters they are contracting, and second, they no know the unharvested crop in the tree is marketable and of economic value. As a result pistachio growers are now testing the potential efficiency of their current harvesters.

Publications

• No publications reported this period

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: This is the interim report for the fourth and final year of a project to develop economically feasible mechanical harvesting for California black ripe 'Manzanillo' table olives. Harvests have been completed. The engineering analysis of the operating parameters of each harvesting technology evaluated will be completed before the presentation of the final 2011 proposal presentation (16 February 2011). The sensory and consumer evaluations of the harvested fruit will be completed in spring and summer of 2011 and a full final report submitted by September 31, 2011. The objectives of this project were defined by, in order, the most limiting factors to mechanical harvesting; 1) fruit damage; 2) effective fruit removal technology; and 3) developing an economically viable harvester and defining its operating parameters. At this point, fruit damage has largely been eliminated and both canopy contact and trunk shaking technologies have been demonstrated to be effective fruit removal technologies. However, in practice both harvesting technologies are limited by tree canopy shape and by their respective platforms. To achieve these objectives we focused on evaluating canopy contact and trunk shaking harvest technologies, evaluating the processed product, preparing trees with young orchard development and mature tree mechanical pruning, and evaluating potential abscission agents. PARTICIPANTS: Louise Ferguson, Extension Specialist, Department of Plant Sciences, 2037 Wickson Hall, Mail Stop II, UC Davis, 1 Shields Ave., Davis CA 95616, [phone] [Office], [phone] [Cell], [e-mail] Jean-Xavier Guinard, Professor, Department of Food Science and Technology, UC Davis, [e-mail] Uriel Rosa, Associate Professor, Department of Bioagricultural and Mechanical Engineering, UC Davis, [e-mail] Jacqueline Burns, Professor, Department of Horticulture, University of Florida, [e-mail] Cooperating Personnel: Soh Min Lee, PhD Candidate, Food Science and Technology, UC Davis Sergio Castro Garcia, Visiting Scientist from University of Cordoba, Spain Kitren Glozer, Associate Project Scientist, UC Davis William H. Krueger, UCCE Farm Advisor, Glenn County Elizabeth J. Ficthner, UCCE Farm Advisor, Tulare County Neil O'Connell, UCCE Farm Advisor, Tulare County Mari-Paz Suarez, Visiting Scientist, University of Seville, Spain John Ferguson, Volunteer Peter Kaleko, Volunteer Skander Slama, Volunteer Industry Cooperators Ranch Cooperators Harvester Cooperators Processor Cooperators Rocky Hill Ranch DSE Bell Carter Olives Erick Nielsen Ranch Erick Nielsen Inc. Musco Family Olive Company TARGET AUDIENCES: The target audience for this information is California's approximately 823 table olive growers comprising the 22,000 acre industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In 2010 this project simultaneously focused on two major objectives: 1) improving the harvesting technology; and 2) increasing harvester efficiency by adapting current orchards with mechanical pruning and developing new hedgerow orchards. The 49 - 62% final efficiency for the Canopy Contact I head was expected. Our 2010 data confirms this; the overall efficiency of the head has not improved, remaining below 64%. The Canopy Contact I head was 7.08% more efficient in mechanically hedged and topped trees having a statistically significant 57.35% average final efficiency in mechanically pruned rows versus 50.27% efficiency in conventionally pruned rows. However, these mechanically topped and hedged trees also had a statistically significant 19.4% lower yield per acre. As harvesting technology efficiency improves, we can determine if the significant decrease in harvest cost will offset the gross return losses generated by mechanical topping and hedging to produce an equal or greater net return. Our results strongly indicate a hedgerow configuration generated by annual 12 foot topping, every other year mechanical hedging 6 feet from the trunk, and 4 foot skirting will produce the flat "wall" of hanging olive shoots that make the fruit most accessible to the canopy contact head. The preliminary 2010 data confirms the 2008 fruit quality data. Both canopy contact heads and trunk shaking can produce a high percentage of cannable olives with low cull percentages equal to those of hand-harvested controls. The percentage of culls is a better method of evaluating harvest technology effects on fruit quality than the total adjusted price per ton as the latter can be strongly affected by fruit size percentages. There was a significant difference in cull percentages between the hand and machine harvested fruit between the two processors. The next step should focus primarily on engineering and be directed by an engineer in cooperation with a commercial harvester fabricator. In conclusion, this four-year project has successfully achieved some of its major objectives. First, the primary limiting factor to mechanical harvesting, final processed fruit quality, has been eliminated. Second, the best two potential harvesting technologies, canopy contact heads and trunk shakers have been identified and refined. For the latter, trunk shakers, the problem of trunk damage has also been eliminated. Third, how to improve harvesting efficiency through tree training and mechanical pruning, and how this will affect net return is being determined.

Publications

• L. Ferguson1, U.A. Rosa2, S. Castro-Garcia3, S.M. Lee4, J.X. Guinard4, J. Burns5, W.H. Krueger1, N.V. O'Connell1, K. Glozer1 Mechanical harvesting of California table and oil olives. Adv. Hort. Sci., 2010 24(1): 53-63

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Report outputs completed during the reporting period that contribute to the goals and objectives of the project (do not include publications here; they are to be reported separately in the block below). Do not include findings or conclusions that have been reached; these are to be reported separately as changes in knowledge in the outcomes section. Include a description of how the results have been disseminated to communities of interest or how the product is being shared. If this is a final report, give a brief summary of the most significant outputs and dissemination activities for the entire life of the project. more ... The "Developing Mechanical Harvesting of California Black Ripe Table Olives" project funded by the California Olive Committee will be completing its third of four years of data collection by the end of fall 2009. The outputs of this ongoing project are being shared through a series of ongoing field days and a continuously updated website. The objective at all events is to demonstrate the latest findings in the development of mechanical harvesting, how they could be utilized and what effect they would have on an individual grower's final net return. Events Glenn County Olive Day: April 16, 2009, Orland CA, 126 attendees Tulare County Olive Day: April 23, 2008, Tulare CA, : 75 attendees Tulare County Preharvest Meeting: August 18, Lindcove Field Station, 47 attendees Glenn County Preharvest Meeting September 7, 2009, Orland Farm Bureau, Orland: 28 attendees Nickles Estate September 29 through October 1,2 and 3, 2009, Arbuckle, Ca , 79 attendees Products The following website is being continuously updated: HTTP://groups.UCANR.org/olive_harvest/ An interactive cost study was developed to demonstrate to growers how mechanical harvesting how mechanical harvesting would affect their net return Services: The following growers are being continued to be advised in their establishment of 800 acres of new olive planting based on these results. Dennis Burreson of Burreson Farms; Glenn county and Javier Garcia of Garcia Farms, Glenn County. PARTICIPANTS: Academic Cooperators: Louise Ferguson Uriel Rosa, Jacqueline Burns, Sergio Castro, Kitren Glozer, Neil O'Connell, Bill Krueger, Soh Min, JX Guinard, John Ferguson and Martipaz Suarez Garcia Ranch Cooperators Rocky Hill Ranch, Nielsen Orchards, Burresson Ranches Processor Cooperators: Bell Carter Olives and Musco Family Olive Company Processing Plants Equipment Cooperators: ENE Enterprises, Agright Inc. and Gold Coast Hydraulics TARGET AUDIENCES: The target audience for this project is the 831 California black ripe table olive growers, who collectively grow 23,421 acres of olive, and who harvest by hand. Of these, thus far two growers, Dennis Burreson and Javier Garcia, both of Glenn County, have planted 800 new acres based on our research results. PROJECT MODIFICATIONS: The major change in this project is that work on abscission chemicals to decrease fruit detachment force and aid harvesting has been discontinued. Our approach of branch trials with potential compounds was not producing any viable results. We need to reexamine our approach and design anew experimental approach.

Impacts
Impact #1. Our research has resulted in three major harvest equipment fabricator/ contract harvester companies; ENE Inc, Coe Harvesters and Agright Harvesting producing new harvesters for us to test in 2009. A fourth harvester is being produced by a grower and Chico State is cooperating with us in developing two other harvesters. These harvesters were successfully tested in 2009. Impact #2.This research has resulted in 800 new acres being established at Burresson and Garcia Farms in Glenn County, using our training system

Publications

• Development of (a) Canopy Shaking and (b) High Frequency Trunk Shaking Machines for Mechanical Harvesting of California Table Olives U. A. Rosa and L. Ferguson: 2009. Annual Report to the California Olive Committee. 12 pp. http://groups.ucanr.org/olive_harvest/Proposals_%26_Reports_Database/
• Developing Mechanical Harvesting for California Black Ripe Processed Table Olives: 2007-2010: Year 3/4 Progress Report: L. Ferguson, J. Burns, J.-X. Guinard and U. Rosa: 2009. 38 pp. http://groups.ucanr.org/olive_harvest/Proposals_%26_Reports_Database/

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Research continues on the stone fruit trials for confirming early season nutritional curves with the objective of detecting and correcting nutritional deficiencies within the season. The pistachio rootstock salinity trial continues. The objective is to determine the soil water extract electroconductivity (ECe expressed in dSm) at which young tree growth and establishment suffers. These results were reported at the Pistachio Day, January 17, 2008 in Visalia California to 389 paticipants. The results were discussed in an educational presentation at the Pistachio Production Short Course Nov. 3-6, 2008 to 113 participants in Visalia, California. The results are also disseminated online at: http://ucce.ucdavis.edu/datastore/datastoreview/showpage.cfmreportnu mber=612&catcol=2806&categorysearch=Pistachio. Progress in the olive hedgerow project and mechanical harvesting project can be viewed at Http://Groups.UCANR.org/olive_harvest/. Meetings disseminating these result were held April 16 in Orland, California, (76 participants), and May 18th in Tulare California, (47 participants) and August 15th, (38 participants) in Tulare California. An Olive Oil Production Short Course was held in Lodi, California April 18 & 19th, 2008 (127 participants). PARTICIPANTS: The University and commercial participants in this project include : Jackie Burns Ph.D. Professor [e-mail] Department of Horticulture U. of Florida Uriel Rosa Ph.D. Assoc. Professor [e-mail] Department of Bioagricultural and Mechanical Engineering UC Davis Jean-Xavier Guinard Ph.D. Professor JX [e-mail] Department of Food Science and Technology UC Davis William H. Krueger; Farm Advisor, Glenn County [e-mail] Neil O'Connell; Farm Advisor, Tulare County NVO'[e-mail] Mr. Rich Jacobsen Rocky Hill Ranch, Exeter California Dave Smith Exeter, CA [e-mail] DSE Matt Coe Coe Orchard Machinery Gridley CA. 530-682-8061 530-695-5121 Erick Nielsen [e-mail] Erick Nielsen Enterprises 4453 County road O Orland CA 95963 Office Phone: [phone] or 530-865-9409 Mobile Phone: [phone] Fax: [phone] Phil Scott Agright Enterprises [e-mail] 12657 Road 28 1/4th Madera CA 93637 Office Phone: [phone] and 3328 Judd Carter [e-mail] Bell Carter Olives Oroville, CA Nicholas Musco [e-mail] Musco Family Olive Company Tracy CA TARGET AUDIENCES: Pistachios: the approximately 1,200 commercial pistachio growers, production managers and crop consultants in California and Arizona. Olives: the approximately 600 commercial olive growers, production managers and crop consultants in California and Arizona. PROJECT MODIFICATIONS: Stone fruits : none. Pistachios : none. Olives : Due to the commercial harvester fabricators developing new trunk shaking and canopy picking head machines we have incorporated evaluation of these machines into our project in 2008 and did preliminary evaluations for incorporating them more fully in 2009.

Impacts
The stone fruit nutrition work has not been implemented within California's stone fruit industries yet. The objective of the pistachio rootstock salinity trial is to determine the soil water extract electroconductivity (ECe expressed in dSm) at which young tree growth and establishment suffers. Treatments were designed to reflect local poor quality groundwater supplies mixed with good quality aqueduct water. Results thus far suggest trees on pistacia Atlantica X p. Integerrima hybrid rootstocks tolerate soil salinity above 5 dSm better than trees on p. Integerrima rootstocks. The trees should reach bearing in 2010. The pistachio roostock salinity evaluations have resulted in approximately 8,000 acres of pistachio trees on the hybrid p.Atlantica x p.Integerrima rootstock being planted in marginal class II soils with marginal, saline water supplies. The olive hedgerow trials demonstrate young trees trained to a an upright canopy with a canopy width of 2m, skirted at 1m and topped at 6m produce as well as trees trained to a normal canopy. This trial should be completed in 2010 if the yields plateau within the alternate bearing cycle. The table olive industry continues to decline (over 3,000 acres removed) even as the olive oil industry continues to increase (> 10,000 acres total), due to the same factor; economically feasible harvesting. Hedgerow oil olives can be mechanically harvested and table olives cannot be due to fruit and trunk damage. Two years of a four year project evaluating mechanical olive harvesters has been completed. The evaluation of mechanical olive harvesters demonstrated picking head harvesters have improved and damage is within tolerable limits. Trunk shaking harvesters produced good quality fruit in 2008 but the harvester produced unacceptable trunk damage. No good potential abscission compounds have been identified. However, the continued efforts by UC researchers to develop a feasible mechanical harvester for table olives has resulted in the harvester fabrication industry developing three new prototypes for UC researchers to evaluate in fall 2009.

Publications

• No publications reported this period

Progress 01/01/07 to 12/31/07

Outputs
Within the stone fruit trial seasonal nutrition curves for establishing early deficiencies, and within season correction, are tentatively established but require confirmation. The pistachio salinity trial is confirming earlier indications that pistachios can be established in soil water ECs up to 8 dS/m and that the CB1 is the most salt tolerant rootstock. The picking head olive harvester has a final effective mechanical efficiency of 72% but produces fruit damage. However, fruit damage is not always obvious after ripe black processing. Thus far hedgerow olive orchards produce as well as conventionally pruned trees, and can be harvested with a pistachio trunk shake harvester. Within the fig trial 'Sequoia' a calimyrna type fig with a large fruited breba has been patented. The postharvest program has tentatively identified additional cultivars for fresh production; the trial is still non-bearing.

Impacts
The stone fruit information has yet to be implemented. The pistachio rootstock trials have resulted in major orchard establishment in saline ground using blended ground and canal water supplies as growers replace cotton with pistachios; approximately 10,000 acres or 6% of the industry. The olive harvesting program has not affected the industry greatly; only two growers of 983 use a picking head harvester. The fresh fig industry using conventional varieties increased fresh fig production by 13% and over 1000 acres of the previously released, unpatented 'Sierra' have been planted.

Publications

• No publications reported this period

Progress 01/01/06 to 12/31/06

Outputs
Pistachios - The original California Pistachio Rootstock Trial plots were not used in 2006. A new trial to further characterize rootstock tolerance of salinity was established in Kern County. Thus far the results are demonstrating that trees on rootstocks with Pistacia integerrima parentage, the Integerrima (AKA Pioneer Gold I or PGI) and the hybrid of P.atlantica X P. integerrima (AKA University of California Berkeley I or UCB-1) are more sensitive to salinity than trees on P. atlantica rootstocks. The salinity threshold and slope established by previous trials is 9.4 dS/m and 8.4% respectively This indicates pistachio rootstocks are more tolerant of salinity than date palms. As these trial progresses through bearing it will be determined if long term salinity is more deleterious than these initial results suggest.

Impacts
Pistachios-the information developed about rootstock salinity tolerance of UCB-1 has resulted in it being the second best selling rootstock in California. Foundation Plant Materials Services produced 1.7 million seeds this year has sold half of them thus far. Additionally Duarte Nurseres has cloned over 1K of UCB1for planting in 2007.

Publications

• None 2006

Progress 01/01/05 to 12/31/05

Outputs
Pistachios - The California Pistachio Rootstock Trial plots are now being used to develop additional information about the effect of rootstocks upon scion growth and productivity. Thus far the results are demonstrating that trees on rootstocks with Pistacia integerrima parentage, the Integerrima (AKA Pioneer Gold I or PGI) and the hybrid of P.atlantica X P. integerrima (AKA University of California Berkeley I or UCB-1) have multiple growth flushes within a season. The buds on these successive flushes are different in origin; buds of the first flush are formed the previous year, preformed, versus buds on later flushes which are formed in the current year, neoformed. These buds appear to be equally productive but the latter are more likely to be less well developed and abscise prematurely. It does not appear rootstock greatly influences end of season carbohydrate status suggesting carbohydrate depletion is not the mechanism of alternate bearing. Thus far it appears decreasing the neoformed growth would decrease management costs by decreasing pruning costs. This suggests mechanical pruning is the best option for trees on all rootstocks.

Impacts
Pistachios-the information developed about UCB-1 has resulted it in being the second best selling rootstock in California. Foundation Plant Services produced and sold 545,000 seed in November, 2005. Additionally, Duarte Nurseries selected a specific rootstock based on the data produced and is now vegetative propagating this individual rootstock; approximately 300 acres have been planted thus far.

Publications

• Ferguson, Louise, H, Reyes, B. Sanden, S.Grattan, L.Epstein, and W.H.Krueger. 2005. Pistachio Rootstocks: in Pistachio Production Manual, Fourth Edition 2005. Ed. L. Ferguson. Fruit and Nut Research and Information Center. Pp 67-74

Progress 01/01/04 to 12/31/04

Outputs
The California Pistachio Rootstock Trials, with four locations for different purposes; all four were used for yield, one was used to evaluate Verticillium tolerance, and one one location for salinity tolerance. All were concluded in 2002. The trials all investigated the behavior of the 'Kerman' female and 'Peters' male on three different rootstocks. The three rootstocks were Pistacia atlantica, Atlantica, P. integerrima, Integerrima, and two hybrids of the two, P. atlantica X P. integerrima, PGII and UCB-1. The results demonstrate trees on Atlantica rootstocks or the two hybrids had significantly better cold tolerance than trees on Integerrima rootstocks. Trees on Integerrima and UCB-1 had equal, and superior, tolerance of Verticillium relative to trees on Atlantica or PGII. Tree on UCB-1 produced significantly better yields than trees on the other rootstocks. Trees on all three rootstocks had equal tolerance of salinity up to 8 dS/m soil salinity but at 12 dS/m trees on UCB-1 lost 35% of their yield while trees on the other rootstocks only suffered 15-28% losses in yield. Within these rootstocks individual trees with superior yields, Verticillium and salinity tolerance have been identified and the germplasm is being preserved for further trials when vegetative propagation of rootstocks can be successfully developed. Since 2003 molecular markers have been done of several of the UCB-1 rootstocks in the above trials to identify the more productive and Verticilllium tolerant rootstocks. A commercial nursery is now interested in propagating some of the superior UCB-1 rootstocks. Cherry: Several sweet cherry rootstock trials have been established over the years. We have evaluated about 20 Prunus mahaleb selections at 5 different sites throughout California since 1996. In 2001, we identified three new improved rootstocks from those evaluations and submitted patents on the 3. Each rootstock is propagated through vegetative means and are more uniform in growth and production than those typically produced through seed. Each rootstock had been screened for resistance to Phytophthora, which is the most problematic disease for mahaleb rootstocks. Other features include low suckering, high productivity, tree size control and high yield efficiency compared with standards currently available.

Impacts
Pistachios - the combined results have demonstrated UCB-1 is a superior rootstock combining cold, Verticillium and salinity tolerance with significantly better yields when budded with a 'Kerman' scion. It is becoming a leading rootstock in the industry. We are now observing a field trial of some of these rootstocks obtained from tissue culture. The objective will be to provide selected rootstocks produced clonally. Cherry - we expect that these rootstocks will either replace the standard Mahaleb rootstock or be an additional option for cherry growers in California.

Publications

• Ahmad, Riaz, L. Ferguson and S. Southwick. 2004. Analyses of pistachio rootstocks by simple sequence repeat and sequence-related amplified polymorphisim molecular markers. Journal of Horticultural Science and Biotechnology. In press.
• Epstein, L., R. Beede, S. Kaur and L. Ferguson. 2004. Rootstock effects on pistachio trees grown in 'Verticillium dahliae' infested soil. Phytopathology 94 (4):345-349. 3.Southwick, S.M. 2003. Mahaleb rootstock named 'UCMH 55'. United States Patent, Plant 2003-0126662, July 3, 2003.

Progress 01/01/03 to 12/31/03

Outputs
The California Pistachio Rootstock Trials, with separate trials for yield, three locations, Verticillium tolerance, one location and salinity tolerance, one location, were all concluded in 2002. The trials all investigated the behavior of the 'Kerman' female and 'Peters' male on three different rootstocks. The three rootstocks were Pistacia atlantica, Atlantica, P. integerrima, Integerrima, and two hybrids of the two, P. atlantica X P. integerrima, PGII and UCB-1. The results demonstrate trees on Atlantica rootstocks or the two hybrids had significantly better cold tolerance than trees on Integerrima rootstocks. Trees on Integerrima and UCB-1 had equal, and superior, tolerance of Verticillium relative to trees on Atlantica or PGII. Tree on UCB-1 produced significantly better yields than trees on the other rootstocks. Trees on all three rootstocks had equal tolerance of salinity up to 8 dS/m soil salinity but at 12 dS/m trees on UCB-1 lost 35% of their yield while trees on the other rootstocks only suffered 15-28% losses in yield. Within these rootstocks individual trees with superior yields, Verticillium and salinity tolerance have been identified and the germplasm is being preserved for further trials when vegetative propagation of rootstocks can be successfully developed. Cherry: Several sweet cherry rootstock trials have been established over the years. We have evaluated about 20 Prunus mahaleb selections at 5 different sites throughout California since 1996. In 2001, we identified three new improved rootstocks from those evaluations and submitted patents on the 3. Each rootstock is propagated through vegetative means and are more uniform growth and production than those typically produced through seed. Each rootstock had been screened for resistance to Phytophthora, which is the most problematic disease for mahaleb rootstocks. Other features include low suckering, high productivity, tree size control and high yield efficiency compared with standards currently available.

Impacts
Pistachios - the combined results have demonstrated UCB-1 is a superior rootstock combining cold, Verticillium and salinity tolerance with significantly better yields when budded with a 'Kerman' scion. It is becoming a leading rootstock in the industry. Cherry - we expect that these rootstocks will either replace the standard Mahaleb rootstock or be an additional option for cherry growers in California.

Publications

• Ferguson, L., Reyes, H.C., Sanden, B., Grattan, S. and Heath. Z. 2002. Salinity tolerance evaluation of pistachio rootstocks; 1994-2002. California Pistachio Industry Annual Report; Crop Year 2002-2003. pp. 122-124.
• Southwick, S., Grant, J., Yeager, J., Glozer, K. and Hansen, R. 2002. Evaluation of Mahaleb rootstock clones. 2002 CCAB Research Report, California Cherry Advisory Board, pp. 1-14.
• Southwick, S.M. 2003. Mahaleb rootstock named 'UCMH 55'. United States Patent, Plant 2003-0126662, July 3, 2003.
• Southwick, S.M. 2003. Mahaleb rootstock named 'UCMH 56'. United States Patent, Plant 2003-0126654, July 3, 2003.
• Southwick, S.M. 2003. Mahaleb rootstock named 'UCMH 59'. United States Patent, Plant 2003-0126655, July 3, 2003.

Progress 01/01/02 to 12/31/02

Outputs
The California pistachio rootstock trials consist of four plot locations and contain three experiments. The trials began in 1989 and are being concluded in the winter of 2002-2003. The trials investigated relative productivity of four different commercial pistachio rootstocks, P. integerrima, P. atlantica, and two hybrids of the two species, in the three major production locations. The results demonstrated trees on all rootstocks produced the best yields in the lower San Joaquin Valley where heat units are higher and soils are deeper, and have a higher clay and boron content. Trees on P. atlantica X P. integerrima rootstocks produced the best yields, followed by trees on P. integerrima and P. atlantica. All four rootstocks produced well with irrigation water up to 8 dS/m but yields declined with more saline water. Trees on P. integerrima and P. atlantica X P. integerrima were equally resistant to Verticillium, and more resistant, than the other interspecific hybrid and P. atlantica, in that order. Pistachios will be most productive if grown on either P. atlantica X P. integerrima or P. integerrima. They can be irrigated with reclaimed water or other poor quality ground water. We have established 5 trial sites in California to evaluate the performance of a diverse group of sweet cherry rootstock candidates. We have been able to develop a group of Prunus mahaleb (mahaleb) rootstocks that have resistance to several strains of Phytophthora spp. From this group we have identified 3 rootstocks that will be released to the industry in the next 1 to 2 years. Patents have been filed and they are under review by the United States Patent Office. Each of the 3 rootstocks can be propagated from cuttings. Typically, mahaleb is propagated by seed and is widely planted in California and the world. There is a substantial variation from tree to tree as a result of the out- crossing used to produce seed for rootstock. Rootstock propagation by cuttings will reduce tree-to-tree variation in field performance. We have found that mahaleb selections 155-1 and 156-5 survive at problem sites while other selections including all standard rootstocks have losses of 40 percent or more. Mahaleb selection 159-5 reduces tree height by approximately 15 to 20% and improves yield efficiency by 6-fold. All rootstocks produce yields as high or higher than standards with equivalent fruit size. In additional trials, we have found that several rootstocks imported from Germany are very dwarfing. They include Gi 148-1, 148-2, 148-8, 209-1, Weiroot 154 and from France Edabriz. These rootstocks are very precocious and tend toward overproduction of flowers. High numbers of flowers can lead to excessive fruit set and small fruit. Continuing efforts will focus on how to manage the overproduction of flowers to insure adequate fruit size.

Impacts
The cherry rootstock project has led to the release of 3 new and improved cherry rootstocks for the California cherry industry. We anticipate that growers will readily accept these rootstocks and plant them. The pistachio rootstock project has demonstrated that this research has demonstrated water previously thought unusable for agricultural production can be used to grow pistachios. With the water allocation decreases initiated in 2003 the information developed here will be used in California pistachio production.

Publications

• S.M. Southwick, K. Glozer, J. Grant and R. Hansen. 2002. Sweet cherry rootstock evaluation and development. Annual report California Sweet Cherry Advisory Board.
• Pistachio Rootstocks Influence Scion Growth and Ion Relations under Salinity Stress and Boron Stress. L. Ferguson, J.A. Poss, S. Grattan, C.M. Grieve, D. Wang, C. Wilson, T.J. Donovan and C.T, Chao. 2002. Journal of the American Society pf Horticultural Science. Vol. 27, No. 2, 194-199.

Progress 01/01/01 to 12/31/01

Outputs
The California pistachio rootstock trials consist of four plot locations. Three projects are conducted within the four plots. The Kearney Agricultural Center (Fresno County), S&J Ranch (Fresno County) and the Paramount Ranch (Kern County), plots were all established in 1989, and are the rootstock evaluation trial. The West Side Field Station plot (Fresno County), established 1992, is dedicated to evaluating rootstock Verticillium tolerance. Within the Paramount plot 64 trees are the rootstock salinity tolerance trial established in 1994. All three trials are demonstrating clear results. In the roostock yield evaluation trial the two hybrid rootstocks, UCB-1 and PGII, both P. atlantica x P. integerrima hybrids, are producing significantly better yields than P. integerrima or P. atlantica, in that order. The significantly better yields are the result of more clusters per tree, not more nuts per cluster or larger nuts. Additionally, three individual trees of each hybrid have been identified and attempts are being made to produce rootstock suckers for clonal propagation. The Verticillium trial is demonstrating clear differences in rootstock tolerance. Trees on P. integerrima and one hybrid of P. atlantica x P. integerrima, UCB-1, are demonstrating equal tolerance of Verticillium. Trees on the second P. atlantica X P. integerrima hybrid, PGII, and P. atlantica, are displaying significantly less tolerance, including mortality, in the given order. The salinity trial is demonstrating all rootstocks possess tolerance of irrigation water salinity up to 8 dS/m. Above 8 dS/m the rootstocks rank in salinity tolerance as follows: P. integerrima, the two P. atlantica X P. integerrima hybrids, and P. atlantica. Interestingly, significant decreases in tree transpiration for trees on all four rootstocks begin at 4 dS/m. These results suggest among tree fruits, pistachios are second only to date palm in tolerance of saline soils and irrigation water. All three of the above trials will be continued through 2002.

Impacts
Results from the three trials above have contributed to an increase in UCB#1 rootstocks use in all production areas. The research in the salinity trial has contributed to pistachios now being planted on poor quality ground on the West Side of the San Joaquin Valley in areas with poor quality sodic soils and poor quality saline irrigation water.

Publications

• No publications reported this period

Progress 01/01/00 to 12/31/00

Outputs
The major project we worked on was continuation of a field project designed to determine the salinity tolerance of, and differences among, the four major commercial pistachio rootstocks. The results demonstrated all three currently commercial pistachio rootstocks are tolerant to 8 dS/m. Above 8 dS/m, at > 10 dS/m soil solution extract, the rootstocks ranked as follows; Pistacia integerrima, P. Atlantica, P. atlantica, X P integerrima. There were no significant differences among the rootstocks. Despite the lack of effect on yield there were significant differences in water uptake by trees at different salinity levels. This suggests the effects of irrigating with saline water are long term and gradual. This makes pistachio rootstocks the most salt tolerant tree fruit crop grown in California, other than dates. This also means pistachios can be grown in areas with marginal quality water and irrigated with reclaimed water. A second major project we continued in 1999 demonstrated trunk girdling Calimyrna figs significantly improves size. However, after four sequential years of girdling the trees are displaying some signs of decline. This suggests girdling should be done on an every other year basis. The results mean a larger proportion of the crop can be sold as higher value dried figs as opposed to being processed into paste. A third major project we continued this year was evaluating the redesigned olive harvester. Currently evaluations of mechanical pruning treatments for mechanically harvested trees indicate that while a hedgerow of four-meter high trees with one meter skirts and a total canopy width of 3.7 meters provide maximum fruit removal surface it decreases crop lead too much. Continuing investigations will focus on methods of hand pruning that make the fruit accessible without decreasing crop load as much. A fourth major project completed this year was an evaluation of rootstocks for Satsuma mandarins. This project demonstrated C-35 rootstocks produce significantly better yields than seven other rootstocks tested, primarily because they produce higher percentages of larger sized fruit.

Impacts
The impact of the pistachio project will be long term. Based upon the data developed in this experiment pistachios are now being planted on marginal ground with poor quality water in areas with no previous permanent tree crops. Additionally, poor quality drainage and well water, as opposed to more expensive aqueduct water, can be used for irrigation. The impact of the fig girdling project is already being felt in higher returns. California fig growers were able to direct an average of 17% more of their crop into higher paying dried figs sales as opposed to lower return fig paste. The mechanical hedging of olives project resulted in 13 of the crop in California being mechanically harvested in 2000. The Satsuma mandarin project has already resulted in a shift to using C-35 rootstocks.

Publications

• No publications reported this period

Progress 01/01/99 to 12/31/99

Outputs
The major project we completed in 1999 was a combined field and greenhouse project designed to determine the salinity tolerance of, and differences among, the major commercial pistachio rootstocks. The results demonstrated all three currently commercial pistachio rootstocks are tolerant to 8 dS/m. Above 8 dS/m the rootstocks ranked as follows; Pistacia integerrima, P. Atlantica, P. atlantica, X P integerrima. This makes pistachio rootstocks the most salt tolerant tree fruit crop grown in California, other than dates. This also means pistachios can be grown in areas with marginal quality water and irrigated with reclaimed water. A second major project we completed in 1999 demonstrated trunk girdling Calimyrna figs significantly improves size and does not harm the trees. This means a larger proportion of the crop can be sold as higher value dried figs as opposed to being processed into paste. A third major project we completed this year demonstrated the newly developed mechanical olive harvester can successfully remove 90% of the accessible fruit. Currently evaluations of mechanical pruning treatments for mechanically harvested trees indicate a hedgerow of four meter high trees with one meter skirts and a total canopy width of 3.7 meters provide maximum fruit removal surface. However, mechanical pruning does decrease crop load. Economic evaluations of both practices will be done in 2000.

Impacts
Based upon the data pistachios are now being planted on marginal ground with poor quality water in areas with no previous permanent tree crops. Because of this research California fig growers were able to direct an average of 17% more of their crop into higher paying dried figs sales as opposed to lower return fig paste. The mechanical hedging of olives project resulted in 7% of the olive crop in California being mechanically harvested in 1999.

Publications

• No publications reported this period

Progress 01/01/98 to 12/31/98

Outputs
The California pistachio rootstock trial evaluated four rootstocks, P. ATLANTICA, P INTEGERRIMA (PGI) and two hybrids of P. ATLANTICA X P. INTEGERRIMA (UCB-1 and PGII) in four typical microclimates. Earlier results demonstrated differential cold tolerance of the young budded trees as follows, from best to worst; Atlantica, UCB-1, PGII, PGI. Yield results demonstrate trees on UCB-1 rootstocks produce the best yields, in all four microclimates, followed by trees on PGII, PGI and Atlantica rootstocks. All four rootstocks are unaffected by salinity up to 8 dS/m but at 12 dS/m UCB-1 suffered a 49% decrease in marketable yield, followed by Atlantica with 19%, PGII with 18% and PGI with 14%. The significant differences in yield among the trees are a result of trees on rootstocks with P. INTEGERRIMA parentage being significantly larger trees by girth and a having a significantly higher number of fruit clusters per tree. There are no significant difference among trees grown on the four different rootstocks in the number of nuts per cluster, or the quality factors of percentage of split or blank nuts. Trees on PGI and UCB-1 rootstocks are significantly more tolerant of low levels of VERTICILLIUM DAHLIAE (less than 2 microsclerotia per gram of dried soil) than trees on PGII or Atlantica rootstocks. However, 16 of tree on UCB-1 rootstocks are demonstrating poor or compromised growth after six years in the ground.

Impacts
(N/A)

Publications

• FERGUSON, L., ET AL. 1997. California pistachio rootstock trials. 1999 California Pistachio Rootstock Trials, California Pistachio Commission Annual Report.

Progress 01/01/97 to 12/01/97

Outputs
The California pistachio rootstock trials have completed their period of juvenile evaluation; 1989-1997. The trials evaluated four rootstocks, PISTACIA ATLANTICA, (Atl), P. INTEGERRIMA, (PGI), P. ATLANTICA X P. INTEGERRIMA (UCBI) and (PGII), in four locations, all budded with P. VERA from the same female tree. The results have demonstrated the rootstocks can be ranked as follows in the following categories. Yield: UCBI>PGI>PGII>ATL; cold tolerance: ATL>UCBI>PGII>PGI; salinity tolerance up to 12 dS/cm2: ATL>PGI>PGII>UCBI: Verticillium tolerance: UCBI>PGI>PGII>ATL; phytopthora tolerance: UCBI>PGII>PGI>ATL; Armellaria tolerance: UCBI>PGI>PGII>ATL. Generally trees with PGI rootstocks grow best in hottest locations but is winter cold is a factor UCBI is the best overall choice for survival, growth and production. It is also the best rootstock for a replant situation. These trials will not continue through the adult years to determine if rootstock has an effect on alternate bearing.

Impacts
(N/A)

Publications

• FERGUSON, LOUISE, et al. 1997. California pistachio rootstock trials - 1989-1997. California Pistachio Commission Annual Report.