Progress 07/01/07 to 06/30/11
Outputs
OUTPUTS: In Arizona (AZ), all field trials with muskmelon grafted plants were completed as of July 2010 in collaboration with commercial propagators and producer. Experimental design includes fumigation as the main plot combined with type of transplants as the sub plot. We also had sections of non-fumigated rows with controlled root-knot nematode (RKN) pressure. Scion and rootstock tested were Olympic Gold and Tetsukabuto (interspecific squash hybrid), respectively. In Florida (FL), commercial trials on tomato were continuously conducted using two sites in Southern FL. The experimental design at site one consisted of a randomized complete block design with 6 blocks with 10 treatments consisting of 2 scions (Biltmore and FL-47) grafted on 3 rootstocks (Aloha, Multifort and H-7997- 50 plants per treatment block). Controls consisted of ungrafted and self-grafted scions. No fumigation treatment was applied to either site prior to planting. Site 2 was a randomized complete block design also with 8 blocks and 11 treatments consisting of a FL-47 scion and the following rootstocks Anchor-T, Multifort, 61-071 RZ, BHN 833, Big Power, Vigostar 12, H-7997, Imperial 643, self-graft and non-graft. An additional treatment using a rooted Multifort was also included in the site 2 study. Each treatment consisted of 14 plants in each block. In FL, an experiment was conducted to demonstrate the significance of grafting position in order to control the tomato rootstock axillary shoot development. An educational DVD was developed and will serve as a resource for beginners to learn various grafting methods in addition to the previously developed grafting information website. The most significant outputs and dissemination activities for the entire life of the project were the successful completion of commercial trials in two different locations (southern AZ and southern FL) over multiple seasons/years. We also completed a number of research experiments in the greenhouse or in a controlled experimental field to collect supporting data for the field experiments. These experiments tested low temperature storage conditions, screened rootstocks for potential RKN resistance in greenhouse or in micro field plots, and examined performance of grafted plants in experimental fields. Dissemination activities include the vegetable grafting information website (http://cals.arizona.edu/grafting), tutorial DVD, and demonstration workshops for growers once in 2008 in FL, and twice in 2008 and 2009 in AZ, with attendance from international experts and industry stakeholders. PARTICIPANTS: PDs:Chieri Kubota (School of Plant Sciences, The University of Arizona), Michael A. McClure (School of Plant Sciences, The University of Arizona), Nancy K. Burelle (USDA ARS US Horticultural Research Laboratory), Michael G. Bausher (USDA ARS US Horticultural Research Laboratory), Erin N. Rosskopf (USDA ARS US Horticultural Research Laboratory), Daniel O. Chellemi (USDA ARS US Horticultural Research Laboratory);Collaborators: Mary Olsen (School of Plant Sciences, The University of Arizona), Russell Tronstad (Dept. of Agricultural Resource Economics, The University of Arizona), Greg McCollum (USDA ARS US Horticultural Research Laboratory), Marshall Lamb (USDA ARS National Peanut Research Laboratory), Naoshi Kondo (Kyoto University, Japan); Research Staff participated in the project: Mark Kroggel (School of Plant Sciences, The University of Arizona), Mark Schmitt (School of Plant Sciences, The University of Arizona), Wanwiwat Lovichit (School of Plant Sciences, The University of Arizona); Graduate students/postdoc participated and trained in the project: Ian Justus (School of Plant Sciences, The University of Arizona) Po Chia (The University of Arizona), Ryo Matsuda (The University of Arizona), Claudia Nischwitz (The University of Arizona) TARGET AUDIENCES: Our target audiences include US growers/producers of fruiting vegetables, seed companies, plant propagators, extension personnel and researchers in related areas. We have organized several events involving growers such as workshops, short courses, open houses, and other outreach activities in AZ and FL. In AZ, we have organized a greenhouse short course (about 100 participants) including lectures and hands-on grafting practicum in 2008 and 2009. We also educated propagators, teaching necessary skills and methodologies for successful grafted seedling production. The ADODR is actively involved in all aspects of this research project and has continuous interactions with USDA, ARS team members, and has also co-hosted a workshop attended by 25 international scientists. Investigators in both AZ and FL received large numbers of inquiries from various groups regarding grafting techniques, healing methods, automation and available rootstocks. The size of US research community working on vegetable grafting increased by nearly 10 times over the three years of our project. Efforts to establish an academia-industry consortium on vegetable grafting have also been made and funding for continuing our research and outreach efforts was obtained, in order to further develop this technology that supports US vegetable production in a more sustainable approach. Mexico started using grafting intensively in high tunnels, greenhouses and open-fields, attracting international investments in developing their grafting capacity. More researchers are now engaged worldwide in research and extension activities relevant to vegetable grafting and the first international symposium on vegetable grafting will be held in October 2011, gathering international expertise. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our project generated various key findings, results, and techniques that are considered as milestones for introducing vegetable grafting to help promote the transition away from use of methyl bromide fumigation. Our greenhouse, microplot, and field trials conducted in FL and AZ provided in-depth information on rootstocks for tomato, bell pepper, and melon that showed various levels of tolerance/resistance to RKN. FL greenhouse bell pepper experiment identified several rootstocks resistant to RKN galling. For tomato, all three tomato rootstocks examined had less J2 in soil than ungrafted scion cultivar. For melon, C. metuliferus showed resistance to galling when used as rootstock. Small experimental field trials in FL demonstrated effective control of RKN when grafting was combined with alternative fumigants in double cropping of muskmelon followed by tomato. AZ and FL greenhouse experiments quantified various levels of RKN resistance of commercial rootstocks of tomato and cucurbits at different root zone temperatures. FL microplot experiments confirmed selected rootstocks performance in RKN inoculated soil. A small experimental field trial demonstrated that grafted cantaloupe plants on a selected rootstock had tolerance to charcoal rot, a fungal pathogen problematic in fall crops in southern AZ. Commercial field trials in AZ and FL demonstrated the efficacy of grafting in terms of RKN resistance (FL trials) and yield increase (AZ spring trials) as well as helped identify management issues. AZ cantaloupe trials could not show the disease tolerance/resistance of grafted plants (in spring or fall), but demonstrated early stand establishment and increased yields for spring crops. On-farm economic analysis indicated that the cost of grafted seedlings and availability of volume of grafted seedlings were two major limiting factors in using the technology. FL commercial trials showed that some commercial tomato rootstocks exhibited RKN resistance when used in soil infested with RKN in southern FL. One issue identified was axillary shoot development from the rootstock. FL investigator experimentally demonstrated that, in contrast to the conventional practice in Asian countries, grafting under the rootstock cotyledonary leaves was critical to prevent the axillary shoot development, which could have a potential impact of reducing the labor input to manage grafted plants in the field. Other outcomes of this project include the development of cold storage methodology for grafted muskmelon seedlings and information resource development. The former could have a potential impact to advance the use of grafted seedlings by significantly increasing the production capacity (by 20-30 times with 3-4 week storage) without increasing the labor requirement. Grafting Information Website received more than 4,500 unique visits during the last 6 months (since it was officially launched) and it is being recognized as a key resource among the researchers and stakeholders.
Publications
- Bausher, M.G. 2009. Tomato rootstock performance to natural populations of root-knot nematode. Proceedings of Methyl Bromide Alternatives Outreach Conference, November 10-13, San Diego, CA.
- Bausher, M.G. 2011. Grafting technique to eliminate rootstock suckering of grafted tomatoes. HortScience. 46:596-598.
- Bausher, M.G. and D.O. Chellemi. 2010. Performance of grafted tomatoes in open-field trials at two locations in Florida. Proceedings of Methyl Bromide Alternatives Outreach Conference, November 2-5, Orlando, FL.
- Kokalis-Burelle, N., E.N. Rosskopf, and M.G. Bausher. 2010. Grafting for control of Meloidogyne incognita on bell pepper, tomato and melons. Proceedings of Methyl Bromide Alternatives Outreach Conference, November 2-5, Orlando, FL.
- Kokalis-Burelle, N., E.N. Rosskopf, M.G. Bausher, G. McCollum and C. Kubota. 2008. Alternative fumigants and grafting for tomato and double-cropped muskmelon production in Florida. Proceedings of Methyl Bromide Alternatives Outreach Conference, November 11-14, Orlando, FL.
- Kokalis-Burelle, N., and E.N. Rosskopf. 2011. Microplot evaluation of rootstocks for control of Meloidogyne incognita on grafted tomato, muskmelon, and watermelon. Journal of Nematology 43: in press.
- Lee, J.-M., C. Kubota, S.J. Tsao, Z. Bie, P. Hoyos Echevarria, L. Morra, and M. Oda. 2010. Current status of vegetable grafting: Diffusion, grafting techniques, automation. Scientia Horticulturae. 127:93-105.
- Louws, F.J., C.L. Rivard, and C. Kubota. 2010. Grafting fruiting vegetables to manage soilborne pathogens, foliar pathogens, arthropods and weeds. Scientia Horticulturae. 127:127-146.
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Progress 07/01/09 to 06/30/10
Outputs
OUTPUTS: To evaluate muskmelon and tomato rootstock varieties for resistance to RKN (Meloidogyne spp.) and other soil-borne diseases and overall horticultural performance, AZ investigators completed experiments of screening RKN resistance at three different temperatures for 16 commercial cucurbit rootstocks (squash, bottle gourd, and wild watermelon), obtained from various seed sources. In Florida, a double crop of TRI-X Brand Palomar watermelon grafted onto two rootstocks (Emphasis and Strong Tosa) and non-grafted watermelon were planted in the existing beds following completion of the tomato trial of the previous year. Additional microplot experiments were conducted concurrently with the watermelon field trial using the same grafted transplants. Microplots were inoculated with nematodes to insure data availability on the host status on rootstocks for Meloidogyne incognita. In spring 2010, commercial trials on tomato were conducted using three sites in Southern Florida. For Site one, we grafted two scions Biltmore and FL47 on Multifort, Aloha, and H-4997 rootstocks. Controls were both non-grafted and self grafted individual plants. For Site two, 11 treatments including nine rootstocks and self and non grafted controls were included using FL47 as the scion. Site three was an organic grower's site under USDA organic standards. We laid out seven rootstock treatments including a self grafted control, using FL91 as the scion per grower's request. All of the plants used in these experiments were produced at the USHRL, Fort Pierce. To evaluate both agronomic field performance and economic viability of grafted muskmelon seedlings in commercial field, AZ investigators conducted and completed commercial trials in the spring 2009 and 2010 in collaboration with an Arizona muskmelon producer and three propagators located in Arizona, Texas and California. Scion and rootstock tested were Olympic Gold and Tetsukabuto (interspecific squash hybrid), respectively. Small sections of the non-fumigated rows were inoculated with RKN to evaluate the grafted plants under controlled RKN pressure. In addition to the field experiments, a small experiment in a field infested with charcoal rot was conducted using the same rootstock and scion in the fall 2009. A vegetable grafting information website (http://cals.arizona.edu/grafting) was developed to disseminate the information to propagators, growers, extension personnel and university researchers. Educational video clips were developed and posted in the website together with the other public sources for beginners to learn various grafting methods. Grafting workshop was held in Arizona as part of the annual grower short course with 100 participants. PARTICIPANTS: PDs: Chieri Kubota (School of Plant Sciences, The University of Arizona) Michael A. McClure (School of Plant Sciences, The University of Arizona) Nancy K. Burelle (USDA ARS US Horticultural Research Laboratory) Michael G. Bausher (USDA ARS US Horticultural Research Laboratory) Erin N. Rosskopf (USDA ARS US Horticultural Research Laboratory) Daniel O. Chellemi (USDA ARS US Horticultural Research Laboratory) Collaborators: Mary Olsen (School of Plant Sciences, The University of Arizona) Russell Tronstad (Dept. of Agricultural Resource Economics, The University of Arizona) Greg McCollum (USDA ARS US Horticultural Research Laboratory) Marshall Lamb (USDA ARS National Peanut Research Laboratory) Naoshi Kondo (Kyoto University, Japan) Research Staff participated in the project: Mark Kroggel (School of Plant Sciences, The University of Arizona) Mark Schmitt (School of Plant Sciences, The University of Arizona) Wanwiwat Lovichit (School of Plant Sciences, The University of Arizona) Graduate students/postdoc participated and trained in the project: Ian Justus (School of Plant Sciences, The University of Arizona) Po Chia (The University of Arizona) Ryo Matsuda (The University of Arizona) Claudia Nischwitz (The University of Arizona) TARGET AUDIENCES: Our target audiences include U.S. growers/producers of fruiting vegetables, seed companies, plant propagators, extension personnel and researchers in related areas. Through the activities funded by this program and communication with propagators as well as producers in AZ and FL, it was considered that lack of trained propagators and higher propagation costs (among other considerations) are significant limiting factors to the wider introduction of vegetable grafting as a methyl bromide alternative, as grafting involves a different set of skills, involving multiple steps, environmental control techniques, and better scheduling, compared to the standard open-field seedling propagation. Recognizing this issue, we have organized several events involving growers such as workshops, short courses, open houses, and other outreach activities in AZ and FL. In AZ, we have organized a greenhouse short course (about 100 participants) including lectures and hands-on laboratory of grafting in April 2010. We also educated propagators, teaching necessary skills and methodologies for successful grafted seedling production. The ADODR is actively involved in all aspects of this research project and has continuous interactions with USDA, ARS team members, and has also co-hosted a workshop attended by 25 international scientists. Investigators in both AZ and FL received large numbers of inquiries from various groups regarding the grafting techniques, healing methods, automation and available rootstocks. The size of US research community working on vegetable grafting increased by nearly 10 times over the three years of our project. Efforts to establish an academia-industry consortium on vegetable grafting have also been underway to seek future funding and continuous support for our research and outreach efforts, in order to further develop this technology that supports U.S. vegetable production in a more sustainable approach. PROJECT MODIFICATIONS: The project duration was extended (non-cost extension) to June 30th, 2011.
Impacts
The 2009 fall experiment in the field infected with charcoal rot (Macrophomina phaseolina) showed that 1) Olympic Gold (Cucumis melo) muskmelon grafted onto Tetsukabuto (Cucurbita maxima x C. moschata) rootstock was tolerant to charcoal rot, showing significantly lower disease incidence than that of direct-seeded plants, 2) as a result, the yield of grafted cantaloupe plants was significantly higher (by 60%) than that of direct seeded plants or non-grafted plants. The 2009 fall commercial trial data were subject to the preliminary economic analyses and indicated that the cost of grafted muskmelon transplants would need to drop significantly in order to justify planting grafted transplants over direct seeded muskmelons. However, given the environmental benefits associated with reduced pesticide use, a possible market premium for growing more environmentally friendly, and the potential for robotic grafting to lower grafting costs, grafted transplants are to become a viable option for muskmelon production. In addition, a capital-intensive irrigation technology like subsurface drip irrigation that limits crop rotations will likely accelerate the need for grafted muskmelon transplants. The 2010 spring commercial trial data on fruit yield and size distribution in AZ confirmed that 1) use of chilling tolerant rootstock supported the early vegetative growth and flowering as well as greater total marketable yields (average of 41% increase), compared with the non-grafted or direct-seeded control, 2) transplant quality largely affected the stand establishment as well as overall yield, and 3) no significant difference was observed in melon yield between fumigated and non-fumigated rows. The total marketable yield increased by as much as 71% when high quality grafted seedlings were used, compared with the conventional direct seeding or non-grafted plants. Damage due to wind was minimum compared with that observed in the previous year. The commercial trials conducted in Florida experienced premature freeze, which lowered the baseline yields. Data are currently analyzed further. Throughout the trials, investigators worked with commercial propagators to transfer key technologies of grafting and building effective controlled environment system for healing grafted plants. During the past project years, the number of US university researchers working on vegetable grafting increased many times and several new information websites on use of grafting in vegetable production have been built, reflecting the need of information dissemination. Our vegetable grafting information site has been utilized as useful resource including broad information such as automation, grafting methods, rootstock, and research news.
Publications
- Justus, I. and C. Kubota. 2010. Effects of low temperature storage on growth and transplant quality of non-grafted and grafted cantaloupe-type muskmelon seedlings. Scientia Hort. 125:47-54.
- Kokalis-Burelle, N., and E.N. Rosskopf. 2010. Microplot evaluation of rootstocks for control of Meloidogyne incognita on grafted tomato, muskmelon, and watermelon. Journal of Nematology 42: In Press.
- Kokalis-Burelle, N., M.G. Bausher, and E.N. Rosskopf. 2009. Greenhouse evaluation of Capsicum rootstocks for management of Meloidogyne incognita on grafted bell pepper. Nematropica 39:121-132.
- Kubota, C. 2009. Challenges of introduction of grafted muskmelon seedlings in southwestern United States. Abstract for the International Symposium on Seed, Transplant and Stand Establishment of Horticultural Crops. September 27 - October 1, Murcia, Spain.
- Kubota, C., M.A. McClure, M. Olsen, and R. Tronstad. 2009. Evaluation of grafted seedlings in commercial muskmelon production in Southwestern United States. Methyl Bromide Alternatives Outreach Conference, November 10-13, San Diego, CA.
- Tronstad, R., C. Kubota, M.A. McClure, and M. Olsen. 2009. Economic considerations of grafted seedlings in southwestern U.S. muskmelon production. Methyl Bromide Alternatives Outreach Conference, November 10-13, San Diego, CA.
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Progress 07/01/08 to 06/30/09
Outputs
OUTPUTS: To evaluate muskmelon and tomato rootstock varieties for resistance to RKN (Meloidogyne spp.) and other soil-borne diseases and overall horticultural performance, AZ investigators completed experiments of screening RKN resistance at three different temperatures for 29 commercial tomato rootstocks, obtained from various seed sources. In Florida, greenhouse studies were completed for evaluating conditions necessary to produce and care for selected rootstocks and scions of tomato and muskmelon (media, containers, and growing conditions). FL investigators have also developed a healing room with temperature and light control and established healing technique suitable for large scale production of grafted seedlings. FL also completed the second year greenhouse experiment using nine rootstocks having nematode and Fusarium wilt (race 1 and 2) resistance grown in untreated field soil. Scion used in this study was RealEZA. In Florida, field experiments were repeated in a field infested with RKN (Fort Pierce, FL), in the fall of 2008 (tomato) and spring of 2009 (watermelon). A split plot experimental design with four replications was used to evaluate rootstock/scion combinations in soil fumigated with methyl bromide, iodomethane, dimethyl disulfide and non-fumigated soil. Sub-plots consisted of three selected rootstocks with reported resistance to nematodes (TX-301, Multifort, and Aloha), and the non-grafted hybrid cultivar FL-47, common to commercial tomato production in Florida. For watermelon, two muskmelon rootstocks (Emphasis and Strongtosa) were evaluated with the non-grafted scion Tri-X Brand Palomar). In addition to the field experiments, microplot experiments inoculated with RKN were repeated using the same rootstock-scion combinations as the field trials to evaluate the host status of rootstocks for RKN. To evaluate both agronomic field performance and economic viability of grafted muskmelon seedlings in commercial field, AZ investigators conducted and completed a commercial trial in fall 2008 and spring 2009 in collaboration with a muskmelon producer. Scion and rootstock tested were Olympic Gold and Tetsukabuto (interspecific squash hybrid), respectively. In fall 2008, small sections of the non-fumigated rows were inoculated with RKN to evaluate the grafted plants under controlled RKN pressure. In addition to the field experiments, small field experiments infested with RKN were conducted using the same rootstock and scion in the spring 2009. To develop short term storage techniques for grafted muskmelon seedlings, Arizona investigators completed the 2-year experiments to evaluate muskmelon grafted seedlings performance under short term storage (2 and 4 weeks) under 9, 12, and 15C storage air temperatures in light provided by white fluorescent lamps at 12 micro-mol/m2/s photosynthetic photon flux. Results and findings were disseminated to target audiences through direct communication as well as outreach activities (workshops, short courses, seminars, demonstrations, and open house event). PARTICIPANTS: [PDs] Chieri Kubota (School of Plant Sciences, The University of Arizona) Michael A. McClure (School of Plant Sciences, The University of Arizona) Nancy K. Burelle (USDA ARS US Horticultural Research Laboratory) Michael G. Bausher (USDA ARS US Horticultural Research Laboratory) Erin N. Rosskopf (USDA ARS US Horticultural Research Laboratory) Daniel O. Chellemi (USDA ARS US Horticultural Research Laboratory) [Collaborators (Second project year)] Mary Olsen (School of Plant Sciences, The University of Arizona) Russell Tronstad (Dept. of Agricultural Resource Economics, The University of Arizona) Greg McCollum (USDA ARS US Horticultural Research Laboratory) [Research Staff participated in the project] Mark Kroggel (School of Plant Sciences, The University of Arizona) Mark Schmitt (School of Plant Sciences, The University of Arizona) [Graduate students/postdoc participated and trained in the project] Ian Justus (School of Plant Sciences, The University of Arizona) Po Chia (The University of Arizona) Ryo Matsuda (The University of Arizona) Claudia Nischwitz (The University of Arizona) TARGET AUDIENCES: Our target audiences include U.S. growers/producers of fruiting vegetables, seed companies, plant propagators, extension personnel and researchers in related areas. Through the activities funded by this program and communication with propagators as well as producers in AZ and FL, it was considered that lack of trained propagators and higher propagation costs (among other considerations) are significant limiting factors to the wider introduction of vegetable grafting as a methyl bromide alternative, as grafting involves a different set of skills, involving multiple steps, environmental control techniques, and better scheduling, compared to the standard open-field seedling propagation. Recognizing this issue, we have organized multiple events involving growers such as workshops, short courses, open houses, and other outreach activities in AZ and FL. In AZ, we have organized a greenhouse short course (a total of 240 participants) including lectures and hands-on demonstrations of grafting in January 2008 and April 2009. We also contributed to seed-company's grafting workshops by introducing updated information on the grafting technology status in North America. In FL, we held a grafting demonstration at the 2009 open house at the Fort Pierce, USDA Laboratory and had over 250 people attend the exhibition and try their hand at vegetable grafting, which included a demonstration of the Helper grafting robot. Because of this demonstration we had interest from three growers to include field test plots on their properties. The growers included one organic and two conventional operations interested in seeing firsthand how grafted tomatoes and peppers will perform under field conditions. Investigators in both AZ and FL received large number of inquiries from various groups regarding the grafting techniques and available rootstocks. The size of US research community working on vegetable grafting increased by 5-10 times over the two years of our project. Efforts to establish an academia-industry consortium on vegetable grafting have also been underway to seek future funding and continuous support for our research and outreach efforts, in order to further develop this technology that supports U.S. vegetable production in a more sustainable approach. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In the production of grafted seedlings, FL identified several key issues specific to the use of grafted seedlings in open-field production. These include poor germination of rootstock, exposure of scion to soil, and rootstock regrowth. All rootstocks tested in the greenhouse in FL had greater tolerance to RKN nematode damage than did the non-grafted control. Identifying degrees and mechanisms of RKN resistance/tolerance of grafted seedlings is important in selecting rootstocks and scion combinations. In FL field trials, similar to the previous year, the non-grafted tomato supported higher populations of root-knot nematodes in soil and roots at the end of the season than all grafted rootstocks. Of the tomato rootstocks tested, Multifort and Aloha provided the best resistance to galling in non-fumigated soil. All fumigants controlled nematodes and no differences in galling occurred among rootstocks in soil treated with fumigants. In microplot trials, similar to previous year, non-grafted Florida 47 plants were more vigorous than Aloha and TX301, with Multifort having intermediate vigor. At the end of the season, RKN populations in soil were not significantly different among the rootstocks. Nematode populations in roots, however, were higher in the non-grafted Florida 47 than in Aloha and TX301. Multifort was intermediate, not differing from either the non-grafted or Aloha and TX301. Non-grafted Florida 47 also had significantly more galling than all other rootstocks at the end of the season. The fall commercial trial data on fruit yield, fruit quality and size distribution in AZ showed that 1) Direct seeded plants yielded the most among tested plant types. 2) Non grafted plants yielded at a comparable level to direct seeded plants. 3) Grafted plants did not show any positive impact other than small increase noticed in Brix. 4) Fumigation and RKN inoculation did not show any significant influence on any of the parameters collected in this trial. For spring trial, we have identified 1) Use of chilling tolerant rootstocks will support the early vegetative growth and flowering as well as greater yields, compared with the non-grafted or direct-seeded control. 2) Tetsukabuto rootstock was considered tolerant to RKN due to the vigorous root development. 3) Spring windy conditions were detrimental to transplants, suggesting necessity to prevent the loss of valuable seedlings due to the wind damage. In the low temperature storage experiments, grafted muskmelon seedlings were successfully stored for 4 weeks at 12 and 15C in light, without affecting post-storage growth, development, and yields. The 4 weeks storage capacity would increase the propagation capacity to 20 times more than that without the capacity. This will help propagators to provide large amounts of grafted seedlings to large scale open field applications.
Publications
- Justus, I. and C. Kubota. 2009. Storing seedlings at low temperature as a key technology to introduce vegetable grafting in North America. HortScience 44:1052.
- Kubota, C., M.A. McClure, N. Kokalis-Burelle, M.G. Bausher, and E.N. Rosskopf. 2008. Vegetable grafting: History, use, and current technology status in North America. HortScience 43:1664-1669.
- Bausher, MG. 2009. Commercial rootstock performance when exposed to natural populations of root-knot nematodes in Florida. HortScience 44:1021.
- Burelle, NK, Bausher, MG, and Rosskopf, EN. 2009. Greenhouse evaluation of Capsicum rootstocks for management of Meloidogyne incognita on grafted bell pepper. Nematropica 39:121-132.
- Chia, P. and C. Kubota. 2009. Efficacy of end-of-day far-red light in controlling tomato rootstock height. HortScience 44:1051.
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Progress 07/01/07 to 06/30/08
Outputs
OUTPUTS: To evaluate muskmelon and tomato rootstock varieties for resistance to RKN (Meloidogyne spp.) and other soil-borne diseases and overall horticultural performance, AZ investigators initiated experiments of screening RKN resistance at three different temperatures for 17 commercial cucurbit rootstocks, 29 commercial tomato rootstocks, one potential tomato and one potential cucurbit rootstock, obtained from 9 different seed sources. In Florida, greenhouse studies were initiated with tomato plants with 13 rootstocks (6 plants each) representing interspecific crosses of various tomato relatives. All grafted plants were produced on-site using a robotic grafting device. The planting media was untreated field soil which was obtained from a grower field site that had been tomato and pepper production for many years. In Florida, a series of field experiments were performed in an experimental pest nursery located at the USDA, ARS Picos Road Farm in Fort Pierce, in the fall of 2007 (tomato) and spring of 2008 (cantaloupe). A split plot experimental design with four replications was used to evaluate rootstock/scion combinations in fumigated with methyl bromide, iodomethane, dimethyl disulfide and non-fumigated soil. Sub-plots consisted of three rootstocks with reported resistance to nematodes (He-man, Multifort, and Aloha), and the non-grafted hybrid cultivar FL-47, common to commercial tomato production in Florida. For cantaloupe, two muskmelon rootstocks (C. metuliferus and Testukabuto) were evaluated with the non-grafted scion Athena on its own rootstock. Each 25 ft. subplot section of bed previously planted with a tomato rootstock received three plants of each muskmelon rootstock. Melons were planted on February 19, 2008, and evaluated throughout the season and at the end of the season as described above for tomatoes. The melon trial was completed May 19, 2008. To evaluate both agronomic field performance and economic viability of grafted muskmelon seedlings in commercial field, Arizona investigators conducted and completed a commercial trial in fall 2007 in collaboration with two seed companies, a propagator, and a muskmelon producer. Ten thousand grafted seedlings and another 10,000 non-grafted seedlings were produced in Texas by a major propagator who sells large quantities of vegetable seedlings in the U.S. To develop short term storage techniques for grafted muskmelon seedlings, Arizona investigators completed the first experiment to evaluate muskmelon grafted seedlings performance under short term storage (2 weeks) under 9, 12, and 15C storage air temperatures in light provided by white fluorescent lamps at 12 micro-mol/m2/s photosynthetic photon flux. PARTICIPANTS: PIs: Chieri Kubota (Dept. of Plant Sciences, The University of Arizona) Michael A. McClure (Dept. of Plant Sciences, The University of Arizona) Nancy K. Burelle (USDA ARS US Horticultural Research Laboratory) Michael G. Bausher (USDA ARS US Horticultural Research Laboratory) Erin N. Rosskopf (USDA ARS US Horticultural Research Laboratory) Daniel O. Chellemi (USDA ARS US Horticultural Research Laboratory) Collaborators (First project year) Mary Olsen (Dept. of Plant Sciences, The University of Arizona) Russell Tronstad (Dept. of Agricultural Resource Economics, The University of Arizona) Greg McCollum (USDA ARS US Horticultural Research Laboratory) TARGET AUDIENCES: U.S. growers/producers of fruiting vegetables, seed companies, plant propagators, extension personnel and researchers in related areas PROJECT MODIFICATIONS: The Spring 2008 trial had to be cancelled due to an unexpected failure in germination of seeds at the propagation facility. Instead, at a small field plot located at the University of Arizona, Olympic Gold muskmelon grafted on three different rootstocks (Tetsukabuto, SrongTosa, and DRO5018) were planted in March 2008 for evaluating early growth, fruit yield and quality as affected by rootstock. The data obtained in this mini trial will be used for selecting the next spring trials.
Impacts
In FL greenhouse experiments, root damage from RKN feeding was greatest on the self-grafted scion. Most grafted plants (rootstocks: Armada, Camel, BB, Ageis, Aloha and Anchor T) showed little or no visual infestations or minimum damage (0-1 rating out of 10), except for TX301 at 2-3 rating, Beaufort with 4-5 rating and Multifort with a mixed rating of 5-6 for two plants and 0 for the remaining three individuals in this group. Florida pest nursery field experiments in the fall 2007 and spring 2008 showed that RKN populations extracted from tomato roots were significantly higher in the herbicide-only plots. Non-grafted rootstocks supported higher populations of RKN in soil and roots at the end of the season than all other rootstocks. The most root galling occurred in herbicide-only soil and in subplots containing non-grafted plants. Multifort and Aloha provided the best resistance to galling in herbicide-only treated soil of the rootstocks tested. No differences in galling occurred among rootstocks in soil treated with methyl bromide, methyl iodide, or DMDS. Tomato yield was highly variable among main and sub-plot treatments with significant interactions which require further analysis. All soil treatments controlled weeds throughout the tomato crop. The effects of soil treatments on nematodes and weeds were sustained in the melon double-crop. Of the rootstocks tested, C. metulifer supported lower RKN populations in both soil and roots at the end of the season than either the non-grafted control or Tetsukabuto. Weed populations remained low through the second crop and there were no differences between treatments until the melon harvest weed counts. Total fruit weight and fruit weight/plant were higher in C. metulifer and Tetsukabuto compared to non-grafted melon. These results will help producers in determining efficacy of grafted plants under local conditions. For the commercial trials in Arizona, despite delays in transportation and planting, grafted seedlings yielded at a comparable level to direct-seeded plants. Preliminary economic analysis was conducted, but because of the minimal yield increase, no economic benefit was observed. The commercial trial also helped us to assess issues we currently face to introduce this technology to U.S. open field production, which are 1) limited local propagation capability, 2) competition amongst seed companies and propagators, 3) high price for seeds and seedlings, and 4) limited information on efficacy. The cold storage experiment showed that Olympic Gold muskmelon seedlings can be held at 12C for 2 weeks without losing regrowth ability and that grafted plants can be stored longer than non-grafted plants. We are currently testing a longer storage duration at the same temperature. This technique should help propagators with limited grafting capacity produce the larger of grafts required for open field production.
Publications
- Bausher, M. G., N. Kokalis-Burelle, E. N. Rosskopf. 2007. Evaluation of rootstocks for management of Meloidogyne incognita on grafted bell pepper. Proc. Annual Intl Res. Conf. Methyl Bromide Alternatives and Emissions Reductions, 112.1-112.3.
- Justus, I. and C. Kubota. 2008. Development of a cold storage technique for grafted muskmelon seedlings. Abstract submitted to International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, October 20-24, 2008, Tucson, Arizona.
- Kubota, C., M.A. McClure, N. Kokalis-Burelle, M.G. Bausher, and E.N. Rosskopf. 2008. Vegetable grafting: History, use, and current technology status in North America. HortScience (in press).
- Tronstad, R., C. Kubota, M.A. McClure, and M. Olsen. 2008. A preliminary comparison of organic, grafted, and conventional cantaloupe production under subsurface drip irrigation. In Niche Markets: Assessment and Strategy Development for Agriculture, Kynda Curtis (ed.), University of Nevada, Reno, Technical Report UCED 2007/08-13, 9:1-9.
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