Final Report for FW11-011
Project Information
During 2012 and 2013 seven varieties of tomatoes were grown inside and outside of a Utah State University-type hoop house (or high tunnel) on the Rick Lattin Farm located in Fallon Nevada. The tomatoes selected represented three types popular with local growers. The types include a beefsteak type, a roma type, and an heirloom. The purpose of the project was to test two hypotheses:
1) Tomatoes grown under high tunnels reduce the incidence of Beet Curley Top Virus (BCTV) in organic, fresh market tomatoes and,
2) The use of locally developed BCTV resistant seeds reduces the incidence of BCTV in high tunnel and field grown organic fresh market tomatoes.
The plants in the tomato trial were evaluated for yield, number of fruits produced, appearance, marketing percentages (2012), and the number of plants that had survived (2013). This data was collected over three harvest periods. In addition, two field days, a formal presentation, and tour were completed.
The preliminary results indicate that plants grown in hoop houses generally produce higher yields with better quality fruit. The commercial varieties also seem to produce more and better fruit than the locally developed tomatoes. A Nevada Cooperative Extension fact sheet detailing the project results to date is being produced for publication in 2014. The results of this project will provide important information to other growers who are considering utilizing hoop houses in fresh market tomato production operations.
Introduction
Small vegetable production in hoop houses is gaining in popularity throughout western Nevada. The increased interest is due to the desire of many people and businesses to purchase locally grown vegetables. Because western Nevada is subject to early and late plant killing freezes, season extending technologies such as hoop houses are an important production aide. The number of hoop houses used in production has grown exponentially, in part, because federal financial assistance provided by the Natural Resources Conservation Service has reduced the out of pocket expense to local growers. This combined with the simplicity and low cost of the Utah State University hoop house design has resulted in a rapid growth in the number of hoop houses used. For example, in the Lahontan Valley of western Nevada there are approximately 84 hoop houses, whereas six years ago there were just a few.
Tomatoes are one of the most popular crops grown by the small growers of western Nevada. Unfortunately, in many years the presence of Beet Curly Top Virus (BCTV) in the tomato plants has severely limited survival and subsequent production. Because of the difficulties in controlling the disease vector (leaf hoppers) and the desire of many of the growers to produce organically, another method of reducing disease incidence without using chemicals is needed. Production of tomatoes in hoop houses has been reported to reduce the incidence of this important disease. A local plant breeder and grower was reported to have developed tomato varieties which displayed resistance to BCTV. However that claim had never been tested in a formal trial.
During 2011 Mr. Rick Lattin and Dr. Bill Mewaldt applied to the Western Sustainable Agriculture Research and Education program for grant funds to test the two hypotheses:
1) Tomatoes grown under high tunnels reduce the incidence of Beet Curley Top Virus (BCTV) in organic, fresh market tomatoes and,
2) The use of locally developed BCTV resistant seeds reduces the incidence of BCTV in high tunnel and field grown organic fresh market tomatoes.
They contacted Mr. Jay Davison, the local Alternative Crop Specialist for University of Nevada Cooperative Extension organization for assistance with the project. Trials were established and completed during 2012 and 2013.
1) The Principle Investigators (PIs) and Technical Advisor (TA) will design a scientifically valid experiment to determine significant differences in infection rates and production of fresh market tomatoes due to Beet Curly Top Virus (BCTV).
2) In the 2012 growing season, the PIs of this project will plant, grow, evaluate, and compare three varieties of open pollinated, locally developed tomatoes and three varieties of commercially available fresh market tomatoes in high tunnels for resistance to BCTV.
3) During the 2012 growing season, the PIs of this project will plant, grow, evaluate, and compare three varieties of open pollinated, locally developed tomatoes and three varieties of commercially available fresh market tomatoes in the field for resistance to BCTV.
4) During the 2012 growing season, the PIs of the project, with the TA, will hold mid-trial and late-trial field days for western Nevada farmers to explain the purpose of the experiments, increase awareness of the fresh market tomato market, and increase the number of contacts of farmers currently and potentially growing fresh market tomatoes.
5) By the end December 2012, the PIs will compile and analyze the data collected from the high tunnel and field experiments. The data will be analyzed using standard statistical techniques (ANOVA) in cooperation with the TA.
6) By the end of February 2013, the PIs, in cooperation with the TA, will write and publish the results of the experiments in a University of Nevada Cooperative Extension (UNCE) Fact Sheet that will be distributed to all local farmers currently engaged in vegetable production and made available to other interested producers via the UNCE website.
7) During March 2013, the PIs and TA will present the results and distribute the fact sheet at the Nevada Small Farm Conference to increase the awareness of the potential of small scale, fresh market tomato production in western Nevada and increase the knowledge levels of the attending producers concerning tomato variety selection and production practices.
8) In October 2012, the PIs/TA will develop, distribute, and evaluate a formal survey of all local farmers growing fresh market tomatoes to measure the success of the project. The information collected will be provided to the Western SARE administration in the form of a final report by December 2012.
Cooperators
Research
During 2012 and 2013, four varieties of tomatoes available on the commercial market and three varieties of locally developed, BCTV resistant tomatoes were grown in a Utah State University type high tunnel and an adjacent field (Table 1). The tomatoes selected represented three types popular with local growers. The types include a beefsteak type, a roma type, and an heirloom. The experiment was located on Fernley sands as described by the Natural Resources Conservation Service’s Fallon-Fernley soils survey. The high tunnel measured 14’ wide and 140’ long. The tomato field trial was situated immediately adjacent to and south of the hoop house planting.
Table 1. Characteristics of tomato varieties planted in 2012 and 2013
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Tomato Variety number
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Tomato Variety Name
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Remarks
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1
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Farm Sweet
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Local beefsteak variety,
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2
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Korena’s Roma
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Local roma variety
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3
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Mewald’s Cherokee
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Local heirloom variety
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4
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Big Beef
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Commercial beefsteak variety
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5
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Roma VF
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Commercial roma variety
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6
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Cherokee purple
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Commercial heirloom variety
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7 Bobcat Commercial beefsteak variety,
The trial was planted in a randomized complete block design with three replications per block. Each treatment consisted of four tomato plants for a total of 144 plants sampled for the experiments each year. The tomatoes were planted on June 3, 2012 and June 6, 2013 as transplants, averaging approximately three to four inches tall. The plants were drip irrigated so that water was not a limiting factor. No chemical fertilizer or pest control materials were applied to the plants during the trial. The evaluation consisted of determining the number of fruits and pounds of tomatoes produced per replication (plot), assigning an average appearance rating (1-10, 10= perfect appearance) for the fruits harvested from each plot and recording the percent marketable fruits for each harvest. During 2013, the number of living plants was also recorded, as disease incidence was very high as compared to 2012 when little to no disease symptoms were present on the plants. In 2013 leaf samples were obtained from all plants and sent to the Nevada State Department of Agriculture pathology lab to test for the presence of beet curly top virus. Three separate harvests of the plots were completed each year. The 2012 harvests occurred August 14, September 28, and October 19, 2012. The 2013 harvests occurred on September 3, September 19, and October 15. The final harvest of 2013 was only possible from the plants growing in the hoop house as the field grown plants had all perished from killing frosts which occurred October 4-6, 2013. Appropriate statistical analysis was completed to determine significant treatment effects at the P< 0.10 level of significance.
A field day was completed on September 6, 2012 and on September 13, 2013 on the Lattin Farm experimental site, and preliminary results of the project were presented on November 3, 2012 at a seminar featuring vegetable production in high tunnels in Northern Nevada. The seminar included lectures on the campus of Western Nevada College and a field tour of the site on Lattin Farms. The preliminary results were also presented at the Nevada Small farm Conference held on February 22, 2013 in Reno Nevada. The final results are slated to be presented at this conference during 2014.
During the 2012 production season almost no BCTV occurred on any of the plants being evaluated or in adjacent production fields. Therefore no valid comparisons regarding the impact of BCTV on the selected varieties or production technique (high tunnel VS field) could be made. During 2013 the disease level appeared to be very high and signs of the disease were evident in the field and hoop house plots. The disease signs included leathery, yellow, curled leaves with purple colored veins. As the disease progressed the entire plant would turn brown and die. However, the viral testing protocol completed by Dr. Shouhua Wang, the Nevada State Plant Pathologist, reported that no evidence of BCTV was discovered in any sample submitted (>300 samples). We have no explanation for this anomaly as the disease signs were obviously evident and production was severely impacted on infected plants.
The first analysis in 2012 examined paired production for each variety, comparing plants grown in a hoop house with those produced in a field system. The analysis included mean yield in pounds, fruit numbers per plot, an appearance rating, and marketability percent by variety for plants produced inside and outside a hoop house.
Table 2 depicts the results of these comparisons. The data was analyzed using a paired t-test statistical package provided in the latest IBM Statistical Package for the Social Sciences (SPSS) program.
Research Outcomes
Education and Outreach
Participation Summary:
Two field days, a formal presentation, and tour were completed.
Education and Outreach Outcomes
Potential Contributions
The second analysis in 2012 evaluated the three commercial varieties with the three local varieties when grown in the field. The evaluations included yields, numbers, appearance ratings, and the percent marketable. Table three presents the results of these evaluations.
Table 3. Yield and quality differences between three commercial and three local tomato varieties
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Tomato Variety
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Ave.Yield (Lbs./plot)
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Number fruits /plot
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Ave. appearance (1-10)#
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Marketable %/plot
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Roma VF
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7.7*
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65*
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7
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65
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Korena's roma
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3.5
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46
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5.5
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59
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Cherokee
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6.9
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14
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6
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71
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Mewaldt’s Cherokee
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6.3
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12
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5
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52
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Big Beef
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7.2*
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24
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8*
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87*
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Farm Sweet
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3.2
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21
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5
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33
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* significant difference between the commercial and local types at P< 0.10 # 1=unmarketable, 10=Perfect The third evaluation examined the same factors as the previous one but the comparison was conducted among plants produced in a hoop house. Table four is composed of these results. Table 4. Yield and quality differences between three commercial and three local tomato varieties grown in a hoop house.
The last factor examined in 2012 was the percentage of production by harvest. This was completed to determine if the plants grown in the hoop house produced fruits earlier than those grown under field conditions. This would be important in Nevada as tomatoes produced early in the season typically sell for more than those produced later. Therefore, while total yields may be similar, total income may be higher from hoop house tomatoes planted at the same time as field grown plants.
The first analysis in 2013 examined paired production for each variety, comparing plants grown in a hoop house with those produced in a field system. The analysis included mean yield in pounds, fruit numbers per plot, an appearance rating and marketability percent by variety for plants produced inside and outside a hoop house.
Table 5 depicts the results of these comparisons. The data was analyzed using a paired t-test statistical package provided in the latest IBM Statistical Package for the Social Sciences (SPSS) program.
Table 5. Yield and quality differences between six tomato varieties grown in a hoop house and under field conditions during 2013.
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