This years’ high tunnel tomato work is a continuation of last year’s variety evaluation research (for a copy of the 2006 progress report see, http://www.public.iastate.edu/~taber/Extension/ Progress%20Rpt%2006/High%20Tunnel%20fin al%20report.pdf. We evaluated 10 varieties in both high tunnel and outdoor field plantings in 2006, and for 2007 selected the top three performing varieties across three maturity classes: early = Sunstart(67 day), 2 nd early = Mountain Fresh (72 day), and main season = Florida 91 (80 day). Our objective was to evaluate a sequential planting scheme using high tunnels and outdoor field plantings to maintain a continuous market supply

Havlovic, Bernard J.

Howell, Nicholas P.

Taber, Henry G.

English

This years’ high tunnel tomato work is a continuation of last year’s variety evaluation research (for a copy of the 2006 progress report see, http://www.public.iastate.edu/~taber/Extension/ Progress%20Rpt%2006/High%20Tunnel%20fin al%20report.pdf. We evaluated 10 varieties in both high tunnel and outdoor field plantings in 2006, and for 2007 selected the top three performing varieties across three maturity classes: early = Sunstart(67 day), 2 nd early = Mountain Fresh (72 day), and main season = Florida 91 (80 day). Our objective was to evaluate a sequential planting scheme using high tunnels and outdoor field plantings to maintain a continuous market supply.</p

Taber, Henry

Havlovic, Bernard

Howell, Nicholas

Digital Repository @ Iowa State University (ISU)

Iowa State University, Horticulture Research Station ISRF07-36  High Tunnel Tomato Production  Henry G. Taber, professor  Department of Horticulture  Bernard Havlovic , superintendent, Armstrong Research Farm  Nick Howell, superintendent, Horticulture Research Station   Introduction This years’ high tunnel tomato work is a continuation of last year’s variety evaluation research (for a copy of the 2006 progress report see, http://www.public.iastate.edu/~taber/Extension/Progress%20Rpt%2006/High%20Tunnel%20final%20report.pdf. We evaluated 10 varieties in both high tunnel and outdoor field plantings in 2006, and for 2007 selected the top three performing varieties across three maturity classes: early = Sunstart (67 day), 2nd early = Mountain Fresh (72 day), and main season = Florida 91 (80 day). Our objective was to evaluate a sequential planting scheme using high tunnels and outdoor field plantings to maintain a continuous market supply.  Materials and Methods The project was established at the Armstrong Research Farm (southwestern Iowa – a well-drained silt loam soil) and the Horticulture Research Station (central Iowa – a well-drained loam soil). The previous crop at both the Armstrong Farm and the Horticulture Station in the high tunnel was tomatoes. Previous crop at the outdoor site on the Armstrong Farm was corn, and at the Horticulture Station tomatoes. Both sites were fertilized according to soil test recommendations. The cultural system consisted of SRM-olive plastic mulch (wavelength selective) and trickle irrigation. Transplants were set 18-inches in-row and rows 4.5 ft on center for high tunnel production and 6-ft on center for field production. All plants were staked, tied, and pruned to the first flower cluster. Irrigation scheduling was via tensiometers. Pest management practices for field production included necessary herbicide, insecticide, and fungicide applications for top production. High tunnel production included only an organic insecticide (Thuricide) application for tomato hornworm control. There were three replications of each variety at each site in the high tunnel and two replications for the May and June field plantings.  Transplant dates were: Armstrong Farm high tunnel on April 18, and field transplant dates of May 12 and June 8; Horticulture Station high tunnel on April 16, and field transplant dates of May 11 and June 8. Mountain Spring, a 72-day maturity, was included in the outdoor plantings for a fourth variety.  Yield data consisted of a weekly harvest at the Horticulture station and twice a week at the Armstrong farm with fruit sorted into marketable and culls. Culls included very small fruit and fruits with rots, radial and concentric cracks, and ripening disorders. The marketable category was graded into four sizes: extra large (> 2 7/8 inch), large (2 7/8 to 2 ½ inch), medium (2 ½ to 2 ¼ inch), and small (< 2 ¼ inch).  Results and Discussion Sunstart variety was the first to begin production, June 28, from the high tunnel planting at both sites (Figure 1). Early yield was generally higher at Armstrong and the cullage was less compared with the Horticulture Station. Low night temperatures at the Horticulture Station, and to a lesser extent at the Armstrong Farm, caused severe cat-facing on the Sunstart fruit accounting for its high percentage of culls (Table 1). Mountain Fresh and Florida 91 production began a week earlier at the Horticulture Station, compared at Armstrong, and production remained reasonably steady, while at Armstrong the yields peaked at the second harvest, July 26. April daily Iowa State University, Horticulture Research Station ISRF07-36  temperatures were much colder than normal at both sites in 2007, as compared with 2006. Armstrong Farm April 2007 average temperature of 47.8oF was 2.7 degrees below normal while 2006 was 4.8 degrees above normal. Horticulture Station April temperature of 48.5oF was 4 degrees below normal compared with 3.1 degrees above normal in 2006. However, May and June 2007 monthly temperatures were above normal at both sites.  As in 2006, there was a stark contrast between the two sites for total high tunnel season yield. Although both sites were planted at similar times and the harvest season identical, Armstrong had higher total and marketable yields, with Mountain Fresh and Florida 91, 22% more compared with the Horticulture Station (Table 1). A large part of the difference was in percentage of culls with the Horticulture Station almost twice Armstrong’s. The lower soil K fertility led to much more non-uniform color (blotchy ripening) development at the Horticulture Station. These total yields (162 lb/10 plants) for an 8-week harvest period are 28% less than 2006 (224 lb/10 plants) values for a similar harvest period.  Field plantings were established with the same three varieties in mid-May, with the addition of Mountain Spring, once the danger of frost passed. The field location was adjacent to the high tunnel at both sites. First harvest occurred for all varieties on July 26 at Horticulture Station. The corresponding date at Armstrong was July 31. However, Sunstart produced substantial fruit a week earlier, July 23 (Figure 2). Armstrong production peaked the week of August 17. At the Horticulture Station, weekly yields steadily declined to August 17. Tomatoes at the Horticulture Station were planted on the same site as in 2006. Therefore, Septoria and bacterial disease severity continued to increase in spite of a weekly fungicide program. This underscores the necessity of the cultural practice to rotate every 3 to 4 years between crops. Mountain Fresh maintained high production at both sites, although Mountain Spring was equivalent to Mountain Fresh at Armstrong where there was lack of disease pressure. Sunstart and Mountain Spring are known to be susceptible to Septoria infection compared with the other varieties grown in this trial.  A second field planting was established on June 8 at both sites to maintain continuous production into the fall. But, because of severe disease pressure, the June planting at the Horticulture Station was eliminated. Data was collected from the first two harvests at Armstrong to determine the timing of initial production.  To maintain uniform fruit production, an early variety, or variety combination, could be planted in a high tunnel followed by a mid-May and early June planting of a second early variety plus a main season variety to stagger peak production times (Figure 3). In 2006, if Sunstart and Mountain Fresh were used in the high tunnel followed a mid-May planting of Sunstart + Mountain Fresh + Florida 91, and early June of Mountain Fresh + Florida 91, the weekly production would be 75 to 100 lb/week per 70 plants (Figure 4). Thus, if you had a market for 30 to 40 boxes (25 lb box) of tomatoes per week you would need 100 plants of each variety planted according to the sequence listed above, i.e. high tunnel would have 100 plants each of Sunstart and Mountain Fresh. This same scheme in 2007 produced similar results except for the August 9 to August 17 time period. The delayed production start by Mountain Fresh resulted in low yields on August 9, and the Mountain Fresh and Florida 91 varieties were of similar maturity for the May planting causing the overlap of production on August 17. Iowa State University, Horticulture Research Station ISRF07-36   Table 1. Total season yield (lb/10 plants) of tomatoes planted in high tunnels. Total = 8 weeks of harvest. Harvest began June 28 and ended August 17 at both sites, 2007.   -------- Armstrong Farm ---------  ----------Hort Station --------- Variety Marketable Total Cull, % Marketable Total Cull, % Sunstart 144 185 22.2 70 144 51.4 Mountain Fresh 162 180 10.0 116 151 23.2 Florida 91 162 186 13.0 114 149 23.5  Armstrong Farm0102030405060708017-Jun 27-Jun 7-Jul 17-Jul 27-Jul 6-Aug 16-Aug 26-AugMkt lbs/10 plants Horticulture Station0102030405060708017-Jun 27-Jun 7-Jul 17-Jul 27-Jul 6-Aug 16-Aug 26-AugHarvest Date, 2007 lbs/10 plantsSunstart MtnFresh Fla91  Figure 1. Comparison of weekly production of three tomato varieties grown in a high tunnel at the Armstrong Farm and Horticulture Station, 2007. Yields are expressed as lb marketable fruit/10 plants. Iowa State University, Horticulture Research Station ISRF07-36    Armstrong-May0510152025303540455017-Jul 22-Jul 27-Jul 1-Aug 6-Aug 11-Aug 16-Aug 21-Aug 26-Auglbs/10 plts Horticulture-May0510152025303540455022-Jul 27-Jul 1-Aug 6-Aug 11-Aug 16-Aug 21-AugHarvest date, 2007lbs/10 pltsSunstart Mtn Spring Mtn Fresh Fla91 Figure 2. Comparison of weekly production of four tomato varieties grown in outdoor field setting at the Armstrong Farm and Horticulture Station, 2007. Transplants set May 11 at Armstrong Farm and May 12 at the Horticulture Station. Yields are expressed as lb marketable fruit/10 plants.       Iowa State University, Horticulture Research Station ISRF07-36      010203040506070809012-Jun 2-Jul 22-Jul 11-Aug 31-Aug 20-Sep 10-OctHarvest Date 2006lbs/10 pltsSunstart HT Mtn Fresh HTMtn Fresh May Mtn Fresh June  010203040506070809017-Jun 27-Jun 7-Jul 17-Jul 27-Jul 6-Aug 16-Aug 26-Aug 5-SepHarvest Week 2007lbs/10 pltsSunstart HT Mtn Fresh HTMtn Fresh May Mtn Fresh June   Figure 3. Weekly harvest yields, lb/10 plants, from a planting of Sunstart and Mountain Fresh in a high tunnel and field planting of Mountain Fresh in mid-May and again in early June, Armstrong Farm 2006 and 2007.  Iowa State University, Horticulture Research Station ISRF07-36  Year Comparison02550751001251501752007-Jun 27-Jun 17-Jul 6-Aug 26-Aug 15-Sep 5-OctHarvest WeekLbs/ 70 plts2006 2007  Figure 4. Weekly harvest yields, a total of 70 plants, from a mid-April planting of Sunstart and Mountain Fresh (10 plants each) in a high tunnel; field planting mid-May of Sunstart + Mountain Fresh + Florida 91 (10 plants each); and field planting early-June of Mountain Fresh + Florida 91 (10 plants each), Armstrong Farm. Not all 70 plants were producing the same week. 

High Tunnel Tomato Production

High tunnels for Iowa tomato production are used for earliness rather than late-season extension beyond the fall frost period. This is probably due to price decline and lower per capita in the fall as consumers change their buying habits. Typically, transplanting in high tunnels is initiated about 4 to 5 weeks before field planting or about early-to mid-April for central Iowa. Our objective was to maintain a steady supply of fresh market tomatoes throughout the growing season by evaluating a combination of cultural practices: proper variety selection (adaptable varieties for early and main season); sequence of planting dates; and the use of high tunnels, row covers, and selective wavelength polyethylene mulches (increased soil temperature compared with black plastic).</p

High tunnels for Iowa tomato production are used for earliness rather than late-season extension beyond the fall frost period. This is probably due to price decline and lower per capita in the fall as consumers change their buying habits. Typically, transplanting in high tunnels is initiated about 4 to 5 weeks before field planting or about early-to mid-April for central Iowa. Our objective was to maintain a steady supply of fresh market tomatoes throughout the growing season by evaluating a combination of cultural practices: proper variety selection (adaptable varieties for early and main season);sequence of planting dates; and the use of high tunnels, row covers, and selective wavelength polyethylene mulches(increased soil temperature compared with black plastic).</p

Iowa State University, Armstrong and Neely-Kinyon Research and Demonstration Farms ISRF06-12  High Tunnel Tomato Production  Henry G. Taber, professor  Department of Horticulture Bernie Havlovic and Nick Howell, farm superintendents  Introduction High tunnels for Iowa tomato production are used for earliness rather than late-season extension beyond the fall frost period. This is probably due to price decline and lower per capita in the fall as consumers change their buying habits. Typically, transplanting in high tunnels is initiated about 4 to 5 weeks before field planting or about early- to mid-April for central Iowa. Our objective was to maintain a steady supply of fresh market tomatoes throughout the growing season by evaluating a combination of cultural practices: proper variety selection (adaptable varieties for early and main season); sequence of planting dates; and the use of high tunnels, row covers, and selective wavelength polyethylene mulches (increased soil temperature compared with black plastic).  Materials and Methods The project was established at the Armstrong Research Farm (southwestern Iowa, in a well-drained silt loam soil) and the Horticulture Research Station (central Iowa, in a well-drained loam soil). The previous crop at Armstrong was field corn and at the Horticulture Station, sod. Both sites were fertilized according to soil test recommendations. The cultural system consisted of SRM-olive wavelength plastic mulch and trickle irrigation. Transplants were set 18-in. in-row and rows 4.5 ft on center for the high tunnels and 6-ft on center for field production. All plants were staked, tied, and pruned to the first flower cluster. Irrigation scheduling was via tensiometers. Pest management practices for field production included necessary herbicide, insecticide, and fungicide applications. High tunnel production included only two insecticide applications for cutworms and tomato hornworm control. Selected varieties and their characteristics are listed in Table 1. There were two replications of each variety at each site.   Transplant dates were: Armstrong high tunnel on April 17 and field transplant dates of May 17 and June 8; Horticulture high tunnel on April 12 and field transplant dates of May 18 and  June 12.  Yield data consisted of a weekly harvest at the Horticulture Station and twice a week at the Armstrong farm with fruit sorted into marketable and culls. Culls included very small fruit and fruits with rots, radial and concentric cracks, and ripening disorders. The marketable category was graded into four sizes: extra large (>2! 78 in.), large (2! 78 to 2! 12 in.), medium (2! 12 to 2! 14 in.), and small (<2! 14 in.).  Results and Discussion Sunstart variety was the first to begin production from the high tunnel planting at both sites (Table 2). Early production began six days earlier at the Armstrong Farm compared with the Horticulture Station, even though plants were set five days later, reflecting the more southern location. Also, early yield was generally higher at Armstrong and the cullage was less compared with the Horticulture station. Sunchief produced unacceptably high cullage at both sites.   There was a stark contrast between the two sites for total high tunnel season yield. Although both sites were planted at similar times and the harvest season almost identical, Armstrong had higher total and marketable yields, with some varieties >1.5 times that of the Horticulture Station (Table 3). A large part of the difference was in percentage of culls with the Horticulture Station almost three times Armstrong. The higher daytime temperatures in the tunnel, and perhaps the sod ground, led to much more non-uniform color (blotchy ripening) development at Iowa State University, Armstrong and Neely-Kinyon Research and Demonstration Farms ISRF06-12  the Horticulture Station. Temperatures >92oF will lead to considerable blotchy ripening and high temperatures ≥104oF, for three hours or more, results in blossom abortion. The Horticulture Station tunnel exceeded these values for many days. The high temperature also reduced the percentage of extra large fruit, but soil fertility levels may also have affected fruit size. Varieties that performed similarly for total yield at both locations were Sunstart and Sunshine, the two earliest varieties.  The best performing varieties at both sites were Mtn Spring, Mtn Fresh Plus, Fla91, and FL47R. At Armstrong, the indeterminate greenhouse variety Blitz performed well but fruit size was more in the large category as opposed to extra large. Blitz and Trust are greenhouse varieties that are not as well adapted to the culture of high tunnel production as early field fresh market types.  The high tunnel effect on daily maximum and minimum temperatures is illustrated in Figure 1. Early in the growing season, a high tunnel advantage lies in elevating daily temperature to hasten plant growth and development. But, as early summer approaches (June) it is critical that maximum ventilation be provided (rolling up sides and ends) to avoid extreme heat (Figure 1). Conversely, high tunnels do not provide much protection against low temperatures near freezing. The nights of April 27, May 6, and May 12 all recorded 37oF outside at the Armstrong site. The high tunnel minimum temperatures on those nights were 39, 40, and 37oF, respectively. At the Horticulture Station, the outside low temperature of 33oF was recorded May 6. The corresponding high tunnel low temperature was 34.5oF. Also note that throughout the early season the minimum air temperature in the high tunnel was close to outside minimum air temperature.  Field plantings were established with the same nine varieties in mid-May once the danger of frost passed. The field location was adjacent to the high tunnel at both sites. First harvest occurred for all varieties, except Fla91, on July 19 at Armstrong. The corresponding date for the Horticulture Station was August 3. However, Sunstart and Sunshine produced substantial fruit a week earlier, July 26. Unlike the high tunnel results, both sites produced similar total yields for most varieties (Table 4). The best performing varieties were the same as in high tunnel production–Mtn Spring, Mtn, Fresh Plus, Fla91, and FL47R. However, the Horticulture Station had almost twice the cullage as the Armstrong Farm. This may be related to more stringent sorting techniques and/or cultural practices such as lower fertility level on the Horticulture sod site.  A second field planting was established in June to maintain continuous supply—June 8 at the Armstrong Farm and June 12 at the Horticulture Station. At both locations the varieties performed similarly for total yield and equivalent to the mid-May planting over the same time period (Table 5). However, the fruit quality was lower at the Horticulture site as reflected in nearly 50% cull fruit, almost twice that of the mid-May planting. Mtn Fresh Plus also had twice the cull fruit compared with the mid-May planting at Armstrong. Frost occurred the night of September 20, terminating harvest.  To maintain uniform fruit production Sunstart and/or Mtn Fresh could be planted in a high tunnel followed by a mid-May and early-June planting of Mtn Fresh (Figure 2). If Sunstart was used in the high tunnel followed by two plantings of outdoor Mtn Fresh this would yield 26 to 35 lb/10 plants per week from July 10 to September 15, except for July 31 when only 8 lb were produced and August 14 where the two plantings overlapped and 91 lb produced. If Mtn Fresh was used for all three plantings, weekly yield would fluctuate considerably, from a high of 101 lb/10 plants on July 24 to 34 lb/10 plants on September 7. Iowa State University, Armstrong and Neely-Kinyon Research and Demonstration Farms ISRF06-12     Table 1. Tomato varieties used in high tunnel and field trials, 2006.  Variety Days to harvest  Fruit size (oz.) Seed cost, per 1M  Comments Sunshine 67 8 $41.00 very early, smooth fruit Sunstart 67 8–11 41.00 First early, poor foliage cover, concentrated set for ~ 2 weeks Sunchief 70 10 47.25 Large vine, good foliage, sunshine maturity with larger fruit size Mtn. Spring 70 10 27.25 Standard commercial variety Florida 91 80 10 51.25 Extra large, attractive fruit, sets well under high temps, vigorous vine Mtn. Fresh + 72 10 25.35 Good flavor, large vine Florida 47R 75 10–12 47.00 Main season, firm, high quality fruit Trust main 7–8 278.00 Standard greenhouse variety Blitz main 8 278.00 Newer greenhouse type, higher yield Sun Leaper 80 7–8 25.00 Sets well under high temperatures All are determinate growth habit, except Trust and Blitz. All are resistant to Fusarium wilt race 1 and 2, Verticillium wilt, Gray leaf spot (except Mtn. Spring, Mtn. Fresh), and Alternaria stem canker (except Mtn. Spring and Mtn. Fresh). Mtn. Fresh is also resistant to nematodes. Sun Leaper only at Horticulture Station in second outdoor planting to replace Mtn. Spring.    Table 2. Early1 season yield (lb/10 plants) of tomatoes planted in high tunnels.2   ------------ Armstrong ---------- ------------Hort Station ----------------- Variety Marketable Total Cull, % Marketable Total Cull, % Sunstart 19.9 23.2 14.2 13.6 16.7 18.6 Sunshine 8.8 11.3 22.1 2.3 3.2 28.1 Sunchief 1.0 2.4 58.3 1.2 1.8 33.3 Mtn. Spring 1.4 1.9 26.3 0 0 -- 1Early equals the first two weeks of harvest. 2Harvest commenced June 23 at Armstrong and June 29 at the Horticulture Station. Planting date was April 17 at Armstrong and April 12 at the Horticulture Station.    Table 3. Total1 season yield (lb/10 plants) of tomatoes planted in high tunnels.2    ------------ Armstrong ----------------- ---------------- Hort Station ---------------- Variety Mktable Extra large3 Total Cull, % Mktable Extra large3 Total Cull, % Sunstart 109 90.2 140 22.5 61 73.8 140 56.2 Sunshine 122 88.9 174 29.7 60 76.7 162 63.2 Sunchief 142 95.4 188 24.4 35 88.6 122 71.1 Mtn Spring 208 91.6 229 9.2 90 88.9 148 39.0 Mtn Fresh 198 93.8 221 10.6 105 92.3 160 34.5 Fla91 208 94.4 227 8.5 100 85.0 154 35.0 FL47R 224 86.0 238 8.5 85 79.4 139 38.7 Blitz 194 77.3 233 16.6 70 65.7 163 57.2 Trust 171 81.4 201 15.0 66 56.1 149 55.4 1Total equals eight weeks of harvest. 2Harvest for high tunnel ended August 14 at Armstrong and August 17 at the Horticulture Station. 3Extra large equals percentage of marketable fruit >2! 78 in. diameter. Iowa State University, Armstrong and Neely-Kinyon Research and Demonstration Farms ISRF06-12    Table 4. Total1 season yield (lb/10 plants) of tomatoes field planted.2    ------------ Armstrong ----------------- ---------------- Hort Station ---------------- Variety Mktable Extra large3 Total Cull, % Mktable Extra large3 Total Cull, % Sunstart 104 82.5 129 19.9 83 77.1 123 31.9 Sunshine 89 67.4 117 24.2 84 75.0 151 44.6 Sunchief 105 80.0 138 23.6 28 100.0 109 73.9 Mtn Spring 116 86.2 141 17.6 97 93.4 134 28.1 Mtn Fresh 172 78.5 192 10.5 166 81.3 212 22.2 Fla91 138 89.1 154 10.0 108 96.3 143 24.5 FL47R 133 85.0 156 14.7 89 83.1 133 33.0 Blitz 81 70.4 109 25.9 75 56.0 152 51.0 Trust 75 68.0 116 35.9 87 62.1 150 42.2 1Total equals seven weeks of harvest. 2Transplants set May 17 at Armstrong and May 18 at the Horticulture Station. Harvest began July 19 at Armstrong and July 26 at Horticulture Station. 3Extra large equals percentage of marketable fruit >2! 78  in. diameter.     Table 5. Total season yield (lb/10 plants) of tomatoes field planted.1    ------------ Armstrong ----------------- ---------------- Hort Station ---------------- Variety Mktable Extra large2 Total Cull, % Mktable Extra large2 Total Cull, % Mtn Spring 93 67.6 108 13.9 -- -- -- -- Mtn Fresh + 94 91.8 117 20.3 66 98.5 116 43.2 Fla91 95 93.5 117 19.1 53 99.1 106 49.8 FL47R 92 80.5 111 17.7 66 96.0 131 49.8 Sun Leaper -- -- -- -- 71 95.0 130 45.4 1Transplants set June 8 at Armstrong and June 12 at the Horticulture Station. 2Extra large equals percentage of marketable fruit >2! 78  in. diameter. Iowa State University, Armstrong and Neely-Kinyon Research and Demonstration Farms ISRF06-12   Daily Maximum Temperature02040608010012023-Apr 3-May 13-May 23-May 2-Jun 12-JunDateoFOutside Max HT max Figure 1. Comparison of outside daily high temperature to high tunnel maximum air temperature. High tunnel temperature probe located between plants at an 8-in. height above the wavelength-selective plastic mulch. Average of 3 locations. Armstrong Research Farm, Lewis, IA.     Armstrong02040608010012012-Jun 2-Jul 22-Jul 11-Aug 31-Aug 20-SepDate 2006lbs/10 pltsMtn Fresh-HT SunStart-HTMtn Fresh-May MtnFresh-June Figure 2. Weekly harvest yields from 10 plants from a planting of SunStart and Mtn Fresh in high tunnel on April 17 and field planting of Mtn Fresh on May 17 and June 8, Armstrong Research Farm.  

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High Tunnel Tomato Production

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Digital Repository @ Iowa State University (ISU)

Digital Repository @ Iowa State University (ISU)

Digital Repository @ Iowa State University (ISU)