North Willamette Research and Extension Center report
Delbert Hemphill
OSU Dept. of Horticulture
Dan McGrath
OSU Dept. of Horticulture
Introduction
The Oregon table beet industry has long used the variety 'Detroit Dark Red Morse Strain,' Scott Viner-type single-row harvesters owned by individual growers, and between-row spacings of 20 or more inches. Preliminary trials in 1998 indicated that beet yields and grades might be improved with a combination of closer row spacings within a bed, hybrid varieties, precision planters, and bed-oriented, multi-row mechanical harvesters. These faster, higher-capacity harvesters would likely be owned by beet processors rather than by individual growers because of their high cost. Our objectives in 1999 were (1) to test the hybrid variety 'Red Ace' against the standard 'Detroit Dark Red' to see if the expected greater vigor and uniformity of the hybrid might have some advantages in a close-row system where plants would be subject to more between-plant competition than at the standard wide row spacings; (2) to again evaluate the 12-inch-row configuration using Oregon State University's Gaspardo precision planter in comparison with grower planters such as the John Deere 71 Flex Planter and the Planet Jr; and (3) to observe the efficiency of harvesting with an AMAC ZR-2 multi-row harvester compared to a single-row Scott Viner harvester.
Methods
Two sites were used: the first was in the north Willamette Valley, southwest of Forest Grove, the second in the central Willamette Valley just west of Dayton, Oregon. The growers agreed to plant large plots, sufficient for truckload quantities of beets at harvest. Several planters were to be tested by different growers to compare with a precision planter used by the OSU researchers. Topping and harvesting included a preliminary topping with a steel-fingered flail topper to remove most foliage, followed by a Parma three-drum, rubber-finger topper, and an AMAC ZR-2 harvester. In-plant cleaning by Stayton Canning Company was conventional.
The same 1.4-sprout-per-seedball seedlot of 'Red Ace' that was used in 1998 was also used in this study. Seeding was on April 23 at Forest Grove and on April 30 at Dayton. The 'Detroit Dark Red' seedlots were those being used by the growers for their commercial plantings.
The research plots at both locations were planted using a Gaspardo SV255 precision, multiple-row vacuum planter set up to plant four rows to a bed. The rows were spaced 12 inches apart on beds spaced on 60-inch centers, giving an average spacing of 15 inches. This planter was used for 'Red Ace' and the growers' 'Detroit Dark Red'. Due to the design of the planter, the vacuum seed plate did not need to be changed among seedlots despite the large differences in seed size between the 'Red Ace' (35,287 seeds/lb) and the two lots of 'Detroit Dark Red' (51,446/lb at Forest Grove and 24,140 at Dayton). Seeding rate was approximately 25 lb/acre for both varieties.
At Forest Grove, the grower used a Planet Jr. configured to plant rows 7 inches apart for an even closer spacing, and a grass seed planter configured to plant beets in a solid mat in beds 60 inches on center. At the Dayton site, the grower used a John Deere 71 Flex Planter to plant his conventional rows on 22-inch centers. This same planter was then reconfigured to plant rows 12 inches apart in 4-row beds on 60-inch centers. The latter planting occurred 1 week after the other three treatments were seeded.
Cultural practices were those normally used by the grower in his table beet production. At Dayton the grower conducted one mechanical cultivation and one hand weeding in addition to his standard herbicide program. No cultivation or hand weeding was done at Forest Grove.
Stands were evaluated on May 14 (Forest Grove only), May 26, and on June 28, 1999. Counts were made for three randomly chosen 1 ft x 4-row (5 ft for bedded plantings) quadrats for each planting treatment. The first stand count includes only the Forest Grove plantings as the Dayton planting had not emerged.
We conducted hand-harvests at the Dayton site on August 18, 1999 and September 2, 1999. The September 2 hand-sampling date was 1 day before the plots were mechanically harvested. Hand-harvest consisted of pulling all beets from 4 lineal ft of each of four rows of each treatment on August 18 and from 3 lineal ft of each of four rows on September 2, 1999. The hand-harvests were replicated three times over different planter passes for each treatment. The replicate areas were 20 and 15 ft2 for each of the three samples taken from 12-inch-row treatments, and 26.67 and 20 ft2 for each of the three replicates for the 20-inch spacing on the August 18 and September 2 dates, respectively. This represents a total of 60 and 45 ft2 and 80 and 60 ft2 for each of the 12-inch and 22-inch-row treatments on the two dates, respectively. All beets were hand-topped and taken to Stayton Canning Company for grading by their staff.
Mechanical harvest was on September 3, 1999 at the Dayton site. Topping was done just ahead of harvest. Truckload quantities of beets were harvested from each treatment. We then measured the area harvested to fill each truck.
Results
Beet Stands
The May 26 stand counts included both the Forest Grove and Dayton sites (Tables 1 and 2). Later stand counts were fairly consistent with the first count and did not show the large mortality experienced in the 1998 season following 6 weeks of rain. The final count on June 28 involved pulling all developing plants in the quadrat. This stand count is reported and forms the basis for stand discussion.
The grass-seed planter used by the grower in the Forest Grove site produced stands that were very poorly distributed across the bed. A chain used to drag the beds immediately after the seed was dropped tended to windrow the seeds to the edges of the beds, and the plants across the bed were often clumped, unevenly spaced, and planted at various depths. The stands from the Planet Jr. were also very uneven. The scatter shoes and seed plates used with this planter tended to distribute the seed in clumps or with uneven spacing. Plants from both these planters tended to emerge at different times depending on their depth of planting.
The two treatments with the Gaspardo were very uniform in emergence and distribution down the row. Most obvious was the uniform seedling size due to uniform emergence and the uniform distribution down the row.
With only two exceptions, stands increased slightly at later counting dates. Emergence weather was good, and there was little reason to expect any unusual mortality. Stands tended to be slightly higher at Dayton than at the Forest Grove site for the two Gaspardo treatments.
Hand-harvests
Due to plant and equipment scheduling needs of the processor, other growers using the equipment, and difficulties with weed control and other limiting factors, the Forest Grove site was not harvested. Yield data from the Dayton site only are reported here.
The processor pay scale is $81/ton for Grade 1 (the smallest marketable beets), $73/ton for Grade 2 (intermediate size), and $16/ton for Grade 3 (oversize). Based on this scale, the dollar values per acre increased about $48/day over the 16 days between August 18 and September 2, an average of about $773/acre across all treatments. The range was from $658/acre for the John Deere 22-inch-'Detroit Dark Red' to $854 for the Gaspardo-'Red Ace' (Tables 3 and 4). Dollar values per acre were similar for the John Deere, 22-inch and the Gaspardo, 12-inch 'Detroit Dark Red' treatments at each harvest. Yields and dollar values of the grower-planted 'Detroit Dark Red' on 12-inch spacing lagged because of the later planting date. 'Red Ace' had a slightly higher yield and dollar value than did 'Detroit Dark Red.'
Machine Harvest
Truckloads and machine-harvested area for the different treatments were 15,940 lb from 0.248 acres for the 12-inch-row 'Detroit Dark Red' Gaspardo planting; 46,800 lb from 0.551 acres for the 12-inch-row 'Red Ace' Gaspardo planting; 28,780 lb from 0.431 acres for the 'Detroit Dark Red' 22-inch-row conventional John Deere 71 planting, and 23,960 lb from 0.368 acres for the truckload of the 'Detroit Dark Red' 12-inch planting that was harvested at the same time as the other three treatments but planted 1 week later.
Yield, grade, and dollar value data are presented (Tables 5 and 6) for one truckload mechanically harvested from each of the treatments at the Dayton location. Truck weights are as reported by the processor. The machine-harvested truckloads of beets were graded by the processor. The dollar values in Table 5 were obtained by applying the grades from the final hand sampling (Table 4) to the machine-harvest yields. The dollar values in Table 6 were obtained using the grade reported by the processor for each truckload.
Machine-harvest yields for the John Deere 12-inch spacing and the 'Red Ace' planting were considerably higher than for the final hand sample, but the yields for the John Deere 22-inch rows and the 'Detroit Dark Red' Gaspardo planting were very similar to those determined by hand harvest. 'Red Ace' clearly outperformed 'Detroit Dark Red.'
Since the processor pays similarly for Grade 1 and Grade 2 and relatively little for Grade 3 ($16/ton), the difference in using the truckload grade and the hand-harvest grade to compute value/acre is very small and does not affect the rank of the treatments. All three 'Detroit Dark Red' treatments produced similar dollar value in the machine harvest, indicating that the close row treatments do not sacrifice yield or dollar value compared to conventional spacing. As harvest efficiency is higher for the AMAC bed harvester than for the Scott-Viner single-row harvester, despite the extra topping operation required by the AMAC, the net returns may be higher for the 12-inch spacing.
Using the cannery truckload grades to judge the comparative maturity of plants in each treatment (Table 6), one can see that the 12-inch-spacing treatments were somewhat behind the 22-inch spacing treatment in beet root development. Note especially the higher percentage of Grade 3 beets for the 22-inch spacing. It is interesting to speculate what the dollar value might have been for the 12-inch spacings if they had been harvested at the same percentage of Grade 3 beets. In our opinion, the 12-inch spacings would have benefited from another week's growth. As in 1998, if we accept the grades reported in Table 6 as accurate assessments of the loads, the closer spacings retarded development of Grade 3 beets.
Recommendations
Based on observations made throughout the season and at harvest, and from the cannery grade sheets for truckloads of high-density beets which were not a part of this study, we feel that it is important that growers considering a shift to high-density beets consider the following:
1. Soil type. Sandy loam soils that will easily separate from the beets at harvest are likely to be the best for this system.
2. Soil moisture at harvest. Excessive amounts of soil may be delivered with the loads of beets from soils that are either too wet or too dry. Muddy beets result from wet soils and clods are a problem with excessively dry soils. Growers may need to irrigate a few days before harvest to ensure that clods are not a problem. Also, this system probably should not be used in fields scheduled for a late harvest when fall rains may be a problem.
3. Weed control. Growers need to select fields with the fewest weed problems and set up suitable cultivators to be used if chemical weed control is not adequate. Failure to adequately control weeds will be a serious problem in this system.
Table 1. Stand counts at Forest Grove, Oregon, 1999. Planting method May 14 May 26 June 28 Per acre Per bed-ft Per acre Per bed-ft Per acre Per bed-ft Grass planter 4 mph 278,784 32 331,056 38 412,368 47 Grass planter 5 mph 574,992 66 653,400 75 740,520 85 Grass planter 6 mph 252,648 29 314,432 36 331,056 38 Gaspardo 'Red Ace' 679,536 78 714,384 82 772,464 89 Gaspardo 'Detroit' 749,232 86 734,712 84 728,904 84 Planet Jr. 'Detroit' 574,990 66 860,310 78 665,016 76 Table 2. Stand Counts at Dayton, Oregon, 1999. Planting method May 26 June 28 Per acre Per lineal-ft Per bed-ft Per acre Per lineal-ft Per bed-ft Gaspardo 12 'Detroit' 967,032 27.8 111 1,059,960 30.4 122 Gaspardo 12 'Red Ace' 755,040 21.7 87 923,472 26.5 106 John Deere 22 'Detroit' 520,742 21.9 88 487,082 20.5 82 Table 3. Yield and dollar value of beets hand-harvested at Dayton, Oregon, 18 August, 1999. Planting method Yield of payable Grade 1 Grade 2 Grade 3 Total value beets, tons/acre % $/acre % $/acre % $/acre ($/acre) John Deere 12-inch 16.1 41.3 539 27.2 320 0.7 2 881 John Deere 22-inch 19.9 35.0 565 42.9 624 3.5 11 1,200 Gaspardo 'Detroit' 12-inch 21.0 40.3 686 39.8 610 1.9 6 1,302 Gaspardo 'Red Ace' 12-inch 24.1 43.6 851 33.0 581 1.3 5 1,437 Table 4. Yield and dollar value of beets hand-harvested at Dayton, Oregon, 2 September, 1999. Planting method Yield of payable Grade 1 Grade 2 Grade 3 Total value beets, tons/acre % $/acre % $/acre % $/acre ($/acre) John Deere 12-inch 21.7 43.0 966 35.0 709 0.0 0 1,675 John Deere 22-inch 25.2 30.5 738 50.5 1,102 3.3 18 1,858 Gaspardo 'Detroit' 12-inch 28.7 34.5 974 42.0 1,068 5.7 30 2,042 Gaspardo 'Red Ace' 12-inch 29.9 36.7 1,089 45.3 1,202 0.0 0 2,291 Table 5. Yield and dollar value for beets harvested by machine at Dayton, Oregon, 3 September, 1999, using the hand-sample grade. Dollar values computed using the grades from the September 2 hand-harvest. Planting method Yield of payable Grade 1 Grade 2 Grade 3 Total value beets, tons/acre % $/acre % $/acre % $/acre ($/acre) John Deere 12-inch 27.0 43.0 1,133 35.0 831 0.0 0 1,964 John Deere 22-inch 27.4 30.5 750 50.5 1,117 3.3 16 1,883 Gaspardo 'Detroit' 12-inch 26.7 34.5 897 42.0 985 5.7 30 1,912 Gaspardo 'Red Ace' 12-inch 36.5 36.7 1,262 45.3 1,406 0.0 0 2,668 Table 6. Yield and dollar value for beets machine-harvested at Dayton, Oregon, 3 September, 1999, using the truckload grade. Dollar values computed using the grades determined on the cannery sample taken from each truckload. Planting method Yield of payable Grade 1 Grade 2 Grade 3 Total value beets, tons/acre % $/acre % $/acre % $/acre ($/acre) John Deere 12-inch 27.0 31 817 41 1,093 3 16 1,926 John Deere 22-inch 27.4 22 541 54 1,197 13 63 1,801 Gaspardo 'Detroit' 12-inch 26.7 24 624 50 1,173 6 31 1,829 Gaspardo 'Red Ace' 12-inch 36.5 25 860 58 1,298 2 14 2,672