Changing Meadowfoam Planting Dates and Planting Method to Reduce Input Costs, Pest Pressure, and Increase Yields.
Meadowfoam is a new oil seed crop, and a key diversification component in the grass seed cropping systems of Oregon’s Willamette Valley. We are exploring late planting, no-till, and broadcast seeding as means of reducing meadowfoam production costs and maximizing the farm system benefits of this rotation.
Farm-scale and small plot trials of no-till and broadcast planted treatments on 4 dates documented that planting of meadowfoam as late as early December continues to show promise as viable options while offering added benefits. An experimental no-till planting into an annual ryegrass full-straw load showed such promise for reducing costs that our cooperators chose to concentrate their efforts in this new direction.
1) Determine if seed and oil yields of late-planted no-till and broadcast meadowfoam compare to yields from traditional tilled or disked fields planted in mid October. (The perennial grass seed straw residue is typically baled for sale prior to planting meadowfoam.)
2) Determine if weed populations are lower in late-planted no-till and/or broadcast meadowfoam. Weed control for the subsequent grass seed crop is a primary reason many growers incorporate meadowfoam production into their cropping system. This is particularly true for grass weeds that cannot be controlled by the herbicides available in the grass seed production system.
3) Determine if meadowfoam fly pest pressure is less in late-planted treatments. The adult fly enters the field at about the time the crop emerges and goes through several generations; populations peak in May in unsprayed fields. Delaying the initial infestation may reduce insect damage and insecticide use.
4) Document grower assessment of the benefits of improved weed control on the subsequent grass seed crop. While many growers consciously use a rotation to meadowfoam to control troublesome weeds, they do not place a specific dollar/a value on this benefit. We will encourage them to attempt to assess the monetary value of any perceived benefits, detriments, or risks.
5) Document grower assessment of the benefits of the new planting timing and methods on workloads and work distribution. Meadowfoam is planted later in the fall than grass seed and harvested earlier in the summer. Thus the major time and machinery inputs into the meadowfoam crop do not directly compete with the grower’s grass seed production workload. Does meadowfoam provide greater benefits in this regard compared to other potential alternative rotational crops such as wheat or oats?
6) Document — using an enterprise data sheet — the cost benefits of the lower inputs required for late season no-till and broadcast planting. Many family farmers are not aware of their full cost of production, or economic benefits, particularly for more qualitative components of the production system. In addition to the easily quantified costs and benefits, we will attempt, via objectives 4 and 5, to incorporate, on a more quantitative basis, some of the less defined benefits and costs.
7) Compare the effectiveness of four methods of information outreach to the larger OMG membership (meadowfoam growers) using: a) The intensive interactions with our grower-collaborators will place them in a position of leadership on these issues within the grower organization. b) Interactions with other individual growers or small groups at the study sites. c) A presentation at the OMG annual fall meeting. d) Articles in the OMG newsletter.
GROWER-EXECUTED ON-FARM RESEARCH. In each of two years we were to have two farm-scale research trials, with an adjacent small plot trial at one site. In 2002-3 we were able to work at only one of the two planned experimental sites because of a problem preparing the second site. The 3 no-till and 3 broadcast planted treatments using the genetic line OMG 5185 were compared in the farm equipment-scale trial. No-till and broadcast plantings of meadowfoam as late as early December continued to show promise as economically viable options for meadowfoam growers. There were no statistically significant differences in seed yield (of 1356 to 1392 kg/ha) between any of the November and December no-till and broadcast plantings. The October 23 no-till planting date treatment yielded significantly less (1288 kg/ha) than all other treatments. Typically meadowfoam yields for OMG growers have been in the 900 kg/ha range, where suspected yield losses as a result of excessive nitrogen and damage by the meadowfoam fly appear to be common.
Excess N caused lodging of all plots at Ioka in 2002-03. Lodging was earlier and more severe the earlier the plots were planted, ranging from 78.5 to 6.7%. Data from previous years give reason to speculate that lodging causes yield loss, and probably was the factor primarily responsible for the lower yields in the Oct 23rd planting. This treatment lodged earlier, and more extensively, than the other treatments. An example of this lodging-associated yield loss is in our meadowfoam experiments at Ioka in 1999-2000, where 60% lodging in OMG 5185 was estimated to result in a 10% yield loss.
We planted at a rate of 325 seeds/m2 . Except for the low densities in the Nov 15th no-till and broadcast plantings (216 and 218 seeds/m2, respectively), the establishment rate was generally similar for the other treatments, ranging from 236 to 288 plants/m2. Treatment means had to differ by 39 plants/m2 to be considered significantly different. We saw evidence of freeze damage to a few germinating broadcast seedlings in the November 15th broadcast treatment. Under good management and growing conditions seeding rate has to vary by at least a factor of 2X from optimum rates to significantly affect yields. Broadcasting by pulling the drill’s seed drop tubes from the disk openers did not achieve equidistance spaced plants.
Minor damage from Select herbicide was seen in the October planting but its effects on yield were not quantified. The yield loss, if any, from the low numbers of the meadowfoam fly was thought to be minor. Grass weeds were few and controlled by the Select application in late winter. The primary weed was Canada thistle, and its abundance was unrelated to the planting treatments. Very hot temperatures and dry weather, similar to that experienced during the flowering and seed maturation period in 2003, have previously been shown to reduce meadowfoam yields. However, we do not know their impact at Ioka this year. In 2001 at Ioka Farms, in an adjacent field under favorable nitrogen regime and spring weather, this same genetic line had a high yield of 1555 kg/ha at the mid-November farm-scale planting. Oil content of this seed will be analyzed this winter.
SMALL PLOT TRIAL. These were to be planted adjacent to one of the farm-scale trials to extend the number of entries, typically adding entries at the extremes of favorable conditions. Since we were unable to use the farm site where we planned to place the small plot experiments we conducted this trial at the OSU Hyslop Experiment Station. The same no-till and broadcast entries were used with the addition of 3 entries to expand the scope of the trial: a Oct 23rd broadcast, an Oct 23rd irrigated entry, and a broadcast entry using a Hege drill rather than the usual Gandy drop spreader. The Oct 23 drilled plots were planted into a roto-tilled seedbed, which was as close as we could get to the traditional disked seedbed often used in the South Willamette Valley.
Herbicide damage from the winter Select application confounded the results. The earlier planted entries suffered more than the later plantings as evidenced by greater numbers of damaged flowers counted just prior to harvest (17.5, 7.0, 3.5, and 0.8% for the four Oct to Dec 20th planting dates, respectively). The number of severely damaged flowers, which produced no seed, was even less (4.9, 0.8, 0.7, 0.8% for the same dates). While these percentages are relatively small compared to the total number of flowers, we do not know if there were other types of damage that may have reduced yields.
Stand Counts: Plots were planted at the rate of 325 seeds/m2. Planting method had a large impact on plant density taken at the 2-3 true-leaf stage. The broadcast seeding resulted in much more equidistant spacing of seedlings. For the first three planting dates the drilled plots had 183 plants/m2, while the broadcast plots had 283 plants/m2 . The fact that the Dec 6th Hege broadcast had the same stand count as the Gandy seeded broadcast confirmed that this equipment was seeding at the same rate. Therefore, we may be seeing strong evidence to accelerate the inclusion of more broadcast seeding treatments in future trials.
The lower plant density of the no-till drilled plots in November and December was due to poor plant establishment between the dead perennial ryegrass crown rows. This may be due to herbicide residues that built up in the soil between the crowns during the 4 years this field was in perennial ryegrass. This poor establishment between crowns was not observed during our several years of no-till experience at Ioka Farms.
The lower plant density in the drilled Oct 23rd entries was due to additional factors. The drilled and irrigated Oct 23rd planted entry had higher plant densities than the non-irrigated entry. It appears that seeds in the non-irrigated plots had started to germinate, but had desiccated and died before the delayed fall rains. The irrigated entry dried out between watering, which may have also negatively affected germinating seeds. The Oct 23rd date entries were planted into a roto-tilled seedbed that would have mixed any residual soil herbicides, and seemingly could have reduced its impact on germinating meadowfoam. However 2002-3 herbicide residue trials at Hyslop by other OSU scientists suggest that in disked fields residual herbicides can adversely affect meadowfoam establishment. The Oct 23rd broadcast entry did not start to germinate until the arrival of regular fall rains the second week of November, thus the seed did not suffer from repeated wetting and drying.
Seed yields: As we have found in previous studies, seed yields of late-planted meadowfoam are comparable to traditionally planted meadowfoam. The yields of the Oct., Nov., and Dec. broadcast entries (1,635; 1,651; 1,676 kg/ha, respectively) had higher yields than the tilled entries (1,504; 1,593; 1,608 kg/ha) P =0.0060. The lower plant density within the drilled plots may be a factor. The non-uniform plant distribution in the drilled rows, combined with lower density, may have reduced the yield potential of these meadowfoam plots. Within planting methods, yields did not differ among the first three planting dates (P =0.1057). Within the broadcast method, yield declined significantly in the latest planted entry (Dec 20th). In an independent trial the previous year at this location, using the traditional planting method, this meadowfoam line yielded 1,429 kg/ha. So, even with the Select damage, the meadowfoam planted into early December, particularly the broadcast entries, achieved satisfactory yields. Oil content of this seed will be analyzed this winter. Weed density data are not yet analyzed.
FULL-STRAW LOAD EXPERIMENT. In conjunction with a non-WSARE on-farm experiment we no-till planted cv. Floral meadowfoam into an annual ryegrass full-straw load. Our late no-till planting enabled adequate control of the volunteer grass sprout; small plots placed within this larger field yielded 1,525 and 1,495 kg/ha for full straw versus straw removed plots, respectively. Our success shifted the meadowfoam focus of our 2003-4 season farmer-cooperators away from perennial grass systems to annual ryegrass, where there is no market for straw. They felt that being able to plant into a full-straw load would give them the greatest potential reduction in production costs and open up more options in their farming systems. Using this desire as our guide, we redesigned the experiments we planted in fall 2003 to emphasize this new development, while retaining the key elements of our original proposal, except for deleting the conventional tillage treatment in the second year.
Objectives 4 through 7 will be addressed in the second year of the study.
Impacts and Contributions/Outcomes
Because this is the first year of the study, and much of the communication with growers is going to take place in the second year of the study, the impacts are still speculative.
This research improves: 1) meadowfoam grower production options, 2) direct grower involvement in learning, 3) profit ($0.5 to 3 million/year), 4) sustainability, and reduces: 5) risk, and 6) environmental impact. Practices proven in 2001, with high yields of 2575 kg/ha from on-farm small plots, were used to guide grower-collaborator’s crop management. In a grower-executed trial using full-sized farm equipment, delayed no-till and broadcast meadowfoam planting in Nov. and Dec. yielded significantly more than the October no-till planting. The yields (1350 to 1392 kg/ha seed) were 50% above the industry average (in spite of excess N). That resulted in 450K kg more seed/1000 ha, mostly profit, and vital for industry R&D competitiveness. Small plot research supported these results. Seeding in non-tilled ryegrass seed crop stubble is the key that allows farm equipment entry onto arable soils long after initiation of fall rains. Soil erosion is low. Delayed planting: 1) extends the time frame to control weeds using glyphosate, 2) reduces the length of season the growing crop is exposed to pest colonization, and 3) shortens the fall growing period to reduce the risk of excessive vegetative growth and lodging that jeopardizes yield. Our success with late no-till planting into a full straw load opened an option that the growers in the valley bottomlands see as the greatest possibility for reducing production costs, primarily by eliminating the cost of using tillage for straw management and preparing the seed bed.
Oregon State University
Dept. of Crop and Soil Science
Oregon State Univ.
Corvallis, OR 97331-3002
Office Phone: 5417406812