Freshly harvested, immature (green) seeds of north american ginseng (Panax quinquefolius L.) were stratified for 12 months either traditionally in buried wooden boxes outdoors, or in plastic pails in a controlled environment room [3 ± 0.2 °C (37.4 ± 0.11 °F)], 85% ± 5% relative humidity) for about 9 months followed by about 3 months at 20 ± 2 °C (69.8 ± 1.1 °F). Embryo growth in Stage II (mid-May to late August when direct seeded) was more rapid [0.016 versus 0.009 mm·d-1 (0.00062 versus 0.00035 inches/day)] under controlled-temperature conditions. Seedling emergence rate did not vary between treatments. Root dry weight (economic yield) was similar for seedling, 2, 3, and 4-year-old plants whether grown from traditionally or controlled-temperature stratified seed. Controlled-temperature stratification of north american ginseng seed is an acceptable alternative to traditional outdoor, in-ground stratification.
John T.A. Proctor, Dean Louttit, and John M. Follett
Richard G Greenland
Planting barley (Hordeum vulgare L.) as a living mulch with onions (Allium cepa L.) reduces soil erosion and protects the onions from wind damage. It can also reduce yield and size of onion bulbs if not managed correctly. In a 4-year study at the Oakes Irrigation Research Site in North Dakota, barley was planted in the spring at the same time that onions were direct-seeded. Barley rows were planted either parallel with or perpendicular to the onion rows. Barley was killed with fluazifop-P herbicide when ≈13, 18, 23, or 30 cm tall. Onion size and yields were reduced when barley was allowed to grow taller than 18 cm before killing it. Total onion yield was usually greater when barley was planted parallel with, rather than perpendicular to, onion rows. Chemical name used: (R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-P).
Michael A. Arnold
Across horticultural crops the trend is to transplant larger plants to achieve the intended landscape effects or to produce the desired yield without the long wait associated with direct seeding or small transplant technology. Consumers want immediate gratification (a landscape design that produces the desired aesthetics without the wait for plants to grow to mature sizes). This trend extends from the use of large herbaceous plants for instant landscape color, transplanting of vegetable plants already in fruit to the home garden for early yield, to transplanting larger shrubs and trees to effect the impression of an established landscape. This trend logically culminates in the transplanting of large, mature specimen trees to create the appearance of a fully mature landscape. This workshop will explore the potential benefits of this approach and the challenges associated with successful transplanting of large trees.
Ronald D. Morse
Advantages of no-till (NT) production systems are acknowledged throughout the world. During the 1990s, production of NT vegetable crops has increased for both direct seeded and transplanted crops. Increased interest in reduced-tillage systems among research workers and vegetable growers is attributed to: 1) development and commercialization of NT transplanters and seeders, 2) advancements in the technology and practice of producing and managing high-residue cover crop mulches, and 3) improvements and acceptance of integrated weed management techniques. Results from research experiments and grower's fields over the years has shown that success with NT transplanted crops is highly dependent on achieving key production objectives, including: 1) production of dense, uniformly distributed cover crops; 2) skillful management of cover crops before transplanting, leaving a heavy, uniformly distributed killed mulch cover over the soil surface; 3) establishment of transplants into cover crops with minimum disturbance of surface residues and surface soil; and 4) adoption of year-round weed control strategies.
Wayne C. Porter and Richard L. Parish
Cabbage (Brassica oleracea L. Capitata) was direct-seeded with a precision seeder or with a bulk seeder. Treatments with the bulk seeder consisted of blending viable, hybrid cabbage seed with nonviable, open-pollinated seed at several ratios to reduce the cost of planting hybrid seed. The study demonstrated that farmers with small acreages can obtain equivalent net income per acre using bulk seeders compared to using more expensive precision seeders. The study also showed that the additional cost per acre of a precision seeder is small compared to other input costs (for the acreage assumptions used here). Low percentages of hybrid seed in the bulk seeder (10% to 50%) were not economical. Precision seeding to a stand reduced the need for thinning labor and resulted in equivalent yields and net income.
Charles L. Webber III and James W. Shrefler
Although CGM has been identified as an organic herbicide for weed control in turf and established vegetable plants, direct contact with vegetable seeds can decrease crop seedling development and plant survival by inhibiting root and shoot development. The objective of this research was to determine the impact of banded corn gluten meal applications on squash plant survival and yields. This factorial field study was conducted during Summer 2005 on 81-cm-wide raised beds at Lane, Okla., with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and nonincorporated), and three application rates (250, 500, and 750 g·m–2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on 19 Aug. The banded application created a 7.6-cm wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 2.5 to 5.0 cm of the soil surface with a rolling cultivator or left undisturbed on the soil surface. `Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was no significant difference between powdered and granulated CGM formulations or incorporating and nonincorporating the CGM for either squash plant survival or yields. As the CGM application rates increased the plant survival and yields decreased. Banded application resulted in significantly greater crop safety (90% plant survival) and yields (445 cartons/ha) than the broadcast (solid) applications (45% plant survival and 314 cartons/ha). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in banded application configuration.
James W. Shrefler, Charles L. Webber III, and Otis L. Faulkenberry III
Producers of organic vegetables often report that weeds are a troublesome production problem. It has been documented that corn gluten meal (CGM), a by-product of the wet-milling process of corn, is phytotoxic. As a preemergence or preplant-incorporated herbicide, CGM inhibits root development, decreases shoot length, and reduces plant survival of weed or crop seedlings. The development of a mechanized application method for CGM and the ability to apply the material in a banded pattern would increase its potential use in organic vegetable production, especially in direct-seeded vegetables. Therefore, the objective of this research was to develop a mechanized method to uniformly apply CGM to the soil surface in either a broadcast or banded pattern. An applicator was assembled using various machinery components (fertilizer box, rotating agitator blades, 12-volt motor, and fan shaped gravity-fed row banding applicators). The equipment was evaluated for the application of two CGM formulations (powdered and granulated), three application rates (250, 500, and 750 g·m–2), and two application configurations (solid and banded). Field evaluations were conducted during Summer 2004 on 81-cm-wide raised beds at Lane, Okla. Differences between CGM formulations affected the flow rate within and between application configurations. The granulated formulation flowed at a faster rate, without clumping, compared to the powdered formulation. While the CGM in the banded configuration flowed faster than the solid application. It was determined that the CGM powder used with the solid application configuration was inconsistent, unreliable, and thus not feasible for use with this equipment without further modifications. These evaluations demonstrated the feasibility of using equipment, rather than manual applications, to apply CGM to raised beds for organic weed control purposes. Several design alterations may increase the efficiency and potential usefulness of this equipment. If research determines equivalent weed control efficacy between the two CGM formulations, the granulated formulation would be the preferred formulation for use in this equipment. This equipment would be useful for evaluating the benefits of banded applications of CGM for weed control efficacy and crop safety for direct seeded vegetables.
Kevin L. Cook and Leonard M. Pike
An `intermediate leaf' hybrid pickling cucumber (TAMU 884304 X ARK H-19 `little leaf') was direct-seeded at four plant densities (94,570; 48,440; 32,290; 25,375 plants/ha) using four within-row spacings (15, 30, 45, 60cm) at two locations and two seasons. Optimum yield based on marketable fruit number, grade distribution and fruit quality occurred with 94,570 plants/ha. Optimum harvest time depended on location and season. Delayed harvest times were also evaluated. Harvests with fruit >5.1cm in diameter had severely reduced brining quality. Fruit did not enlarge or enlarged slowly to oversize. This resulted in a mixture of fruit ages within the largest marketable fruit grades. It is recommended that `little leaf' lines and their hybrids such as `intermediate leaf' be harvested when fruit 3.8 to 5.1cm in diameter appear and before oversize fruit are produced. Spacing did not significantly effect length/diameter ratio(LDR) but LDR was significantly greater for delayed harvests.
S. B. Sterrett, C. P. Savage Jr., and K. M. McManus
Studies were conducted in 1988 and 1989 to evaluate the influence of planting time and method on plant establishment and yield of fall broccoli. In 1988, plant establishment of direct-seeded broccoli was not improved with application of vermiculite (63 kg/ha). a cross-linked polyacrylamide polymer (17 kg/ha), or both as anti-crustants over the untreated check (37.6%, 32.2%, 24.6%, and 31% of target population, respectively). In 1989, transplants were compared with double-seeding (planting two seeds 25 mm apart). With seed. germination of 55% in the early planting (8 Aug.). plant populations of double-seeding and transplants were similar, but 42% germination of double-seeding in the late planting (28 Aug.) resulted in lower plant populations than from transplants. While yield reflected differences in plant populations, the percentage of marketable heads from transplants was significantly greater (90.6%) than from seedlings (78.9%). These data suggest that broccoli transplants are a viable option when high soil temperatures may be detrimental to seed germination.
R.M. Wheeler, C.L. Mackowiak, J.C. Sager, B. Vieux, and W.M. Knott
Lettuce (Lactuca sativa cv. Waldmann's Green) plants were grown in a large, tightly sealed chamber for NASA's Controlled Ecological Life Support Systems (CELSS) program. Plants were started by direct seeding and grown in 64 0.25-m2 trays (six plants per tray) using nutrient film technique. Environmental conditions included: 23°C, 75% relative humidity, 1000 ubar (ppm) CO2, a 16/8 photoperiod, and 300 umol m-2 s-1 PPF from metal halide lamps. Although the chamber was typically opened once each day for cultural activities, atmospheric ethylene levels (measured with GC/PID) increased from near 15 ppb at 23 days after planting (DAP) to 47 ppb at 28 DAP. At harvest (28 DAP), heads averaged 129 g FW or 6.8 g DW per plant, and roots averaged 0.6 g DW per plant. Some tipburn injury was apparent on most of the plants at harvest. By 28 DAP, stand photosynthesis rates for the entire chamber (approx. 20 m2) reached 17.4 umol CO2 m-2 s-1, while dark-period respiration rates reached 5.5 umol CO2 m-2 s-1. Results suggest that good yields can be obtained from lettuce grown in a tightly sealed environment.