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- Author or Editor: Richard L. Parish x
A new slow-release powdered fertilizer product has been developed for use in the landscape industry. A series of tests was conducted to evaluate this product in several landscape applicator modes: turf broadcast, turf gun, and soil injection (for trees). Variables included concentration, nozzle size and type, pressure, agitation, and holding time in the tank before spraying. The product worked well in a wide variety of spray equipment and operating conditions. It could be sprayed at a rate of 0.030 kg N/L in nozzles as small as DG 8002 (0.011 L·s–1 flow rate) without nozzle plugging and at rates of up to 0.060 kg N/L in larger nozzles. The product settled out of suspension rapidly, so good agitation was critical. No differences were noted due to nozzle type or spraying pressure. Suspensions could be held overnight if properly reagitated before spraying. Foaming was a problem with this product. An antifoam agent should be considered. Large-diameter filters minimized problems.
Flame “cultivation” for weed control was developed about 50 years ago. The practice was very popular with Southern cotton farmers through the 1950s and 1960s, but lost favor when petroleum prices rose drastically in the 1970s. There is now a new interest in the practice of flame cultivation as a partial or total replacement for herbicides in vegetable crops. This interest is fueled by three factors: 1) an increasingly negative public perception of herbicides on vegetables, 2) a very limited selection of herbicides labeled for vegetables, and 3) limited efficacy of some of the herbicides that are registered. Flame cultivation, in combination with mechanical cultivation, can replace or supplement herbicides in some vegetable crops. The mode of action of flame cultivation is the bursting of cell walls in the weeds as the weeds are heated by a carefully directed LP gas flame. With most vegetable crops, the crop plants must be protected in some manner. This can be done with a water shield (flat fan water spray), height differential between weeds and crop, physical shield, etc. Much of the early work on flame cultivation of vegetables was done with sweet corn. Work is now underway on flame cultivation of lima beans and southernpeas, where multiple flame cultivations have proven effective at controlling weeds for which no herbicide is available.
A simple, inexpensive device to measure the linear tear strength (tensile strength) of a strip of turfgrass sod was constructed for use in a research program. The device was fabricated from readily available components. A standard torque wrench served as the force-measuring device, providing torque readings that were converted readily to linear force measurements. The device worked very effectively.
Application of granular materials is an important part of most turfgrass maintenance programs, but is not often studied by horticulturists. Agricultural engineers have conducted many research studies over the past 50 years on the theory, testing, and use of granular applicators. Understanding the theory of granular distribution can aid horticulturists and turfgrass professionals in the effective use of spreaders. This article will review relevant engineering studies and interpret some of the results to provide help in using spreaders more effectively. Proper operating mode, proper pattern adjustment, and the use of an appropriate swath width can greatly improve pattern uniformity. For instance, a half-width pattern has been proven more effective at pattern improvement than right-angle patterns, and the detrimental effect of humidity on spreader pattern has been demonstrated.
This article is a review of the current status in planting and transplanting equipment and practices for vegetable crops. A review of horticultural and agricultural engineering literature is supplemented by information from an informal survey of members of American Society of Agricultural Engineers (ASAE) committee PM-48, Fruit and Vegetable Production Engineering, and other engineers and horticulturists working in this field. Areas covered include precision seed metering, seed placement, and high-speed transplanting with automated plant handling.
The initial investment of a precision seeder is cost prohibitive to many small vegetable growers. This study was initiated to evaluate the use of a relatively inexpensive bulk seeder to plant cabbage (Brassica oleracea L. Capitata). Cabbage was direct-seeded with a precision seeder or a relatively inexpensive bulk seeder. Treatments with the bulk seeder consisted of blending viable hybrid seed with nonviable, nonhybrid seed at several ratios to reduce hybrid seed cost and optimize plant spacing. Seed ratios represented 10, 20, 30, 40, 50, and 100% viable seed. Pre-thin plant stands of 30 and 40% hybrid seed treatments were similar to precision-seeded plant stands. Average head size was greatest with 10, 20, and 30% hybrid seed ratios. Marketable yields were similar for all hybrid seed ratios except the 10% ratio. Production costs per acre for the precision seeder were between that of the 40 and 50% ratios. Net income for 40% hybrid seed was similar to that of the precision seeder.
A precision seeder (Stanhay Model 870) and a bulk seeder (Planet Jr.) were used to evaluate the effects of precision seeding, seed spacing, and row configuration on yield and grade-out of two cultivars of root turnips. Seed spacings for the precision seeder included within-row (WIR) spacings of 56, 112, and 168 mm in single plant line/row and 112 and 168 mm in two plant lines/row. Seed spacings with the bulk seeder were obtained by using 100% viable seed or a 50% viable: 50% killed seed mix. The experiments were conducted during the spring and fall on two rows on a 1.2-m-wide bed. Total yield was not affected by plant population or seeder. Plant population, however, caused a shift in yield among grades. Yield of culls increased as plant population increased. Yield of extra-large (>114 mm) roots decreased as plant population increased. Turnips seeded 168 mm apart in a single line/row yielded more extra-large and large (25-114 mm) grade roots and less medium (4-24 mm) and cull (<4 mm or misshapen) roots. More consistent results were obtained with the precision seeder than the bulk seeder. During both seasons, yield was lower for the hybrid (`Royal Crown') cultivar than for the open-pollinated (`Purple Top White Globe') cultivar.
Two studies were conducted on bed and row configurations. The first compared erosion effects on stand count with single and double drill plantings; the second evaluated bed heights. Vegetables are usually planted on raised beds in the Deep South. Both single and double drills per bed are common. The double drills offer higher yields in some cases, but may be difficult to maintain because of erosion on the bed sides after heavy rainfall. A series of plantings of cabbage (Brassica oleracea L. Capitata group) and broccoli (Brassica oleracea L. Italica group) was made over a period of nearly a year to compare stands from single and double drills. Heavy rainfall did not occur after any of the 18 plantings, so bed erosion did not occur. Differences in percent stand were few, although in a few cases the double drill planting resulted in higher stands. A field study was conducted to determine the optimum bed height for leafy greens crops grown on shaped beds. Bed heights of 5, 10, 15, and 20 cm (2, 4, 6, and 8 in) were evaluated with crops of mustard [Brassica juncea (L.) Czerniak.] and turnip (Brassica rapa L. Rapifera group) during three crop seasons. Few significant differences in stand count, yield, or product quality resulted from the different bed heights. A trend toward lower yields, quality, and reduced efficacy of precision cultivation was noted with the 5-cm (2-in) bed height.
Concerns over ground water, nonpoint pollution, and soil erosion have indicated a need for reduced use of preemergent herbicides and reduced tillage. This study was initiated to determine the feasibility of using postemergent, burndown herbicides under hooded sprayers in the production of southernpeas. Two rates of paraquat, glufosinate, and glyphosate were applied at two application timings. All herbicides controlled rice flatsedge but not goosegrass. Since an untreated strip was left surrounding the drill, complete weed control did not occur in this system. In most cases, delaying application of the herbicides by 2 weeks tended to result in lower yields. However, no differences from a delay in cleaning the hoed check were noted. Plots treated with paraquat at 1.0 pt/A – timing 1 and glufosinate at 7.0 lb a.i./A – timing 2 had yields lower than the hoed check. Based on this study, southernpeas can be grown successfully without the use of a preemergent herbicide by proper timing of a hooded application of a burndown herbicide with proper timing.
Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.