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- Author or Editor: Dyremple Marsh x
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The enzyme-linked immunosorbent assay was used to determine the competitive ability of three Rhizobium strains introduced into Antiguan soil. Strain-specific antisera were prepared against each strain. Field experiments were conducted in Antigua using Rhizobium strains USDA 3384, USDA 3473, and USDA 3474 as a peat-base inoculant and pigeon pea as the test crop. Nodules from the respective treatments were removed and prepared for ELISA studies. There was cross reactivity between the antisera, but it was greatly reduced or eliminated by repeat adsorption with the cells of the cross-reacting strains. Nodule occupancy by plants treated with Rhizobium 3384, 3473, and 3384 was 70%, 90%, and 100%, respectively. Nodules from 3384 and 3474 treated plants contained cells with no antigenic homology to the three antisera. We concluded that these nodules were developed from indigenous Rhizobium strains found in Antiguan soils.
Chemically fixed nitrogen is a costly import for Caribbean Basin Countries. Increased cost of fertilizer only serves to reduce crop yields in these areas. This greenhouse research was undertaken to evaluate the N2 fixing capabilities and yield potential of several Phaseolus vulgaris lines developed for use in Caribbean Basin countries. Ten common bean lines from breeding programs at the Universities of Puerto Rico and Wisconsin and two efficient Rhizobium phaseoli strains were used for the study. Plants treated with Rhizobium UMR 1899 and UMR 1632 had significantly higher stem and leaf dry weight than the control plants. Bean lines WBR 22-34, WBR 22-50, WBR 22-55, PR9056-98B and the cultivar Coxstone showed increased dry matter accumulation over that of the control plants. Plants treated with the Rhizobium strain UMR 1899 had the highest stem and leaf dry matter accumulation. Nodulation was significantly higher when plants were treated with UMR 1632. The lines WBR 22-34 and PR 9056-98B produced more nodules than the other lines used. Pod yield as measured by number of immature pods was highest for PR 9056-98B when inoculated with Rhizobium UMR 1899.
The use of cowpea as a forage for Central Missouri has been limited. High mid summer temperatures and frequent drought suggest that an alternative forage for livestock may be advantageous during the hot summer months. The ability of cowpea to withstand drought, high temperature and maintain high foliage protein, justifies research of the forage potential of this crop. Forage yield potential of two cowpea cultivars was evaluated in field experiments in 1968 and 1989, For both years a split plot experimental design was utilized with cowpea cultivar the main plot and harvest date the subplot Dry matter yields for both cultivars were similar at the early harvest dates. However, both fresh and dry shoot yields of Vita 3 (V3) were significantly higher than that of California Blackeye #5 (CB #5) at the later harvest stages. CB #5 plants produced a significantly higher stem dry weight while V3 produced higher leaf dry matter. Foliage regrowth after clipping was substantial for both cowpea cultivars. However, V3 produced 30% higher growth than CB #5. In vitro dry matter digestibility (IVDDM) varied with sample date (plant age) and plant parts sampled. IVDDM was 77% for leaves and 60% for stems of CB#5, and 80% for leaves and 65% for stems of V3.
The germination percentage of eastern gamagrass under normal field conditions ranges from 5 to 10%. These rates are considered low and methods to improve stand establishment in this species are necessary, Studies were initiated to determine if cupule removal and seed hydration were effective in improving the germination percentage of eastern gamagrass. Seeds from which the cupules were removed were incubated for 30 days at 5° C in 100% ethylene glycol (EG). Control were seeds incubated in distilled water. At 12, 18, 24 and 30 days after the start of incubation, seeds from each group were removed and subjected to rapid warming at 25 - 27° C. Cupule removal significantly increased seed germination by as much as 55% over the control. Seeds with cupule removed and incubated in EG had a 65% germination rate,
Abstract
Greenhouse and field studies were conducted to determine the influence of container type and cell size on cabbage [Brassica oleracea (L.) Capitata Group] transplant growth and subsequent yield. Cabbage seedlings were grown in the greenhouse in two types of containers, Sutton polystyrene and Speedling styrofoam “Todd Trays”. Four sizes of each tray were tested, ranging from 8.0 to 80.5 cm3 for polystyrene and 7.5 to 80 cm3 for styrofoam. In general, stem diameter, plant height, and leaf area of seedlings increased with increase in container size, but container type had no influence. In the field, head width and length were similar for all treatments. Plants grown from the large cell sizes had higher head weight than those from small cell sizes.
The USDA, Louisiana State University, and Lincoln University have released a new southernpea cultivar named WhipperSnapper. The new cultivar is the product of a plant breeding effort to incorporate genes conditioning superior yield and seed characteristics of Asian vegetable cowpeas into American snap-type southernpeas. The new cultivar was developed for use by home gardeners and market gardeners as a dual-purpose cultivar that can be used to produce both fresh-shell peas and immature, fresh pods or snaps. Typical ready-to-harvest WhipperSnapper snaps are green colored, 6.4 mm in diameter, 7.6 mm in height, and 24 cm long; the pods are slightly curved at the attachment end. Typical mature-green pods suitable for fresh-shell harvest exhibit an attractive yellow color, are 25 cm long, and contain 14 peas. Fresh peas are cream-colored, kidney-shaped, and weigh 24.5 g/100 peas. Dry pods exhibit a light straw color, and the dry peas have a smooth seed coat. The quality of WhipperSnapper seed is excellent. In replicated field trials, WhipperSnapper produced significantly greater yields of both snaps and peas than the snap-type cultivar Bettersnap. WhipperSnapper has potential for use as a mechanically-harvested source of snaps for use by food processors in mixed packs of peas and snaps. Protection for WhipperSnapper is being sought under the Plant Variety Protection Act.
Methods to improve the grain yield of red kidney bean without the addition of commercially fixed nitrogen will have significant benefits to farmers in Jamaica and other tropical regions. Red kidney beans provide a major portion of the dietary protein for most families in these regions. Our experimental objective was to evaluate the nitrogen fixing capabilities of several breeding lines of Phaseolus vulgaris when inoculated with Rhizobium strains isolated from Jamaican soils. Surface sterilized seeds of 11 Phaseolus lines were inoculated with inoculum prepared from 5 day old Rhizobium YEM mixture. Rhizobium used were T2 and B17 from Jamaica and UMR 1889. The greenhouse study was arranged as a completely randomized design. Bean lines 9056-101, 9056-98B, 8954-5 and 8954-4 showed improved nodulation and N2 fixation when inoculated with UMR 1899. The combination of breeding line 8954-5 and Rhizobium strain B17 produced the highest nodule number and shoot dry weight of 193 and 0.72 g, respectively. The Rhizobium strain B17showed some ability to compete successfully for nodule sites against known effective strains.
Home gardeners and farmers in the southern United States have traditionally grown southernpeas to produce both fresh-shell peas and immature, fresh pods, or snaps. American growers do not presently have access to a single variety that is ideally suited for both uses. In 1988, a plant breeding effort was initiated to incorporate genes conditioning superior yield and seed characteristics of Asian “vegetable cowpeas” into American snap-type southernpeas. This effort resulted in the development of `WhipperSnapper', which is suited for use as a dual-purpose variety that can be used to produce both snaps and fresh-shell peas. Typical ready-to-harvest `WhipperSnapper' snaps are green colored, 6.4 mm in diameter, 7.6 mm in height, and 24 cm long. Typical mature-green pods suitable for fresh-shell harvest exhibit an attractive yellow color, are 25 cm long, and contain 14 peas. Fresh peas are cream-colored, kidney-shaped, and weigh 24.5 g per 100 peas. Dry pods exhibit a light straw color, and the dry peas have a smooth seedcoat. The total `WhipperSnapper' yield of snaps can be as much as 62% greater than the total snap yield of the snap-type variety `Bettersnap'; pea yield can be as much as 69% greater. The quality of `WhipperSnapper' seed is excellent and much superior to that of `Bettersnap'. `WhipperSnapper' can be used by home gardeners and market gardeners to produce abundant quantities of snaps and fresh-shell peas during seasons too hot for successful culture of such table legumes as snap beans. `WhipperSnapper' also has the potential for use as a mechanically harvested source of snaps for use by food processors in mixed packs of peas and snaps.
Abstract
Cowpea [Vigna unguiculata (L.) Walp] has not been considered as a doublecrop alternative in the midwestern United States. Forage potential of cowpea following green peas (Pisum sativum L.) was studied in two field experiments in central and southern Minnesota. Dry-matter yield was higher in 1981 than in 1982 for all cowpea cultivars tested. Increasing the plant population improved yields for ‘California Black-eye Number 5’, ‘Alabama Giant Blackeye’, ‘Freezegreen’, and the breeding lines MN 139, MN 150, and Au 704, but not for ‘Colossus’. In vitro dry matter digestibility (IVDMD) was >63% for both stems and leaves in all cultivars and was not affected by plant population. Crude protein (CP) in leaves exceeded 20% for all treatments. We conclude that cowpea has excellent potential for supplying high-quality forage from double-cropping systems in the midwestern United States.