The number of people of Caribbean, African, and Asian descent living in the United States is quite high. Most of these people live in diverse ethnic centers, such as New York, San Francisco, Chicago, Miami, and Atlanta. It might be profitable to provide traditional foods (2, 3) for these groups. Many of these foods already are imported into the United States. However, importation sometimes is not possible because of (a) inadequate storage facilities, (b) low cost effectiveness, and (c) small amounts that need to be imported (J.R. Suah, CARDI, personal communication). Three of these crops that may be grown in Missouri are hot pepper, ‘Scotch Bonnet,’ a low moisture pumpkin, ‘Calabash,’ and yam. ‘Scotch Bonnet,’ pepper grown under tropical conditions is semiperennial with peak production occurring in the first year. ‘Calabash’ pumpkin, requires a growing season of at least 7 months. Yam requires a 6- to 10-month growing period under tropical conditions. The potential production of these vegetables in the United States has not been adequately investigated. We, therefore, investigated their performance under mid-Missouri growing conditions.
Increasing seed moisture has been beneficial in improving seedling emergence of some crops. Seed moisture contents of three cowpea (Vigna unguiculata) genotypes (MN13, Pinkeye Purple Hull, and IT 82E-16) and two pigeonpea (Cajanus cajan) (ICPL 85024 and ICPL 8304) were modified by incubating a 10 seed: 4 celite: 13 water (by weight) mixture at 15C. Conditioned seeds had moisture contents ranging from 46% to 64%, while nontreated seeds ranged from 4% to 8%. Matriconditioned and nontreated seeds had <15% emergence at 28 days after planting (DAP) in dry field conditions, where precipitation was <41 mm. In greenhouse tests at 14 DAP, matriconditioning had a negative effect on seeds in flooded, moist, and dry soils. The percent emergence for these seeds was 40% when compared to 60% for nontreated ones. Conditioning did not affect percent emergence at 7 DAP, days to first emergence, and percentage of germinated, unemerged seeds at 14 DAP. In the dry soil, emergence was less and later, and more germinated, unemerged seeds were present at 14 DAP. Cowpeas averaged 56% germination and pigeonpeas were 27%.
A greenhouse experiment was conducted to examine the relationship between tissue B concentration and dry matter accumulation in broccoli. `Pirate ' was grown in fine silica sand and supplied nutrient solutions containing 0.2, 0.8, 1.4, 2.0, 2.6, 3.2, 3.8, and 4.4 mg·liter-1 B. Plants were sampled for the 5th, 10th, and 15th fully expanded mature leaf, and plant material was collected' for dry matter measurement and boron analysis at each growth stage. The lowest specific leaf weights for the 5th, 10th, and 15th leaves were obtained with the 4.4 mg·liter-1 treatment. At maturity, leaf, petiole stalk, and shoot dry weights were lowest at 4.4 mg·liter-1 B. Treatments supplying less than 3.2 mg· liter-1 B, resulted in a notable decrease in tissue B concentrations from the 5th to the 15th leaf. There was a linear increase' in B concentration in all leaf tissue samples as B treatment increased. At maturity, optimum B concentrations of 531.5, 73.7, 29.8, and 64.6 mg·g-1 were found for the lamina, petiole, stalk, and head, respectively. These concentrations occurred in plants receiving treatment levels of 2.0-3.8 mg·liter-1 B.
Efforts to produce specialty crops by Missouri farmers have been met with varying success. This success is reduced by the lack of established cultural practices necessary for the economic production of these crops. Ten kiwano plant introductions obtained from the Central Regional Plant Introduction Station in Ames, Iowa, were planted in the greenhouse. Seedling vigor was determined by shoot length, shoot dry weight, and number of leaves produced. Uniform seedlings from each accession were transplanted in the field with within row spacings of 0.9 m and 1.3 m. Seedling vigor varied significantly between accessions. Yields of field grown kiwano were affected by plant spacing, with the closer spaced plants having the higher yields. Plant spacing had no effect on fruit color, fruit length, or fruit width. Incidents of fusarium wilt were prevalent at both plant spacings.
Sweetpotato (Ipomoea batatas) cultivars, Carver, Potojam, Jewel and Centennial were evaluated for slip production, using topsoil, sawdust, sand and a general-purpose peat-based commercial growing media as bed covers. Temperature measured 2 inches (5.1 cm) below the surface of the hot bed varied with covers and date measured. Sand maintained the highest bed temperature, 77 °F (25.0 °C) at 0800 hr and 79 °F (26.1 °C) at 1400 hr, throughout the growing season. Peat-covered roots produced the maximum number of slips/plot (111), while roots covered with topsoil and sawdust produced comparable yields, 55 and 45 slips/plot, respectively. Slip production varied according to harvest date, with the third harvest producing the most slips/plot (83 and 153, in year 1 and year 2, respectively), which, was likely related to increased temperatures. Cultivar significantly influenced number of slips, length of slips, and number of roots per slip. `Potojam' was the most prolific slip producer for both early and mid season production under all bed covers.
Studies were undertaken to determine the critical Zn levels for cowpea [Vigna unguiculata (L.) Walp] grown in low N medium and inoculated with Rhizobium. Cowpea ‘California Blackeye No. 5’ was grown for 40 days in a sand culture using Zn application rates of 0, 0.06, 0.5, 1.0, 1.5, 2.0, 2.5, 2.8, 3.0, 3.1, 3.4, 3.7, 4.0, and 4.5 ppm Zn as ZnSO4. N2 fixation was estimated by acetylene reduction. Critical Zn deficiency levels were determined as 12.5, 20, 30, and 50 ppm for upper leaf petioles, upper leaf blades, lower leaf petioles and lower leaf blades, respectively, Critical Zn toxicity levels for these tissues was determined as 145, 273, 300, and 440 ppm, respectively. It was concluded that upper, recently matured, leaf petiole tissue should be used to assess plant Zn status. The percentage of reduction of N2 fixation was greater than the percentage of reduction in dry-matter accumulation under Zn-deficient conditions. N2 fixation increased linearly with increased Zn content of nodules and roots. At Zn levels above 150 ppm for both tissues, however, N2 fixation declined significantly. Applied Zn did not affect the growth and development of the root system and had little effect on reproductive development.
Zinc concentration, nitrogen fixation (C2H2 reduction), nodulation and dry-matter distribution in the early maturing cowpea [Vigna unguiculata (L.) Walp] line Mn 13 were examined at 5 levels of Zn (0.0, 0.6, 1.5, 2.5 and 5 ppm) under field and greenhouse conditions. Significant increases in nodule number, nodule dry weight, and acetylene reduction occurred when plants received the higher Zn levels. In all plant parts sampled, there was increased Zn accumulation with increased Zn application, with roots having the maximum accumulation. Seeds per pod and seed yield (kg/ha) were highest at the higher applied Zn levels. The yield response to added Zn was reflected primarily by an increase in the number of seeds per pod. Zinc nutrition is important to the nodulation and fixation processes, and it may affect both Rhizobium nutrition and dry-matter accumulation.
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.
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.