Exogenously applied plant growth regulators may affect development of onion, but little is know about how concentration or timing of application can affect bulb grade and quality. Two concentrations of the growth regulators abscisic acid, gibberellic acid, indole-acetic acid, jasmonic acid, kinetin, and maleic acid hydrazide, and water controls, were applied at the 7- and 20-leaf stages to the middle of the leaf whorl in greenhouse grown onion plants. Leaf and bulb weights were lighter, and bulb diameters were smaller, from plants treated with growth regulators applied at the 7-leaf stage than those from plants treated at the 20-leaf stage. Bulbs produced on plants treated with water were the same size, or larger, than those produced on plants treated with individual growth regulators.
Vincent M. Russo
Bell pepper yields can be improved if appropriate cultural methods are used. Cultural methods evaluated at the South Central Agricultural Research Laboratory are reviewed. Yields were best from plants grown on soil with deep `A' horizon and soil pH approaching neutral. Fertilizer applied at 1.2 or 1.5 fold the recommended rate did not improve yield. Planting by mid-May was superior to later plantings. Delaying harvest up to 2 weeks after the first fruit reached US # 1 grade improved marketable yield up to 1.8 fold over plants whose harvest was not delayed. This was because crown fruit increased in size and branch fruit attained marketable size. Knowledge of the cultural methods best suited for pepper in a geographical area should aid in increasing marketable yield.
Vincent M. Russo
Onions (Allium cepa L.) can be established from seed or transplants. The latter planting material can be dormant or actively growing when transplanted to the field. Onion transplants can be produced in a greenhouse, but additional information is needed regarding the cultural requirements after transplanting. Greenhouse-grown transplants of ‘Candy’, intermediate-day variety, and ‘Texas Grano 1015 Y’, short-day variety, were established at densities of ≈34,000, 68,000, or 102,000 plants/ha and 100 (recommended) and 400 kg·ha−1 of nitrogen in mid-March of 2006 and 2007. Nitrogen fertilizer rate did not affect yield. Yield of ‘Candy’ was greater than for ‘Texas Grano 1015 Y’. Yield of both cultivars increased as density increased, and yield of ‘Texas Grano 1015 Y’ was higher in 2006 than in 2007. ‘Candy’ had higher numbers of large-sized bulbs and ‘Texas Grano 1015 Y’ more small bulbs. Bulb nutrient content was affected by year with nitrate-N, potassium, sodium, and SO4 being higher in 2006 and nitrite-N, calcium, magnesium, PO4, and soluble solids higher in 2007. ‘Candy’ had a higher soluble solids (°Brix) content than did ‘Texas Grano 1015 Y’. In 2007, precipitation was higher than in 2006. This may have contributed to the year response and it appears that ‘Candy’ was better able to respond in a more uniform manner to the changed environmental conditions. For plants developed from greenhouse-grown transplants, the recommended rate of fertilizer and the highest plant density are beneficial to improved marketable yield.
Vincent M. Russo
The effects of planting date and plant density on total and marketable yield were examined for the edible dry beans `Aurora' and `Fleetwood', erect type I geneotype cultivars, over three years. For `Fleetwood' alone, fertilizer levels and application of a spray-on-soil polymer mulching material were examined for effects on yield. The mulching material was degraded by rain prior to canopy closure but patches were present at harvest. Using continous recording thermometers, temperatures over two week periods following sowing of `Fleetwood', from 23 cm below the surface of mulched and bare soil were converted to soil degree days (SDD). `Fleetwood' generally had higher yields than `Aurora'. Earlier planting improved yields. In one of three years increasing plant density increased yields. Increased fertilization did not affect yield. Application of mulch did not affect yield. However, spray-on-mulch did increase SDD after the earliest planting date. Cultural systems for existing production, or potential production areas, must be developed for the conditions of each location.
Vincent M. Russo
Amendment of soil with microorganisms during the growth cycle of one crop may affect development of succeeding crops. Species of Rhizobium bacteria or abuscular-mycorrhizal fungi were added alone to, or in combination with, potting soil in pots in a greenhouse. Controls were no amendments. Seed of peanut (Arachis hypogaea L.) were planted and two levels of a combination NPK fertilizer, the recommended and one-fourth the recommended rate, were applied. After harvest of peanut and remoistening of soil, seed of the bell pepper (Capsicum annuum L.) or navy bean (Phaseolus vulgaris L.) were sown into the same planting medium in pots without additional inoculation with microbes. Dry weights of above-ground vegetative and edible portions of crops were determined. Inoculum type only affected peanut top and total dry weights. The recommended fertilizer level did not affect peanut yield but did cause improvement in bell pepper and navy bean yield over that of the deficient fertilizer rate. In field experiments, peanut was planted into soil receiving Rhizobium spp. bacteria, or arbuscular-mycorrhizal fungi alone or in combination. Controls consisted of no amendment. Only the recommended fertilizer rate was used. In the next 2 years, bell pepper or navy bean were established in plots without use of additional microbial amendment. Yields and nutrient contents of crops were determined. Type of inoculum did not affect yield or nutrient content in any crop. Bell pepper marketable yield was unaffected by year, and navy bean seed yield was higher in 2004 than in 2005. In both years, navy bean yields were below U.S. averages. Concentrations of most nutrients in edible portions of bell pepper and navy bean were lower in 2004 than in 2005. Results of the field trials were generally similar to those of greenhouse studies. Use of inocula did not provide substantial benefits to yield or nutrient content of peanut or vegetable crops that followed.
Vincent M. Russo
Use of biological amendments in vegetable transplant production may affect plant development. Rhizosphere bacteria can alter conditions in the root zone and affect plant growth even if root tissue is not colonized. Arbuscular mycorrhizae (AM) affect plant development through symbiotic relations. Abiotic factors may mediate effects of biotic amendments. Organically certified potting medium was inoculated with a mix of Sinorhizobium sp. bacteria or a mix of AM fungi. Controls consisted of no amendment. Bell pepper, Capsicum annuum L., cv. Jupiter, seed were sown in the medium and irrigated either twice a day for 3 minutes per application or three times a day for 2 minutes per application. Seedlings were treated with 8, 16, 24, or 32 mL·L–1 of an organically certified liquid fertilizer beginning 3 weeks after sowing. Use of bacteria improved plant height and dry weight. Interactions of bacteria and fertilizer rate or irrigation regime affected plant height or dry weight. When irrigated twice a day, plants were tallest when provided 16 mL·L–1 fertilizer, and heaviest when provided 24 mL·L–1 fertilizer. When irrigated three times a day, plants were taller at the lower rates of fertilizer and heaviest at the highest rate of fertilizer. Use of AM had little effect on plant height and dry weight. Most of the responses when AM was the amendment were the result of fertilizer rate and irrigation regime. When irrigated twice a day, AM-treated plants were tallest and heaviest when provided at least 24 mL·L–1 fertilizer. Regardless of biological amendment, plant heights were correlated with plant dry weights over fertilizer rates and irrigation regime. Use of Sinorhizobium sp. appeared to provide a benefit to the development of bell pepper transplants.
Vincent M. Russo
It is not known how plant spacing affects fresh yield in transplanted nonpungent jalapeño peppers (Capsicum annuum L.). Transplants of a nonpungent jalapeño, cv. Pace 105, were established at 8, 16, 24, 32, 40, and 48 cm between plants in mid-April of 2006 and 2007 and in early July in 2007. Fruit were harvested once when 5% of marketable-sized pods in rows were red. Distance to first flower and yield characteristics were determined. Fruit were culled based on pod size and presence of blemishes. Height on the stem to the first flower averaged 15.8 cm over all treatments. Plants in the Spring 2006 season had the highest marketable and cull yields. Numbers of marketable fruit/ha were higher at the 8-cm spacing than at the 40- or 48-cm in-row spacings. There was little difference in marketable yield as a result of in-row spacing. The greatest number of cull fruit per plant was on plants spaced 48 cm apart. Plant spacing had no effect on number of cull fruit or cull yield/ha. Culls accounted for ≈22% of total yield. Individual cull fruit weights were ≈50% less than for marketable fruit. Spacings tested did not appear to greatly affect development or yield of this pepper. This will allow producers to have the option of either using fewer plants on the same amount of land or more plants on less land without much reduction of quantity or quality of yield.
Vincent M. Russo
Abiotic and biotic factors, and government farm policy, affect peanut (Arachis hypogaea L.) production especially in the Southern Plains of the United States. A coincident increase in vegetable production has led to interest in diversification of production on land that has historically supported peanut. A multi-year experiment was conducted from 1998 to 2001 to determine how rotating bell pepper (Capsicum annuum var. annuum L.) and sweet corn (Zea mays L.) with peanut affect yields of all three crops. In the first year, the site was planted to peanut, except for those areas of the field that would have monocultured bell pepper or sweet corn throughout the experiment. In following years, parts of the field that were planted with peanut were planted with either peanut, bell pepper, or sweet corn. Except for the monocultured crops, plots had 2 years of peanut and one year each of bell pepper or sweet corn in one of four rotations. Yields were determined and terminal market value was assigned to crops. Cumulative yields for monocultured bell pepper and sweet corn were 27.8 and 22.8 Mg·ha-1 after 4 years. The best yield of bell pepper or sweet corn in any rotation was 15.3 or 11.3 Mg·ha-1, respectively. Rotation did not affect peanuts, and cumulative yields for monocultured peanut were 8.39 Mg·ha-1 and averaged 2.13 Mg·ha-1 per year in rotations. Cumulative yields for all crops in rotations where vegetables were planted in the last 2 years averaged 21.5 Mg·ha-1 as opposed to 13.8 Mg·ha-1 when vegetables were planted in the middle 2 years of a 4-year rotation. Yields of all crops were modified by environmental conditions, and terminal market price affected crop value so that high yields were not always associated with high returns.
Vincent M. Russo and James Shrefler
Extending the season can provide opportunities for vegetable producers. Bunching onion, or scallions (Allium fistulosum L.), is a crop that can be a candidate for protected production used to extend the growing season. The cvs. Evergreen Hardy White (white), Deep Purple (red), and Nabechan F1 (white) were sown at monthly intervals from Sept. 2010 to Aug. 2011 in containers under greenhouse and hoop house conditions at Lane, OK. Days to harvest and yield variables were determined. Crop failure occurred in a greenhouse for all plants sown in July, for ‘Deep Purple’ sown in August, and for those sown in a hoop house in February and March and May through August, days to harvest was generally less for plants sown in the greenhouse, and for ‘Deep Purple’, but all plants took longer to reach marketable size than is indicated for field production. Yields for plants grown in the greenhouse were higher than for those grown in the hoop house. Greenhouse production provides more flexibility and protection from environmental conditions so that bunching onions can be grown for extended season production. However, environmental controls under greenhouse conditions need to be refined to reduce length of growing season while maintaining, or improving, yields of optimally sized plants. Programs to improve nutrition in school systems and introduction of “Farm to School” and “extended season” initiatives present opportunities for production of some vegetables including bunching onion, or scallions. “Farm to School” programs allow the use of fresh, locally grown foods to be incorporated into school menus. Bunching onions can be used fresh or prepared items. Use of protected culture in greenhouses and hoop houses may allow for extended season production of these onions so that they can be used during non-typical growing periods especially, when locally produced field-grown crops are not available.
Vincent M. Russo and Merritt Taylor
The cost of transporting manure can affect profit. Manure was applied either annually or biennially to bell pepper (Capsicum annuum L.), cv. Jupiter, cucumber (Cucumis sativus L.), cv. Earli Pik, and sweet corn (Zea mays var. rugosa Bonaf.), cv. Incredible (se endosperm genotype), produced using organic methods and compared with production of these crops using conventional methods and annually applied synthetic fertilizer. Conventional and organically maintained portions of the field were separated by a 25-m buffer zone planted with sweet corn, which was provided with manure. The experiment was conducted from 2005 to 2008 at Lane, OK. Nutrient contents of soil and edible portions were determined as were yields. Economic analyses comparing costs of production and profit were conducted. There were yield responses resulting from year. Bell pepper yield was little affected by type of fertilizer application. Cucumber and sweet corn benefited from use of manure over conventional fertilizer. There was no pattern of alternating increased or decreased nutrient content in edible portions or in the soil as a result of annual or biennial application of manure. Treatment with manure produced higher returns than did conventional fertilizer. Annual treatment with manure produced higher returns in bell pepper and sweet corn than did treatment with manure in alternate years; the opposite was true for cucumber. Annual application of manure appears to be necessary for most of the vegetable crops tested.