Root-knot nematodes (RKN; Meloidogyne spp.) are an economically important pathogen on many agricultural plants and are the most commonly reported nematodes on vegetable crops in the United States ( Koenning et al., 1999 ). Because of environmental
. In a greenhouse experiment, these products were evaluated for their effects on lettuce seedling emergence, growth, and P uptake. Four soils were collected from California fields in vegetable crop rotations, chosen for their limited P availability
Abstract
An alley cropping trial with various vegetable crops and Leucaena leucocephala (Lam.) de Wit was carried out on an Oxic Paleustalf soil in southern Nigeria. With application of N, P, and K fertilizer, there were no yield differences between crops grown with alley cropping compared to control plots. With no fertilizer application, alley-cropped paitsai (Brassica chinensis L.) enhanced yield and plant mineral concentration. Alley cropping gave higher plant stand of direct-seeded paitsai, mainly due to reduced soil erosion.
Abstract
Although the total vegetable area in the developing countries of the world is larger than those with well-developed economies by about 6 times, the mean yield per hectare for all vegetables is only half (Table 1). Moreover, the export of vegetables in developing nations is rather low, because quality is demanded in the export market, and uniform quality control is difficult in the fragmented vegetable areas of the tropics. Individual farms average only a hectare or less. Former big landholdings have been fragmented by the system of land tenure and customs of inheritance. A few large commercial growers may cultivate as much as 10 to 50 hectares. The largest single area devoted to vegetables in a country is usually formed by processing companies cultivating as much as 200 hectares. Many farmers grow vegetables as cash crops after their main crops of rice, corn or tobacco.
-tillage seeders, vegetable transplanters, and machinery to control high-residue cover crops have increased the efficacy of this system in recent years ( Hoyt et al., 1994 ; Morse, 1999 ). However, mechanical weed control remains a challenge in no-tillage, high
Vegetable Crops
Vegetable Crops
Large volumes of compost produced from waste materials like yard trimmings, household trash (municipal solid waste), or biosolids (wastewater sludge) will likely become available for use by the Florida vegetable industry in the future. Using compost to produce vegetables has the potential to increase water and fertilizer conservation and reduce leaching from inorganic fertilizers in Florida's sandy soils. Compost quality for vegetable production systems should be based on soluble salts, phytotoxic compounds, C:N ratio, plant nutrients, trace metals, weed seeds, odor, moisture, pH, water-holding capacity, bulk density, cation exchange capacity, and particle size. In Florida, immature compost contained phytotoxic compounds that were harmful to crop germination and growth. Amending soil with mature composted waste materials has been reported to increase the growth and yields of vegetable crops grown in Florida. However, a beneficial response does not always occur, and the magnitude of the response is often not predictable.
Cover crops have been used in agricultural systems for thousands of years and are still an important part of vegetable production in the Northeast. Winter rye (Secale cereale) is by far the dominant cover crop species on conventional vegetable farms in the New England states. It is use is primarily for erosion control. Winter rye is popular since it is cheap, easy to establish, can overwinter in the harsh winters of northern New England, is efficient in “capturing” excess nitrogen at the end of the cash crop season, and it can produce substantial amounts of organic matter in the spring. As many positive attributes that winter rye has, it is important to be aware of many of the other potential cover crop species that are available to us. For example, many conventional growers are exploring the use of leguminous cover crops as an alternative to chemical nitrogen fertilizers which are more readily leached and are only going to get more expensive. Cover crops can also be seeded and managed in innovative ways to suppress weeds and other pests, add organic matter and conserve soil moisture.
Abstract
Individual seedling emergence forces were determined for nine vegetable crops with an universal testing instrument (Model TTCM Instron). The seed energy content also was calculated with an oxygen bomb calorimeter. Seed weights of the different crops were correlated with seedling forces and the seed energy content. The time required to achieve the maximum force varied among crops and the pressure exerted varied from 26 mN for table beet (Beta vulgaris L.) to 3400 mN for snap bean (Phaseolus vulgaris L.). Equipment was developed to measure the combined seedling emergence forces of 50 seedlings. Snap bean seeds were sized into three groups: 200, 275, and 350 mg per seed. Total force, percent seedling emergence, force per seedling, pressure exerted, and energy content increased in a linear trend as seed size increased. An inverse relation existed between the capacity of seeds to use reserve materials and seed size. Small-sized seeds were more efficient in using reserve materials than large ones.