This experiment was designed to compare best management practices for conventional and conservation tillage systems, chemical IPM vs. organic vegetable production, and rotation effect on tomatoes. Three vegetables were grown under these management practices with sweet corn (1st year) and fall cabbage or cucumber (2nd year), and fall cabbage on half of the field plots and tomatoes on the other half. The treatments were: 1) conventional-tillage with chemical-based IPM; 2) conventional-tillage with organic-based IPM; 3) conservation-tillage with chemical-based IPM; 4) conservation-tillage with organic-based IPM; and 5) conventional-tillage with no fertilizer or pest management (control). This poster describes sweet corn, cabbage, and cucumber yields from the various treatments over two 3-year rotations. Sweet corn yields were 34% higher in treatments with chemical fertilizer and pest control than with organic methods. Ear worm damage was high (58%) in the organic treatment compared to the chemical IPM program (14%). Fall cabbage was planted after sweet corn and cucumber harvest (all treatments were reapplied). Marketable cabbage yields were in the order: conventional-tilled-organic > strip-tilled-chemical > conventional-tilled-chemical > strip-till-organic > control for both years. Percent culls (< .9 kg heads) were in reverse order of marketable heads. Cabbage insect control was similar in chemical IPM and organic management. Cucumber yields were in the order: conventional-tilled-chemical > conventional-tilled-organic = strip-till-chemical > strip-tilled-organic > control for both years. Insect damage on cucumber fruit was 51% for organic systems and 1% for chemical methods of production. No differences were seen between tillage system within the same production system (chemical vs organic).
G.D. Hoyt, J.E. Walgenbach, and P.B. Shoemaker
David L. Trinka and Marvin P. Pritts
Micropropagated (MP) raspberries (Rubus idaeus L. var. idaeus) are sensitive to moisture and temperature extremes and to certain preemergent herbicides used at transplanting. We examined fertilizer placement and row covers in conjunction with various weed management strategies to identify beneficial practices for newly planted, MP primocane-fruiting `Heritage' raspberries. Uncontrolled weed growth during plant establishment inhibited raspberry cane growth and production into the second and third growing seasons. Handweeding and herbicide treatments successfully controlled weeds, but soil moisture was apparently insufficient for optimum growth of the MP raspberries when these treatments were imposed, even with normal rainfall in early summer and drip irrigation in late summer. Polyethylene and straw mulches during the establishment year provided both weed control and adequate soil moisture, resulting in more cane growth in the first and 2nd year, and higher yields the 2nd year. Primocane density after the third growing season still was influenced by first-year weed management practices. Raspberry plants responded best to straw mulch without row covers as plant growth was better in both years. Canes were thicker, yields were higher, and a larger portion of the total crop was harvested early. Row covers were beneficial only in bare-soil treatments, and method of fertilizer placement had no effect on any measured variable. Mulching newly transplanted MP raspberries is an alternative to herbicide use that also provides physiological benefits to the plant through microclimate modification.
S. Varlamoff, W.J. Florkowski, J.L. Jordan, J. Latimer, and K. Braman
A survey of Georgia homeowners provided insights about their use of fertilizers and pesticides. Knowledge of current homeowner practices is needed to develop a best management practices manual to be used by Master Gardeners to train the general public through the existing outreach programs. The objective of the training program is to reduce nutrient runoff and garden chemicals and improve the quality of surface water in urban water-sheds. Results showed three of four homeowners did their own landscaping and, therefore, fully controlled the amount of applied chemicals and the area of application. Fertilizers were primarily applied to lawns, but a high percentage of homeowners also applied them to trees, shrubs, and flowers. Insecticides were applied by a larger percentage of homeowners than herbicides. Control of fire ants (Solenopsis invicta) was likely the reason behind the frequent use of insecticides. The desire for a weed free lawn was the plausible motivation behind the use of herbicides, which were used mostly on lawns. Fungicide use was infrequently reported by Georgia homeowners. The pattern of fertilizer and pesticide use suggests that the developed manual should emphasize techniques and cultural practices, which could lower the dependence on chemicals, while ultimately assuring the desired appearance of turf and ornamental plants.
Donald J. Merhaut and Julie P. Newman
Lilies are produced throughout the year in coastal areas of California.
Cultural practices involve daily applications of water and fertilizer, using both controlled release fertilizers (CRF) and liquid fertilizers (LF). However, many production facilities are in proximity to coastal wetlands and are therefore at greater risk of causing nitrogen pollution via runoff and leaching. Due to federal and state regulations, nurseries must present a plan of best management practices (BMPs) to mitigate nutrient runoff and leaching and begin implementing these practices in the next 2 years. In the following studies, we determined the potential for nitrate leaching from four different types of substrates (coir, coir: peat, peat, and native soil). There were four replications of each treatment, with a replication consisting of one crate planted with 25 bulbs. Two cultivars were used in two separate experiments, `Star Fighter' and `Casa Blanca'. Nitrate leaching was determined by placing an ion-exchange resin bag under each crate at the beginning of the study. After plant harvest (14–16 weeks), resin bags were collected and analyzed for nitrate content. Plant tissues were dried and ground and analyzed for nitrogen content. Based on the results of these studies, it appears that the use of coir, peat, and soil may not influence plant growth significantly. Substrate type may mitigate the amount of nitrate leaching through the media. However, the cultivar type may also influence the degree of nitrate mitigation, since leaching results varied between the two cultivars.
Carl J. Rosen and Mohamed Errebhi
Applying appropriate rates of nitrogen fertilizer during the growing season for potatoes on irrigated sandy soils is an important concern from both a production and environmental standpoint. Although potatoes on sandy soils are responsive to nitrogen fertilizer, high rates of nitrogen applied early in the growing season have been associated with nitrate leaching due to unpredictable rainfall. Use of lower nitrogen rates applied more frequently through the season is one strategy to minimize nitrate losses and improve nitrogen use efficiency. Portable nitrate electrodes were used to measure nitrate concentrations in petiole sap. Diagnostic criteria based on final yield and nitrate sap concentrations at various growth stages were developed over a three year period. This rapid test can now be used to make an immediate assessment of nitrogen status of the plant and a prediction for whether supplemental nitrogen will be needed. On-farm trials are currently being carried out to demonstrate the use of the saptest as a best management practice.
Matthew Byers, George Antonious, and Keenan Bishop
Using USLE standard plots, on 10% slope, on uniform Lowell silt loam soil, the influence of three soil treatments and two representative vegetable crops on soil runoff losses was determined. Yields (1990 and 1991) for each crop × soil treatment combination were also determined. Soil losses were determined by catching runoff, filtering, air drying and massing representative samples. With total volume per plot known, grams sediment per liter runoff were converted to kg/ha. Overall mean yields of pepper were 2.9, 4.7, and 3.7 and pumpkin were 47.3, 87.1 and 76.1 kg/7.3-m row, respectively. Mean sediment losses over five rainfall events in 1991 in peppers were 52, 1158, and 5362; and in pumpkins were 72, 3011, and 7271 kg/ha, for fescue, plastic and no-mulch treatments, respectively. Clearly, fescue in .6-m strips between rows, with comparable yields demonstrated (1991) and negligible sediment losses, was the best management practice (BMP).
Wayne L. Schrader, Ronald E. Voss, Kent J. Bradford, and Carol O'Neil
The Univ. of California's Vegetable Crops Research and Information Center (VRIC) has developed a new World Wide Web site that allows the rapid development and peer review of multi-discipline, research-based information. The VRIC website (http://vrichome.ucdavis.edu) disseminates peer-reviewed fact sheets, research results, updated publications, and multi-media educational resources relating to critical issues, best management practices, postharvest handling, and marketing of vegetable crops. The website disseminates multi-discipline information originating from the Univ. of California, the USDA, and cooperating agencies and universities. The VRIC website proactively sends peer-reviewed critical-issue fact sheets to selected news media, government, industry, and academic contacts. These fact sheets help personnel frequently contacted by the media during crises to answer questions effectively. The website directs visitors to additional agricultural information resources and contains information on careers and educational opportunities available in the field of vegetable crops.
S. B. Sterrett, D. B. Taylor, C. W. Coale Jr., and J. W. Mapp Jr.
An interdisciplinary approach had been developed to examine the production, economic, and marketing feasibility of new crops. The methodology requires the determination of yield potential and product quality, construction of production budgets, and completion of marketing window analyses. Potential for integration of new crops into the existing farm enterprise is assessed using linear programing techniques that consider labor and equipment constraints, crop rotations and best management practices. Risk analyses consider yield, production costs, and price of both new and traditional crops. By using this method, broccoli has been identified as a potential new crop for eastern Virginia, with labor requirements and slush ice availability being the major constraints to integration into vegetable production in this area.
Scott A. Harrison
A paucity of data exists on the water quality impacts of fertilizer nutrients used for turfgrass management. The primary macronutrients N and P have been shown to cause the eutrophication of surface water bodies, and excessive nitrate (NO- 3) concentrations in drinking water have been linked to methemoglobinemia in infants. Several studies have indicated that runoff quantities from high-quality turf areas are minimal; therefore, nutrient transport by this mechanism should not be a major concern. The leachability of N is favored by the presence of soluble forms in permeable soils receiving rainfall or irrigation in excess of field capacity. Most of the factors contributing to this condition are manageable. However, a wide range of turfgrass types, uses, and management expertise make it difficult to generalize the overall impact of turfgrass fertilization on water resources. While research has demonstrated the ability to minimize nutrient loading, characterization of nonresearch sites is critical to gain a legitimate understanding of environmental impacts. Once developed, best management practices can be effective only if understood and adopted by applicators.
Vincent Njung’e Michael, Yuqing Fu, and Geoffrey Meru
, exhibit insensitivity to recommended chemical pesticides ( Lamour and Hausbeck, 2000 , 2003 ; Ploetz et al., 2002 ). Therefore, host resistance in Cucurbita crops is important to augment P. capsici management practices ( Babadoost, 2016 ; Hausbeck