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Forty-five cultivars of lettuce (Lactuca sativa) were field-grown using best management practices at the Louisiana State University Agricultural Center (LSU AgCenter) Botanic Gardens in Baton Rouge during the Fall 2011 and Fall 2012 seasons. Recommended cultivars were selected for commercial production in Louisiana based on fresh weight and lettuce size (width and height). Nitrate (NO3–) concentration was analyzed for each cultivar, as lettuces are known to accumulate and concentrate NO3–, and were then compared with the U.S. Environmental Protection Agency’s (EPA) oral reference dose (RfD—the EPA’s maximum acceptable oral dose of a toxic substance) of 1.6 mg NO3-nitrogen (N) per kilogram body weight per day. Recommended butterhead cultivars were Caliente and Harmony (21.6 and 13.9 ppm NO3–, respectively); recommended green-leaf cultivars were Salad Bowl and Tango (10.6 and 4.6 ppm NO3–, respectively); recommended red-leaf cultivars were Red Salad Bowl, Red Sails, and New Red Fire (15.2, 15.4, and 24.0 ppm NO3–, respectively). The only recommended romaine cultivar was Green Towers (11.2 ppm NO3–), and recommended crisphead cultivars included Raider and Ithaca (17.6 and 14.9 ppm NO3–, respectively). Of the highest yielding cultivars, New Red Fire accumulated the greatest NO3– concentration: 24.0 ppm in both years 1 and 2. The NO3– concentration is less than the levels of concern for both men and women 20 to 74 years old, 3.9% of the RfD for men and 4.59% of the RfD for women.

High lead (Pb) contamination of soils is a threat to human health. Indirect ingestion occurs within the food chain through activities such as growing vegetables with an ability to accumulate lead in edible tissues. Many university extension systems recommend growing vegetables in raised beds to avoid lead contamination. However, there is limited scientific evidence of the efficacy of raised beds in reducing lead uptake in vegetable crops. To address the soil-lead exposure pathway from garden to consumption, this study supplements gaps in the literature pertaining to raised-bed garden practices by evaluating lining materials. Simulated raised beds were constructed to evaluate barriers (neoprene rubber sheeting, landscape fabric and a no barrier control) placed between contaminated (500 ppm) and uncontaminated garden media. The resulting data suggests that neoprene rubber sheeting is not an effective barrier to prevent lead uptake in vegetable crops. In fact, the neoprene barrier contained elevated amounts of lead contributing to higher levels of lead (p ≤ 0.05) within the plant tissue as compared to a no barrier treatment.

Environmental concerns as well as labor costs associated with the use of polyethylene plastic mulch have turned producers’ focus to alternative mulch treatments. A preliminary study was conducted to evaluate nutsedge control, mulch degradation, and cucumber yields on biodegradable mulches at two locations (Louisiana and Mississippi). Mulch treatments included two paper-based mulch products, two biodegradable plastic mulches, the industry standard non-biodegradable black plastic mulch, and an unmulched control. The heavy weight paper-based mulch and light weight paper mulches in the Louisiana location were reduced to 50% or less coverage at the end of the study. Similarly, the paper-based mulches both degraded below 40% at the conclusion of the study at the Mississippi location. The heavy weight paper mulch was able to hold back nutsedge (p ≤ 0.05) at similar rates as the two biodegradable plastic mulches and industry standard plastic mulch, while the light weight paper mulch and unmulched plots were ineffective at reducing emerged sedges. There were no statistical differences in nutsedge control (averaging &lt, 14 emerged plants per 1.5 m subplots) between all mulch materials at the conclusion of the study in the Mississippi location. Combining both states yield data, the heavyweight mulch (8.7 fruit, 5.3 lb) performed comparably to the industry standard plastic mulch (5.8 fruit, 3.5 lb) in terms of both average fruit number and average weights harvested off 9.1 m rows at each harvest date.

University-based horticulture departments and extension agents have explored the relationship between gardening programs and consumer knowledge and preferences. Studies have established positive correlations between garden participation and increased science scores and heightened environmental stewardship. The objective of this research was to determine if participation in “Lettuce Grow” garden workshops cohosted by the Louisiana State University Agriculture Center (LSU AgCenter) and Volunteers of America Greater Baton Rouge (VOA-GBR) had positive effects on child care providers’ garden knowledge and willingness to implement garden programming with children aged 5 years and younger. Participation led to a 67% increase (P ≤ 0.05) in horticulture knowledge for participants and resulted in 76.2% of the child care providers actively engaged in growing a garden with youth aged 5 years and under. Based on this experience, we highly recommend universities partner with local nonprofits to engage in deeper meaning, science-based garden extension projects.

Agriculture is fundamental to meeting Americans’ basic needs—clothing, housing, and food. As the average farmer’s age increases, there is a need to develop programs to encourage youth to pursue careers in agriculture and become the next generation of farmers. This study developed and implemented a horticultural curriculum focusing on vegetable production at a summer camp setting. Targeted participants were aged 9 to 12 years. Pre- and posttests were given to both the treatment group (campers participating in the victory garden track) and the control group (campers participating in a Wetlands track). The pre- and posttest evaluated campers’ science-based knowledge and confidence. The study was replicated 16 times (weeks) over a 2-year study. Lesson topics included propagation, victory gardens, soil, recycling, plant parts, pollination, photosynthesis, and insects. Campers in the treatment group had improvement of general horticulture knowledge from pretest to posttest responses 18% improvement in 2010 and 11% improvement in 2011. Posttest scores of treatment campers were greater 20% in 2010 and 16% greater in 2011 (P ≤ 0.05) than control campers in both years of the study. Treatment campers were more confident (P ≤ 0.05) in explaining to others how to grow a plant and in their ability to grow more than one type of plant. Analysis of the 2nd year of data-indicated treatment campers were more likely (P ≤ 0.05) to feel confident in their ability to plant a seed that would later grow into a plant.

Home gardeners living in areas with alkaline water sources do not have easy or economically affordable means of acidifying irrigation water for vegetable production. One solution for achieving optimal vegetable yields using alkaline irrigation water is to grow the vegetables in a modified medium. To date, no medium on the retail market suits such growing needs. Therefore, medium recipes with varied levels (0, 4, or 8 lb/yard3) and sources of calcium [dolomitic lime, calcium sulfate (CaSO4)] and magnesium [dolomitic lime, magnesium sulfate (MgSO4)] were tested using an alkaline irrigation on ‘Oakleaf’ lettuce (Lactuca sativa), ‘Earliana’ and ‘Salad Delight’ cabbage (Brassica oleracea var. capitata), and ‘Snow Crown’ cauliflower (Brassica oleracea var. botrytis) crops. Additionally, crops were grown in two environments, under a high tunnel and on a nursery yard. High tunnel and nursery yard sites were used to test media performances in the presence of, and eliminating, rainwater to simulate container-grown vegetables growing in both a home garden situation and a commercial greenhouse production situation. The base mix of all media treatments in the study was 80 bark : 20 peat and fertilized with 12 lb/yard3 slow-release fertilizer at a rate of 1.8 lb/yard3 nitrogen (N), 0.5 lb/yard3 phosphorus (P), and 1 lb/yard3 potassium (K). This initial fertilizer application was incorporated to each medium before filling containers. Four treatments were tested against a commercially available medium, industry standard (IS) treatment (a commercially available bagged medium), and a control medium [treatment C (no supplemental calcium or magnesium fertilizer)] by supplementing the base mix with the following fertilizer levels: 4 lb/yard3 each of CaSO4 and MgSO4 (treatment 1); 4 lb/yard3 dolomitic lime (treatment 2); 4 lb/yard3 each of dolomitic lime, CaSO4, and MgSO4 (treatment 3); 8 lb/yard3 dolomitic lime (treatment 4). Media treatments 1 through 4 outperformed the IS and C media treatments in nearly all crops. All crops grown on the nursery yard, and cabbage grown under the high tunnel, had greater yields when grown in medium treatment 3, compared with the IS and C media treatments (P ≤ 0.05). All crops grown in medium treatment 2 on the nursery yard produced greater yields than the IS and C media treatments (P ≤ 0.05).

University-based horticulture departments have explored the relationship between garden programs and increased horticulture knowledge among primary and secondary students. Studies have established positive correlations between youth garden programs and increased garden knowledge. The objective of this research was to determine if participation in a garden workshop series had positive effects on youth detained in juvenile detention centers garden-based knowledge and immediate mood. Participation led to a 17% increase in garden-based knowledge (P ? 0.05) and a positive shift in mood (P ? 0.05) on two of the three days of the workshop series. Based on this experience, we highly recommend juvenile detention centers incorporate garden programming as additional educational opportunities for detained youth.

Adverse weather such as flooding affects Louisiana strawberry production. Floodwater is an ideal medium for the growth of foodborne pathogens and may cause contamination of soil, water, and fresh produce. To evaluate the microbial safety of strawberries after flooding, four flooding scenarios were investigated. Five raised beds were exposed to a simulated flood event. Treatments included High Flood High Contamination (HFHC), High Flood Low Contamination (HFLC), Low Flood High Contamination (LFHC), Low Flood Low Contamination (LFLC) and a Control (C). High flood groups (HF) were exposed to 890 L of floodwater where strawberries were fully submerged, while low flood groups (LF) were exposed to 600 L of floodwater where strawberries did not come into direct contact with the floodwater. Three strains of generic Escherichia coli were spiked into the floodwater to establish a baseline population of approximately 106 colony forming units per liter (CFU/L) (high contamination) and 102 CFU/L (low contamination). Strawberry plants in all treatments were flooded for 4 h until floodwater receded. Strawberries were harvested when mature and sampled during shelf-life at 4 °C at 0, 48, 96, and 144 h. Soil samples were collected in the field every 48 h for one week. Even though the generic E. coli was not detected (

Preharvest contamination of produce with food borne pathogens has been a major food safety issue. In this study, we investigated the effect of surrounding vegetation on the survival of natural and inoculated generic Escherichia coli on watermelon rinds in an agricultural field setting. There was no significant difference (p > .05) on the populations of natural generic E. coli (1–1.46 log Most Probable Number (MPN)/sample) and coliforms (

Cumene and 4-cumylphenol are the primary constituents of concern in a groundwater plume at a chemical facility located in Plaquemine, Louisiana. Phytoremediation, a method that uses plants to remove contaminants from water and soil, was posed as a solution to removing the constituents of concern and creating hydraulic control of the plume. Five tree species, eastern redcedar, bald cypress, black willow, eastern cottonwood, and water oak, were chosen as potential remediators. Eastern redcedar and water oak did not tolerate the saline, contaminated water. Bald cypress, black willow, and eastern cottonwood trees were irrigated with deionized water, deionized water containing 0.5 mg·L−1 (0.5 ppm) cumene and 1 mg·L−1 (1 ppm) 4-cumylphenol as the low concentration, or deionized water containing 1 mg·L−1 (1 ppm) cumene and 4 mg·L−1 (4 ppm) 4-cumylphenol referred to as the high concentration. Both bald cypress and black willow were the best tree species for remediation of the groundwater as they were able to sequester the constituents of concern in their lower root tissue. Mean concentration of 4-cumylphenol detected in bald cypress roots at the end of the study were 1.72 mg·kg−1 in the low concentration water treatment and 1.50 mg·kg−1 in the high concentration water treatment. Mean concentration of 4-cumylphenol detected in black willow roots at the end of the study were 16.58 mg·kg−1 in the low concentration water treatment and 25.65 mg·kg−1 in the high concentration water treatment. Bald cypress was ultimately chosen for full scale planting in the fall of 2008.