The loss of the soil fumigant methyl bromide (MeBr) and adoption of soil fumigant alternatives has been challenging for farmers, particularly for those crops in which pathogens previously controlled by MeBr have emerged as significant problems, but it has resulted in some unanticipated benefits for the scientific community and the environment. Applauded as one of the most effective environmental agreements to date, the universally accepted Montreal Protocol on Ozone Depleting Substances has had a significant impact on the environment, reducing the release of halogenated compounds from anthropogenic sources enough to mitigate global warming by an estimated 1.1°C by 2021. The funding associated with various MeBr transition programs has increased collaboration across scientific disciplines, commodity groups, industry, and regulatory agencies. Chemical alternatives and improved application strategies, including the development of gas-retentive agricultural films, coupled with sound efficacy data and grower ingenuity have resulted in the sustained production of many of the impacted crops; although there has been some loss of acreage and value, particularly for Florida fumigated crops, for some, value has continued to increase, allowing production to continue. The loss of a single, broad-spectrum tool for pest control has led to a deeper understanding of the specific pest complexes impacting these at-risk crops, as well as the development of new, biologically based management tools for their control while increasing our understanding of the role of the soil microbiome in pest control and crop production.

Nitrogen (N) is one of the main nutrients that drive rice grain yield and is intensely managed especially in lowlands under irrigated conditions. A set of experiments was conducted in mid‐ and high‐altitude sites in Rwanda to investigate the response of five genotypes under different sowing dates and different N management. Genotype grain yields were higher and more stable at mid‐altitude across sowing dates. N rates strongly affected grain yield at mid‐altitude (p < .0001), but not at high altitude. Postponing basal N had positive effects on yield and yield components in both sites, with more pronounced effects at high altitude. Increasing N rate beyond 120 kg/ha led to a decrease in percentage of panicles per tiller and spikelet fertility and a decrease in grain yield due to excessive tillers at both high altitude and mid‐altitude. Thus, basal N application should be recommended at high altitude and the increase in N rate up to 120 kg/ha at mid‐altitude. A strict observation of recommended planting date should be followed at high altitude, and the use of cold‐tolerant genotypes is encouraged.

The use of high tunnels, which allows growers to extend their season and improve yields, is increasing in the Southeastern U.S., yet growers face challenges related to weed and disease management, particularly in organic systems. On-station experiments were conducted during fall 2021 and spring 2022 in a split-plot design to assess the efficacy of anaerobic soil disinfestation (ASD) in high tunnels for the organic production of direct-seeded baby leaf lettuce. Soil treatments (ASD, Compost, and Control) and lettuce types (romaine and oakleaf cultivars) were included in whole plots and subplots, respectively. The ASD-treated soils received molasses and granular organic fertilizer as carbon and nitrogen sources. The Compost treatment involved the application of yard waste-based compost and the same organic fertilizer, while the Control soils received organic fertilizer only. The ASD treatment period lasted 8 days rather than the typical 21-day period evaluated in Florida. Crop yield, biometrics (leafy dry matter content, specific leaf area, specific leaf weight), and lettuce quality attributes (leaf color, soluble solids content, total titratable acidity, ferric reducing antioxidant power, ascorbic acid content, total phenolics) were assessed following harvest. In both trials, numerical differences in lettuce fresh weight yield between soil treatments were evident, though not statistically significant. Differences in leaf quality attributes were driven by lettuce cultivar rather than soil treatments. Bottom rot incidence caused by Rhizoctonia solani was reduced by 93% and 87% in the ASD-treated plots compared with the Compost- and Control-treated soils during the spring 2022 trial. The ASD-treated soils had a reduced population density of broadleaf weeds in both baby leaf lettuce production trials. The current study presents novel evidence of the potential of integrating ASD into HT organic production systems without reducing the yield and quality attributes of direct-seeded baby leafy greens compared with common grower practices.

Historical repository of UF/IFAS Extension numbered publications made available on the EDIS website. UF/IFAS Extension is a federal, state, and county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences and to making that knowledge accessible to sustain and enhance the quality of human life.

Due to increasing marketing and production risks in specialty crop production, a shift toward more protected culture systems such as a high tunnel production system is crucial to keep specialty crop farms profitable and sustainable in the United States. In this publication, we analyzed the cost of constructing high tunnels and caterpillar tunnels in Florida and examined the major contributors to their establishment costs. The findings are intended to assist farmers in deciding whether or not to add high tunnel or caterpillar tunnel systems to their farming operations.