Tomato (Solanum lycopersicum L.) is an important vegetable crop in Florida, a state located in the south-eastern region of the United States. The state is the second largest producer of tomatoes in the country and contributes to almost 90% of the domestic winter tomato supplies. However, tomato farmers in Florida have come under increasing pressure due to climate changes, foreign imports, and rising production costs. The purpose of this paper is to analyze whether Florida tomato growers will continue to sustain their production given the seasonal and geographic production advantage, yet against various internal and external threats emerging throughout the fresh produce supply chain. We developed our study on a multi-disciplinary conceptual model of network (supply chain) relationship and primary and secondary data gathered from various stakeholders and the literature. We found that Florida farmers have done remarkably well by adapting to warming temperatures and changing consumer expectations about environmental sustainability and responsible labor practices. However, foreign competition, labor shortage, the rising costs of inputs, extreme weather events (hurricanes), and pests and diseases due to humid climate continue to affect the sustainability of the Florida tomato production. Our paper suggests various farm-, market-, and institution-level adaptation mechanisms for preventing the regional production advantage of the Florida tomato industry from eroding. Newer immigration laws are necessary for easing the labor situation. In order to have a level playing field with respect to the use of protected agriculture technology such as in Mexico and Canada, U.S. farmers in general and Florida farmers in particular need government support. Florida farmers need to diversify their fresh produce market strategies, finding new product streams. There is also a need for reforming the product certification landscape, which some growers find cumbersome and cost prohibitive. Growers may gain from being better able to convey to consumers the information regarding their effort put into environmental sustainability, workers welfare, and safe food.

Huanglongbing (HLB), also known as citrus greening, is an insidious disease in citrus and has become a threat to the sustainability of the citrus industry worldwide. In the U.S., Candidatus Liberibacter asiaticus (CLas) is the pathogen that is associated with HLB, an unculturable, phloem-limited bacteria, vectored by the Asian Citrus Psyllid (ACP, Diaphorina citri). There is no known cure nor treatment to effectively control HLB, and current control methods are primarily based on the use of insecticides and antibiotics, where effectiveness is limited and may have negative impacts on beneficial and non-target organisms. Thus, there is an urgent need for the development of effective and sustainable treatment options to reduce or eliminate CLas from infected trees. In the present study, we screened citrus-derived endophytes, their cell-free culture supernatants (CFCS), and crude plant extracts for antimicrobial activity against two culturable surrogates of CLas, Sinorhizobium meliloti and Liberibacter crescens. Candidates considered high-potential antimicrobial agents were assessed directly against CLas in vitro, using a propidium monoazide–based assay. As compared to the negative controls, statistically significant reductions of viable CLas cells were observed for each of the five bacterial CFCS. Subsequent 16S rRNA gene sequencing revealed that each of the five bacterial isolates were most closely related to Bacillus amyloliquefaciens, a species dominating the market of biological control products. As such, the aboveground endosphere of asymptomatic survivor citrus trees, grown in an organic orchard, were found to host bacterial endophytes capable of effectively disrupting CLas cell membranes. These results concur with the theory that native members of the citrus microbiome play a role in the development of HLB. Here, we identify five strains of Bacillus amyloliquefaciens demonstrating notable potential to be used as sources of novel antimicrobials for the sustainable management of HLB.

Microorganisms associated with medicinal plants are of great interest as they are the producers of important bioactive compounds effective against common and drug-resistant pathogens. The characterization and biodiversity of fungal endophytes of the Petiveria alliacea plant and their antimicrobial production potential are of great interest as they are known for their antimicrobial and anticancer properties. In this study, we investigated the endophytic fungal microbiome associated with P. alliacea, and the endophytic fungal isolates were classified into 30 morphotypes based on their cultural and morphological characteristics. Ethyl acetate extract of fungal endophytes was obtained by liquid–liquid partitioning of culture broth followed by evaporation. The crude extract dissolved in dimethyl sulfoxide was screened for antimicrobial activity against three bacterial strains (Escherichia coli ATTC 25902, Staphylococcus aureus ATTC 14775, Bacillus subtilis NRRL 5109) and two fungal strains (Candida albicans ATTC 10231 and Aspergillus fumigatus NRRL 5109). Among the crude extracts from endophytes isolated from leaves, 65% of them showed antimicrobial activity against the bacteria tested. Similarly, 71 and 88% of the fungal crude extracts from endophytes isolated from root and stem, respectively, showed inhibitory activities against at least one of the bacterial strains tested. Crude extracts (at a concentration of 10 mg/mL) from ten of the fungal isolates have shown a zone of inhibition of more than 12 mm against both Gram-positive and negative bacteria tested. Sequenced data from isolates showing strong inhibitory activity revealed that Fusarium solani, F. proliferatum, and Fusarium oxysporium are the major endophytes responsible for bioactive potential. These results indicate that Petiveria alliacea harbors fungal endophytes capable of producing antimicrobial metabolites. Future studies need to focus on testing against drug-resistant bacteria (ESKAPE group) and other pathogenic bacteria and fungi.

Incorporating renewable fuel into practice, especially from algae, is a promising approach in reducing fossil fuel dependency. Algae are an exceptional feedstock since they produce abundant biomass and oils in short timeframes. Algae also produce high-valued lipid products suitable for human nutrition and supplement. Achieving goals of producing algae fuels and high-valued lipids at competitive prices involves further improvement of technology, especially better control over cultivation. Manipulating microalgae cultivation conditions to prevent contamination is essential in addition to promoting optimal growth and lipid yields. Contamination of algal cultures is a major impediment to algae cultivation that can however be mitigated by choosing extremophile microalgae. This work describes the isolation of alkali-tolerant / alkaliphilic microalgae native to South Florida with ideal characteristics for cultivation. For that purpose, water samples from Lake Okeechobee were inoculated into Zarrouk's medium (pH 9-12) and incubated for 35 days. Selection resulted in isolation of three strains that were screened for biomass and lipid accumulation. Two alkali-tolerant algae Chloroidium sp. 154-1 and Chlorella sp. 154-2 were poor lipid accumulators. One of the isolates, the diatom Fistulifera sp. 154-3, was identified as a lipid accumulating, alkaliphilic organism capable of producing 0.233 g L-1 d-1 dry biomass and a lipid content of 20-30% dry weight. Lipid analysis indicated the most abundant fatty acid within Fistulifera sp. was palmitoleic acid (52%), or omega-7, followed by palmitic acid (17%), and then eicosapentanoic acid (15%). 18S rRNA phylogenetic analysis formed a well-supported clade with Fistulifera species.

Regenerative agriculture increasingly relies on organic soil amendments to improve soil fertility and crop productivity. This study evaluates the effects of dried algae (DA), vermicompost (VC), liquid hydrolyzed fish and seaweed fertilizer (LA), and a control (S0, untreated soil without amendments) on the soil fertility, growth, nutrient uptake, and physiology of sunn hemp (Crotalaria juncea L.), a key cover crop for soil improvement. Treatments were applied at 1 ton/ha (DA), 3 ton/ha (VC), and 8 mL/L (LA). Plants were grown for 10 weeks, during which plant growth, chlorophyll content, and biomass were measured. Soil and plant samples were analyzed for macro- and micronutrients. S0 and DA treatments produced the highest biomass, with S0 showing the highest total carbon and organic matter content. LA-treated soils exhibited elevated phosphorus, potassium, and sodium levels, while DA and S0 shoots had significantly higher sulfur and zinc concentrations. LA treatment notably increased chlorophyll content by the study’s end. Overall, DA demonstrated strong potential as a nutrient-rich organic amendment, while S0 provided a robust baseline for biomass production. VC enriched phosphorus and potassium but resulted in the lowest total biomass. LA promoted shoot growth and chlorophyll content but required root development and sodium management optimization. These findings highlight the need to align the amendment choice with soil characteristics and environmental conditions to optimize crop productivity and soil health in sustainable farming systems.