Strawberry Production Systems Research Articles

Mycorrhizal Biotechnology Reduce Phosphorus in the Nutrient Solution of Strawberry Soilless Cultivation Systems

Among the bio-tools that contribute to making the strawberry production system more sustainable are arbuscular mycorrhizal fungi (AMF), which can be used as biofertilizers. Thus, five doses of phosphorus (P) applied to plants with AMF and a control (100% P, no AMF) were analyzed in order to differentiate the horticultural potential of the ‘Camarosa’ cultivar. We used an on-farm inoculant made up of six fungal species. The univariate and multivariate analyses showed that the addition of AMF to the growing substrate made it possible to reduce the P supply in the nutrient solution by 75% without compromising the fruit yield. In addition, this combination improved the phytochemical quality of strawberries, the plant’s root system morphology, and the accumulation of nutrients in plant organs (roots, crowns, aerial part and fruits). We conclude that the use of a multi-species on-farm inoculant based on AMF associated with a reduction in the P supply in the nutrient solution modifies the horticultural potential of the ‘Camarosa’ cultivar. We confirmed the action of a native AMF community as a biofertilizer.

Antibiose de genótipos de morangueiro ao ácaro-rajado

ABSTRACT: The spotted spider mite, Tetranychus urticae (Koch, 1836), is one of the most important pests of strawberry production systems worldwide. Because plant resistance is an important integrated management strategy, the present study investigated the effects of 12 strawberry genotypes on the biological characteristics of this pest under laboratory conditions (25 ± 2 °C and RH 60 ± 10%; 12:12-hour photophase). The experiment was carried using 12 treatments (genotypes), divided into 20 replications each, in a completely randomized design. The response variables were the biological parameters of the spider mite and its survival rate. The development and survival of T. urticae were influenced by different strawberry genotypes. The Camarosa cultivar together with genotypes Selection 05 and 2017-04-03 negatively affected the development and survival of T. urticae. The Selection 02 genotype had greatest susceptibility to the spider mite, which allowed fast development and high survival rate. The reproductive parameters of T. urticae were affected differently as a function of the strawberry genotype, with the Camarosa cultivar and the genotypes Selection 05 and 2017-04-03 being unfavorable to development, suggesting a possible resistance based on antibiosis.

Why does strawberry fruit weight distribution show positive skewness? A simulation model reveals the underlying processes of fruit production

It is widely accepted that the weight distribution of plant fruits conforms to a standard normal distribution. However, some overlooked evidence suggests that some fruits, including strawberries, exhibit positive skewness in fruit weight distribution. This intriguing observation has received limited attention thus far. To shed light on this phenomenon, we conducted a comprehensive simulation study utilizing greenhouse-grown strawberries as our research subject. We modeled the entire process from bee pollination to pollen fertilization on the stigma and fruit growth. The experimental results demonstrated the reliability of the proposed simulation model and revealed that the positive skewness of the fruit weight distribution was the result of the multiplication of several complex intermediate variable distributions, which led to an approximately lognormal distribution. The simulation model and the derived conclusions presented in this paper offer a plausible explanation for the weight distribution patterns observed in strawberry production systems. Furthermore, research results have the potential to be applied to other berry plants that undergo similar bee pollination processes, thereby expanding our understanding of fruit weight distributions across different species.

Assessing the efficacy of a tabletop day-neutral strawberry production system for Minnesota

Assessing the efficacy of a tabletop day-neutral strawberry production system for Minnesota

EXPLORING THE ALLURE OF STRAWBERRIES

Strawberry is a member of family Rosaceae. Fragaria x ananassa are two important species which grown throughout the world. It is a rich source of Vitamin C, also contains sugar, organic acid, and major constituent is water. It is utilized in fresh form as well as processed such as jam and juices. Organic food products are beneficial for the people around the globe. From the past years, organic food production is increased abruptly. Plasticulture strawberry production system is used which enhances the yield of strawberry doubles times as compared to matted rows. Different kinds of plastic mulches used which give protection to plant and soil and increase the yield. As we know due to health concerns that occurred due to excessive use of chemicals and fertilizers, it is hazardous to use chemical fertilizers on unpeelable fruits like strawberry. It enhances risks for human health. Many constituents of strawberries such as ellagic acid, anthocyanins, and ellagitannins provide different health benefits to humans. It has anticarcinogenic and anti-antioxidant properties, and they prevent human from heart diseases and many other problems such as obesity.

Probiotic Bacteria, Anaerobic Soil Disinfestation, and Mustard Cover Crop Biofumigation Suppress Soilborne Disease and Increase Yield of Strawberry in a Perennial Organic Production System.

Black root rot complex and crown rot of strawberry caused by soilborne fungi limit sustainable strawberry production in the northeastern United States, especially in perennial systems, including matted row and plasticulture. As pathogen populations build up over time in the rhizosphere and infect the root system, feeder roots are pruned, which diminishes nutrient and water uptake and causes stunted plant growth or death. Alternative management options are needed for many organic and small growers who can't use chemical fumigants due to new regulations and potential health hazards. Strawberry plug plants were grown on beneficial microbe-inoculated or uninoculated planting mix followed by transplanting in fruiting field plots that either was biofumigated with mustard cover crop (MCC), anaerobically disinfested (ASD), or left untreated. Different combinations of plug plants and field plot treatments were used to determine the efficacy of individual treatments or synergistic effects from combination treatment. Plug plants were transplanted in pretreated plastic mulched raised beds and grown following a typical organically recommended production system. Plants grown on TerraGrow (TG)-inoculated planting mix showed enhanced plant vigor in the fruiting field compared with untreated plants. Weeds that grew through planting holes were significantly (P ≤ 0.045) suppressed in ASD plots compared with untreated plots in the first year. Plants treated with a combination treatment of TG and ASD had significantly higher fruit yield in both years (2019 and 2020), although the difference was greater in the second year. Plant vigor and survival in treated plots except MCC were also significantly higher in the second year compared with the untreated control. Suppression of pathogenic microbes and plant vigor improvement in treated plots appear to be the factors providing beneficial effects and higher net economic return. Taken together, our results suggest that a combination of beneficial microbes and ASD could be an alternative to synthetic fumigation in a perennial strawberry production system.

INFLUENCE OF INTERCROPPING ON SOIL MICROBIAL ACTIVITY AND STRAWBERRY DEVELOPMENT

Strawberry is one of the most important berry crop grown around the world and their consumption increases every year. The introduction of new practices promoting farm sustainability and long-term soil health in strawberry production systems is very essential. Towards environment- and climate-friendly farming practices intercropping can be used to improve soil microbiological activity and biodiversity, and reduce the use of pesticides and mineral fertilizers, while the right choice of intercropped plants is of great importance to achieve these goals. The trials on strawberry intercropping were established in Latvia in 2021. Three treatments with different intercropping plant rotations, including crimson clover, pea, garlic, marigold, and winter rye mix with vetch, were compared to conventional strawberry growing using straw mulch. Trial was installed in three locations: two organic farms and the Institute of Horticulture (LatHort). Thus representing climatically different regions and different soil conditions. Strawberries were grown in 1.2 m distant rows, where in the intercropping treatments, each second interrow was occupied by companion plants. Soil microbial activity was evaluated during vegetation seasons by determining soil respiration rate (SRR) and dehydrogenase activity (DHA) several times per season in 2021 and 2022. Strawberry vegetative development was evaluated at the end of each vegetation season. During the investigation period, soil microbial activity fluctuated during vegetation seasons, depending on growing conditions. In 2021, SRR varied from 1.9 – 3.3 CO2 mg L- 1, while in 2022, from 2.1 - 3.4 CO2 mg L-1. DHA varied from 46 – 134 INTF, µL×????−1 × h in 2021 and 60 – 101 INTF, µL×????−1 × h in 2022. Intercropping had low influence on microbial activity and results differed within each location. Strawberry plant biomass differed among locations and treatments with the highest above-ground biomass observed in LatHort during second growing season in conventional growing system (790 g plant-1).

Soil bacterial communities are influenced by soil chemical characteristics and dispersal limitation in commercial strawberry production systems.

Bacterial communities play multiple functional roles in soil that have positive and negative feedbacks on plant health. However, relatively few studies have focused on the ecology of soil bacterial communities in commercial strawberry production systems. The objective of this study was to determine if ecological processes influencing soil bacterial communities are consistent among commercial strawberry production locations and plots within the same geographic region. Soil samples were collected using a spatially explicit design from three plots in two commercial strawberry production locations in the Salinas Valley region of California. Soil carbon, nitrogen, and pH were measured for each of the 72 soil samples and bacterial communities were characterized using 16 S rRNA sequencing. Multivariate analyses showed bacterial community composition was differentiated between the two strawberry production locations. Analyses of communities within plots demonstrated soil pH and nitrogen were significant predictors of bacterial community composition in one of the three sampled plots. Bacterial communities displayed spatial structure in two plots at one location based on a significant increase in community dissimilarity with increasing spatial distance. Null model analyses identified a lack of phylogenetic turnover among bacterial communities in all plots, but a greater frequency of dispersal limitation in the two plots where spatial structure was also observed. Overall, this work suggests that ecological factors influencing soil bacterial communities are not consistent among different strawberry production locations or plots which may impact the ability to predict or manage the effect of soil microbiomes on strawberry health.

Effect of fumigants and non-fumigants on nematode and weed control, crop yield, and soil microbial diversity and predicted functionality in a strawberry production system

Fumigants are commonly used to control soil-borne pathogens of high-value crops, but they may also impact non-target soil microorganisms. Increasing interest in the use of sustainable management practices to control plant- and root-parasitic nematodes has resulted in the formulation of non-fumigant nematicides (chemicals or bionematicides) which are considered environmentally friendly alternatives to fumigants. However, the impact of these new products compared to standard fumigants on soil-borne pathogens, plant production, and the diversity and composition of non-target microbial communities in all crops remains unclear. To begin to address this knowledge gap, we examined the effect of fumigants commonly used in Florida (United States) strawberry production and newly formulated non-fumigant nematicides on nematode and weed control, plant growth, crop yield, and bacterial and fungal community diversity and predicted functionality. We found the standard fumigants increased crop yields and reduced weed pressure more than non-fumigants. Both fumigants and non-fumigants were an efficient management strategy to control sting nematodes. Treatments also impacted the abundance of specific beneficial and antagonistic taxa. Both fumigants and non-fumigants reduced soil bacterial and fungal diversity, an effect that remained for six months, thus suggesting a potential residual impact of these products on soil microorganisms. However, only fumigants altered soil microbial community composition and reduced network complexity, inducing a decrease or even a loss of some predicted bacterial and fungal functions, particularly during the first weeks after fumigation. Nevertheless, soil collected at the end of the season showed significant levels of root-knot nematode suppression in a growth chamber experiment, irrespective of the previous treatment. By linking the effect of fumigants and non-fumigants on soil-borne pests, plant and production, and the soil microbiome, this study increases our knowledge regarding the environmental impact of these products.

Stakeholder-driven adaptive research (SDAR): better research products

AbstractRapid changes in economic, environmental and social conditions generate both problems and opportunities in agriculture. The cycle from problem identification through discovery of potential solutions is lengthy. The objective of this study was to use collaborative methods to speed the cycle of discovery in sustainable organic strawberry (Fragaria × ananassa) production systems in the southeastern USA. This method, stakeholder-driven adaptive research (SDAR), combines farmers' experiential knowledge with scientists' experimental knowledge to develop rigorous research design collectively. Farmers evaluated our biological research and co-designed research experiments with scientists. Farmers and other stakeholders (1) evaluated on-station experiments individually and then made recommendations as a group, (2) served as advisory council members to direct our goals and objectives, and (3) conducted farmer field trials where they implemented aspects of our on-station experiments under their management regimes. The results eliminated potential solutions that were not feasible, ineffective or too costly for farmers to adopt. Key results included eliminating treatments using high tunnel systems altogether on one field trial on a University of Florida (UF) research facility, adding a leguminous cover crop mix treatment, adding companion planting, and eliminating strawberry cultivars Strawberry Festival and Florida Beauty from our research trials. Our proposed methodology allows farmers and other stakeholders to inform the biological research from design through dissemination to reduce the time needed to create research products in an era of rapid bio-physical, social and economic change. Accelerating the discovery cycle could significantly improve our ability to identify and address threats to the USA and global food and fiber production system.

Annona (Annonaceae) by-products derivatives: Toxicity to the European pepper moth and histological assessment

Obtaining derivatives with insecticidal properties from abundant plant biomass (waste) represents a good opportunity to transform environmental problems into innovative solutions for pest management programs. In the present study, we evaluated the toxicity of the aqueous emulsions of the ethanolic extract of Annona mucosa and Annona sylvatica (Annonaceae) seeds on the European pepper moth Duponchelia fovealis (Lepidoptera: Crambidae), a major pest of strawberry plants. In addition, we evaluated anti-feeding and developmental inhibitory effects, as well as macro and microscopic damage to the excretory and nervous systems of European pepper moth larvae. In the contact bioassay, the aqueous emulsion of A. mucosa extract provided the fastest action on larvae with LT50 of 6.10 h, followed by chlorfenapyr (Pirate®) (LT50 = 8.2 h) and the aqueous emulsion of the A. sylvatica extract (LT50 = 10.3 h). In contrast, the commercial bioinsecticide based on acetogenins (Anosom® 1 EC) had a higher LT50 (32.8 h). In addition to the lethal effects, the aqueous emulsions tested caused significant phagodeterrence (>90%) and inhibited the development of D. fovealis. Macroscopic observation revealed the presence of edemas as well as the darkening on the surface of the larvae's cuticle. Histological analyses detected alterations. Our results suggest that aqueous emulsions produced from ethanolic extract of A. mucosa and A. sylvatica seeds, a residue in fruit processing industrial complexes (pulp factories), are alternatives for the management of D. fovealis, especially in organic and/or ecological strawberry production systems.

Bradysia aff. impatiens and Bradysia aff. ocellaris in the semi-hydroponic strawberry production system in Southern Brazil

ABSTRACT: Soilless cultivation of strawberry is in expansion in Brazil due to factors like the reduction of phytosanitary problems and the possibility of extending the crop period, as well as the ergonometric facility for management of the culture. However, black fungus gnats (Sciaridae, Diptera) are ubiquitous pests in the greenhouse production system, causing direct and indirect damage to plants. ThIS study evaluated the occurrence of black fungus gnats species in semi-hydroponic cultivation of strawberry and to identify the species, as well as to describe the symptoms in infested plants. The research was developed in commercial productions of strawberry, in five municipalities (Arroio do Padre, Canguçu, Capão do Leão, Pelotas and Turuçu) during July to December 2017, where adult samples were collected twice a month, with petri dish traps containing water and neutral detergent placed inside the greenhouses between the plants. A total of 2030 adult gnats belonging to two species were collected. Bradysia aff. impatiens, accounted with 90.79% of the total, and Bradysia aff. ocellaris, accounted with 9.21%. In order to assist the correct determination of species, males of both species were identified and illustrated. With respect to the symptoms observed during the research, it was possible to verify since the wilted crown of plants to the death of plants, which were confirmed by the presence of larvae in the root system. As the occurrence of these insects is recent in strawberry, there is no pesticide registered in Brazil, so management strategies (cultural, physical, and sanitary) also are discussed.

Prospecting the unpredicted potential traits of Cladophialophora chaetospira SK51 to alter photoperiodic flowering in strawberry, a perennial SD plant

Due to the economic importance of strawberry, many countries have established national breeding programs aimed at improving the flowering time and fruiting season to achieve year-round fruit availability. The ability of crops to produce fruits throughout the year with “flowering on command” is still a challenge in strawberry production systems. Although growth promotion by dark septate endophytic (DSE) fungi has been reported, the symbiotic association that alters flowering behaviors in photoperiodic fruit crops has not been studied. Here we established an experimental scheme for inducing the short-day (SD) strawberry cultivar Fragaria vesca to initiate flowering under a long-day (LD) photoperiod in symbiotic association with DSE fungus. We evaluated the relationship between growth-promoting and flower-inducing activities using Pearson's correlation analysis. Symbiotic association with C. chaetospira SK51 markedly stimulated SD strawberry cultivar to initiate early flowering, with the greatest flower induction (94.8%) and highest number of fruits (10.6 fruits/plant) during cultivation under a 16-h LD photoperiod at 23 °C, defined as non-flower-inductive conditions, considered as a new finding. We found that the interactions between C. chaetospira SK51 and strawberry plants markedly contributed to accelerating the earliness of the flowering time, as flower buds were initiated 90 days earlier than in the untreated control. Interestingly, we show that plant response in flowering by co-cultivation of C. chaetospira SK51 is constantly induce under various soil types and pHs. Based on Pearson's correlation coefficient analysis, we suggest that flowering behavior has a weakly non-significant relationship with growth-promoting activities, indicating that the control of flowering has a different or indirect pathway. Strawberry plants in symbiosis with C. chaetospira SK51 might be well-adapted to all regions and help preserve crops resilience against adverse climate conditions. These findings provide an essential resource and new insight for photoperiodic flowering research and innovation that can be adopted to deliver sustainable solutions that eventually will lead to extending and increasing crop production.

Can hemp hurd or paper mulch and biochar application improve weed management in matted-row strawberry production systems?

AbstractDuring 2015 and 2016, studies were conducted at Absaraka and Dickinson, North Dakota to evaluate the impacts of hemp (applied at 1156 m3 ha−1) and commercial paper mulch, as well as soil-applied biochar (applied at 11.25 m3 ha−1), on weed suppression and strawberry growth during the establishment year, and on weed suppression and strawberry yield during the production year, in a matted row production (MRP) system. During 2015, biochar influenced dry weed biomass only within the hemp mulch, with slightly more weed biomass associated with biochar application compared to zero biochar (3.1 vs 0.4 g m−2), suggesting that biochar may have increased weed germination and/or emergence from beneath hemp mulch. Biochar application also slightly increased soil pH, from 6.9 in non-amended soil to 7.0 in amended soil. Strawberry runner number during 2015 was greater in association with hemp or paper mulch compared to zero mulch (4.5 and 4.9 vs 2.4 runners plant −1, respectively). This result mirrored a similar differential in per berry mass across sites (7.6 and 7.4 vs 6.2 g berry −1 for hemp mulch, paper mulch and zero mulch, respectively). These results may be related to hemp and paper mulch reducing maximum soil temperatures during summer 2015. During the establishment year, both hemp and paper mulch suppressed weeds well compared to zero mulch, although at Absaraka hemp mulch provided slightly better weed suppression than paper mulch. During the production year, both mulches continued to suppress weeds compared to zero mulch at Dickinson. However, at Absaraka, only hemp mulch provided weed suppression compared to zero mulch, possibly because of faster paper degradation caused by greater numbers of large precipitation events and greater relative humidity at Absaraka compared to Dickinson. Weeds were removed from plots during 2015 to allow separation of weed suppression from other possible mulch impacts; therefore, yield data do not reveal striking differences among mulch treatments. Because previous research has demonstrated the impact of weed management during the establishment of strawberries in a matted row system, we concluded that hemp mulch may provide more durable weed suppression compared to paper mulch, which would increase strawberry yield protection in an MRP system. Material cost may be an issue for implementing hemp mulch, as hemp hurd cost was 25 times paper mulch at the application rates used in this study. However, hemp mulch could still be a beneficial option, especially for organic strawberry growers desiring a renewable and environmentally sound replacement for plastic mulch who are able to find affordable local sources of this material.

Wood-based biochar for small fruit production in southern Quebec, Canada

The market for small fruits (grapes, blueberries, strawberries, and raspberries) is valued at more than $100 million CAD per year in Quebec, Canada. Wood-based biochar is an amendment that improves soil quality, which may boost small fruit growth and production. The objective of this research was to determine if wood-based biochar could increase the yield and quality of grape, blueberry, strawberry, and raspberry in southern Quebec. We evaluated the fruit yield as well as the quality parameters like average fruit weight, fruit firmness, color, juice pH, total soluble solids, total phenolic content, and antioxidant activity. Field trials were established on commercial farms with grape, blueberry, strawberry, and raspberry production systems in plots that received wood-based biochar and no biochar in spring (April–May). Small fruits were harvested at their ripening stage for yield and quality evaluation in the fall (July–October). Biochar application did not improve yield and quality parameters of small fruits, except it gave a marginally higher yield of grape (3.7 vs. 4.4 t·ha−1, P = 0.08) and a higher average fruit weight of strawberry (11.9 vs. 13.2 g, P < 0.05). There was no difference in the quality of the fruit from biochar-amended and control plots in the first year of biochar application, possibly because the quality parameters are affected more by weather conditions, handling, and storage than by soil quality. This work suggests that wood-based biochar (<5 t·ha−1) has a limited first-year impact on small fruit yield and quality in southern Quebec, Canada.

Discovery of three loci increasing resistance to charcoal rot caused by Macrophomina phaseolina in octoploid strawberry.

Charcoal rot caused by Macrophomina phaseolinais an increasing economic problem in annualized strawberry production systems around the world. Currently there are no effective postfumigation chemical controls for managing charcoal rot, and no information is available on the genetic architecture of resistance to M. phaseolina in strawberry (Fragaria ×ananassa). In this study, three multiparental discovery populations and two validation populations were inoculated at planting and evaluated for mortality in three consecutive growing seasons. Genome-wide SNP genotyping and pedigree-based analysis with FlexQTL™ software were performed. Two large-effect quantitative trait loci (QTL) increasing charcoal rot resistance were discovered and validated in cultivated germplasm. FaRMp1 was located on linkage group 2A in the interval 20.4to 24.9 cM, while FaRMp2 was located on linkage group 4B in the interval 41.1to 61.2 cM. Together these QTLs explained 27% and 17% of the phenotypic variance in two discovery populations consisting of elite breeding germplasm. For both QTLs, the resistant allele showed some evidence of partial dominance, but no significant interaction was detected between the two loci. As the dosage of resistant alleles increased from 0 to 4 across the two QTLs, mortality decreased regardless of the combination of alleles.A third locus, FaRMp3 on 4D, was discovered in FVC 11–58, a reconstituted F.×ananassa originating from diverse F. virginiana and F. chiloensis accessions. This locus accounted for 44% of phenotypic variation in four segregating crosses. These findings will form the basis for DNA-informed breeding for resistance to charcoal rot in cultivated strawberry.

Dynamics of Soil Nitrogen Availability Following Sunn Hemp Residue Incorporation in Organic Strawberry Production Systems

Sunn hemp (Crotalaria juncea L.), as a summer leguminous cover crop, is often grown before fall planting of strawberries (Fragaria ×ananassa Duch.) in Florida. Although sunn hemp has been suggested as a green manure for supplying nitrogen (N) to subsequent crops, limited information is available regarding the contribution of sunn hemp biomass to soil N availability in Florida sandy soils with low levels of organic matter. This is especially true for organic strawberry production where nutrient management remains one of the major yield-limiting factors. This study was conducted in Citra, FL, and assessed the dynamics of N availability after soil incorporation of sunn hemp in organic strawberry production systems established on sandy soils in a subtropical environment. Sunn hemp was planted at a seeding rate of 44.9 kg·ha−1 on 19 July 2017 and 24 July 2018 and terminated 65 days after seeding; a summer weedy fallow was used as the control. Containerized strawberry seedlings of Sweet Sensation® ‘Florida127’ were transplanted on 13 Oct. 2017 (22 days after sunn hemp incorporation) and 4 Oct. 2018 (8 days after sunn hemp incorporation). Immediately after sunn hemp incorporation, anion exchange membranes (AEMs) were buried in the soil to monitor soil NO3-N fluxes, together with traditional soil testing to measure extractable soil NO3-N concentrations. In the 2018 season, soils incorporated with sunn hemp residues were also incubated in the laboratory at 24 °C over 8 weeks to determine the N release pattern by quantifying soil NO3-N and NH4-N. Overall, nitrate fluxes monitored by AEMs in the first 3 weeks after sunn hemp incorporation were significantly higher in the sunn hemp treatment than in the weedy fallow control (by 66% to 185%) in both years. Sunn hemp incorporation also led to a considerable increase in extractable soil NO3-N concentration (by 20% to 94%). The early and fast release of plant available N (PAN) from sunn hemp residues was confirmed by the 8-week laboratory incubation study, which demonstrated that the net N mineralization rate of sunn hemp remained highest over the first 2 weeks of the incubation period. Sunn hemp showed a positive impact on organic strawberry early-season fruit yield in both years, with significant increases in marketable (by 59%) and total (by 52%) fruit weight yields and marketable fruit number (by 46%) in 2017 and total fruit number (by 15%) and weight yield (by 14%) and marketable fruit number (by 13%) in 2018. Given the typical waiting period between sunn hemp residue soil incorporation and strawberry planting as well as the lag in nutrient uptake shortly after transplanting, a large fraction of N released from sunn hemp residues is likely not taken up by strawberry plants. Our findings highlight the challenges of using sunn hemp residues to improve N availability for meeting crop demand and enhance fruit yield in organic strawberry production while minimizing environmental N losses in Florida sandy soils.

What is the profile of strawberry producers in the south Brazilian region and what do they think about substrate cultivation?

ABSTRACT Strawberry production in the south part of Rio Grande do Sul has already been consolidated and, recently, this production has undergone several changes in its cultivation system. The profile of the strawberry producers in this region, and the cultivation systems they use, considering socioeconomic and technological characterization, had not been formally studied since then. This study aimed to characterize the socioeconomic profile of producers, as well as the strawberry production system. Data were obtained through a questionnaire, with questions related to the socioeconomic aspects of the producers and the technical aspects of their cultivation systems. Most of the interviewed producers are male, 26-50 years old, owing up to 20 hectares land, with a monthly income of up to four minimum wages and relying only on family labor. They are considered family producers and have already been growing strawberries in substrate, or are interested in using this modern soilless culture system.

Effects of Chemical and Solar Soil-Disinfection Methods on Soil Bacterial Communities

The actctivated carbon + solar radiation membrane is an eco-friendly soil disinfestations method for managing soil-borne plant pathogens. However, little was known the impact of Activated carbon + solar radiation membrane on bacterial community structure in strawberry production systems under field conditions. A comprehensive evaluation of the impacts of different soil disinfection methods on the bacterial community structure is fundamental to understand the role of disinfection in maintaining soil health. The changes in the soil bacterial diversity and community composition were detected using realtime fluorescence quantitative PCR (RTFQ PCR) and next-generation sequencing techniques to better understand the effect of soil disinfection. The bacterial community composition was monitored after disinfection using dazomet (DZ), chloropicrin (CP), 100 kg/ha activated carbon + solar radiation membrane (AC1), 200 kg/ha activated carbon + solar radiation membrane (AC2), and 300 kg/ha activated carbon + solar radiation membrane (AC3) and compared with the control (CT). The results indicated that the different dosages of activated carbon (AC1, AC2, and AC3) did not affect the bacterial community structure. On the other hand, DZ and CP considerably reduced the soil biomass and abundance of bacterial species. Chemical fumigants influenced the bacterial community structure, with DZ treatment leading to the dominance of the phylum Firmicutes, accounting for approximately 54%. After fumigation with CP, Proteobacteria and Acidobacteria were the dominant phyla. Beta diversity analysis and principal coordinate analysis revealed that the bacterial communities in the soil treated with DZ and CP formed clusters. Redundancy analysis indicated that soil pH, available potassium, and available phosphorus were the key factors influencing microbial metabolic functional diversity. Thus, it was verified that the damage caused by activated carbon + solar radiation membrane—a potential alternative for chemical fumigant—to the soil bacterial community was less than that caused by chemicals DZ and CP.

Flumioxazin soil persistence under plastic mulch and effects of pretransplant applications on strawberry

AbstractWeeds are managed in Florida strawberry production systems with plastic mulches, fumigants, and herbicides. There are limited post-transplant options to control weeds that emerge in the planting holes in the plastic-covered beds, but flumioxazin at 107 g ai ha−1 can be applied pretransplant under the plastic mulch to control broadleaf and grass weeds. Three research trials were conducted in Balm and Dover, FL, in 2017 and 2018 to evaluate tolerance of the strawberry cultivar ‘Radiance’ to flumioxazin rates ranging from 54 to 6,854 g ha−1 and to estimate herbicide persistence under the plastic mulch. Shoot damage was observed at 428 to 857 g ha−1 (4× and 8× the label rate, respectively), but a significant increase in the number of dead plants was not observed until the treatment rate was 857 g ha−1 at one site and 3,427 g ha−1 at a second site (8× and 32× the label rate, respectively). Berry yields were unaffected by rates lower than 857 g ha−1. Flumioxazin persisted throughout the growing season (approximately 150 d) with no reduction in soil concentration. We conclude that applied at the label rate, flumioxazin is a safe pretransplant weed management option for season-long weed control in strawberry with no yield reduction at rates below 8× the label rate. Caution is recommended for growers who plant a second crop on the same bed.