Field Crop Production Research Articles

Predicting Subsurface Drainage Requirement for Different Soil Desalinization Goals in Coastal Reclamation Areas

ABSTRACTBuilding subsurface drainage systems for more efficient salt leaching with the natural rainfall or artificial irrigation is a widely accepted practice for saline soils reclamation, but the high initial cost of the system construction often limits its adoption, and the uncertainty in drainage intensity requirement to meet desired desalinization goals for field crop production challenges the system design. In this paper, we proposed a soil desalinization model based on the field hydrology model‐DRAINMOD, predicted number of years required to lower soil salinity to a threshold level under different subsurface drainage conditions, and estimated the net return from different subsurface drainage system layout based on a case study in a coastal reclamation area in eastern China. The results showed that, DRAINMOD accurately predicted water table fluctuations in artificially drained fields: the root mean square error to standard deviation ratio (RSR) was 0.4 and 0.54, and the Nash Sutcliffe efficiency (NSE) was 0.84 and 0.68, respectively, during the model calibration and validation periods. The DRAINMOD based soil desalinization model predicted a negative relationship between subsurface drainage intensity and the soil desalinization period, that is, improving drainage condition shortened the time requirement for soil desalinization. For the study area, the model's predictions showed that installing subsurface drainage at 20 m spacing and 1.2 m deep lowered soil salinity to the slightly saline level in less than 7 years under the rainfall leaching only, and such system layout produced the maximum economic return based on the local agricultural practice. The results indicate that, early investment in adequate subsurface drainage systems is beneficial for field crop production in the salt impacted farmland areas. Findings from this research may provide technical references for saline soil reclamation or land improvement in both rain fed and irrigated agricultural areas.

Agronomic Interventions for Alleviating Water Stress and Optimizing Productivity of Field Crops: A Review

Water scarcity is the most significant concern facing agriculture today. Agriculture currently utilizes more than 70% of the world's freshwater, with much of it lost through evaporation, leaching and runoff. Drought escape and drought tolerance are the two significant mechanisms for plant growth under water-stressed conditions. Drought, a primary abiotic factor, limits crop productivity. It is a climatic phenomenon characterized by a prolonged lack of rainfall, resulting in moisture loss from the soil and a lack of water potential in plant tissues. It prevents the crop from obtaining its potential yield and substantially reduces crop production. Field crop rely on rainfall and are vulnerable to unpredictable drought stress throughout their vegetative and reproductive growth cycle. Drought stress is typical during the flowering stage in mostly crops, resulting in lower yield when cultivated with scarce rainfall. It can be reduced through agronomic means, such as mulching, tillage, intercropping and nutrient management, as well as chemical measures, such as the use of soil additives herbal hydrogel (Gond katira), foliar spray of salicylic acid and potassium nitrate. Herbal hydrgel helps in reducing the effect of drought stress on plants while also promoting increased plant growth and opverall performance. Foliar application of salicylic acid boosted bioactive chemical synthesis in the presence of water deficiency. Potassium nitrate to enhance water uptake, promote longer pod length and improve drought tolerance in plants.

Heavy Metals in the Cultivated Soils of Central and Western Serbia

Concern over the harmful impacts of heavy metal pollution in soil has increased dramatically on a global scale. For the sake of environmental preservation, accurate estimates of the heavy metal concentrations in soil are essential. This study provides valuable data regarding heavy metal concentrations in soil collected from field crops production area in Central and Western Serbia. Five wider localities in the zones of Central and Western Serbia were selected for the collection of soil samples. Based on our research, focused on determining the total contents of heavy metals in the soil and the degree of pollution in the environment caused by their behavior, distribution, and origin, it can be concluded that there is pronounced variability in relation to localities. Heavy metal contents were mostly within the same ranges as those in similar soils from Europe and around the world. Any pollution control system must include heavy metal monitoring, including the methodical collection of data on the concentrations of heavy metals in a particular environment. Before environmental degradation occurs, it is crucial to set pollution limits and implement efficient monitoring procedures.

Agronomic performance of cowpea cultivars in first crop in Southwest of Minas Gerais, Brazil

The cowpea (Vigna unguiculata (L.) Walp.) is well adapted to high temperatures, water deficits and low fertility soils, being widely cultivated in regions less favorable to common beans. Its grains are rich in proteins, vitamins and minerals, representing an important food source and a promising alternative for producing protein at low cost, in a short space of time, given the precocity of its cycle. However, in the state of Minas Gerais there is only a recommendation for one cowpea cultivar, the Poços de Caldas cultivar. In addition to being quite old, it is no longer found in crop production fields. The aims of study was to evaluate the agronomic performance of cowpea cultivars and to recommend cultivars adapted to cultivation in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil. The experiments were carried out in Passos city, Minas Gerais State, Brazil, during the first crop period, in 2021/2022 and 2022/2023 years, with 10 commercial cowpea cultivars, in a randomized block experimental design, with five replications. The mass of a thousand seeds and the grain index correlated directly with the yield. Cultivars with the lowest grain yields promoted the highest pod lengths and number of grains per pod. The best morphophysiological results for cowpea were obtained in 2021/2022 year. The most adapted cowpea cultivars for period of first crop in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil, were BRS Novaera, BRS Guariba, and BRS Xique-Xique and least indicated was BRS Marataoã. More studies are needed to consolidate cowpea cultivation in the Southwest Region of Minas Gerais, mainly in second-crop crops.

Mental Health Among LGBTQ+ Farmers in the United States

ABSTRACT Objectives The objective of the current study is to describe mental health among lesbian, gay, bisexual, transgender, and queer (LGBTQ+) people who work in agriculture in the U.S. Methods This study uses a survey of LGBTQ+ adults who work in agriculture in the U.S. (N = 148), including questions about LGBTQ+ identity, farming background, depression symptoms (PHQ-8) and diagnosis, anxiety symptoms (GAD-7) and diagnosis, suicide risk, and stress. Data were analyzed using SPSS, including descriptive statistics, chi-square tests, and Mann-Whitney U tests. Results Over one-third (36.1%) had probable depression (PHQ-8 ≥ 10), and 71.9% were experiencing mild to severe depression symptoms. Nearly half (46.2%) had probable anxiety disorder (GAD-7 ≥ 8), and 69.7% experienced mild to severe anxiety symptoms. Over half (51.7%) were at significant risk for suicide. Greater proportions of men had probable anxiety disorder, probable depression, and suicide risk compared to non-men. Greater proportions gay participants had probable depression, as did beef producers. Perceived stress was higher for men, lesbian and gay participants, transgender participants, and those in beef production. Resilient coping was highest among participants who were genderqueer or genderfluid, bisexual, and those in field crop production. Conclusion LGBTQ+ farmers in the current sample experienced depression and anxiety at higher rates than general farming or general LGBTQ+ samples, although suicide risk was lower than for general LGBTQ+ samples. Future research should explore how working in agriculture may be protective against suicide risk for LGBTQ+ farmers, as well as how specific farm stressors are related to LGBTQ+ farmer mental health.

The finger weeder cultivator for intra‐row mechanical weed control: Effects of uprooting force on selected weed species

AbstractMechanical weed control tools are commonly used in the production of many vegetable and field crops. This study aimed to determine the impact of weed species and growth stage on the finger weeder performances and to reveal the relation between root morphology, uprooting force and control efficacy. A one‐month field experiment with two model species, Triticum aestivum L. (grass) and Sinapis alba L. (broadleaf), showed that finger weeder control efficacy was affected by species and growth stage: Finger‐weeder application during the first two growth stages (cotyledon and second leaf) was more effective for S. alba than for T. aestivum (p < 0.0001), but at fourth‐leaf stage values for control efficacy were not significantly different (p = 0.134). In an experiment conducted in pots it was found that, at all three growth stages, the uprooting force required for S. alba was significantly lower than that for T. aestivum (p < 0.0001), indicating a lower anchoring force of the former. Determination of root‐morphology parameters revealed significantly higher root parameters, like length, in T. aestivum than in S. alba at the early developmental stages. Correlation of the control efficacy and uprooting force revealed a 2.5‐N threshold value for effective weed control. Additionally, net‐house and field experiments showed significant differences in the uprooting forces required for 10 different Mediterranean grasses versus broadleaves weed species at all developmental stages. To translate these findings into applicative recommendations, future research should characterize the relationship between the operational factors of this tool and the required uprooting force.

Maximization of brackish water productivity for the sustainable production of striped catfish (Pangasianodon hypophthalmus) and grain sorghum (Sorghum bicolor (L.) Moench) cultivated under an integrated aquaculture–agriculture system

Freshwater scarcity, salinity, and poor soil fertility are the major challenges affecting both food and feed productions in arid and semi-arid regions of the world. Utilization of brackish water in the production of saline-tolerant fish and valuable field crops under an integrated system is promising in the maximization of yield per crop. The aim of this study, therefore, was to (1) assess the effect of saline aquaculture wastewater on the growth, yield, forage quality, and nutritive composition of sorghum seeds and (2) assess the effect of different water qualities on the survival, growth performance, and health status of Pangasianodon hypophthalmus. The experiment was conducted in a randomized completely block design of four salinity treatments with three replicates, i.e., control (freshwater mixed with inorganic fertilizers), 5000 ppm, 10,000 ppm, and 15,000 ppm. Our results indicated that although the control exhibited the highest growth (plant height, leaf number, internode number, leaf area, and soil–plant analysis development), grain, and forage yield, no significant differences were noted among the treatments. Likewise, no significant difference in the grain nutrient composition was noted among all the treatments. Assessment of the forage quality revealed improved crude protein content in the control compared to the saline treatments. However, no significant differences in the leaves and stalks fiber fractions were noted among all the treatments. Furthermore, rumen fermentation in terms of in vitro digestibility indicated no significant differences in the in vitro digestible dry matter, digestible organic matter, metabolic energy, net energy, microbial protein, short-chain fatty acids, and total dissolved nutrients among the treatments. However, rearing P. hypophthalmus in water salinities exceeding 10,000 ppm reduced the growth performance and health status of fish. Therefore, the integration of sorghum and P. hypophthalmus production in water salinities not exceeding 5000 ppm is a viable alternative to maximize brackish water productivity in freshwater-scarce regions.

Cover crops and reduced tillage did not alter soil chemistry in first 3 years

AbstractCover crops have been promoted for increasing soil organic matter, which is critically low in many mid‐Southern US row crop production fields. This study was conducted to inform adaptive management in the early transition period of conservation adoption. Temporal change in soil chemistry was investigated with a split‐field experiment conducted over a 3‐year period in Mississippi corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotational cropping systems that newly implemented winter cover crops and simultaneously reduced tillage. Relative to the untreated (i.e., winter fallow and multiple tillage passes) half of each study field, the chemical soil properties of the treated (i.e., winter cover crop and reduced tillage) half of each study field were not significantly different at the 0.05 significance level. This was true for soil organic matter, all macronutrients, pH, cation exchange capacity, base saturations, and micronutrients, with the exception of iron. Given these results, it is unlikely that growers adopting cover crops while reducing tillage will be able to accumulate significant soil organic matter in the early transition period.

On Huber's Robust Technique and Quantile Regression Models for the Total Production of Field Crops in Oman

On Huber's Robust Technique and Quantile Regression Models for the Total Production of Field Crops in Oman

Newly established, multifunctional woody polycultures preserve agroforestry soil health benefits of a widespread U.S. land retirement program

Soil health degradation within intensively managed annual crop systems threatens the long-term economic sustainability of maize- and soybean-dominated production regions like the U.S. Corn Belt. While Conservation Reserve Program (CRP) efforts to perennialize portions of farmland to improve soil health have been largely successful, many landowners intend to return CRP land to high revenue maize and soybean cultivation. The CRP could be a pathway for a regionally tailored and profitable form of agroforestry focused on fruit and nut production potential, known as multifunctional woody polycultures (MWPs). In theory, MWPs should provide similar soil health benefits as CRP agroforestry, as soil health benefits are generally robust across agroforestry practices. We conducted a study in the heart of the U.S. Corn Belt to compare soil health responses between newly established (<10 years) CRP and MWP agroforestry systems and adjacent annual crop production fields. Because organic inputs from plant litter and roots are more consistent under untilled perennial vegetation systems compared to intensively managed annual crop systems, we hypothesized that CRP and MWP would entail similar enhancements to physical, soil organic matter (SOM), and biological soil health. Our results indicate establishing untilled, perennial CRP and MWP systems can quickly improve physical and biological soil health relative to annual crop production, based on decreased soil bulk density, greater soil water infiltration, and increased soil enzyme activity. Unexpectedly, CRP and MWP elicited divergent SOM responses. Notably, only MWP increased surface soil organic carbon stocks relative to annual crop fields, likely reflecting species-variant plant biomass growth rates. Our study demonstrates MWPs can manifest similar improvements to physical and biological soil health as CRP agroforestry on a relatively short timescale. The sensitivity of transition-state SOM responses between CRP and MWP demonstrates the importance of woody perennial selection to maximize specific soil health outcomes.

Albania’s agricultural economy: Transformation, opportunities and challenges for modern agricultural enterprises

The European agricultural market is currently in a state of uncertainty – climate change, military operations on arable land and the partial blocking of traditional grain export routes have changed the usual food security balances and brought the world closer to the risks of global hunger. The study aimed to provide recommendations for the development of the Albanian agricultural sector, considering the current situation and the historical background of the country’s agriculture. Using such methods as statistical analysis, induction, classification, comparison and synthesis, the dynamics of development of both the Albanian economy as a whole and the specifics of its agricultural sector in the period from 1992 to 2022 were investigated. Modelling and generalisation methods were also used. The study obtained and analysed statistical information from previous years on such a basic economic indicator as gross domestic product and studied the dynamics of agricultural field crop production and the structure of their crops. Separately, the volume of Albania’s foreign trade in the agro-industrial complex was analysed in terms of imports of agricultural products, exports, and the balance of these two indicators. The elasticity of private farms was assessed and steps to reform the national assortment policy were proposed. These recommendations were developed considering the Albanian specifics of the relatively small average land area of rural households. In addition, the result of the work is the development of proposals for joint farming and the creation of a national unique trade advantage in the agricultural sector, which will have an economic effect in foreign markets. The practical significance of the study lies in an objective assessment of the current economic situation in the Albanian agroeconomy and the development of several recommendations that may be useful to representatives of the Ministry of Agriculture and Rural Development of Albania.

The color of biodegradable mulch films is associated with differences in peanut yield and bacterial communities

Biodegradable mulch films (BDMs) are increasingly used in agricultural production as desirable alternatives to the current widespread use of polyethylene (PE) mulch films in China. However, potential effects of different colors of BDMs on field crop production and microbiomes remain unexplored. Here, the differences in bacterial communities of peanut rhizosphere soil (RS) and bulk soil (BS) under non-mulching (CK), PE, and three different colors of BDMs were studied. The results indicated that all treatments could increase the soil temperature, which positively affected the growth of the peanut plants. Moreover, mulching affected the bacterial community structure in RS and BS compared to CK. Furthermore, certain BDM treatments significantly enriched N-fixing bacteria (Bradyrhizobium and Mesorhizobium) and functional groups, increased the closeness of bacterial networks, and harbored more beneficial bacteria as keystone taxa in the RS. This in turn facilitated the growth and development of the peanut plants under field conditions. Our study provides new insights into the micro-ecological effects of mulch films, which can be affected by both the mulch type and color. The observed effects are likely caused by temperature and prevalence of specific microbial functions under the employed films and could guide the development of optimized mulching materials.

Emergence and spread of the barley net blotch pathogen coincided with crop domestication and cultivation history.

Fungal pathogens cause devastating disease in crops. Understanding the evolutionary origin of pathogens is essential to the prediction of future disease emergence and the potential of pathogens to disperse. The fungus Pyrenophora teres f. teres causes net form net blotch (NFNB), an economically significant disease of barley. In this study, we have used 104 P. teres f. teres genomes from four continents to explore the population structure and demographic history of the fungal pathogen. We showed that P. teres f. teres is structured into populations that tend to be geographically restricted to different regions. Using Multiple Sequentially Markovian Coalescent and machine learning approaches we demonstrated that the demographic history of the pathogen correlates with the history of barley, highlighting the importance of human migration and trade in spreading the pathogen. Exploring signatures of natural selection, we identified several population-specific selective sweeps that colocalized with genomic regions enriched in putative virulence genes, and loci previously identified as determinants of virulence specificities by quantitative trait locus analyses. This reflects rapid adaptation to local hosts and environmental conditions of P. teres f. teres as it spread with barley. Our research highlights how human activities can contribute to the spread of pathogens that significantly impact the productivity of field crops.

Effect of Hand Frequency Weeding on Crop Growth Parameters and Yield

An effort made to reveal the literatures review about hand weeding frequency attributed on crop yield and crops growth parameters. This review paper has been literature reviewed necessary material that help assesses effect of hand hoeing on crop growth and weed management. Various weed controls methods practiced by small scale farmers of different agro ecology zones in order to compact the injurious effect of weeds on crop yields and growth parameters. Among available farmers practice I used for controlling weeds is hand-hoeing weed control system. Farmer practice of hand- weeding is very time consuming, physically demanding, and not cost efficient for a farmer especially where labour is scarce than other methods While, an advantage of manual control is that it minimizes soil disturbance, and decreases the likelihood of erosion and seed germination. A few farmers have started using herbicides to control weeds. However, herbicides have been found to be less effective than hand-weeding, as they require specific conditions which may be more limiting than other control method. This paper intended to reflect the current state to investigate the effect hand hoeing weeding frequencies on yield and growth parameters is still by far the most widely practiced cultural weed control technique in field crop production throughout the traditional agricultural sector, because of the prohibitive costs of herbicides and fear of toxic residue coupled with the lack of knowledge about their use.

ДОСЛІДЖЕННЯ ЕФЕКТИВНОСТІ ВНЕСЕННЯ КАРБАМІД-АМІАЧНОЇ СУМІШІ АПЛІКАТОРОМ «DRAGON» ПРИ ВИРОЩУВАННІ ПШЕНИЦІ ОЗИМОЇ

The purpose of this research is determination of the effect of various methods of application of KAS by the DRAGON applicator from “ROPA-Ukraine” on the agrophysical and agrochemical parameters of the soil under crops during the growing season of winter wheat, the formation of biometric indicators and indicators of the yield structure and productivity of agrophytocenosis plants. Materials and Methods. Field studies on the application of KAS by the DRAGON applicator were conducted in the fields of the «Ploskivske» STOV farm, village Ploske, Bilotserkiv district, Kyiv region, on winter wheat crops and were accompanied by laboratory analyses and field observations. Statistical processing of accounting data was carried out by the method of variance analysis. The scheme of the experiment provided for the introduction of liquid KAS mineral fertilizers with the DRAGON applicator on the surface of the soil (plants) and into the soil with the help of injectors. Observations analyses and accounts accompanied experiments. To determine the structure of the crop, sample sheaves were selected. Conclusions regarding the effectiveness of applying a specific agrotechnical method were based on the results of comparing the values of the evaluation criteria obtained in the experiment with the values of the control variant. Results showed that application of fertilizers affects the supply of plants with available nutrients and is an effective means of increasing the productivity of field crops, including winter wheat. According to the results of the analysis of soil samples throughout the growing season of winter wheat, the content of mobile forms of phosphorus and potassium in the soil was high and very high in all variants of the experiment. Before the onset of winter, the compaction density, depending on the variant of the experiments and the soil layer, was from 0.94 to 1.30 g/cm2. At the time of vegetation recovery, the density of the 0-40 cm soil layer was within 0.82-1.36 g/cm3. The maximum compaction density – 1.36 g/cm3 – was in the version of feeding by injection. At the same time, its indicators did not go beyond the optimal parameters. The difference between the number of plants per unit area, before reaching the phase of full ripeness on variants with different methods of KAS, was 9.5%: with injection application of fertilizers, the density of standing plants was 4.949 million pcs./ha, for surface – 5.420 million units/ha. The biological yield of winter wheat grain on the control option, where fertilization was not applied, was 75.7 c/ha. Fertilization of KAS crops contributed to an increase in yield by 6.7-13.6 t/ha. Conclusions. The use of the DRAGON - 6000 applicator manufactured by ROPA Ukraine LLC when applying KAS contributes to the retention of productive moisture, loosening of the soil, the rate of accumulation of above-ground mass, graininess of ears, the formation of better agrochemical and biometric indicators of the soil under crops during the growing season of winter wheat, the formation of better biometric indicators and indicators of the yield structure and productivity of agrophytocenosis plants. Keywords: Applicator, injector, fertilizers, fertilizer application method, urea-ammonia mixture, productive moisture, soil compaction, biological yield, yield structure.

Effect of Epigenomics on different stresses of Horticultural crops

Horticultural Crops are affected by many environmental stresses including both biotic as well as abiotic. However, eventually, these are facing major challenges to enhance the productivity of field crops due to changes in environmental conditions. In order to cope with the fickle environments, plants are innately evolved with intricate gene signalling cascades and stress avoidance mechanisms. Epigenetic modifications are one such regulation which influences the plant stress responses under adverse environments. These epigenetic changes include the potential DNA methylation, histone modification and small RNAs coupled with the regulation of gene expression without altering the DNA sequences which eventually enhances the tolerance adoptive responses to the adverse environments. The epigenetic modifications in the genome develop a stress memory in plants which further enables them to better combat with extreme stress conditions. In this review, we attempted to recapitulate the recent progress and emphasize how the changes of DNA methylation, histone modification, and small non-coding RNA regulation alters in different growth stages of plants in response to major abiotic stresses such as salinity, drought, cold and heat. We also discuss the importance and prospects of epigenomics towards the possible improvement of plant responses to abiotic stresses for Climate resilient agriculture.

Ingineering and technological problems of improving the environmental safety of crop production

The article deals with engineering and technological problems of improving the environmental safety of crop production as a complex biotechnical system, for the environment, consumers of crop production and machine operators who ensure production in the field. It is noted that the impact of agriculture on the environment and humans is not only promoting global warming, participation in environmental pollution by pesticides and undigested remnants of mineral and organic fertilizers, the pollution of the production of field crops with residual amounts of pesticides and food is not absorbed nitrogen, toxic threat environment in the area of the machine, but unsustainable use of non-renewable resources, the availability of which depend on agricultural technologies. The main directions of minimizing environmental pollution and reducing dependence on non-renewable resources as a result of agricultural activities are shown.

ARTIFICIAL NEURAL NETWORKS FOR PREDICTING THE NUMBER OF FIELD CROP PESTS

Every year, farms face the problem of ensuring the necessary development and growth of field crops due to the high probability of field crops being affected by certain types of pests. Pests can significantly impair the development of crops if their population is not controlled. This will reduce the harvest. To ensure a certain level of field crop production, it is necessary to take a series of measures to reduce the risk of harvest losses and optimize the costs of protecting plant growth. A key element of effective farmland management is the reliable prediction of the number of pests using artificial neural networks and their appropriate configuration. This approach will reduce harvest losses and preserve the ecosystem of a particular region. Reliable forecasting of pest numbers is guaranteed to create conditions for minimizing the cost of growing crops. However, machine learning can only be implemented if there are relevant results of monitoring the number of pests and the factors that influence changes. These factors include solar activity, temperature, and humidity. Such studies were conducted and samples were formed. Neural networks of different structures were used for forecasting, such as the radial basis function and the multilayer perceptron. The results of the forecasting show a sufficiently high accuracy, which will significantly improve production efficiency.

Plot Size and Shape in Field Crops Cultivation in Türkiye

The size and shape of the agricultural parcel are important factors in improving the agricultural structure. These factors positively affect farmers, especially in matters such as the use of agricultural tools and machines in field crop cultivation, time saving and good soil cultivation. In this context, the size and aspect ratio of the existing parcels are directly linked to the income to be obtained from the unit area. Land consolidation projects are ongoing in approximately 30% of the total agricultural area in Türkiye. In addition, the state's efforts to give agricultural land to landless farmers continue in Türkiye. Considering our current agricultural production capacity, planning the new parcels to be created during these studies will significantly contribute to our field crop production. For this purpose, the average parcel size was determined by analysing the land distribution norm values of 4321 settlement units within the scope of the Agricultural Reform Law No. 3083 on Land Arrangement in Irrigation Areas, published in 1984, and the size of 1868 sufficient income lands within the scope of the Soil Conservation and Land Use Law No. 5403, published in 2014. As a result of this study, it was concluded that, on average, an agricultural parcel of 64 decares in irrigated lands and 157 decares in dry agricultural lands is the most suitable size for growing field crops. Likewise, it was concluded that the parcels were rectangular in shape and the aspect ratio was close to 1:2.

Adjuvant Pluronic F68 Is Compatible with a Plant Root-Colonizing Probiotic, Pseudomonas chlororaphis O6

Plant probiotic bacteria are being increasingly used to maximize both the productivity and quality of field crops. Pseudomonas chlororaphis O6 (PcO6) is a plant root colonizer with probiotic activities. This bacterium produces an array of metabolites, including a group of phenazines that are functional in plant protection. The paper reports responses of PcO6 to a nonionic triblock copolymer surfactant, Pluronic F68. This Pluronic exhibits membrane “healing” activity and improves cryopreservation recovery in eukaryotic cells. The product is FDA-approved and is applied as an adjuvant in formulations used in agriculture, medicine, and biotechnology. Growth of PcO6 on lysogeny broth at 25 °C was unhindered by 0.1 and 1.0 g/L F68, reduced at 10 g/L, and with significant inhibition at 100 g/L F68; micelle formation could account for inhibited growth at higher doses. Phenazine production was not changed by F68, whereas the surfactant activity of F68 induced the spread of bacterial colonization on 0.5% agar. Exposure of cells to fluorescein-labeled F68 resulted in intense fluorescence, stable to washing, showing a direct association of the Pluronic with the bacterium. However, neither protection nor harm was found for PcO6 cells suspended in either 0.1% or 1% F68 after three freeze (−20 °C)/thaw cycles. These findings suggest that F68 could be compatible for use in agricultural formulations with little effect on probiotics such as PcO6.