Soybean Response to Seed Coating with Chitosan + Alginate/PEG and/or Inoculation

Inoculated or coated soybean seeds are often sown in agricultural practice. These treatments play a different role depending on the chemical composition of the preparation. The aim of the field experiment was to demonstrate the effectiveness of the developed coating (chitosan + alginate/PEG) and commercial inoculant (HiStick® Soy) applied alone or in combination to soybean seeds. Uncoated (control) seeds were sown for comparison. The research was carried out in 2018–2020 using the cultivar ‘Mavka’. The experiment was located in Makowisko, Podkarpackie Province, Poland. Coating composition was developed in a laboratory belonging to the Łukasiewicz Research Network—Institute of Biopolymers and Chemical Fibers in Łódź, Poland. The main role of the coating is to protect soybean seeds from low temperatures. HiStick® Soy inoculant contains Bradyrhizobium japonicum bacteria which increase nodulation on the roots. The conducted research demonstrated that sowing only coated seeds was not very effective, because the suitable number of nodules had not developed on soybean roots. The application of the inoculant alone positively affected the assessed traits compared to control, however, plant population was lower than expected. The highest seed yield was obtained after sowing coated seeds in combination with the inoculant (4.32 t·ha−1) and only inoculated seeds (4.23 t·ha−1) compared to control (3.64 t·ha−1). The test of the novel seed-coating agent showed that it had an good effect and efficacy, but only in combination with the inoculation procedure.

A rapid in vitro phenotypic assay of walnut shoots for pre-screening resistance to Phytophthora pini

Phytophthora species cause crown, root, and aerial canker diseases in diverse horticultural crops, resulting in a loss of yield, quality and plant death. Breeding programs are interested in developing genotypes resistant to these and other pathogens, but current screening methods for tree crops are time-consuming, potentially spanning many years. Here we present a rapid in vitro assay in which walnut shoots obtained from tissue culture can be challenged with Phytophthora zoospores and monitored for symptom development within a week. As a proof of concept, two cultivars, scion variety ‘Chandler’ and clonal rootstock ‘RX1’, with known different degrees of crown rot susceptibility, were inoculated in vitro with P. pini (formerly included in P. citricola complex), and results of the assay reproducibly matched the differences in disease susceptibility generally observed for these two walnut selections under greenhouse and orchard conditions. In addition, when the in vitro assay was used for inoculations with P. capsici, which is not pathogenic on walnut, no disease development was observable, indicating that the assay can discriminate between species of Phytophthora that are aggressive on walnut and those not known as walnut pathogens. Our results suggest that this in vitro shoot inoculation procedure may provide rapid assessments useful for pre-screening resistance to Phytophthora in walnuts. Further testing of the assay is justified to determine whether it can resolve more subtle differences in resistance and whether it can be useful with other perennial hosts of Phytophthora.

Development of Bulk Metallic Glasses and their Composites by Additive Manufacturing - Evolution, Challenges and a Proposed Novel Solution

Bulk metallic glasses (BMGs) and their composites (BMGMCs) have emerged as competitive materials for structural engineering applications exhibiting superior tensile strength, hardness along with very large elastic strain limit. However, they suffer from lack of ductility and subsequent low toughness due to the inherent brittleness of the glassy structure which makes them amenable to failure without appreciable yielding. Various mechanisms and methods have been proposed to counter this effect out of which, recently Additive Manufacturing has gained widespread attention. It is proposed that additive manufacturing can overcome these difficulties in single step due to inherent existence of very high cooling rate in the process which is essential for glass formation. This, when coupled with careful selection of alloy chemistry is proposed to be the best solution to fabricate near net shape parts in a single step with excellent properties. In this report, an effort has been made to describe one possible route to achieve this. Solidification processing employing carefully selected inoculants based on edge to edge matching technique along with the carefuly controlled inoculation procedure is proposed to reflect upon enhanced mechanical properties. It is hypothesized that number density, size and distribution of ductile crystalline phase would best be able to improve microstructure and hence properties. This is meant to be controlled by manipulating type, size and the amount of inoculants. The proposed methodology is claimed to bear maximum potential.

Natamycin, a Biofungicide for Managing Major Postharvest Fruit Decays of Citrus

The antifungal polyene macrolide natamycin was evaluated as a postharvest biopesticide for citrus fruits. Aqueous spray applications with 1000 µg/ml were moderately to highly effective against green mold after inoculation but did not reduce sporulation of Penicillium digitatum on infected fruits. Treatments with natamycin were significantly more effective against green mold on grapefruit and lemons than on oranges and mandarins with 92.9%, 88.5%, 57.5%, and 60.9% reductions in decay as compared with the control, respectively. The biofungicide was compatible with a storage fruit coating but was less effective when applied in a packing coating. However, when either fruit coating was applied following an aqueous natamycin treatment (i.e., staged applications) the incidence of decay was reduced to ≤10.7% as compared to the untreated control with 81.9%. The incidence of sour rot of lemons and mandarins was also significantly reduced from the untreated control by natamycin (1000 µg/ml), but propiconazole (540 µg/ml) and propiconazole + natamycin (540 + 500 µg/ml) mixtures generally were significantly more effective than natamycin alone when using a severe inoculation procedure. Experimental and commercial packingline studies demonstrated that natamycin-fludioxonil or -propiconazole mixtures applied in a storage fruit coating or as an aqueous flooder treatment were highly effective and typically resulted in a >85.0% reduction of green mold and sour rot. Resistance to natamycin has never been documented in filamentous fungi. Thus, the use of natamycin, in contrast to other registered postharvest fungicides for citrus, can be an anti-resistance strategy and an effective treatment in mixtures with other fungicides for the management of major postharvest decays of citrus.

Genetic resistance to fusariosis and base rot in interspecific F1 progenies of passion fruit (Passiflora spp.)

Fusariosis and base rot, caused by the fungi Fusarium oxysporum f. sp. passiflorae and F. solani, respectively, seriously damage the cultivation of sour passion fruit in Brazil. This work aims to obtain and evaluate F1 hybrids of Passiflora spp. wild plants resistant to fusariosis and base rot using genotypes of P. edulis (commercial species) and certify interspecific hybridizations using microsatellite markers. Hybridizations were performed using a P. edulis female parent and P. nitida and P. mucronata male parents for crosses aiming fusariosis resistance, and P. nitida, P. cincinnata and P. quadrangularis for hybridizations aiming tolerance to base rot. 35 microsatellite markers were used to confirm hybridization. The washed roots method was used for fusarium resistance tests and inoculation procedure with a mycelium disk fixed on a small wound on the plant stem for base rot. The interspecific hybridizations provided 49 potentially hybrid genotypes. Confirmation of hybridization by microsatellite marker was verified for 57% of the analyzed genotypes. The hybrids 115-1, 115-3, 115-4, 115-5, 115-6, 115-7, 115-9 and 128 are indicated as promising genotypes for a new stage of the breeding program. In the resistance evaluation of 13 F1 hybrids to F. oxysporum f. sp. passiflorae, the genotypes 142 and 143-2 were selected as the most resistant to continue the breeding program.

A Greenhouse Method to Evaluate Sunflower Quantitative Resistance to Basal Stalk Rot Caused by Sclerotinia sclerotiorum

Resistance of sunflower to basal stalk rot (BSR) caused by the fungus Sclerotinia sclerotiorum is quantitative, controlled by multiple genes contributing small effects. Consequently, artificial inoculation procedures allowing sufficient throughput and resolution of resistance are needed to identify highly resistant sunflower germplasm resources and to map loci contributing to resistance. The objective of this study was to develop a greenhouse-based method for evaluating sunflower quantitative resistance to BSR that would be simple, space- and time-efficient, high throughput, high resolution, and correlated with field observations. Experiments were conducted with 5-week-old sunflower plants and Sclerotinia-infested millet seed as inoculum to assess the impact of pot size and temperature and to determine the most favorable inoculum rate and placement. Subsequently, an additional experiment was performed to assess the correlation of the greenhouse inoculation procedure with field results by using a panel of 32 sunflower genotypes with known field response to BSR previously determined in multiyear, multilocation artificially inoculated trials. Experimental observations indicated that the newly developed greenhouse inoculation procedure provided improved resolution to identify highly resistant genotypes and was strongly correlated with field observations. This method will be useful for screening of sunflower experimental and breeding materials, disease phenotyping of genetic mapping populations, and evaluation of resistance to different pathogen isolates.

Development of Bulk Metallic Glasses and their Composites by Additive Manufacturing – Evolution, Challenges and a Proposed Novel Solution

Bulk metallic glasses (BMGs) and their composites (BMGMCs) have emerged as competitive materials for structural engineering applications exhibiting superior tensile strength, hardness along with very large elastic strain limit. However, they suffer from lack of ductility and subsequent low toughness due to the inherent brittleness of the glassy structure which makes them amenable to failure without appreciable yielding. Various mechanisms and methods have been proposed to counter this effect out of which, recently Additive Manufacturing has gained widespread attention. It is proposed that additive manufacturing can overcome these difficulties in single step due to inherent existence of very high cooling rate in the process which is essential for glass formation. This, when coupled with careful selection of alloy chemistry is proposed to be the best solution to fabricate near net shape parts in a single step with excellent properties. In this report, an effort has been made to describe one possible route to achieve this. Solidification processing employing carefully selected inoculants based on edge to edge matching technique along with the carefuly controlled inoculation procedure is proposed to reflect upon enhanced mechanical properties. It is hypothesized that number density, size and distribution of ductile crystalline phase would best be able to improve microstructure and hence properties. This is meant to be controlled by manipulating type, size and the amount of inoculants. The proposed methodology is claimed to bear maximum potential.

Dry Transfer Inoculation of Low-Moisture Spices Containing Antimicrobial Compounds

ABSTRACT Inoculation of a food product for use in subsequent validation studies typically makes use of a high concentration cocktail of microorganisms suspended in aqueous media. However, this inoculation method may prove difficult particularly when the food product is a low-moisture food containing antimicrobial compounds, such as some dried spices. In this study, a dry transfer method for inoculation of clove powder, oregano leaves, ginger powder, and ground black pepper with a five-serovar cocktail of Salmonella was developed and compared with a traditional aqueous inoculation procedure. Spices were inoculated at three levels, 10, 8, and 6 log CFU/g, by using both an aqueous suspension of Salmonella and a dry transfer of Salmonella from previously inoculated silica beads. At the highest inoculation level, the dry transfer method resulted in a significantly higher microbial load (P < 0.05) for ground cloves and oregano, but not for ginger and ground black pepper. At the intermediate inoculation level, differences were apparent only for ginger and black pepper. Inoculation levels of 6 log CFU/g resulted in recoveries below detection limits for both methods of inoculation. Additional examination on the survival of Salmonella on silica beads after inoculation and in clove powder after dry transfer from silica beads showed linear rates of decline, with a rate of −0.011 log CFU/g/day for beads and −0.015 log CFU/g/day for clove powder. The results suggest that dry transfer of Salmonella via inoculated silica beads is a viable alternative when traditional aqueous inoculation is not feasible.

Encapsulated propionic acid as a silage additive

Various propionic acid (PA) based additives are used to successfully inhibit fungi in silages. These additives are all introduced directly, and an encapsulated formulation of PA has not yet been examined for its antifungal abilities. The current study's objective was to test the possibility of using encapsulated PA as a silage additive. Carboxymethylcellulose (CMC)-based films (film A) and CMC/β-cyclodextrin-based films (film B) were used as biodegradable matrix platforms for encapsulated PA delivery and tested on whole-crop wheat and corn silages. Films were added as a mixture combined with the silage or divided at the top and bottom of the bulk silage system. A Lactobacillus plantarum inoculation procedure was also examined for its effects. In the wheat ensiling experiment, film B resulted in the highest PA concentrations after 2 weeks (1.4% and 1.1% in dry matter for the mixed and divided films, respectively). Mixed film A also produced high levels of PA after 2 weeks. Lactic acid (LA) concentrations peaked after 2 weeks and the highest final concentrations were obtained in the L. plantarum treatment. The highest PA concentrations in the corn silages were measured at the end of the experiment. Film B tended to result in slightly higher PA concentrations than film A. LA concentrations peaked after 2 weeks and the highest final content was obtained with film B. Overall, this study demonstrates that addition of encapsulated PA to biodegradable CMC films may provide an advanced safe approach for retaining silage quality and wastage reduction.