Short Communication. Virulence of barley leaf rust in the South of Russia in 2017-2019

Aim of study: To analyze the structure of Puccinia hordei populations by virulence in southern Russia during 2017-2019. Area of study: South of Russia, the leading Russian region for barley production where barley leaf rust is an important foliar disease. Material and methods: Uredinial samples of P. hordei were collected at the production sites of winter barley in the south of Russia. Single uredinial isolates (total 95) were tested for virulence with 17 differentials with Rph resistance genes. Main results: No isolates found virulent to the host line with the Rph13 gene. There was a decrease in the number of fungal isolates virulent to the host lines with Rph5 and Rph7 genes. In 2017 and 2019, isolates containing a large number of virulence alleles (from 11 to 15) prevailed. In 2018, isolates with low (1-5) and medium (6-10) frequency of virulent alleles prevailed, as well as avirulent isolates. The values of the Nei index via diversity showed high similarity of the pathogen populations in 2017-2018 (N = 0.05) and minor differences in 2017-2019 and 2018-2019 (N = 0.13 and 0.16, respectively). The greatest frequency of virulence alleles in accordance with the Nei (Hs) index was noted for the 2018 population (Hs = 0.36). For the 2017 and 2019 populations, this indicator was average (Hs = 0.29 and 0.20, respectively). Research highlights: Analysis of genetics of the P. hopdei population is important for the strategy of varietal distribution in the region and development of rust-resistant cultivars.

Short Communication. Sodium chloride levels in pacu (Piaractus mesopotamicus) fingerling feeds free of fish meal

Aim of study: To evaluate the effects of increasing NaCl levels on the zootechnical performance of pacu fingerling. Area of study: The experiments were conducted at the Aquatic Organism Production and Reproduction Systems Laboratory belonging to the Federal University of Paraná (UFPR), in the Palotina Sector, Paraná Estate, Brazil. Material and methods: Seven hundred and fifty fingerlings with an average weight of 3.41 ± 0.09 g were distributed in circular boxes, in a completely randomized design consisting of six treatments and five replications. Treatments comprised soybean- and maize-based diets containing increasing levels of NaCl (0.00, 0.25, 0.50, 0.75, 1.00 and 1.25%). The experiments were conducted for 50 days. At the end of the experimental period the fish were fasted for 24 hours, anesthetized, weighed and measured to calculate zootechnical performances. Performance data were subjected to an analysis of variance followed by Tukey’s test when significant differences were found between the means (p<0.05). Main results: The influence (p<0.05) of dietary NaCl levels on final weight, feed intake, apparent feed conversion, specific growth rate, average weight gain, clean trunk production, head carcass yield, headless carcass yield, feed intake and survival was assessed. The results indicate that non-salt treated fingerlings along with the 0.25% salt inclusion treatment led to better feed use, as evidenced by apparent feed conversions of 1.64 and 2.02, respectively. Research highlights: The inclusion of NaCl in pacu fingerling soybean and maize-based diets is not recommended.

Simulation modelling of mechanical systems for intra-row weeding in a precision farming approach

Aim of study: To test new approaches to perform mechanical weeding inside the row in horticulture and tree fruit fields. The idea is to weed the row by skipping the crop by means of a rotating system instead of a traditional crosswise one. Area of study: North of Italy. Material and methods: Numerical models have been developed to simulate mechanical weeding over time by generating numerical maps to quantify the different kind of worked areas. Main results: Considering the efficiency of weed control on the row, the rotating plant-skipping system with vertical axis (RPSS-VA model) with two working tools gives the best performance index (1.1.RWA% = 95.9%). A similar performance can be obtained by the crosswise displacement plant-skipping system (CDSS model, 1.1.RWA% = 95.9 %), but with very high crosswise translation velocity (with va/vr ratio = 1/5, 1.1.RWA% = 94.5%). With regard to the outwards worked area the RPSS-VA models give the best performances (2.2.%OWAR index from 127.2% up to 282.3%). To reduce the worked area outside the row, the FBTS models give lower index (2.1.OWAR%), while the RPSS-HA works only on the row, but with the lower 1.1.RWA% index among all tested models (55.8%). Research highlights: Rotating systems resulted more efficient than traditional ones, and provide considerations on the use of electric drive power instead of hydraulic one. This study highlights also the need of new approaches in designing lighter working tools. Lastly, the proposed classification of the worked areas could be used as reference standard.

Technologies used at advanced dairy farms for optimizing the performance of dairy animals: A review

Superior germplasm, better nutrition strategies, health care facilities and improved dairy husbandry practices have boosted milk yield and its quality with a rapid rate. Per cow productivity has risen up sharply with considerable increase in the population of dairy animals. Recent era has witnessed the extension of large dairy farms around the world. Demand for high quality and increased quantity of milk is of the prime concern for all the dairy farms. With an increase in the size of animals in a farm, the labour requirement also rises up. Availability of skilled labour at low wage rate is becoming difficult. In last couple of decades, the cost of microprocessors has been reduced to an affordable level. The economic availability of engineered processors, artificial intelligence, improved data statistics combined with expert suggestions has created a revolution in livestock farming. Advanced engineered devices have become alternative to reduce high labour cost. This review focuses on latest knowledge and emerging developments in animal’s welfare focused biomarker activities and activity-based welfare assessment like oestrus, lameness and others. Use of enhanced sensors and data technologies with expert based solutions is anticipated to bring out a substantial improvement in existing dairy farming practices.

Biotechnological approaches to develop nitrogen-fixing cereals: A review

Agricultural yields are often limited by nitrogen (N) availability, especially in countries of the developing world, whereas in industrialized nations the application of chemical N fertilizers has reached unsustainable levels that have resulted in severe environmental consequences. Finding alternatives to inorganic fertilizers is critical for sustainable and secure food production. Although gaseous nitrogen (N2) is abundant in the atmosphere, it cannot be assimilated by most living organisms. Only a selected group of microorganisms termed diazotrophs, have evolved the ability to reduce N2 to generate NH3 in a process known as biological nitrogen fixation (BNF) catalysed by nitrogenase, an oxygen-sensitive enzyme complex. This ability presents an opportunity to improve the nutrition of crop plants, through the introduction into cereal crops of either the N fixing bacteria or the nitrogenase enzyme responsible for N fixation. This review explores three potential approaches to obtain N-fixing cereals: (a) engineering the nitrogenase enzyme to function in plant cells; (b) engineering the legume symbiosis into cereals; and (c) engineering cereals with the capability to associate with N-fixing bacteria.

Effect of plant growth regulators on two different types of eggplant flowers regarding style length and fruit setting

Aim of study: (i) to explore differences between eggplant flowers capable of setting fruit including long (LGs) and medium style flowers (MEs) and those which suffer from severe problems with fertility and fruit setting including short style ones (SRTs); (ii) to study the effect of plant growth regulators on floral morphology and fruit setting. Area of study: Isfahan University of Technology, Isfahan, Iran, 2017 and 2018. Material and methods: First the floral morphology and initial fruit setting of 13 eggplant genotypes from Iran were investigated. Then the differences between LGs and SRTs of two genotypes were explored. Finally, the effect of 1-naphthaleneacetic acid (NAA) and spermidine (Spd) on floral morphology and initial and final fruit setting of these two genotypes was determined. Main results: Results showed SRTs were not capable of fruit setting. Compared to SRTs, LGs had larger central canals, higher protein, total sugar, reducing sugar and K concentrations, as well as longer polar axis and pollen tubes and greater pollen viability. Although 1.5 mM Spd and 20 mg L-1 NAA resulted in increasing of LGs and MEs, and also total initial fruit set, surprisingly, no significant differences were observed in the final yield and final fruit set between the control and these treatments. Researching highlights: Since the rate of fruit dropping was higher in those treatments compared to the control, plants with more SRTs likely regulate their final load by abscising their flowers, and plants with more LGs regulate them by abscising their fruits.

Prioritization of olive breeding objectives in Spain: Analysis of a producers and researchers survey

Aim of study: Trait prioritization of potential olive (Olea europaea L.) breeding objectives has been evaluated in this work from two surveys to researchers working on olive and olive producers / orchard managers. Area of study: Olive growing area in Andalusia (South of Spain) Material and methods: Twenty-five breeding objectives were associated to plant growth, fructification, oil content and composition, resistance to pest and disease and tolerance to soil and climatic conditions. Two assessment methods were applied (ranking and rating), showing similar results in both the researchers and producers surveys. Main results: Higher productivity was the objective with the highest score, followed by Verticillium wilt resistance and higher oil content. After them, tolerance to water stress and resistance to Xylella fastidiosa were among the preferred objectives. Conversely, the least preferred objectives were late harvesting, high fruit size and tolerance to water lodging and calcareous soils. In the producers’ survey, results have been consistent among the different types of orchards and farmers’ characteristics. It is also interesting to notice that more than 50% of the producers expressed their willingness to orchard enlargement or renewal in the three coming years and 25% of them would change the olive cultivar. They would be willing to pay an average 43% overprice for new cultivar fulfilling their requirements and 75% would support the use of genetic modified olives. Research highlights: These results should be considered to analyze the scope of current breeding programs and define the main criteria to be considered for future works aiming at developing new olive cultivars.

Optimizing wheat seed treatment with entomopathogenic fungi for improving plant growth at early development stages

Aim of study: Entomopathogenic fungi (EPF) are biocontrol agents, plant growth promoters, and increase tolerance to biotic-abiotic stresses. In this study we investigated the factors associated to the application method, which are crucial for the interaction between the fungus and the host plant at initial crop growth stages. Area of study: The study was performed in Cordoba (Spain) Material and methods: Three experiments were performed to investigate: (i) the effect of different concentrations of the surfactant Tween® 80 (0, 0.5, 1, 5, and 10%) on wheat seed coating with conidia of Metarhizium brunneum and seed and conidia viability; (ii) the performance of wheat seedlings at first growth stages after their inoculation with Beauveria bassiana or M. brunneum via seed coating or soil drenching; and (iii) the role of soil sterilization and seed disinfection on leaf concentration of chlorophyll (SPAD) and B. bassiana or M. brunneum colonization. Main results: Tween® 80 concentration linearly improved seed coating (up to 127%) without altering wheat seeds and fungal conidia germination. Seedling length of inoculated plants was significantly increased with B. bassiana and M. brunneum (67% and 46%, respectively) via seed coating. Seed disinfection was key to achieve an enhancement in wheat SPAD (10-18%) with B. bassiana or M. brunneum concerning Control, that combined with sterilization of soil showed the highest endophyte colonization rates (up to 83.3% with both fungi) Research highlights: The surfactant concentration, application method, seed disinfection, and soil sterilization are key parameters to improve the potential benefits on the EPF-plant relationship.

Nutraceutical profiles of apricots (Prunus armeniaca L.) as a source of fruit quality traits for breeding

Aim of study: In a social context of increasing concern about healthy diets, the development of new varieties with enhanced content in nutraceutical compounds is an important objective of the fruit breeding programs currently developed. In this sense, apricot is a fruit crop very appreciated by consumers worldwide due to its organoleptic characteristics, but also plays an important role in human nutrition due to its content of phytocompounds as sugars, organic acids, vitamins and polyphenols. Area of study: The identification of sources of variation for these traits could be useful for apricot breeding worldwide. Material and methods: New selections from the apricot breeding program carried out at the Instituto Valenciano de Investigaciones Agrarias (IVIA, Spain) and traditional varieties have been analysed aimed at identifying sources of genetic variation for fruit quality. For this purpose, sugar content, organic acids and ascorbic acid were studied during three crop years. Main results: Results revealed sucrose and glucose as the major sugars, malic and citric acid as the main organic acids, and diverse ascorbic acid content among the cultivars studied. Research highlights: Some accessions point as potential sources to increase fruit quality. In addition, the study showed that apricot peel is an excellent source of nutraceutical compounds. Moreover, this study opens up new possibilities to study the genetic control of these traits in apricot in the future.

Community structure of epigeic arthropods in barley (Hordeum vulgare L.) soils

Aim of study: The study of epigeic arthropods provides information on how ecosystems respond to different management practices. Changes in the structure of epigeic groups reflect changes in the ecological status of habitats. We assessed the influence of semi-natural habitats and environmental variables on the dispersion of the epigeic groups. Area of study: Southwestern part of Slovakia Material and methods: Between 2018 and 2020, six barley (Hordeum vulgare L.) fields were selected each year. Five pitfall traps were placed on each field and environmental variables (soil pH and moisture, light conditions, soil N, P, K) were analysed. We collected 8,730 individuals belonging to 14 taxonomic groups. The variables of the study sites (habitat, locality name, cadastral area, altitude, coordinates of localities) were also analysed. Main results: We observed a decrease in the average number of individuals in the direction from pitfall traps 1 (semi-natural areas) to 5 (barley crop) between July and August. The number of individuals was similar in May and June. The dispersion of epigeic arthropods was affected by soil moisture, pH soil, phosphorus, potassium and nitrogen. In the beetles model group, which was represented by the highest number of individuals, we confirmed an increasing number of individuals with increasing values of K, P, N and soil moisture. The neutral pH of the soil was optimal for beetles. Research highlights: The ecotone rule does not apply during all months, so we have contributed new information about the ecotone rule. Agricultural intensification affects soil arthropods, a taxonomic group with an important role in the functioning of agricultural ecosystems.