Replacement of inorganic trace minerals by chelated minerals in pullet diets (12 to 20 weeks of age)

Aim of study: An experiment was carried out aimed to evaluate the effects of different levels and sources of trace mineral to laying pullets with two initial body weights (BWs). Area of study: The experiment was carried out in Federal University of Goiás, Goiânia, Goiás, Brazil Material and methods: Two hundred and eighty eight Bovans White pullets aged 12 weeks old were allotted in a completely randomized design and a 2×3 factorial arrangement, wherein the main effects included initial BW (light-weight and heavy-weight) and three dietary trace mineral sources and levels (100% inorganic, 100% chelated and low-dose corresponding to 50% chelated), totalizing six treatments with eight replicates of six birds. The performance, the metabolizability coefficient of nutrients, and the onset of lay were evaluated at rearing phase (12 to 20 weeks). At 17th and 20th weeks of age, the relative weight of reproductive and digestive organs, abdominal fat, and tibia quality were assessed. A residual effect was evaluated at production phase on productive performance and egg quality. Main results: The mineral source did not affect the performance of pullets. Birds fed 50% chelated mineral produced the lowest eggshell. The heavy-weight birds showed higher egg weight and eggshell quality. The lighter birds showed lower abdominal fat weight and lower tibia robustness index. Research highlights: The replacement of 100% of inorganic mineral for chelated mineral do not result in decrease of bird performance at rearing and at production phase, but a minimum amount should be provided to ensure growth and nutrient metabolizability

Short communication: Comparison of hemato-immunological parameters in rainbow trout (Oncorhynchus mykiss): Palomino vs naturally pigmented varieties

Aim of the study: To evaluate hemato-immunological parameters in the Palomino trout compared to naturally pigmented rainbow trout. Area of study: Fars province (SW Iran). Material and methods: Sixty fish of both varieties (30 Palomino and 30 naturally pigmented) were sampled from the same pond. After blood sampling, hematological parameters, total serum protein and immunoglobulin (Ig), phagocytic activity, respiratory burst activity, serum lysozyme, and bactericidal activity were measured. Main results: Number of white blood cells, total protein, total immunoglobulins, lysozyme, and bactericidal activities in serum of Palomino trout were significantly higher than those in naturally pigmented rainbow trout. However, no significant changes were observed in no. of red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, differential leukocyte count, phagocytic, and respiratory burst activity. Research highlights: The immune system performance of Palomino trout was similar to naturally pigmented fish. However, in some cases, the immune response of Palomino fish may be even more robust than that of naturally pigmented fish. This finding helps us to favor Palomino trout in breeding programs and genetic modification

Bayesian analysis of additive and non-additive genetic variances of body weight gain traits in crossbred population of Japanese quail

Aim of study: To select the appropriate model for body weight gain (BWG) traits in different ages and estimation of additive and non-additive genetic variances based on the best model, of a crossbred population of quail. Area of study: Zabol, Iran Materials and methods: Four strains of Japanese quail, including Italian Speckled, Tuxedo, Pharaoh, and A&M Texas, were used to create a crossbred population in a partial diallel design over 4 generations. BWG traits were calculated as the average growth performance of the bird in a 5-day period from hatch to 45 days of age. Analyses were performed using the Bayesian method by fitting 24 models including the additive and non-additive genetic effects. The deviance information criteria (DIC) was used for the selection of an appropriate model for each trait. Main results: Based on DIC, the maternal genetic, maternal permanent environmental, dominance and epistasis effects had a significant contribution to the best model for BWG traits before 25 days of age, whereas these effects were not significant on BWG traits at the end of ages. With the best model, direct heritability of BWG traits in different ages ranged from 0.037 (BWG15-20) to 0.199 (BWG5-10). The maternal genetic and maternal permanent environmental as a proportion of phenotypic variance was less than 10% and 5%, respectively. The ratio of dominance and epistasis variance was in the range of 0.016-0.019, and 0.016-0.019, respectively. Research highlights: Non- additive genetic effects are important for the early BWG traits and must be included in the evaluation models to have accurate estimates

Short communication: A study case on polycyclic plantations (PP) as innovative models for sustainable combined production of noble hardwood and biomass

Aim of study: To verify the short rotation coppices (SRC) aboveground biomass production; to define the best planting intra-row spacing for walnut and poplar growth and wood production, with the last goal to assess the possibility of obtaining competitive yields in comparison to those produced by traditional monocultures. Area of study: Po Valley, municipality of Meleti (Northern Italy). Material and methods: A randomized block design with three replications was applied for the experimental design. The growth-monitoring activities started in 2009 and have continued for 5 years on the SRC, 10 years on poplar clone ˈI-214ˈ, whereas on common walnut they are still going on but only data concerning the twelfth year are reported in this work. The normality of distribution was evaluated for growth and yield data of species in the SRC model; all data were analysed with ANOVA; growth data were included in a linear mixed model analysis to evaluate the effect of age, spacing and their interaction, and the effect of SRC rows on growth and yield of poplar and walnut. Main results: After 5 years of cultivation under SRC system, biomass yields obtained from the poplar clone ˈAF2ˈ were 39.9 Mg ha-1, from the elm 31.9 Mg ha-1 and from the plane 14.8 Mg ha-1. After 10 years high timber production was obtained from poplar clone ˈI-214ˈ (average volume 98.2 m3 ha-1). After 12 years, walnut trees reached a diameter at breast height (DBH) of 17.8±0.2, 18.9±0.2 and 18.7±0.3 cm, respectively, for planting distances of 6, 7 and 8 m, and showed diameter increments of 1.5-2.0 cm yr-1. With these growth rates, walnut can reach a merchantable dimension within 25-30-years. Research highlights: Polycyclic wood plantations are a recent arboriculture model able to produce, on the same site, different assortments using various crop trees characterized by different growth rates and turnovers. This new type of mixed plantation is more environmentally sustainable compared to monoculture and allows diversification of production, obtaining continuous wood yields over the years (5, 10, 20, 30 years)

The modernization of traditional vineyards into intensive trellis systems reduces the species richness and abundance of reptiles

Aim of the study: Traditional vineyards have, in the last few decades, been transformed into trellis systems, but little research has been carried out into the consequences as regards biodiversity. We compared the abundance and species richness of reptiles in conventional-traditional vineyards and trellis vineyards. Area of study: The study was conducted in a wine appellation area of origin denominated as Montilla-Moriles, Southern Spain. Material and methods: Reptile’s species richness and abundance were estimated by walking transects in 24 different vineyards (12 trellis and 12 traditional vineyards) in four consecutive years. Main results: The results showed an extremely low abundance in both management systems, since no reptiles were recorded in 43.1% of the transects. However, there was a greater abundance and diversity of reptiles in the traditional vineyards than in the trellis vineyards, with 7 vs. 3 species being found in traditional and trellis vineyards, respectively. Research highlights: The lack of refuge in trellis vineyards owing to the vertical growth of plants, whose branches grow higher from the ground, is probably the main cause of the lower abundance and species richness found in trellis systems, since both types of vineyard had bare ground owing to ploughing and the application of herbicides. Since the transformation of traditional vineyards into those with trellis systems is often subsidized, this modernization should be accompanied by certain agri-environmental measures (e.g., cover crops, artificial refuges or natural hedges) in order to compensate for the associated negative effects

Weed flora in crop rotation and winter wheat monoculture

Aim of study: The goal of the study described in this manuscript was to evaluate qualitative and quantitative changes in weed flora infesting winter wheat stands grown in crop rotation and wheat monoculture. Area of study: South-eastern Poland, Europe (2018-2020). Material and methods: The experiment was established in the system of randomized blocks (25 m x 6 m) in three replications. Winter wheat was sown in (1) crop rotation (CR): potato – winter wheat – peas – winter barley; and (2) in monoculture (MON). Weed infestation was evaluated in two terms: (1) at the tillering stage and (2) at the waxy maturity stage of winter wheat. Main results: The number and air-dry weight of weeds evaluated in both terms were higher in MON than in CR. Before wheat harvest, its plots in MON were massively infested by Apera spica-venti and significantly populated by Avena fatua and Anthemis arvensis. In this evaluation term, the weeds of the upper and middle levels accounted for 88.4% of the whole weed community in CR and for 97.7% in MON. In both terms of evaluation, greater biodiversity of the weed community was observed in CR than in MON. Research highlights: Indicators used to assess the weed flora in crop rotation and monoculture, i.e. weed species composition, number and air-dry weight of weeds, weed distribution in wheat crop levels, and Shannon-Wiener's diversity index

Effects of a megafire on the arbuscular mycorrhizal fungal community and parameters in the Brazilian Cerrado ecosystem

Aim of the study: To evaluate the effects of a mega-fire on the arbuscular mycorrhizal fungi (AMF) community and parameters in soils under Cerrado vegetation. Study area: Chapada dos Veadeiros National Park, Goiás, Brazil. This site suffered the biggest fire in its history on October 10, 2017, with an affected area of 66,000 ha. Material and methods: We analyzed AMF spore density, roots’ mycorrhizal colonization rate, easily extractable glomalin (EEG), as well as the AMF genera present. These parameters were evaluated in burned and unburned areas of five common phytophysiognomies of the region. Main results: Fire presence immediately affected the mycorrhizal community parameters in Cerrado soils, which tended to increase afterwards. The presence of AMF genera did not differ between burned and unburned areas, with Acaulospora, Claroideglomus, Diversispora, Glomus, Funneliformis, Sclerocystis, and Gigaspora being present. The recovery of AMF community conditions in the Cerrado after fire events could also be observed in the mycorrhizal parameters evaluated, as the values of spore density, roots’ mycorrhizal colonization rate, and EEG were similar in the burned and unburned areas. Research highlights: AMF diversity, and especially their community parameters, show great recovery after fire events, since they are crucial in processes like nutrient cycling and soil aggregation

Short communication: Organic fertilization for the improvement of production and quality of ripe figs

Aim of study: The use of natural inputs in farming practices and the consumption of in natura products have been on the rise. Natural crop fertilizing sources gains force when the intent lies in crop by way of an ecologically correct agricultural system. To this end, this paper targeted assessing the use of cattle (CM) and bird manure (BM) in organic fertilization of fig culture in organic handling, and its effect on the production of ripe figs. Area of study: Federal University of Paraná, Curitiba, Paraná, Brazil. Material and methods: In 2011, an experimental fig orchard was established using the ‘Roxo de Valinhos’ cultivar. The experimental outline adopted was in randomized blocks, with 3 repetitions and 7 treatments comprised of: the control and 6 types of fertilization using CM and/or BM. Harvests were performed in 2016 and 2017. The characteristics evaluated were mean weight, length and diameter of individual fruits, mean weight and number of fruits per tree, total soluble solids content, total titratable acidity and pH. Main results: Organic fertilization with 5 L of CM per fig tree promoted the best results in all biometric variables as compared to the plants that were not fertilized. Considering quality, only 5 L of CM or 1.25 L of BM provided equal total titratable acidity in comparison with control. Plants fertilized with 2.5 L of CM produced figs with higher maturation index against plants fertilized with 5 L of CM or 1.25 L of BM. Research highlights: Considering the fig tree productivity and quality of ripe figs, organic fertilization with CM and BM promoted good characteristics

Tree species with potential for reforestation in coastal zones of the humid tropics

Aim of study: The native species of warm humid climates Ceiba pentandra, Tabebuia rosea, Gliricidia sepium, Enterolobium cyclocarpum and Brosimum alicastrum are often included in Mexican reforestation programs. We evaluated the growth response in sandy soils of these species that could serve as pioneers in the restoration of coastal areas. Area of study: Alluvial plain in Frontera, Tabasco, Mexico. Material and methods: A total of 1080 plants were planted in 2014 and evaluated for 23 months in 30 plots under a randomized block design with six replications. The sample plots each occupied 36 m2 (each with 16 plants). Survival percentage, stem height (SH), basal diameter (BD) and basal area (BA) were quantified. Survival and growth variables were analyzed using logistic regression and ANOVA for repeated measures, respectively. Main results: At the end of the experiment (2016), high survival was demonstrated in G. sepium (88 %) and in C. pentandra (86 %), while B. alicastrum presented total mortality at six months. The highest values of SH and BD were presented in C. pentandra (2.9 m and 7.8 cm, respectively) and in G. sepium (2.6 m and 4.2 cm, respectively). Gliricidia sepium differed significantly from C. pentandra in terms of BA (5.9 vs. 23 m2 ha-1, respectively). Research highlights: The native species C. pentandra and G. sepium presented high survival and growth in the sandy soils; G. sepium showed strong adaptation to the environment and C. pentandra offered suitable coverage, characteristics that are necessary for the success of reforestation and restoration programs

Effect of potato contact parameters on seed metering performance using discrete element method

Aim of study: To study the effect of potato surface with or without sandy loam soil on seed metering performance, we investigated the motion behaviour of the potato seed particles during the seed metering process using a self-designed across-bridge metering device by discrete element method (DEM). Area of study: Tonganyi Town, Dingxi, Gansu, China Material and methods: First, the contact characteristics of potatoes were measured using some novel devices. Second, simulations were performed under the same experimental conditions to verify the reliability of the contact parameters. Finally, the velocity and angular velocity of the seed in the seed box and the number of seeds taken by the large spoon during the taking and clearing process were analysed using ANOVA. Main results: The coefficients of static friction (SF) and rolling friction (RF) of seed particles with soil were smaller than those without soil and had the highest values between particles and plastic, followed by between particles and steel, and between particles. Further, the rates of metering single seed particle in simulation and experiment were 98.17% and 97.57%, respectively. The rate of missing seed particles was 1.83% and 2.43%, respectively; it was found to significantly decrease as RF increased from 0.01 to 0.06 to 0.12, and the resultant angular velocity and velocity also significantly decreased as SF increased from 0.1 to 0.5 to 1.0. In addition, the number of seeds taken by the large spoon also reduced. Research highlights: Therefore, potato seed particles surface with or without soil can significantly affect the seeding performance and highlight the need for surface treatment using mechanised metering