Spanish Journal of Agricultural Research

Factors that affect profitability in the Spanish pig farming industry

Alba CARDIL — 2023-07-12

Aim of study: To identify factors that boost the financial profits of pig producers. These factors refer to the company, the industry and the territory where they are located. We also incorporated an environmental factor according to greenhouse gas emissions.

Area of study: Spain.

Material and methods: The data used came from a sample of 1,810 Spanish entities that provided unbalanced panel data for the 2003-2018 period.

Main results: In recent decades, the pig farming industry has undergone considerable development characterised by an increase in production, exports and in the productivity of pig farms. The study enabled us to detect the factors that most influence the profitability of pig producers, bearing in mind the possible existence of endogeneity problems between some of the variables analysed.

Research highlights: The results obtained have practical implications, insofar as they facilitate decision-making as regards the location and characteristics that farms must possess in order to obtain competitive profitability.

Analysis of operating speed and power consumption of a gear-driven rotary planting mechanism for a 12-kW six-row self-propelled onion transplanter

Md Nasim REZA — 2023-07-12

Aim of study: To determine the optimal working speed of a gear-driven rotary planting mechanism for a self-propelled riding-type onion transplanter in order to choose an adequate forward speed for effective onion (Allium cepa L.) seedling planting.

Area of study: Daejeon, Korea.

Material and methods: The gear-driven rotary planting mechanism was composed of six planting hoppers that received free-falling onion seedlings through the supply mechanism and deposited them into the soil. To determine the optimal working speed for accurate transplantation of the seedlings, mathematical working trajectory modelling of the planting mechanism, virtual simulations, and validation field experiments were carried out.

Main results: According to the model simulation, a forward speed of 0.15 m s^-1 of the transplanter and a rotating speed of 60 rpm of the planting mechanism were favourable for seedling uprightness and minimum mulch film damage. For the proposed transplanting mechanism, the free-falling distance was calculated as 0.08 m, and the accuracy for the seedling deposition into the hopper was demonstrated as 97.16% through the validation test. From the field tests, a forward speed of 0.15 m s^-1 combined with a transplanting frequency of 60 seedlings min^-1 was found to be optimum for obtaining a high seedling uprightness (90^o), a low misplant rate (7.66%), a low damage area on mulch film, and low power consumption (36.53 W).

Research highlights: The findings of this research might be helpful in improving the design of the onion transplanting mechanism and accelerating the automation process for seedling transplantation.

A method to optimize the pesticide dose considering the combined influence of plant, pest, pesticide, and spray equipment on bioefficacy

Divaker DURAIRAJ — 2023-07-31

Aim of the study: To develop a method to optimize the pesticide dose considering the combined influence of plant, pest, pesticide, and spray equipment on bioefficacy.

Area of study: Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.

Material and methods: A controlled droplet applicator generated droplets from 200 to 50 μm. The target leaf's deposition density of a preset droplet size can be controlled by timing the spray. A sequence of bioassays was performed at various droplet densities at each pesticide (imidachloprid 17.8% SL) dose and droplet size to determine the mortality of cotton aphids (Aphis gossypii) and jassids (Amrasca biguttula) feeding on immature cotton plants. Calculating the number of droplets per target area needed to cause 50% and 90% mortality (LN50 and LN90) yielded a series of model curves. Field tests were done on the computed optimal doses of the pesticide for a spray apparatus (electrostatically charged spray) to assess the spray's bioefficacy against A. gossypii and A. biguttula.

Main results: In comparison to uncharged mist blower spray, which had a bioefficacy of 91% for an LN90 dose of 110 g a.i. L^-1, the spray had an 89% bioefficacy on A. gossypii. Using the electrostatic spray, it was 91% effective against A. biguttula and 98% effective against an uncharged mist blower at a dose of 110 g a.i. L^-1 of LN90.

Research highlights: This generalized method of modelling could effectively compute the optimal pesticide dose for any plant, pest, pesticide, and spray equipment combination.

Effect of green seaweed meal blend on feed quality and zootechnical performance in shrimp (Penaeus vannamei) juveniles

Jessie VARGAS-CÁRDENAS — 2023-07-27

Aim of study: To evaluate a green seaweed meal in the diets of Penaeus vannamei juveniles, comprising Ulva spp., Caulerpa spp. and Enteromorpha spp. as a feed blend at inclusion levels at 4% and 8%.

Area of study: Universidad Nacional Agraria La Molina, Lima, Perú.

Material and methods: Analyses were conducted to determine the pellet quality through percentages of dry matter retention (DMR), protein loss and water absorption capacity; and to evaluate the effect of this seaweed meal in the digestibility and zootechnical shrimp performance. Three treatments (diets) were formulated to contain 0% (control diet), 4% (M4) and 8% (M8 of green seaweed meals (blend)), in isonitrogenous (crude protein; 300 g kg^-1) and isocaloric (3.3 Mcal kg^-1) diets. The shrimps were reared at a density of 286 juveniles m^-3 for 29 days in a recirculating aquaculture system (RAS).

Main results: Among the diets, M4 had the highest DMR value (97.06%), whereas M8 had highest water absorption capacity (185.48%) with lower % of protein loss between the treatments diets. No differences were observed in the zootechnical performance, except for survival (p<0.05), with the M8 diet having highest mortality rate (44.4%) between the treatments diets.

Research highlights: Incorporating 4% green seaweed meal in shrimp feed supported adequate growth and survival of juvenile P. vannamei with adequate DMR values, water absorption capacity, protein loss and high apparent dry matter digestibility and apparent digestibility of the reference diet.

Effect of feeding restrictions on development of juvenile cobias, Rachycentron canadum

André B. SOUZA — 2023-07-27

Aim of study: A 45-day trial was conducted to evaluate fasting as a possible way of food strategy during production of juvenile cobias (Rachycentron canadum).

Area of study: The study was conducted in the State of Espírito Santo, Brazil.

Material and methods: The following different protocols were used to organize their feeding: C, fish fed to satiety twice a day for 45 days; U1, fish fed to satiety twice a day on alternate days; U2, fish fed to satiety twice daily for five consecutive days, followed by two days of food deprivation, cyclically; U5, fish subjected to food deprivation for five days and then fed to satiety twice a day for 40 days; U10, fish subjected to food deprivation for ten days and then fed to satiety twice a day for 35 days; and U15, fish subjected to food deprivation for fifteen days and then fed to satiety twice a day for 30 days.

Main results: No mortality was observed during the trial period. The different feeding protocols significantly affected juvenile cobias development and wellbeing. The final weight (g) of cobia juveniles was C – 91.9 ± 9.1; U1 – 75.0 ± 11.2; U2 – 72.2 ± 6.0; U5 – 70.3 ± 6.1; U10 – 63.4 ± 4.6; U15 – 54.4 ± 4.7. No compensatory growth was observed during the entire experimental period.

Research highlights: Continuous fasting had a more severe effect than intermittent fasting. Significantly greater hepatocyte counts were correlated with longer fasting periods. Fasting protocols should not be recommended for juvenile cobias.

Fermented soybean meal in broiler diets exposed to stress induced by corticosterone: Effect on growth performance, gut health and immune response

Fakhreddin ABEDDARGAHI — 2023-07-31

Aim of study: To investigate the effect of fermented soybean meal (FSBM) on responses of broiler chickens exposed to stress condition.

Material and methods: Two hundred and eighty-eight day-old male chickens were allocated to six treatments in a 2 × 3 completely randomized factorial design involving two factors: factor 1 was the subcutaneous injections of CORT or corn oil (as control) at 2 mg/kg body weight twice per day during 3 days; and factor 2 were 3 levels (0, 10 and 20%) of FSBM in replacement of the original soybean meal.

Main results: The replacement of soybean meal by FSBM increased FI and BWG without any significant effect on FCR (10 days), while FCR was increased significantly by CORT injection. Corticosterone injection caused a significant decrease in the ratio of villus height (VH) to crypt depth (CD) in the duodenum and jejunum. The height of villi in the duodenum increased significantly at 20% FSBM replacement. The antibody titers against Newcastle disease (28 and 2 day), coliform count (28 day) and activity of digestive enzymes (10 day) were not affected by either FSBM replacement or CORT injections. Corticosterone injection significantly increased tall-like receptor-4 (TLR4) and immunoglobulin A (IgA) expression, while decreased heat shock protein-70 (HSP70) expression. FSBM replacement down-regulated the expression of TLR4, HSP70, and IgA in small intestine compared to the control group. In stress condition induced by CORT injection, 10% FSBM replacement decreased HSP70 and IgA expression in the jejunum and ileum, while had no effects on TLR4.

Research highlights: Partial replacement of soybean meal by FSBM in diets had positive effects on performance, intestinal morphology and immune response in chicks exposed to stress.

Leaf chlorophyll contents in some European pear cultivars grafted on different rootstocks and its relation with growth and yield

Zaki A. FAIZI — 2023-07-25

Aim of study: To investigate the effect of different combinations of pear rootstocks and cultivars on the contents of leaf photosynthetic pigments and their relation with some growth and yield characteristics.

Area of study: Ondokuz Mayis University, Samsun, Türkiye, in two years, 2021 and 2022.

Material and methods: The pear cultivars ‘Santa Maria’, ‘Williams’, and ‘Deveci’ were grafted on eight rootstocks: two quince clonal rootstocks (BA29 and QA), five pear clonal rootstocks (FOX9, FOX11, OH×F333, OH×F87, FAROLD40) and Pyrus communis L. seedlings. Growth and yield attributes were calculated and chlorophyll and carotenoid contents were determined by the spectrophotometric method, using 99.8% methanol solvent for chlorophyll (chl) extraction.

Main results: Chl a/b in the case of rootstocks, chl a and total carotenoids in the cultivars were found statistically significant; the ratio chl a/b ranged 1.71-2.30 in the case of rootstocks; in the case of cultivars chl a ranged from 17.77 (cv. ‘Santa Maria’) to 19.88 (cv. ‘Deveci’) μg mL^-1, and carotenoids ranged 0.21-0.95 μg mL^-1. Under the main impact of cultivars, rootstocks and their combinations, a significant difference was seen in the growth and yield attributes.

Research highlights: A negative correlation coefficient was observed between photosynthetic pigments and morphological characteristics; however, the correlation coefficient was positive for canopy volume and annual shoot growth. Canopy management, especially with the use of rootstocks and cultivars that result in weaker growth, is helpful for improving chlorophyll content and yield performances.

Trends and gaps in tomato grafting literature: a systematic approach

Elen P. P. BENTO-DA-SILVA — 2023-07-24

Aim of study: To investigate the trends and existing research gaps in tomato grafting by employing scientometric methods.

Area of study: In silico at SCOPUS database.

Material and methods: Research articles were retrieved by combining the search terms related to tomato and grafting. The articles were selected according to pre-established criteria. Temporal trends and scientometric indexes were determined. Bibliometric mappings were conducted to determine the main countries, authors, and journals that published articles on tomato grafting; and to acquire collaboration and keywords co-occurrence networks. Technical aspects of tomato grafting were analyzed.

Main results: A total of 397 research articles published from 1944 to 2020 were analyzed. The number of publications on tomato grafting increased at an annual rate of 8.8%. The USA and Spain are notable in terms of the number of published and cited articles. The USA and European countries had the highest number of collaborations. European authors had the strongest research connections. Interspecific grafts (61.83%) and experiments in controlled conditions (82.87%) predominated. The growing interest in tomato grafting has been observed as a means of overcoming environmental issues as well as yield and quality improvement.

Research highlights: Collaboration among research groups contributed to a higher research impact on the theme. The mitigation of abiotic stresses and fruit quality has risen as significant concerns for tomato crops.

Testing local isolates of entomopathogenic nematodes against the green stink bug Nezara viridula L.

Marina V. PUSHNYA — 2023-08-07

Aim of study: The green vegetable bug Nezara viridula L. is a polyphage that is spread all over the world, but in the last 10 years it has entered the territory of the Russian Federation. The use of biological protection against this pest is an important task in the country. We used the entomopathogenic nematodes (EPN) Steinernema feltiae and Steinernema carpocapsae to control N. viridula.

Area of study: Federal Research Center of Biological Plant Protection (FRCBPP), Krasnodar Krai, Russia, 2019-2020.

Material and methods: A laboratory test was carried out with adults and nymphs of N. viridula. Each species of EPN (S. carpocapsae and S. feltiae) was used at doses of 50, 75 and 100 individuals infective larvae per insect. The initial material for analysis was collected on soybean crops in the crop rotation of the FRCBPP. The experimental results were assessed using ANOVA.

Main results: Laboratory tests of the EPN S. carpocapsae and S. feltiae caused the death of up to 98.0% of nymphs and up to 91.4% of adults of N. viridula. The species S. feltiae turned out to be the most effective, as allowed the pathogen to develop in shorter periods of time, and caused the death of 81.9-91.4% adults and of 92.0-98.0% nymphs.

Research highlights: This study showed that during the period of growth and development of larvae, the use of EPN is more effective in nymphs than on adults.

Zinc and phosphorus availability to wheat as affected by humic substances in calcareous and siliceous growth media

Aurora MORENO-LORA — 2023-06-15

Aim of study: Humic substances (HS) have an impact on the dynamics of phosphorus (P) and zinc (Zn) in soil and consequently can affect the availability of both nutrients to plants. This work aimed to study the effect of humic substances on the availability of P and Zn to wheat depending on the main sorbent surfaces in growth media.

Area of study: Growth chambers of the Higher Technical School of Agricultural Engineering, University of Seville, Spain

Material and methods: To this end, a pot experiment was performed involving three factors: i) HS rates, ii) Zn fertilization, and iii) type of growth medium, calcareous and noncalcareous (siliceous).

Main results: Biomass production and Zn uptake by plants decreased with increasing HS rates. Humic substances decreased Zn uptake more markedly in the siliceous medium. Negative effects of HS can be ascribed to altered crop nutrition and the high aromaticity of HS that can promote phytotoxic effects. The antagonistic effect between P and Zn was less evident in the calcareous medium than in the siliceous medium. This is probably explained by the reduced availability of Zn and the consequent decrease in uptake by plants in the calcareous medium compared to the siliceous medium. These differences observed between both media can be ascribed to different adsorption dynamics depending on the main sorbent surfaces.

Research highlights: The addition of HS, at the intermediate rates studied, had a positive effect on the microbial activity of the rhizosphere in the calcareous medium. Thus, not only crop functioning, but also soil biology, can be affected by the application of HS. This effect can be different depending on the HS rates applied and the type of growth medium.

Assessment of DSSAT and AquaCrop models to simulate soybean and maize yield under water stress conditions

Ali DEHGHAN MOROOZEH — 2023-07-07

Aim of study: To evaluate the performance of DSSAT and AquaCrop models in the estimation of soybean and grain maize yield under water stress conditions in a semi-arid region.

Area of study: Kermanshah, Iran.

Material and methods: AquaCrop and DSSAT were assessed to simulate soybean and maize. Both models were calibrated using field data. Field experiments were performed in a randomized complete block design with eight and four irrigation treatments for soybeans and maize, respectively with three replications. Measures of Normalized Root Mean Square Error (nRMSE) and Nash-Sutcliffe Model Efficiency were used to evaluate the accuracy of the models. For this purpose, simulated values of leaf area index / green crop canopy, grain yield, biomass, and soil moisture were compared with measured data.

Main results: Results indicated that the CROPGRO-Soybean in DSSAT software simulated more accurate crop growth of soybean than AquaCrop. The average nRMSE of the DSSAT model for estimating soil moisture, leaf area index, grain yield, and biomass were 6%, 14%, 16% and 20%, respectively. For maize, AquaCrop simulated crop growth more reliably than CERES-maize. The average nRMSE of 3%, 10%, 13% and 27% of the Aquacrop model in simulating the parameters of soil moisture, green crop canopy, biomass, and grain yield.

Research highlights: Considering the better performance of AquaCrop for maize and DSSAT for soybean in the study area, it is not possible to propose a specific model to simulate the growth of all crops in a region.

Editorial Board 21 (3)

Journal Editorial Office SJAR — 2023-08-29