Variability in pomological traits of dog rose (Rosa canina L.) under the ecological conditions of the Republic of Croatia

Wild or dog rose (Rosa canina L.) is a successful colonizer of various habitats and different soil types and is widely distributed across the Republic of Croatia. In this research, in order to estimate pomological variability in native dog rose populations, four genotypes from four locations in different geographic areas of Croatia were selected and sampled. The genotypes selected were: genotype G1, originating from the continental part of Croatia (Pitomača); genotypes G2 and G3, originating from the Mediterranean part of Croatia (Kukurini and Posedarje, respectively); and genotype G4, originating from the upland part of Croatia (Gračac). Fruits were harvested at optimum harvest dates in 2010 and 2012. Genotype had a significant effect on each studied pomological trait (length, width, geometric mean diameter, sphericity, volume, surface, shape index, weight, flesh weight, flesh ratio and total dry matter content), while year significantly affected all parameters except sphericity and shape index. The highest values for most pomological traits in 2010 and 2012 were found in the G4 and G3 genotypes, respectively. This research highlighted the existence of high variability in pomological traits among dog rose populations in Croatia, which emphasizes the possibility of further breeding and cultivation.

Modeling the relationship between the characteristics of agricultural holdings and the presence of organic farming

Organic farming is a fast growing market segment in the global food industry. Ecological and health benefits of organic farming are frequently emphasized. In addition, we have recently witnessed the promotion of its role in the development of rural areas by means of creating jobs and strengthening ties with local economies. This paper analyzes the relationship between the presence of organic farming and the main characteristics of agricultural holdings in the case of European Union countries. The objective is to identify factors which have a significant relationship with the organic farming sector and which can affect its future development. The results have shown that large farms are dominant in farm land management in the EU, which is related to the fact that there is a significant correlation between the availability of agricultural areas and the economic value of farms (r = 0.881**). There is a positive and significant correlation between the economic value of a holding and the number of livestock units on the farm (r = 0.940**), which indicates that animal husbandry has strong economic potential. When it comes to the relationships between the structural and economic indicators of agricultural holdings and the presence of organic farming, the results have shown that the number of organic producers is positively and significantly correlated with the available agricultural areas (r = 0.675**), and a strongly positively correlated with the economic value of farms (r = 0.810**). The areas under organic farming are also directly correlated with the utilized agricultural area (r = 0.836**), as well as with the number of livestock units (r = 0.793**), but they are slightly negatively correlated with livestock density (r = -0.211). Therefore, high livestock density can be a limiting factor for the further intensive growth of organic farming areas, considering the significant impact of animal husbandry on the environment.

The response of garden pea cultivars to simulated drought

This study aimed to estimate genetic variability among four pea cultivars and determine seed physiological quality and initial growth of garden pea (Pisum sativum L.) under drought stress. Seeds of the pea cultivars were subjected to water stress induced by polyethylene glycol PEG 6000 at three stress levels (0; -0.15; -0.49, and -1.03 MPa). The experiment was conducted under laboratory conditions, in a completely randomized design with four replications, to estimate germination energy, germination, abnormal seedlings, fresh and dry shoot and root biomass, and drought tolerance index. Drought stress significantly affected germination and the other traits, with the stress effects being proportional to the stress level applied. Findings point to the fact that the osmotic potential of -0.49 MPa might be the germination sensitivity threshold for pea cultivars. The pea cultivar C1 was the most tolerant, having the highest germination, fresh and dry shoot and root biomass, and DTI under severe drought stress. Further research on the assessment of physiological and biochemical responses to drought stress is needed to confirm the findings of the present study.

How long can primed soybean (Glycine max L.) seeds be stored in natron paper bags?

Priming of legume seeds before sowing was performed by Roman farmers in order to increase the germination rate and synchronize germination, as reported by the Roman naturalist Gaius Plinius Secundus. Several centuries later, this technique is still used for a wide range of species. However, in order for this measure to be used successfully in production, it is necessary to find a solution for the successful storage of primed seeds. The storage potential of primed soybean seeds was determined by a temperature of 25 °C during the period of 90 days. Soybean seeds were primed with KNO3 (1%), AsA (100 mg L-1) and KCl (1%) solutions, and then stored in natron paper bags, and their quality was tested every 15 days. The results showed that a reduction in the quality of primed seeds was considerably faster than in non-primed seeds. Primed soybean seeds were successfully stored at a temperature of 25 °C for 60 days after priming, and then a significant reduction in their quality occurred. One of the causes of seed quality reduction was an increase in MDA content, especially after 75 and 90 days of storage. Also, free proline concentration was reduced while the content of vitamin C increased after 15 days primarily in seeds primed in AsA and KCl solutions, and decreased after 45 days.

Evaluating land cover types from Landsat TM using SAGA GIS for vegetation mapping based on ISODATA and K-means clustering

The paper presents the cartographic processing of the Landsat TM image by the two unsupervised classification methods of SAGA GIS: ISODATA and K-means clustering. The approaches were tested and compared for land cover type mapping. Vegetation areas were detected and separated from other land cover types in the study area of southwestern Iceland. The number of clusters was set to ten classes. The processing of the satellite image by SAGA GIS was achieved using Imagery Classification tools in the Geoprocessing menu of SAGA GIS. Unsupervised classification performed effectively in the unlabeled pixels for the land cover types using machine learning in GIS. Following an iterative approach of clustering, the pixels were grouped in each step of the algorithm and the clusters were reassigned as centroids. The paper contributes to the technical development of the application of machine learning in cartography by demonstrating the effectiveness of SAGA GIS in remote sensing data processing applied for vegetation and environmental mapping.

Soil quality and proposal for fertility improvement of arable soil in Rasina District

During the regular control of soil fertility in the Rasina District, it was established that the plots of land were distributed across Vertisol, Eutric Cambisol and Fluvisol types of soils, and to a lesser extent on Pseudogley and Ranker. The tested samples had different textures - sandy loam and loam, clay-sandy loam and clay loam, and clay. Plots of land that were of very acidic and acidic reactions were predominant, with medium amounts of humus, very low amounts of available phosphorus, and high amounts of available potassium. High or very high cation absorption capacity was found in about half of the examined fields; a deficient content of exchangeable Ca was recorded in 22% of plots and that of exchangeable Mg in 16% of plots, while an unfavorable Ca/Mg ratio was measured in 44% of plots. The overall sensitivity to acidification was mainly moderate (50.6% of plots) and strong (20.2% of plots). Very high concentrations of mobile Al, which could be toxic to plants, were found in 5 field plots.

Irrigation scheduling strategies for pepper based on evaporation and reference evapotranspiration

The experiment with drip irrigated pepper was conducted at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad in 2019. The irrigation was scheduled on the basis of the water balance method. Two methods were used to compute the daily evapotranspiration of pepper (ETd): reference evapotranspiration (ETo) and evaporation from an open water surface (Eo). Crop coefficients (kc) and corrective coefficients (k) were used to convert ETo and Eo values into ETd. Kc and k were 0.3-0.4, 0.6-0.7, 0.9-1.1, 0.8-0.9 and 0.4, 0.7, 1.0 and 0.8 for initial stage, crop development, mid season, and late season, respectively. ETo was calculated by the Hargreaves equation. Eo values were measured by a Class-A pan located at a meteorological station near the experimental plot. Irrigation started when readily available water (RAW) in the 0.3 m soil layer was completely absorbed by plants. Differences in crop yield (Y) and irrigation water use efficiency (IWUE) obtained using Eo (42.58 t ha-1, 15.20 kg m-3) and ETo (40.78 t ha-1, 14.56 kg m-3) were not statistically different. Evapotranspiration rate was 364.2 mm and 337.3 mm in Eo and ETo variant, respectively. The fact that the differences in Y and IWUE between different calculations of ETd were not statistically significant indicates that both methods can be recommended for irrigation scheduling programs for pepper in the climatic conditions of the Vojvodina region. However, priority should be given to ETo due to the easy accessibility and reliability of data.

Occurrence of oxidative stress in sheep during different pregnancy periods

The objective of this paper was to evaluate oxidative stress during different pregnancy stages in Lohi sheep reared in Libya. Investigations were carried out on Lohi sheep between 1.5 and 5 years of age. A total of 40 sheep were sub-grouped into various stages of pregnancy along with non-pregnant controls as follows: non-pregnant (n=10), early pregnancy (n=10), mid pregnancy (n=10), and late pregnancy (n=10). Blood samples were collected from pregnant sheep and preserved at -20°C and further used for evaluating the concentrations of total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and paraoxonase (PON-1). In pregnant sheep, TAS, TOS, MDA, SOD, CAT, and PON-1 values were significantly (P < 0.05) different. TOS and MDA increased from non-pregnant ewes to early, mid and late stages of pregnancy whereas TAS, SOD, CAT, and PON-1 significantly (P < 0.05) decreased with the progression of pregnancy. The study suggests that the use of oxidant and antioxidant markers along with the blood metabolic profile should be the recommended procedure for monitoring health status during pregnancy to evade reduced productive performance and economic losses.

Nutritional attributes of wheat bread fortified with convectively dried chokeberry powder

Chokeberry (Aronia melanocarpa L.) has a positive effect on human health, and therefore it can be used as a beneficial component for food (e.g. wheat bread) fortification. Dried chokeberry powder (CP), obtained by convective drying at 50, 60, and 70°C, fortified bread samples by replacing wheat flour at levels of 1, 2.5, 5 and 10%. Bread samples fortified with chokeberry were characterized by a decrease in total starch and protein contents and an increase in total sugar, mineral (Mg, Ca, Cu), and fat components; unsaturated oleic acid was reduced, unlike unsaturated linoleic and linolenic acids. All developed mathematical models for starch, protein, fat, and minerals in bread supplemented with CP were characterized by statistically insignificant residual variances and high values of R2. Z-score analysis showed the optimal segment and total scores of bread fortified with CP. Chokeberries dried at a temperature of 60°C showed the best nutritional attributes. Wheat bread enriched with CP in the amount of 10% had the highest level of fortification.

Survey of apple collar and rootstock blight in Serbia

Apple production in Serbia is characterized by the introduction of new technologies and the establishment of intensive plantations based on modern systems. In intensive apple production systems, sudden and rapid decay of young apple trees exhibiting collar and rootstock blight symptoms in the first few years after planting is becoming a prevalent issue. However, knip or nursery trees with lateral branches (feathers) on rootstock M.9 i.e. oneto five-year old are most seriously affected. Based on a longitudinal survey of young apple plantations in Serbia and the results of pathogen detection and identification using conventional and molecular methods, the plant pathogenic bacterium Erwinia amylovora was found as the causative agent. By increasing the incidence of collar and rootstock blight in young apple trees, E. amylovora is gaining importance as the most destructive disease in apple production. In order to control E. amylovora effectively and apply appropriate control measures, it is necessary to survey the development of lesser-known symptoms caused by this pathogen, which are becoming prevalent in Serbian agroecological conditions.