Fruit of walnut (Juglans regia L.) belongs to stone fruits. This means that the lignified, stony endocarp, a shell, contains delicious kernel. On the tree a nut is surrounded by the green husk.In ...Slovenia and in the other parts of the world heavy tools (such as stone, hammer and hand-crusher for nuts) are used to remove nutshell. In the intensive walnut production heavy tools are not competitive with today world economy. This is because the priority in walnuts and nuts kernel production is to reduce costs. Walnut shell cracking devices are invented to reduce walnut handling costs and consumer price. Characteristics of this device and walnut kernel quality are presented in this research.
Slaughterhouse waste (SW) is potentially a good source of biomethane; however, its excessive ammonia content quickly causes inhibition of microbial processes. Our aim was therefore to remove ammonia ...from SW before putting it into a biogas reactor. Experimental 120 L pressure container was constructed to observe NH3 removal from diluted slaughterhouse waste at constant air flow of 144 NL/min, temperature 130 °C, and at different pressures: 300 kPa, 600 kPa, and 900 kPa. SW was first allowed to hydrolyze for 14 days at 38 °C. The SW was diluted with water (DSW) to 8.4% dry matter (DM) and forcibly aerated for 334 min. From the DSW, 0.7%, 3.8%, and 9% of initial total N were removed at 300 kPa, 600 kPa, and 900 kPa, respectively. However, the C/N ratio changed only slightly, from the initial 4.38 to 3.17, which is not a promising result for biomethanization. Further research on the presented system with the addition of bases might be promising to remove more ammonia.
Drying grass fodder in Europe’s Alpine countries is becoming increasingly important due to positive effects on the fatty acid composition of milk. A proper approach and technology of fodder drying ...can raise its quality to the level of grass silage. In principle, drying fodder means extracting water from fodder by means of ventilation – the air, the key to the speed of drying. Besides low relative air humidity, its flow rate through the fodder is also important. In the literature, the lower- and upper-bound limits of air flow rates can be found, with a difference of 85 % between the two. The article describes a test, measuring energy consumption and the efficiency of drying at a low air flow, often used in practice, and a high air flow. It was found that a high air flow results in 38 % higher energy consumption per kilogramme of extracted water, compared to a low air flow. The executed test has proved that drying at a higher air flow will not have a proportionally greater effect.
In 2012 on the Laboratory Field of Biotechnical Faculty the field trial was carried out, trying to establish the influence of the soil cultivation on the fuel consumption, on the physical-mechanical ...soil properties of the seed bed and at the end on the field emergence of maize. A rotary harrow was used for soil preparation just before maize planting and it was adjusted to the soil cultivation depths of 5 cm, 10 cm and 15 cm. The trial was designed as random blocks. A tractor with stepless transmission and nominal power of 73 kW and a rotary harrow with working width of 2.5 m were used. The speed of soil cultivation was 5.0 km h-1 on the tractometer and the engine rotational frequency was 1900 rpm. The fuel consumption per hour, the fuel consumption per hectare and the energy consumption per hectare increased by increasing the adjusted soil depth cultivation from 5 cm to 15 cm using the rotary harrow. At the adjusted soil cultivation depth of 10 and 15 cm cm, the vertical soil resistance at depths between 8 and 13 cm was lower than at the adjusted soil depths of 5 cm. No significant differences were found regarding the soil physical properties in the seed bed and the field emergence of maize among three adjusted soil cultivation depths. The soil cultivation depth of 10 cm proved to be the most appropriate in view of the fuel consumption, energy consumption as well as the physical-mechanical soil properties of the seed bed and plant emergence.
A novel prototype of a modified centrifugal sheller was evaluated in terms of undamaged kernels, damaged kernels, fragments of kernels and unbroken nuts. Trials were carried out with walnut varieties ...‘Elit’, ‘Franquette’ and ‘G-139’. First, morphological characteristics (fruit height, width, thickness), relative moisture content and walnut shell strength was measured on randomly selected samples. The maximum force was measured at constant weight of dried nuts perpendicular to the longitudinal axis in ‘Elit’ (287.38 ±107.09 N) followed by ‘Franquette’ (223.36 ±101.00 N) and ‘G-139’ (98.08 ±30.76 N). Shelling walnuts with the centrifugal sheller resulted best output in ‘Franquette’ with 78.05% of whole undamaged kernels, 8.76% of damaged kernels and 7.15% of fragments, while 6.05% remains unbroken; ‘Elit’ only 76.42% of whole kernels, 10.02% of damaged kernels, 9.48% of fragments and 4.08% unbroken nuts. ‘G-139’ gave significantly poorer quality with 60.05% of whole kernels, 21.43% of damaged kernels and 13.63% of fragments and 4.89% unbroken nuts. The output of whole kernels yielded by modified centrifugal sheller is in significant correlation with the walnut thickness of particular variety.
Technical testing of the equipment for the application of plant protection products (PPP) was performed in Southeastern Slovenia in the period from 2004 to 2013. The technical conditions of boom or ...orchard sprayers was examined in details and the following parts were checked: drive, anti-drip valves, nozzles, filters, pipes and tubes, manometers, all valves, pressure regulators, agitator, pump, liquid discharge, spray solution reservoir and spray boom or fan system. The analysis revealed a poor condition of most devices in the initial years. However, technical suitability improved drastically until 2013. Technical condition was not directly related to the region of inspection although the lowest number of defective sprayers was recorded in the Posavje region. This can be linked to higher frequency of use and maintenance of the sprayers in this region as it stands out as the area with larger farms. Occasional technical disorders of the equipment can be recorded each year. It is therefore essential to continue with regular technical inspection to ensure optimal and accurate functioning of the sprayers.
The paper focuses on the testing of a model for determining the distribution of potato tubers in the soil. Analytical testing of the model was performed at the laboratory of the Biotechnological ...Faculty (University in Ljubljana) in 2015 and in the same year, the model was tested in practice on a field owned by the company Zeleni Hit d.o.o. in Ljubljana. After the laboratory testing, the results were analyzed and additional steps were taken to expedite field measurements. To optimize the determination of the distribution of potato tubers in the soil, the program was upgraded to include three-dimensional data acquisition. This allows accurate determination of the horizontal, vertical and longitudinal spans of the distribution of tubers in the soil. Specifically, the program calculates the shape of the tubers, vertical cover of tubers with soil and their minimum distance from the left and right edges of the ridge. The program also locates the center of the tubers, which is a key parameter (along with tuber mass) for determining the area of the tuber cluster. The laboratory testing of the model revealed successful data processing of the program and adequate precision analytics. The testing of the model in the field on Arizona potato variety revealed that the model includes all the data necessary for further processing. Based on the calculated data, it can be assumed with great certainty that the model enables the acquisition of all necessary data and accurately determines the distribution of potato tubers in the soil, ideal shape of the ridge and the minimum necessary depth and distance for the planting of Arizona seed potatoes.
Spraying parameters are important factors when spraying wheat heads against fusarium head blight (FHB) to control the deoxynivalenol level in the grain and to obtain high and quality yields. In 2019 ...and 2020, field trials were conducted in order to establish the effect of the spraying pressure (2 bar, 4 bar, and 6 bar) of special nozzles with a variable flow rate Agrotop VR 1.5 on the head fungicide coverage, yield parameters, and the deoxynivalenol (DON) value in the grain. The coverage of the front and rear sides of wheat heads increased with the increase of spraying pressure from 2 to 6 bar. In 2019, when the infection with FHB was more severe, no significant differences appeared in the yield and the hectoliter weight at a lower spraying pressure, while the DON value at this pressure approached the maximum permissible level. In that year, the DON value exponentially fell with the increase of spraying pressure. In 2019, the thousand grain weight was higher at the spraying pressure of 6 bar than at the pressures of 2 and 4 bar. The results show that also a lower spraying pressure (2 bar) and a volume application rate (117 L/ha) below the recommended one suffice to retain the DON value in the grain below the maximum permissible level, even in years with more severe infection.
Optimal planting speed of vacuum maize planters is usually suggested by planter’s manufacturers, while increased planting speed may influence plant spacing and finally yield. Our hypothesis was that ...by increasing planting speed over the suggested level plant spacing variability will also increase which will result in decrease of silage and grain yield and saving of seed and energy. The field trial consisted of three planting speeds of 7, 9 and 11 km/h in the form of random blocks. The following measurements were taken as follows: plant spacing, silage and grain yield, fuel and energy use at planting. Results in this study show that planting speed did not have significant influence on silage and grain yield of maize, while up to 10% less seed was needed per hectare and fuel and energy use was lower for 15%. By the increase of planting speed the distance between the plants in a row, and in most cases also the plant spacing variability increased. It was noticed that by increasing planting speed plant density decreased. This research established that at higher planting speeds significant increase of the silage yield per individual plant and of the grain yield per individual plant was achieved. The ear parameters also show that the kernel mass per individual ear, the ear mass, and the cob mass, as well as the individual kernel mass, are larger at the planting speed of 11 km/h than at the planting speed of 7 km/h. At the latter planting speed, significantly higher fuel consumption per hectare and higher energy use was achieved than at the other two planting speeds. Overall the main benefits of planting speed of 11 km/h is saving seed and energy at planting while maintaning the same level of silage and grain yield compared to lower planting speeds used in the trial.
Highlights - Planting speed of vacuum planter did not influence the silage and grain yield of maize. - At a higher planting speed up to 10% less seed was needed per hectare and fuel and energy use was reduced up to 15%. - Silage and grain yield per individual plant increased by increasing planting speed. - Increasing of planting speed plant density decreased. - Plant spacing parameters were significantly affected by planting speed.
The aim of our experiment was to improve fungicide spray deposition and coverage of potato leaves by using air-injector nozzle types. We used two standard nozzle types - a flat fan nozzle ST and a ...hollow cone nozzle TR, as well as a couple of air-injector nozzle types - an air-injector compact nozzle IDK and a symmetric double flat fan air-injector nozzle TWIN (with a 30 ° forward and a 30 ° backward spray jet angle). Water-sensitive paper was placed on the upper, middle and lower part of the plant in order to determine the quality of fungicide deposition and the ability of droplets to penetrate lower parts of the plant. When using the air-injector compact nozzle IDK, potato leaves were covered well at all three levels of the plant. The use of the above-mentioned nozzle resulted in the lowest reduction in coverage value and droplet impression area from the top towards the lowest part of the plant. Furthermore, the nozzle created large enough droplets with sufficient mass and speed to penetrate the dense canopy all the way to the lowest part of the plant. When using the symmetric double flat fan air-injector nozzle TWIN, the angle of both spray jets was excessively wide in order for the droplets to reach the lower part of the plant despite a very large droplet impression area. The use of both standard nozzle types resulted in a poor spray mixture coverage of the middle and lower part of the plant. This predominantly occurred due to insufficient droplet size and the subsequent lack of kinetic energy. Results show that the use of a newer air-injector compact nozzle IDK improves the deposition and coverage of potato leaves with spray mixture.
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