Pokus s različitim varijantama suzbijanja korova u usjevu kukuruza proveden je u 2021. godini na lokaciji pored naselja Markovo Polje na praškasto ilovastom tlu. Primijenjene su tri varijante ...suzbijanja korova: 1. mehaničko suzbijanje korova između redova kukuruza motokultivatorom, a unutar redova ručno okopavanje motikom, 2. mehaničko suzbijanje korova samo između redova kukuruza motokultivatorom bez suzbijanja unutar redova, 3. bez ikakvog suzbijanja korova. Na pokusnom polju je pronađeno 14 različitih vrsta korova od kojih su prevladavali Amaranthus retroflexus (običan štir), Ambrosia artemisiifolia (ambrozija), Chenopodium album (bijela loboda) i Sorghum halepense (divlji sirak). Najmanja zakorovljenost pokusnih parcela očekivano je bila na parcelama gdje je primijenjena varijanta 1 suzbijanja korova, kod varijante 2 je prosječna masa korova po 1 m2 bila 223%, a kod varijante 3 čak 334% veća u odnosu na varijantu 1. Prinosi kukuruza su bili obrnuto proporcionalni sa zakorovljenosti pokusnih parcela, najviši prinosi su ostvareni kod varijante 1 s prosjekom od 6015 kg ha-1, kod varijante 2 prosječni prinos je bio 2907 kg ha-1, a kod varijante 3 1242 kg ha-1. Kombinacija mehaničkog suzbijanja korova i ručnog okopavanja može biti alternativa korištenju herbicida na manjim obiteljskim gospodarstvima i u ekološkom uzgoju kukuruza.
An experiment with different variants of weed control in the maize crop was carried out in 2021 at a location next to the Markovo Polje settlement on silty loam soil. Three variants of weed control were applied: 1. mechanical weed control between the maize rows with a motocultivator and manual hoeing within the rows, 2. mechanical weed control only between the maize rows with a motocultivator without control within the rows, 3. without any control of weeds. In the experimental field, 14 different types of weeds were found, of which Amaranthus retroflexus, Ambrosia artemisiifolia, Chenopodium album and Sorghum halepense prevailed. As expected, the lowest weed infestation of the experimental plots was on the plots where variant 1 of weed control was applied, in variant 2 the average mass of weeds per 1 m2 was 223%, and in variant 3 it was even 334% higher compared to variant 1. Maize yields were inversely proportional to the weed infestation of the experimental plots, the highest yields were achieved in variant 1 with an average of 6015 kg ha-1, in variant 2 the average yield was 2907 kg ha-1, and in variant 3 1242 kg ha-1. The combination of mechanical weed control and manual hoeing can be an alternative to the use of herbicides on smaller family farms and in organic maize production.
Suzbijanje korova jedan je od najvažnijih čimbenika u svim poljoprivrednim biljnim proizvodnjama, a osobito u ratarskoj proizvodnji zbog velikih površina na kojima se ona odvija. Nakon otkrića visoko ...učinkovitih herbicida suzbijanje korova u poljoprivredi godinama se provodilo gotovo isključivo kemijskim metodama, ali intenzivna uporaba kemijskih sredstava je rezultirala značajnim negativnim učincima na okoliš i ljudsko zdravlje. Veliki napredak u elektronici i računalnim tehnologijama te razvoj sustava za navođenje vozila zajedno s uvođenjem precizne poljoprivrede su otvorili mogućnost korištenja robota u suzbijanju korova. Posljednjih godina su razvijeni robotski sustavi s različitim metodama suzbijanja korova kao što su selektivna kemijska aplikacija, mehaničko uklanjanje korova, korištenje plamena, pare, električnog pražnjenja i lasera. U radu su navedeni primjeri različitih izvedbi robota za suzbijanje korova.
Weed control is one of the most important factors in all agricultural plant productions, but especially in arable production due to the large areas where it takes place. After the discovery of highly effective herbicides, weed control in agriculture has been carried out for years almost exclusively by chemical methods, but the intensive use of herbicides has resulted with the serious negative effects on the environment and human health. Rapid advances in electronics, computers and computer technologies and the development of vehicle guidance systems together with the introduction of precision agriculture have opened the possibility of using robotic systems in weed control. In recent years, many robotic weed control systems have been developed with different weed control methods such as selective chemical application, mechanical weed removal, using flame, steam electric discharge and laser. Examples of different versions of robots for weed control are presented in this paper.
The objective of this study was to determine the influence of housing system on the physical, morphological, and mechanical properties of Japanese quail (Coturnix coturnix japonica) eggs. A total of ...240 eggs were collected from Japanese quails kept in two different housing systems: cage housing and aviary housing system (120 eggs from each housing system). Eggs from cage housing system were significantly (P<0.05) heavier than eggs from aviary housing system (11.85 g vs. 10.93 g), and were also longer, wider and had significantly (P<0.05) larger geometric mean diameter, surface area and volume. No statistically significant difference in albumen and yolk content was observed between eggs from cage and aviary housing system. Eggs from aviary housing system had significantly higher shell content and shell strength and required greater force to eggshell breaking. The average force required to breaking the shell of Japanese quail eggs from cage and aviary housing system in all three axes was 14.36 N and 12.70 N, respectively.
The aim of this study was to compare physical, morphological and mechanical characteristics of eggs collected from two duck breeds (Pekin duck and Cherry Valley duck). A total sample of 120 eggs (60 ...eggs of each duck breed) was collected from one-year-old free range raised ducks. The Cherry Valley duck eggs were significantly heavier (94.23 vs. 71.91 g) than Pekin ducks (P<0.01), had larger dimensions and higher shape index (73.80 vs. 70.16). There was no statistical difference between egg specific gravity. According to egg components proportion, the Cherry Valley duck eggs had higher percentage of albumen, while the Peking duck eggs had higher percentages of yolk and shell. The Pekin duck eggs had significantly higher yolk to albumen ratio and Haugh unit value (P<0.01). The average force required to rupture Cherry Valley duck eggs in all three axes (50.32 N) was significantly higher (P<0.01) than average force required to rupture Pekin duck eggs (42.64 N). The highest egg rupture force at both duck breeds tested in this study was determined in loading along the X-front axis, while the least resistance to rupture force was determined along the Z-axis.
An experiment with different variants of weed control in the maize crop was carried out in 2021 at a location next to the Markovo Polje settlement on silty loam soil. Three variants of weed control ...were applied: 1. mechanical weed control between the maize rows with a motocultivator and manual hoeing within the rows, 2. mechanical weed control only between the maize rows with a motocultivator without control within the rows, 3. without any control of weeds. In the experimental field, 14 different types of weeds were found, of which Amaranthus retroflexus, Ambrosia artemisiifolia, Chenopodium album and Sorghum halepense prevailed. As expected, the lowest weed infestation of the experimental plots was on the plots where variant 1 of weed control was applied, in variant 2 the average mass of weeds per 1 m2 was 223%, and in variant 3 it was even 334% higher compared to variant 1. Maize yields were inversely proportional to the weed infestation of the experimental plots, the highest yields were achieved in variant 1 with an average of 6015 kg ha-1, in variant 2 the average yield was 2907 kg ha-1, and in variant 3 1242 kg ha-1. The combination of mechanical weed control and manual hoeing can be an alternative to the use of herbicides on smaller family farms and in organic maize production.
Weed control is one of the most important factors in all agricultural plant productions, but especially in arable production due to the large areas where it takes place. After the discovery of highly ...effective herbicides, weed control in agriculture has been carried out for years almost exclusively by chemical methods, but the intensive use of herbicides has resulted with the serious negative effects on the environment and human health. Rapid advances in electronics, computers and computer technologies and the development of vehicle guidance systems together with the introduction of precision agriculture have opened the possibility of using robotic systems in weed control. In recent years, many robotic weed control systems have been developed with different weed control methods such as selective chemical application, mechanical weed removal, using flame, steam electric discharge and laser. Examples of different versions of robots for weed control are presented in this paper.
The aim of this paper was to quantify vertical stress distribution in silty loam soil by applying three combinations of tyre inflation pressures of front and rear wheels of a four-wheel drive tractor ...weighing 3560 kg. The tyres on the tractor were bias-ply, front 11.2-24 and rear 16.9-30, and inflation pressures were 67, 100, and 150% of the recommended pressure. Soil stresses were measured at 10, 30, and 50 cm depths using a stress transducer consisting of ten sensors with a 10 cm distance between sensor centres. Decrease in tyre inflation pressure resulted in a decrease of maximum soil stress at all measured depths. Tyre inflation pressures greatly influenced soil stresses measured in the topsoil. Maximum soil stress in the topsoil depth below front wheel tyres was significantly higher than that below rear wheel tyres. There were no significant differences between tyre contact areas at recommended, high, and low tyre inflation pressures.
Various physical and mechanical properties of sunflower (Helianthus annuuscv.Alexandra) seeds and kernels were determined as a function of moisture content. The average length, width, thickness, ...equivalent diameter, unit mass, and sphericity of seeds were 9.61, 4.82, 3.20, 5.32 mm, 0.0524 g, and 54.24%. In the moisture range from 5.29% to 20.08% w.b., studies on the rewetted seeds showed that the bulk density of seed decreased from 416.32 to 391.05 kg/m3and kernel increased from 533.67 to 701.69 kg/m3, respectively. The true density of seeds decreased from 648.21 to 582.66 kg m-3, while for kernel it increased from 868.30 to 1081.43 kg/m3. The porosity of seeds increased from 35.78 to 44.27%, while porosity of kernel increased from 38.53 to 46.11%. In the same moisture range, the static coefficient of friction for seeds on three different material surfaces varied from 0.421 to 0.572 on aluminium, from 0.501 to 0.811 on plywood and from 0.537 to 0.861 on rubber.
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