Partial Differential Equations for Cereal Seeds Distribution

During the recent years all crop species achieved the best possible field distribution so a high yield is to be expected. In this paper the solutions of two different diffusion equations are determined, which describe the optimal distribution of cereal grains over a field. Therefore, there are two different partial differential equations of cereal seed distribution-distinction is made between the longitudinal spacing (seeds in a row), and transverse distance (between two rows), as well as the sowing depth. In particular, closed forms of solutions are derived in each case. Although the result of the diffusion equation with respect to the distribution of the lateral seed distance of two adjacent rows is already known, a new solving method is presented in this paper. By this method, the partial differential equation is reduced to an ordinary one, which is easier to solve. In this paper it is shown that the distribution of lateral resp. longitudinal and in-depth wheat seed distances is achieved by a normal Gauss function resp. a log-normal function. Furthermore, it is demonstrated that the fitting functions of the best experimental results of wheat seeding distributions are particular solutions of the individual differential equations. Normal Gauss function describes lateral distribution with R2 = 0.9325; RSME = 1.2450, and log-normal function describes longitudinal distribution with R2 = 0.9380; RSME = 1.4696 as well as depth distribution with R2 = 0.9225; RSME = 2.0187

IMPACT OF TEHNICAL SPRAYING FACTORS ON LEAF AREA COVERAGE IN PERMANENT CROPS

Istraživanja su obavljena u vinogradu i nasadu jabuke s dva tipa raspršivača, aksijalni (Hardi Zaturn) i radijalni (Hardi Arrow). Istraživan je utjecaj glavnih tehničkih čimbenika raspršivanja (tip mlaznice, brzina rada i norma raspršivanja) na pokrivenost tretirane površine, prosječni promjer kapljica, broj kapljica/cm2 i zanošenje tekućine. Brzina rada raspršivača podešava se na 6 i 8 km/h, a norma raspršivanja na 250, 325 i 400 l/ha za nasad jabuke te 250, 300 i 350 l/ha za vinograd. Koriste se plave (TR 8003), žute (TR 8002) i zelene (TR 80015) Lechler mlaznice. Istraživanje se postavlja kao trofaktorijalni poljski pokus sa 18 tretmana u 4 ponavljanja, kakoza tip raspršivača tako i za vrstu nasada. Po tretmanu na stablo/trs postavljeno je 60 vodoosjetljivih papirića koji su obrađeni pomoću računalne analize slike i računalnog programa ImageJ. Uz glavna svojstva istraživanja, utvrđuju se indeks lisne površine i gustoće, brzina i protok zračne struje, radni tlak, usmjerenje mlaznica te se prate vremenski uvjeti tijekom istraživanja. Prije samog istraživanja raspršivači se testiraju prema europskom standardu EN 13790. Smanjivanjem ISO broja mlaznice, povećanjem brzine rada raspršivača te povećanjem norme raspršivanja povećava se pokrivenost tretirane površine, broj kapljica/cm2 i zanošenje tekućine, a smanjuje se prosječni promjer kapljica. Usporedbom dobivenih rezultata istraživanja eksploatacijom aksijalnog i radijalnog raspršivača u vinogradu i nasadu jabuke, bolje rezultate postiže radijalni raspršivač (Hardi Arrow) u oba slučaja. Najbolji odnos pokrivenosti tretirane površine i zanošenja tekućine u vinogradu ostvaruje se s pokrivenošću tretirane površine od 64,22% i zanošenja tekućine od 17,11% (zelena mlaznica, brzina rada od 6 km/h, norma raspršivanja od 350 l/ha te radni tlak od 10,99 bar). U nasadu jabuke navedeni odnos ostvaruje se s pokrivenošću tretirane površine od 59,55% i zanošenja tekućine od 21,10% (zelena mlaznica, brzina rada od 8 km/h, norma raspršivanja od 325 l/ha te radni tlak od 16,84 bar).Researches are conducted in vineyard and apple orchard with two different types of mist blowers, axial (Hardi Zaturn) and radial (Hardi Arrow). The influence of major technical spraying factors (type of nozzle, working speed and spray volume) were observed on coverage of the treated area, average droplet diameter, number of droplets per cm2 and drift. The working speed of sprayer was set at 6 and 8 km/h, and spray volume on 250, 325 and 400 l/ha for apple orchard and 250, 300 and 350 l/ha for vineyard. Researchers used Lechler blue (TR 8003), yellow (TR 8002) and green (TR 80015) nozzles. The research was set as three - factorial field experiment with 18 treatments in 4 repetitions, for different type of sprayer and permanent crops. We used 60 water sensitive papers for that treatment, which were processed with digital image analysis and ImageJ software. In addition to the main features of the research, research showed leaf area index and density, speed and flow of air current, working pressure, orientation of the nozzles and weather conditions, which were monitored during the study. Before the research, mist blowers are tested according to the European standard 13790. By decreasing the ISO number of nozzles and by increasing the working speed and spray volume, we found increase of area coverage, number of droplets per cm2and drift, and decrease of average droplet diameter. Also, by comparing the results of research exploitation by axial and radial mist blower in the vineyards and apple orchards, better results are achieved with radial mist blower (Hardi Arrow) in both cases. The best relationship of area coverage and liquid drift in vineyard were achieved with 64.22% area coverage and 17.11% of liquid drift (green nozzle, working speed of 6 km/h, spray volume of 350 l/ha, and working pressure of 10.99 bar). In apple orchard the best relationship of area coverage and liquid drift were achieved with 59.55% area coverage and 21.10% of liquid drift (green nozzle, working speed of 8 km/h, spray volume of 325 l/ha, and working pressure of 16.84 bar)

UPOTREBA VODOOSJETLJIVIH PAPIRIĆA ZA PROCJENU POKRIVENOSTI LISNE POVRŠINE U VOĆNJAKU JABUKE

Three commercial mist-blowers were tested in an apple orchard at the end of vegetation development in October 2008, using pure water and water sensitive papers (WSP). The width between apples rows was 3.5 m, the average width of tree top was 1.6 m and the average apple height was 3.6 m. All the machines had the same “Albuz ATR 80” red nozzles and the tractor’s PTO had a rotational speed of 540 rpm. The average temperature during testing was 17.05 °C; the average air humidity was 56.55 %, and the average wind speed was 0.9 m/s from the West. The spraying equipment used was: (A) “Tifone Vento” 1500, water levels of 1000 l/ha, maximum. air velocity of 30 m/s and 18638 m3/h of airflow, 14 nozzles, travel velocity of 5 km/h and work pressure of 17 bars; (B) “Myers N1500”, water level of 1000 l/ha, maximum. air velocity of 34 m/s and 36580 m3/h of airflow, 14 nozzles, travel velocity of 5 km/h and work pressure bar of 11 bar; (C) “Hardi Zaturn 1500”, water level of 1000 l/ha, maximum. Air velocity of 38 m/s and 44590 m3/h of airflow, 18 nozzles, travel velocity of 5 km/h and work pressure of 7 bar. The “Tifone” mistblower had 10048 m3/h total amount of air on the left side of the blower and 8590 m3/h on the right side. With this amount of air, the average WSP coverage on the left side was 44.05 %, and on the right was 41.33 %. The“Myers” mistblower had 18120 m3/h total amount of air on the left side of the blower and 18460 m3/h at the right side. With this amount of air, the average WSP coverage on the left side was 33.61 %, and on the right side was 37.98 %. (C) The “Hardi” mistblower had 24940 m3/h total amount of air on the left side of the blower and 19650 m3/h on the right side. With this amount of air, the average WSP coverage on the left side was 45.85 %, and on the right side was 42.47 %. The WSP were photographed by a “Canon EOS 1000D”. The pictures were then converted by “Irfan View 4.0”, and finally elaborated by “Adobe Photoshop”, “Global Lab Image/2” and “Graduate” softwares.U radu su prikazani rezultati istraživanja tri raspršivača pri radu u voćnjaku jabuke tijekom listopada 2008. Prilikom usporedbe korištena je čista voda uz primjenu metode vodoosjetljivih papirića (VOP). Širina redova u nasadu iznosila je 3,5 m, uz prosječnu širinu krošnje od 1,6 m, i visinu stabla od 3,6 m. Ispitivani raspršivači bili su opremljeni mlaznicama „Albuz ATR 80“(crvene boje), a sva ispitivanja obavljena su pri 540 min-1 priključnoga vratila traktora. Prosječna temperatura zraka u vremenskom intervalu ispitivanja iznosila je 17,05°C, s prosječnom vrijednosti vlažnosti zraka 56,50%. Prosječna brzina vjetra iznosila je 0,90 m/s u smjeru rada raspršivača. Testirani raspršivači bili su „Tifone Vento“, „Myers N1500“ i „Hardi Zaturn“. „Tifone Vento“ imao je sljedeće parametre rada: hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 30 m/s i ukupnu količinu zraka od 18 638 m3/h, 14 mlaznica, radnu brzinu od 5 km/h i radni tlak od 17 bar. „Myers N1500“ imao je sljedeće parametre rada: hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 34 m/s i ukupnu količinu zraka od 36580 m3/h, 14 mlaznica, brzinu kretanja od 5 km/h i radni tlak od 11 bara, dok je „Hardi Zaturn“ imao hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 38 m/s i ukupnu količinu zraka od 44590 m3/h, 18 mlaznica, brzinu kretanja od 5 km/h i radni tlak od 7 bara. Raspršivač „Tifone“ na lijevoj strani stroja imao je prosječnu količinu zraka od 10048 m3/h te je ostvario prosječnu pokrivenost na VOP-u od 44,05 %. Na desnoj strani stroja utvrđena je prosječna količina zraka od 8590 m3/h i prosječna pokrivenost na VOP-u od 41.33 %. Raspršivač „Myers“ na lijevoj strani stroja imao je prosječnu količinu zraka od 18120 m3/h te je ostvario prosječnu pokrivenost na VOP-u od 33.61%. Na desnoj strani stroja utvrđena je prosječna količina zraka od 18460 m3/h i prosječna pokrivenost na VOP-u od 37.98% Kod raspršivača „Hardi“ utvrđena je prosječna količina zraka na lijevoj strani od 24940 m3/h te je postigao prosječnu pokrivenost na VOP-u od 45.85 %. Na desnoj strani stroja utvrđena je prosječna količina zraka od 19650 m3/h i ostvarena je prosječna pokrivenost od 42,47 % na postavljenim VOP-ima. Prilikom istraživanja korištena je metodika, pri čemu su VOP fotografirani, a slike su konvertirane softverom “Irfan View 4.0” te kasnije obrađivane “Adobe Photoshopom”, “Global Lab Image/2” i “Graduate” softverom

UPOTREBA VODOOSJETLJIVIH PAPIRIĆA ZA PROCJENU POKRIVENOSTI LISNE POVRŠINE U VOĆNJAKU JABUKE

Three commercial mist-blowers were tested in an apple orchard at the end of vegetation development in October 2008, using pure water and water sensitive papers (WSP). The width between apples rows was 3.5 m, the average width of tree top was 1.6 m and the average apple height was 3.6 m. All the machines had the same “Albuz ATR 80” red nozzles and the tractor’s PTO had a rotational speed of 540 rpm. The average temperature during testing was 17.05 °C; the average air humidity was 56.55 %, and the average wind speed was 0.9 m/s from the West. The spraying equipment used was: (A) “Tifone Vento” 1500, water levels of 1000 l/ha, maximum. air velocity of 30 m/s and 18638 m3/h of airflow, 14 nozzles, travel velocity of 5 km/h and work pressure of 17 bars; (B) “Myers N1500”, water level of 1000 l/ha, maximum. air velocity of 34 m/s and 36580 m3/h of airflow, 14 nozzles, travel velocity of 5 km/h and work pressure bar of 11 bar; (C) “Hardi Zaturn 1500”, water level of 1000 l/ha, maximum. Air velocity of 38 m/s and 44590 m3/h of airflow, 18 nozzles, travel velocity of 5 km/h and work pressure of 7 bar. The “Tifone” mistblower had 10048 m3/h total amount of air on the left side of the blower and 8590 m3/h on the right side. With this amount of air, the average WSP coverage on the left side was 44.05 %, and on the right was 41.33 %. The“Myers” mistblower had 18120 m3/h total amount of air on the left side of the blower and 18460 m3/h at the right side. With this amount of air, the average WSP coverage on the left side was 33.61 %, and on the right side was 37.98 %. (C) The “Hardi” mistblower had 24940 m3/h total amount of air on the left side of the blower and 19650 m3/h on the right side. With this amount of air, the average WSP coverage on the left side was 45.85 %, and on the right side was 42.47 %. The WSP were photographed by a “Canon EOS 1000D”. The pictures were then converted by “Irfan View 4.0”, and finally elaborated by “Adobe Photoshop”, “Global Lab Image/2” and “Graduate” softwares.U radu su prikazani rezultati istraživanja tri raspršivača pri radu u voćnjaku jabuke tijekom listopada 2008. Prilikom usporedbe korištena je čista voda uz primjenu metode vodoosjetljivih papirića (VOP). Širina redova u nasadu iznosila je 3,5 m, uz prosječnu širinu krošnje od 1,6 m, i visinu stabla od 3,6 m. Ispitivani raspršivači bili su opremljeni mlaznicama „Albuz ATR 80“(crvene boje), a sva ispitivanja obavljena su pri 540 min-1 priključnoga vratila traktora. Prosječna temperatura zraka u vremenskom intervalu ispitivanja iznosila je 17,05°C, s prosječnom vrijednosti vlažnosti zraka 56,50%. Prosječna brzina vjetra iznosila je 0,90 m/s u smjeru rada raspršivača. Testirani raspršivači bili su „Tifone Vento“, „Myers N1500“ i „Hardi Zaturn“. „Tifone Vento“ imao je sljedeće parametre rada: hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 30 m/s i ukupnu količinu zraka od 18 638 m3/h, 14 mlaznica, radnu brzinu od 5 km/h i radni tlak od 17 bar. „Myers N1500“ imao je sljedeće parametre rada: hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 34 m/s i ukupnu količinu zraka od 36580 m3/h, 14 mlaznica, brzinu kretanja od 5 km/h i radni tlak od 11 bara, dok je „Hardi Zaturn“ imao hektarsku dozu vode od 1000 l, maksimalnu brzinu zraka od 38 m/s i ukupnu količinu zraka od 44590 m3/h, 18 mlaznica, brzinu kretanja od 5 km/h i radni tlak od 7 bara. Raspršivač „Tifone“ na lijevoj strani stroja imao je prosječnu količinu zraka od 10048 m3/h te je ostvario prosječnu pokrivenost na VOP-u od 44,05 %. Na desnoj strani stroja utvrđena je prosječna količina zraka od 8590 m3/h i prosječna pokrivenost na VOP-u od 41.33 %. Raspršivač „Myers“ na lijevoj strani stroja imao je prosječnu količinu zraka od 18120 m3/h te je ostvario prosječnu pokrivenost na VOP-u od 33.61%. Na desnoj strani stroja utvrđena je prosječna količina zraka od 18460 m3/h i prosječna pokrivenost na VOP-u od 37.98% Kod raspršivača „Hardi“ utvrđena je prosječna količina zraka na lijevoj strani od 24940 m3/h te je postigao prosječnu pokrivenost na VOP-u od 45.85 %. Na desnoj strani stroja utvrđena je prosječna količina zraka od 19650 m3/h i ostvarena je prosječna pokrivenost od 42,47 % na postavljenim VOP-ima. Prilikom istraživanja korištena je metodika, pri čemu su VOP fotografirani, a slike su konvertirane softverom “Irfan View 4.0” te kasnije obrađivane “Adobe Photoshopom”, “Global Lab Image/2” i “Graduate” softverom

The Impact of Conventional and Sensor Spraying on Drift and Deposit in Cherry Orchard

The research results of the spraying technical factors\u27 impact on ground and air drift, and the deposit on the treetop in cherry orchards, are presented in the paper. Two different spraying systems (classical and sensory system) are investigated, Agromehanika AGP 200 ENU sprayer being used. The research is conducted according to ISO standard 22866 (Plant Protection Equipment - Drift Measurement Methods in Field Conditions). The impact of spraying norm as factor A (A1 – 250 l/ha; A2 – 200 l/ha); the nozzle type as factor B (B1 – Lechler TR 8002 C; B2 – Lechler ITR 8002 C) and the fan air velocity as factor C (C1 – 18 m/s; C2 – 12 m/s) are examined by the variance analysis. To spray and evaluate the drift, Tartazine organic dye solution with 4% concentration is used. The filter papers, used as collectors, according to the specified ISO standard, are placed directly in the spraying zone. The sampled filter papers are washed out with 10 ml of deionised water under laboratory conditions. After washing, the colour intensity, i.e., the solution wave-length, is read by a spectrophotometer (Varian Cary 50 UV-Visible). Different drift intensity (ground and air drift) and treetop deposits are realized by the usage of various treatments of technical spraying factors and various spraying systems. Unlike the ground and air drifts, the deposit within the treetop does not show statistically significant change by using a sensory spraying system, i.e. by using a selective application

Impact of technical spraying factors on leaf area coverage in an apple orchard

Istraživanja su obavljena u nasadu jabuke sa dva tipa raspršivača, aksijalni (Hardi Zaturn) i radijalni (Hardi Arrow). Istraživan je utjecaj glavnih tehničkih čimbenika raspršivanja (tip mlaznice, brzina rada i norma raspršivanja) na pokrivenost tretirane površine, prosječni promjer kapljica, broj kapljica/cm2 i zanošenje tekućine. Brzina rada raspršivača podešava se na 6 i 8 k/mh, a norma raspršivanja na 250, 325 i 400 l/ha. Koriste se plave (TR 8003C), žute (TR 8002C) i zelene (TR 80015C) Lechler mlaznice. Istraživanje se postavlja kao trofaktorijalni poljski pokus sa 18 tretmana u 4 ponavljanja, za svaki tip raspršivača. Po tretmanu se na stablo postavlja 60 vodoosjetljivih papirića koji se obrađuju pomoću računalne analize slike i računalnog programa ImageJ. Glavni tehnički čimbenici raspršivanja ostvaruju statistički vrlo značajan utjecaj (**) na glavna svojstva istraživanja. Smanjivanjem ISO broja mlaznice, povećanjem brzine rada raspršivača te povećanjem norme raspršivanja povećava se pokrivenost tretirane površine, broj kapljica/cm2 i zanošenje tekućine, a smanjuje se prosječni promjer kapljica. Usporedbom dobivenih rezultata istraživanja sa aksijalnim i radijalnim raspršivačem u nasadu jabuke, bolje rezultate (*) postiže radijalni raspršivač. Najbolje podešenje tehničkih čimbenika raspršivanja (pokrivenost tretirane površine od 59,55 % i zanošenja tekućine od 21,10 %) ostvaruje se sa radijalnim raspršivačem te zelenom mlaznicom (TR 80015C), brzinom rada od 8 km/h, normom raspršivanja od 325 l/ha i radnim tlakom od 16,84 bar.Research is conducted on an apple orchard with two different types of orchard sprayers, axial (Hardi Zaturn) and radial (Hardi Arrow). The influence of major technical spraying factors (type of nozzle, working speed and spray volume) were observed on coverage of the treated area, average droplet diameter, number of droplets per cm2 and drift. The working speed of sprayer was set at 6 and 8 km/h, and spray volume on 250, 325 and 400 l/ha. In research, Lechler blue (TR 8003C), yellow (TR 8002C) and green (TR 80015C) nozzles were used. The research was set as three - factorial field experiment with 18 treatments in 4 repetitions, for each type of sprayer. Sixty water sensitive papers (WSP) were used for the treatment, which was processed with digital image analysis (DIA) and ImageJ software. The major technical spraying factors have a high significant statistical impact (**) on the main properties of the research. By decreasing the ISO number of nozzles and by increasing the working speed and spray volume, we found increasement of area coverage, number of droplets per cm2 and drift, and decreasement of average droplet diameter. By comparing the results of the research by axial and radial orchard sprayer in apple orchard, better results (*) were achieved with a radial sprayer. The best adjustment of technical spraying factors (area coverage of 59,55 % and 21,10 % of liquid drift) was achieved by a radial sprayer and with green nozzle (TR80015C), working speed of 8 km/h, spray volume of 325 l/ha, and working pressure of 16,84 bar

PESTICIDE APPLICATION TECHNICS IMPROVEMENT

Sveučilišni udžbenik Unapređenje tehnike aplikacije pesticida plod je višegodišnjega teorijskoga modeliranja, praktičnoga ispitivanja i sakupljanja podataka koji se odnose na tehničke sustave u zaštiti bilja i njeno okruženje u užem smislu. U ovome prvome izdanju uglavnom su obuhvaćena područja kojima se autori bave više godina. Cilj autora je potpun i jasan prikaz metodologije rješavanja konkretnih problema u upravljanju poljoprivrednom tehnikom u zaštiti bilja, izravno primjenjivih u praksi - “Know-How”, sa što je god moguće više upotrebljivih podataka. Izvori su, uz domaće, uglavnom američki i zapadnoeuropski. Knjiga je namijenjena svima onima koji se već služe poljoprivrednom tehnikom u zaštiti bilja i onima koji tek svladavaju osnove pravilne primjene tehničkih sustava u svakodnevnoj praksi, bez obzira na veličinu poljoprivrednoga gospodarstva. Neke osnove fizičke logike, analize i sinteze pojedinih zakonitosti pri uporabi i pesticida i tehničkih sustava detaljno smo obradili i pojasnili, zbog velike važnosti razumijevanja problematike.The academic textbook Pesticide application tehnics improvement is the result of several-year recording theoretical models, numerous practical tests, and data collection relating to technical systems in plant protection and its environment in the narrowest sense. In this first edition, the authors cover the area they have dealt with for many years. The authors aimed to present complete and clear methods how to solve specific problems in the agricultural practice management, plant protection, and direct practice application – ‘‘Know- How\u27\u27, with as many as possible useful data. References used, along with local ones, are mostly American and from Western Europe. This textbook is intended for those who already use the agricultural technique in plant protection and those who are just acquiring the basics of technical systems proper application in daily practice, regardless the size of the agricultural farm. The authors covered in details and explained some bases of physics logic, analysis, and synthesis of specific laws while using pesticides due to extremely importance in understanding the problem area

PESTICIDE APPLICATION TECHNICS IMPROVEMENT

Sveučilišni udžbenik Unapređenje tehnike aplikacije pesticida plod je višegodišnjega teorijskoga modeliranja, praktičnoga ispitivanja i sakupljanja podataka koji se odnose na tehničke sustave u zaštiti bilja i njeno okruženje u užem smislu. U ovome prvome izdanju uglavnom su obuhvaćena područja kojima se autori bave više godina. Cilj autora je potpun i jasan prikaz metodologije rješavanja konkretnih problema u upravljanju poljoprivrednom tehnikom u zaštiti bilja, izravno primjenjivih u praksi - “Know-How”, sa što je god moguće više upotrebljivih podataka. Izvori su, uz domaće, uglavnom američki i zapadnoeuropski. Knjiga je namijenjena svima onima koji se već služe poljoprivrednom tehnikom u zaštiti bilja i onima koji tek svladavaju osnove pravilne primjene tehničkih sustava u svakodnevnoj praksi, bez obzira na veličinu poljoprivrednoga gospodarstva. Neke osnove fizičke logike, analize i sinteze pojedinih zakonitosti pri uporabi i pesticida i tehničkih sustava detaljno smo obradili i pojasnili, zbog velike važnosti razumijevanja problematike.The academic textbook Pesticide application tehnics improvement is the result of several-year recording theoretical models, numerous practical tests, and data collection relating to technical systems in plant protection and its environment in the narrowest sense. In this first edition, the authors cover the area they have dealt with for many years. The authors aimed to present complete and clear methods how to solve specific problems in the agricultural practice management, plant protection, and direct practice application – ‘‘Know- How\u27\u27, with as many as possible useful data. References used, along with local ones, are mostly American and from Western Europe. This textbook is intended for those who already use the agricultural technique in plant protection and those who are just acquiring the basics of technical systems proper application in daily practice, regardless the size of the agricultural farm. The authors covered in details and explained some bases of physics logic, analysis, and synthesis of specific laws while using pesticides due to extremely importance in understanding the problem area

TECHNICAL-TECHNOLOGICAL ASPECTS OF APPLYING NEW FORMS OF PLOUGHSHARE

Istraživanje trošenja materijala lemeša različite izvedbe u oranju četverobrazdnim i peterobrazdnim plugom premetnjakom obavljeno je tijekom listopada i studenog 2001. godine na karbonatnom humogleju praškasto glinaste strukt ure. Brzina kretanja agregata u oranju bila je između 4,79 do 6,40 km/h, u prosjeku 5,58 km/h. Oranje je u prosjeku obavljeno na dubinu 25,5 cm. Lemeši su ukupno korišteni 309 sati. Ukupno su poorali 226 ha te je utrošeno 1,37 sati rada po ha. Svaki je lemeš poorao 22,6 ha. Ukupna masa svih lemeša prije istraživanja iznosila je 38625 g, a po završetku 30460 g. To je za 8165 g ili 21,13% manje od početne mase. Najviše su se istrošili lemeši oznake D1 i L1, koji su izgubili na masi 760 g, odnosno 930 g, ili 33,5%, odnosno 38,1%. Oni su nakon završenih testiranja postali neupotrebljivi za daljnji rad. Troškovi njihove uporabe iznose 10,06 kn/ha. Na lemešima oznake D2 i L2 nakon rada i gubitka 33,3% početne mase neupotrebljiv je postao vrh. Troškovi toga lemeša pri oranju su 5,83 kn/ha. Kod treće skupine lemeša, koju čine lemeši oznake D3, L3 i D4, L4, prosječni gubitak mase iznosio je 770 g ili 18,5%, a troškovi upotrebe iznose između 4,41 do 5,57 kn/ha. S njima se moglo i dalje nastaviti oranje. Na lemešima oznake D5 i L5, s gubitkom 27,1% početne mase, za daljnji rad je postao neupotrebljiv samo vrh lemeša. Njihovi troškovi su 3,03 kn/ha.Investigation of the various ploghshare materials wear on the five bottom plough was conducted in October and November, 2001. The ploughing was carried out on a carbonate humogley of powder clay texture. While working, the power unit work speed ranged from 4.9 km/h to 6.40 km/h, averaging 5.58 km/h. The ploughing was done at depth of 25.5 cm on the average. The ploughshares were used for 309 hours. The total of 226 ha were ploughed consuming 1.37 h/ha. Each ploughshare ploughed 22.6 ha. Total weight of all ploughshares amounted to 38625 g prior the investigation and 30460 g at its end. It is by 8165 g i.e. 21.13% less compared to the initial weight. The loss of 760 and 930 g i.e. 33.5 and 38.1% referred mostly to D1 and L1 respectively. After the investigation they became useless for further work. Their use costs amount to HRK 10.06/ha.Tip of the ploughsahres D2 and L2 were useless after their work resulted in 33.3% loss of the initial weight. The third group of the ploughshares including ploughsahres D3, L3, D4 and L4 was characterized by an average weight loss of 770 g i.e. 18.5% whereas use costs ranged from 4.41 to 5.57 HRK/ha. They were able for continued ploughing. Tip of the ploughsahers D5 and L5, known for the loss of 27.1% of the initial weight became useless for the further work. Their costs were 3.03 HRK/ha

Utjecaj frakcija zrna kukuruza i tehničkih čimbenika podešavanja na kvalitetu rada sijaćice PSK4

U radu su prikazani rezultati kvalitete sjetve pri simulaciji na ispitnome stolu. Utvrđivanje kvalitete rada sijaćice prikazano je s pomoću koeficijenata kvalitete sjetve (ISO standard 7256/1 i 7256/2), odnosno MISS, MULT i QFI indeksa. Ispitan je utjecaj četiriju različitih frakcija sjemena kukuruza dvaju hibrida na kvalitetu sjetve. Simulacija sjetve obavljena je s različitim tehničkim čimbenicima podešavanja sijaćice na ispitnome stolu (dva podtlaka, tri radne brzine sijaćice i četiri položaja skidača viška sjemena). Provedenom simulacijom sjetve utvrđena je statistički značajna razlika utjecaja različitih oblika/frakcija zrna, položaja skidača sjemena, podtlaka i radne brzine sijaćice na razmak zrna unutar reda prilikom sjetve oba istraživana hibrida. Podtlačna sijaćica PSK4 ostvarila je na ispitnome stolu pri radnoj brzini od 4 km ha-1 i položaju skidača sjemena na oznaci 10 visoke koeficijente kvalitete sjetve te se temeljem ostvarenoga QFI indeksa >98,6% može svrstati u grupu vrlo dobrih sijaćica. Nadalje, pri upotrebi hibrida H1 ostvaren je prosječni razmaka zrna u sjetvi unutar reda od 19,60 cm, koji osigurava sjetvu od 72.448 biljaka ha-1, dok je sjetvom hibrida H2 ostvaren prosječni razmak sjetve od 19,51 cm (72.831 biljaka ha-1). LSD0,05 testom utvrđena je statistički značajna razlika razmaka zrna unutar reda između navedenih hibrida