•Sugar beet nitrogen fertilization was optimized using leaf nutrient status samples.•Root yield and yield quality parameters were used as training and test data.•Ensemble decision trees and ...artificial neural network regression were used.•Na had high variable importance for root yield and sucrose content.•The top accuracy had a median R2 of 0.927 and ranged from 0.842 to 0.998.
Nitrogen fertilization has a crucial role in sugar beet production, especially concerning root yield and quality. This study employed a machine learning approach to predict root yield and quality parameters based on the nutrient status of sugar beet leaves in relation to nitrogen fertilization. The field experiment included the following N fertilization treatments for sugar beet production: control (N0), presowing (N1 = 45 kg N ha−1) and presowing with top-dressing (N2 = 99 and 154.5 kg ha−1). Leaf samples were collected during the vegetation period in six intervals (May-Sept) to determine the levels of N, K and Na in the leaf dry matter. The machine learning regression based on ensemble decision trees and artificial neural network was used to determine the relationship of leaf samples based on varying N fertilization with yield parameters. Among the leaf elements analyzed, Na exhibited the highest average relative variable importance for root yield, sucrose content, and other quality parameters during the season with greater precipitation. In the season with less precipitation, N content at the beginning of July showed higher importance on root yield (74.6). The evaluated machine learning methods consistently achieved high accuracy across various combinations of input data and yield parameters, with a median R2 of 0.927 and a range from 0.842 to 0.998.
Cilj ovog rada bio je analizirati provedenu zaštitu u suzbijanju pjegavosti lista šećerne repe (Cercospora beticola Sacc.) te prikazati ostvaren prinos i kvalitetu šećerne repe u petogodišnjem ...razdoblju (2016. – 2020.). U analiziranom razdoblju prvo tretiranje fungicidom provodilo se zbog prevencije već u prvoj ili drugoj dekadi lipnja. Ovisno o vegetacijskoj sezoni, zaštita je provedena u 4 (2016. – 2018.) ili 5 navrata (2019. i 2020.). Razmak između tretiranja je bio između 14 i 20 dana. Zadnje tretiranje provelo se krajem prve dekade kolovoza. U svakom tretiranju fungicidima korištena je kombinacija organskih sistemičnih fungicida i sredstava na bazi bakra (bakreni oksiklorid) što se pokazalo uspješnim u očuvanju lisne rozete. Prinos korijena šećerne repe iznosio je prosječno 74,4 t/ha, a sadržaj šećera u korijenu 15,86%. Najveći prinos korijena bio je 2016. godine (80,8 t/ha), kada je zaštita od gljivice Cercospora beticola bila provedena u 4 navrata. Najmanji prinos i sadržaj šećera ostvaren je 2019. godine, (65,2 t/ha i 12,24%), jer je nakon tuče u srpnju šećerna repa retrovegetirala.
The aim of this study was to determine the influence of different pH values of water solution (pH 4.5, 5.5, 6.5, 7.5 and 8.5) and temperatures (10, 15 and 20 ºC) on fibre flax seed germination and ...seedlings morphological characteristic (seedling root and stem length and total seedling length). The study was conducted in the controlled conditions by rolled filter paper in 4 replicates for 7 days. The average germination rate of flax seed was 84%. The highest germination rate was found at 20 ºC (88%) which was very significant (P<0,01) as compared to germination rate at 10 ºC where it was decreased by 9%. The highest share of normal seedlings was determined at pH 5.5 (70%) and the lowest at pH 8.5 (59%). There was no statistically significant influence of different pH on morphological characteristic of fibre flax seedlings (seedling root and stem length and total seedling length). The statistically significant difference (P<0.01) was determined in the length of the seedlings depending on the temperature, whereby after 7 days the largest seedlings were developed at 20 ºC (14.4 cm) and the shortest at 10 ºC (2.1 cm). In general, the lowest pH value (4.5) as well as the highest pH value (8.5) in this study resulted in a lower share of normal and healthy seedlings (63% and 59% respectively) and compared with seedlings of other pH values they developed a smaller root and stem.
The aim of this study was to analyse sugar beet root growth during 2014 vegetation period at two different nitrogen fertilization rates N1 = 45 kg/ha N and N2 = 99 kg/ha N. The sugar beet plant ...samples were collected in 12 terms from the end of May to the second half of September. During each sampling the total of 10 individual plants were analyzed. Fresh sugar beet roots were weighted and root diameter (cm), number and distance between the cambium rings (cm) were determined. The average share of root crown in the whole root mass was around 33% as of 20th September. The different nitrogen rates did not have a significant impact on the observed parameters and as of 20th September the average sugar beet root mass was 1782.8 g/plant, the root diameter was 13.1 cm and there were on average 8.2 cambium rings in a root.
In order to determine the dynamics of fresh mass and dry matter accumulation (leaves and storage root) together with sugar beet root yield and technological quality, a field experiment was set up in ...spring 2014. Sugar beet was sown in five different densities: 30,000, 50,000, 70,000, 90,000 and 110,000 plants/ha. To determine leaf and root dry matter, sugar beet plants were collected four times from June to September 2014. On 17th June sugar beet root dry matter was on average 43.1 g/plant and by 17th September it increased to 330.7 g/plant. The leaf dry matter was highest on 17th August (63.9 g/plant). The root diameter of mature beet (on 17th September) varied from 13.0 cm (70,000 - 110,000 plants/ha) to 14.3 cm (30,000 and 50,000 plants/ha). The highest root dry matter accumulation per 1 cm root diameter increment was from mid-June to mid-August, when it reached from 78.8 g/plant (50,000 plants/ha) to 351.5 g/plant (90,000 plants/ha). Generally, the average root yield was 55.7 t/ha, sucrose content 13.73% and white sugar yield 6.5 t/ha; the highest root yield (62.4 t/ha), sucrose content (14.40%) and white sugar yield (7.8 t/ha) was achieved with 110,000 plants/ha.
This study analyzes the dynamics of sugar beet root, crown, and leaves fresh and dry matter (FM and DM, respectively) accumulation per plant and their mass ratio at different plant densities and ...nitrogen fertilization. The biennial field trials were set as four different planting densities (60,000, 80,000, 100,000 and 140,000 plants ha-1) and three methods of nitrogen application in spring: control – without nitrogen fertilization (N0), presowing only (N1), and presowing with topdressing (N2). Close to the maturation, the mean DM of the whole root, crown, and leaves on September 20, 2014 amounted to 28.8, 7.3 and 4.0 t ha-1, respectively, whereas it amounted to 20.7, 4.1 and 2.3 t ha-1 in 2015, respectively. Moreover, with regard to the plant densities, the highest root DM was at 140,000 and 100,000 (31.6 t ha-1 in 2014 and 22.4 t ha-1 in 2015), compared to the wider plant densities of 80,000 and 60,000 plants ha-1 (22.4 t ha-1 in 2014 and 18.1 t ha-1 in 2015). Nitrogen fertilization positively influenced on dry matter accumulation, but it was different within the years. On September 20, 2014, a presowing fertilization (N1) increased the root DM by 17%, compared to the control, whereas in 2015 the presowing with topdressing (N2) increased the root DM by 30%. The root-to-leaves FM ratio amounted to 1:3.9 on May 30, 2014, whereas it amounted to 1:0.1 on September 20, 2014. The leaves FM was at its largest on June 20, 2015, when the root-to-leaves ratio amounted to 1:1.1, and gradually decreased to 1:0.1 on September 20, 2015.
U ovome je istraživanju kroz dvije godine analizirana dinamika porasta svježe mase (FM) i mase suhe tvari (DM) cijeloga korijena, glave korijena i listova šećerne repe te njihov omjer masa ovisno o broju biljaka po jedinici površine (60.000, 80.000, 100.000 i 140.000 biljaka ha-1) i gnojidbi dušikom u proljeće: kontrola (N0), samo predsjetva (N1) te predsjetva gnojidba s prihranom (N2). Pri sazrijevanju, 20. rujna, prosječna masa suhe tvari cijeloga korijena, glave korijena i lisne rozete šećerne repe u 2014. godini iznosila je 28,8, 7,3 i 4,0 t ha-1, dok je u 2015. bila manja i iznosila je prosječno 20,7, 4,1 i 2,3 t ha-1. Štoviše, u odnosu na gustoću sjetve, prosječno veća masa suhe tvari cijeloga korijena izmjerena je pri 140.000 i 100.000 (31,6 t ha-1 u 2014. i 22,4 t ha-1 u 2015.), i to u odnosu na sklop od 80.000 i 60.000 biljaka ha-1 (22,4 t ha-1 u 2014. i 18,1 t ha-1 u 2015.). Gnojidba dušikom pozitivno je utjecala na akumuliranje suhe tvari, ali je utjecaj gnojidbe bio različit ovisno o godini istraživanja. Tako je 20. rujna 2014. predsjetvena gnojidba (N1) povećala masu suhe tvari cijeloga korijena za 17% u usporedbi s kontrolom, dok je u 2015. predsjetva gnojidba i prihrana (N2) rezultirala povećanjem mase suhe tvari cijeloga korijena za 30% u odnosu na kontrolu. U 2014. je omjer svježe mase korijena i lisne rozete 30. svibnja bio 1: 3,9, a 20. rujna 1: 0,1. U 2015. godini omjer mase cijeloga korijena i lisne rozete bio je najširi 20. lipnja (1:1,1), a postupno se masa lisne rozete sazrijevanjem korijena smanjivala, tako da je 20. rujna omjer iznosio 1:0,1.
The aim of this study was to analyse sugar beet growth in field conditions during 2014 growing season. Sugar beet (hybrid Serenade, KWS) was sown on March 18th at inter–row spacing of 50 cm and four ...different intra–row spacings: 13 cm, 15 cm,17 cm and 19 cm. During the growing season sugar beet plants samples were taken in eight terms from June to September. In each sampling term sugar beet leaf and root fresh weight (g/plant) were determined. Also, diameter, number and distance between cambium rings and the number of cambium rings of 1 cm diameter were determined at the cross section of the widest hypocotyl part. Sowing density had a significant effect (P≤0.05) on all observed parameters. Average fresh leaf weight for all densities of 717.84 g/plant was the highest in late July and early August. Generally, during the growing season the plants sown at wider intra–row spacings (17 and 19 cm) had on average higher root weight compared to average root weight in narrower intra–row spacings (13 and 15 cm). Average root diameter of all sowing densities increases from 4.13 cm in the first decade of June to 12.51 cm in the second decade of September wherein the diameter varied from 11.55 cm (intra–row spacing 13 cm) to 14.79 cm (intra–row spacing 19 cm). Intensive formation of cambium rings for all densities was found out in June, where at the beginning of the June, the average number of cambium rings was 4.9, while and at the end of it was 7.3. In September, sugar beet root had on average of 8.4 cambium rings. On July 30th the largest number of cambium rings at 1 cm root diameter was on the average 1.52.
The aim of this study was to examine subsequent effects of carbocalk liming on soil characteristic, maize yield components and grain yield. For this study the field experiment (Sopje, ...Virovitica-Podravina County) was established on an acidic planosol (pH(KCl)=3.42) amended once in 2000 with increasing rates of air–dried carbocalk (0, 15, 30, 45 and 60 t ha-1). Even though liming in 2000 increased maize grain yield in 2013 growing season as compared to the control, the highest maize grain yield of 5.42 t ha-1 was achived with liming at 30 t ha-1 carbocalk, whereas the lowest maize grain yield (4.39 t ha-1) of limed treatments was at 60 t ha-1 carbocalk. The highest decrease of soil acidity in 2013 for 3.41 pH units as compared to the control, was at 60 t ha-1 carbocalk in 2000. Increasing carbocalk doses in 2000 had a subsequent effect on increase of P and decrease of K availability in 2013.
The field trial with increased rates of air-dried carbocalk (waste of Osijek Sugar Factory; 39% CaO) was conducted in autumn of 2000 on planosol in the amounts 0, 15, 30, 45 and 60 t ha-1. Liming ...considerably influenced on maize yields by increases up to 26% (4-year mean) with variation these effects among the years from 7% to even 50%. Yields of sugar beet were increased due to liming up to 43% (30 and 43 t ha-1, for 0 and 30 t ha-1of lime, respectively). However, liming was closely related to lower sugar beet root quality (sucrose = 14.6% and 13.4%, amino-N = 2.62 and 4.58 mmol 100 g-1, for 0 and 60 t lime ha-1, respectively). By using 60 t carbocalk ha-1significantly increased maize leaf P (+45%), Ca (+35%), Mg (+57%) and decreased K (-7%), Zn (-54%) and Mn (-71%) compared to the control treatment (3-year means). Analogical comparison for sugar beet leaf (the 2004 growing season only) resulted by differences as follows: P (+57%), Ca (-18%), Zn (-53%), Mn (-90%), B (-36%), and non-significant differences for K, Mg and Na. Mean concentrations of the nutrients in maize leaves found by our study were as follows: 0.344 % P, 2.42% K, 0.812% Ca, 0.332, mg Mg kg-1, 33.2 mg Zn kg-1and 130.3 mg Mn kg-1, respectively. Adequate concentrations of these elements were found in maize leaves with emphasis that by using 60 t of lime ha-1concentrations of Zn were close to inadeaquate concentration of 20 mg Zn kg-1. Also, adequate ranges of sugar beet leaf P (mean 0.374% P), K (mean 3.99% K), Ca (1.23% Ca) and Zn (mean 24.5 mg Zn kg-1) were found. The levels of leaf B, Mg and Mn were out the adequate ranges (deficit of B: mean 7.4 mg B kg-1; oversupplies of Mg and Mn: means 1.18% Mg and 160 mg Mn kg-1, respectively).
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