In 2017, we conducted a field experiment to test the influence of a mixture of two plant growth-promoting bacteria (Pseudomonas fluorescens and Azospirillum brasilense) on the yield of three potato ...varieties. In addition, the influence of the mixture on potato susceptibility to infection by the pseudofungus Phytophthora infestans and fungus Alternaria solani and to attacks by the Colorado potato beetle (Leptinotarsa decemlineata) was investigated. It was the first experiment of its kind in Europe. In the unusually hot and dry year, a positive influence on the yield (17%-31%) was found in all three varieties when the tubers were soaked in the bacterial mixture prior to sowing. We observed no significant differences in potato resilience/susceptibility to harmful organisms among the different treatments (soaked tubers, sprayed tubers, untreated tubers); however, there were significant differences in the productivity between the tuber varieties. The results of our research indicate the bacterial mixture used in this study has a high potential to support satisfactory potato yields under dry conditions and under low levels of infection by foliar fungal diseases and attacks by foliar insects.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Four types of nozzles were tested on large-scale trials with a 40 m2 plot unit size. The Avi Twin 110-01 (80 L ha−1), 110-02 (160 L ha−1), 110-03 (240 L ha−1), and 110-04 (320 L ha−1) symmetric ...double fan injector nozzles were tested during the 2020/2021 and 2021/2022 growing seasons. This study aimed to evaluate the performance of spray nozzles with regard to deoxynivalenol (DON) accumulation in durum wheat grains. Artificial inoculation with Fusarium spp. was performed after durum heads were protected with fungicide. The percentage of heads covered with fungicide droplets, grain yield, yield-related traits, technological quality parameters, and concentrations of DON were determined. Compared to the control (without fungicide treatment), the Avi Twin 04 nozzle caused a reduction of 45.0% in the DON concentration on average across both growing seasons. This positively corresponded to the percentage of heads covered with fungicide droplets, which was highest when this nozzle was utilized. In both trial years, the DON reduction caused by the 110-04 twin nozzle was higher than that caused by the 110-01 nozzle. Treatment with the 110-04 nozzle more effectively improved the grain yield, 1000-kernel weight, and test weight compared to treatment with the 110-01 nozzle and the untreated control. The differences in technological quality were less pronounced when different spray nozzles were used.
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.
Simultaneous planting and final ridge formation using a deeper planting depth is necessary in order to achieve good soil cover of tubers and fewer green tubers. Three planting depths were used: ...planting depth 1 (the shallowest), planting depth 2 (the medium), and planting depth 3 (the deepest). Planting depth 3 led to the largest minimum distance of tubers from the ridge side, and the smallest percentage of tubers in the upper layer of the ridge (0 to 5 cm). However, the highest yield and percentage of green tubers and the smallest marketable yield occurred at the shallowest planting depth (1). The tuber cluster covers 80 to 90% of the area of the ellipse. Empty spaces surrounding the tuber cluster in the ridge also affect the percentage of green tubers in the ridge, which predominantly occur at planting depth 3 and are the rarest at planting depth 1.
Green tubers are often a problem in a modern potato production system. They can lead to a substantial reduction in marketable yield and potato quality. This study examined the effects of ridge top ...width on reduction of green potatoes, ridge geometry, soil cover of tubers, tuber position in the ridge and potato yield. Three different ridge top widths were analysed in the trial, i.e. 10, 28 and 38 cm. Final trapezoid-shaped ridges were formed simultaneously with planting. By increasing the width of the ridge top, especially to 38 cm, the horizontal distance between the tubers and the ridge side was increased. In the ridges with a 28- and 38-cm top width, a larger area between tuber cluster and ridge sides was achieved than in ridges with a 10-cm ridge top width. A 38-cm ridge top width led to the largest area of empty space between the tubers and the ridge sides. The increase in the ridge top width increased the cross-sectional area 0–5 cm below top of the ridge. The above-mentioned factors helped to decrease the weight and percentage of green tubers in the ridges with top widths of 28 and 38 cm compared to 10 cm, particularly by reducing greening of tubers at the ridge sides. The increase in ridge top width also increased the theoretical area of the ellipse that represents the largest possible area for the growth of tubers in a ridge. The area of the tuber clusters in the ridge was 220–360 cm
2
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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.
Modern hybrid maize varieties dominated for several decades both in Slovenia and elsewhere in the world. The production is maintained only of few landrace populations, but some are maintained at ...Slovenian Gene Bank. Improvement of local varieties is possible by recurrent selection and may in the case of their specific characteristics deserve their cultivation for specific purposes. Presented experiments have been conducted to characterize selected old Slovenian accessions in two regions - in central Slovenia and in Bela Krajina. Yields of corn at both locations and both years were significantly depending on the genotype. 'Rdeča Bohinjka' and partially 'Rumena Bohinjka' and, similarly, the 'LJ 180' had a predominantly low yields but were also the earliest, while modern hybrid variety 'P 9074' and 'Ronaldinio KWS ' had the expected highest yield. Yield of 'P 9074' grown at the Laboratory field of the Biotechnical Faculty was almost twice higher than the second best accession 'Metliška Plut'. However it is this semi-flint accessions 'Metliška Plut' that proved very suitable at all four experiments and is recommended for further maintenance and varietal testing as it can serve as appropriate alternative in a less intensive production.
In Slovenia, only tefluthrin is registered for controlling wireworms. In order to investigate the potential alternatives for controlling wireworms in potato, the field experiment was conducted in the ...period from 2011 (year 1) to 2012 (year 2). As alternatives, different Brassica crops (year 1: rapeseed, oilseed radish and white mustard; year 2: rapeseed, oilseed radish, oilseed rape, kale and white mustard) were tested (fresh foliage was incorporated into the soil by ploughing) for their biofumigant effect. Results of our investigation showed that in both years the potato yield was affected by measures of pest control; however, none of the tested biofumigant plants proved to be a potentially promising candidate in wireworm control. The rapid release of volatiles after plant chopping before and during incorporation into the soil could be the reason of inefficacy in our experiment. In our study, most wireworm damage occurred on biggest potato tubers. Moreover, edge effect of the field played an important role in our experiment in year 1. Treatment (chemical or biological) of wireworms only at the edge part of the field could offer a cost-effective, time-saving and environmentally more friendly way of controlling studied pest organism.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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