Ivan Plaščak

IMPACT OF TECHNICAL SPRAYING FACTORS ON VERTICAL LIQUID DISTRIBUTION WITH AGROMEHANIKA AGP 440 AXIAL FAN SPRAYER

Original scientific paper The influence of technical spraying factors on vertical distribution of liquid and air velocity was observed and measured with vertical patternator device. In research, Lechler yellow (TR 8002C) and red (TR 8004C) nozzles are used with two different sets of fan rotor blades (two different air velocities) at 540 rpm of PTO. The research was set as controlled three factorial experiment (without the influence of weather factors) with 8 treatments in 4 repetitions, for each side of Agromehanika AGP 440 axial fan sprayer. Technical spraying factors (ISO nozzle number, settings of fan blades and spraying height) have a high significant impact (**) on the main properties of the research (vertical distribution of liquid and air velocity). By decreasing the ISO nozzle number and air velocity the increase of liquid deposit is found on vertical patternator and with the increase of measuring height a non-uniform distribution of liquid and air velocity is found. In addition, a non-uniform distribution of liquid and air velocity is established between the left and right sides of the machine. With regression analysis between the vertical distribution of liquid and air velocity on both sides of the machine, a statistically significant coherence is determined (left side of the machine: r = 0,96; p < 0,01; right side of the machine: r = 0,97; p < 0,01).

Damage of seminal maize hybrid in harvesting and husking

One of the biggest challenges for the safe maize production is the yield stability in a wide range of environments with different soil fertility, weather conditions, prevailing pests and diseases as well as cultural practices. In order to achieve it, new hybrids with higher tolerance to biotic and abiotic stress are continuously being created. In order to compare performance of maize hybrids in environments with different levels and types of stress, and relate it to the stalk lodging incidence, we compared performance of 64 maize hybrids obtained by crossing 16 inbred lines with four inbred testers in three different environments. Two environments at same location (Rugvica) differed in crop rotation, and the third environment at location Botinec was considered as dry because of low water capacity of the soil. Mixed models that included all design elements and genetic background of hybrids were used to analyze the effect of lodging on yield in different environments. The results show that stalk lodging had a significant effect on yield, but significant lodging x environment interaction indicates that this effect was rather environment specific.Sweet pepper Istra F1 hybrid was grown in a greenhouse on K rich soil. For evaluation of K antagonism, two K rates (55 and 85 kg ha-1) were applied in a randomized complete block design with four replications. Total number of fruits, total number of BER affected fruits as well as average fruit mass were recorded for each harvest. Fruit and leaf K and Ca content were determined at three plant growth stages (at the stage of the first, third and fifth fruit cluster). Higher K rate gave higher : average fruit mass (169.45 g), total number of fruits per plant (7.95), number of BER affected fruits per plant (3.82), K in leaves (5.44% DM), K in fruits (6.35% DM), but negatively correlated with Ca concentration in fruits (0.57% DM) and leaves (3.24% DM). This resulted in decreased marketable yield of sweet pepper fruits.

Wheat and Barley Yiels Affected by the Rotation of Oilseed Rape as the Preceding Crop

Oil rape is a valuable fodder because in early spring and late autumn it produces green forage used for the nutrition of domestic animals. It has been replacing sunflower and soy in colder and wetter regions. It is additionally advantageous because it leaves behind more nitrogen in soil, which is beneficial to other plants in plant rotation. There are some possible ways for the fixation of nitrogen in soil and they are as follows: by the means of oil rape straw ; by relatively long roots ; by the action of nitrogen bacteria, which perform the nitrogen synthesis within their root system, which is the case in some leguminous plants. Oil seed rape is expected to be wider used in crop rotation of West and Middle Europe, Croatia included. Due to this various sorts have been introduced and potential positive impacts have been studied in order to boost the process. This paper presents information on barley and wheat yield in case when they were sown after oil seed rape and corn. The aim of the research is to determine the presence of positive impacts upon the soil with special attention paid to a potential increase of nitrogen content after oil seed rape was grown. The preceding crops had statistically significant effect. Rape yield was significantly higher compared to the one with corn as preceding crops. Very similar results were obtained in 2007.The maize hybrids seed from three different FAO groups (FAO 400, FAO 500 and FAO 600) in four fractions (KO, KP, SO and SP) produced in two climatically different years (extremely dry 2000 and extremely wet 2001) had been different in quality and chemical composition. The effects of year, genetic specifity and seed fraction at the kernel mass, chemical composition (starch, proteins, cellulose, oil and moisture content) and seed vigour have been evaluated. The influence of agroecological conditions during two production years have been exposed at seed chemical composition and vigour indicators (cold test – CT and bulk seed electrical conductivity - EC). The genetic specificity and seed fraction had significant influence at all tested indices, with the exception of the influence of the fraction at the starch content