No abstract

There is a worldwide trend that supports the rational use of chemicals in agriculture. It has become common knowledge that irresponsible application of pesticides can cause food security issues, by endangering human and animal health while also having negative environmental consequences. The aim of this experiment was to assess the qualitative parameters of spraying treatments in vineyards. To achieve this, a vineyard and orchard sprayer machine was used for the application of treatments under a gradient of pressures (3, 5, 7, 9 bar). Water-sensitive collectors were placed at three heights (0.8 m, 1.5 m, 2.5 m). Following spraying was determined using DepositScan: the volume median diameter characterization of droplets (DV 1, DV 5, DV 9), and coverage degrees of sprayings. Results indicated that best coverage degree and larger droplets tend to be deposited 1.5 m from the ground, which corresponds with the highest proximity to the positioning of the nozzles of the machine during application, and lowest coverage is found at the top, where droplets deposited also tend to be smaller. For the anti-drift nozzle model used in the study, the best coverage was obtained at a pressure of 5 bar. For sustainability of agricultural practices and rational use of pesticides, more research is required for optimization of increased precision spraying that could ensure high coverage at lower doses of chemicals and coarse droplets. In this way the quantity of product sprayed is expected to be reduced, due to minimization of off-target losses and increased efficiency. This can ensure that negative environmental impacts are lowered. Improved treatment application at higher positioning of the canopy remains a challenge and shall receive more attention.

During the process of maize seed production, in order to ensure the genetic purity of parental forms of hybrid maize, an important work performed is the removal of male inflorescences from plants on mother rows. Hand detasseling has high precision but is labor-intensive. Mechanical detasseling offers the possibility to cover large acreages in a short period of time, but the number of leaves removed has a varying influence on plant performance and seed yield. The aim of this study was to simulate three types of damages on plants similar to those induced through mechanical detasseling and to assess the effects for five inbred lines during the course of three years. Results show that when tassels alone were removed, the average seed yield decreased an average of 4–21%. When two leaves were removed with the tassel, yield decreased an average of 22–31%, while when plants were cut above the main ear, seed yield decreased an average of 31–66%. Environmental conditions influenced seed yield, especially high temperatures during flowering. Yield response to tassel and leaves removal varied between the inbred lines. Genotype controls maize ear and kernel characters, while environmental factors exercise a strong influence on seed yield, due to the succession of years with contrasting weather conditions in a key phenophase. Within the trend of full mechanization in agriculture, identification of inbred lines that cope better with plant damage can assist in optimizing seed production.

Semi-natural grasslands are particularly important in mountainous areas of Romania, being the only source of forage for many farmers. The aim of this study was to investigate the changes in forage quantity and quality as a result of Urea Ammonium nitrate (UAN) liquid fertilization. The experiment was carried out in the eastern part of Apuseni Mountains, Romania on a Festuca rubra L.-Agrostis capillaris L. grassland located at 1240 m altitude. Studies were made over three years of experimental trial (2014–2016) and covered four experimental plots in three replicates, as follows: V1–control plot, unfertilized; V2–plot fertilized with 50 kg UAN ha−1 year−1; V3–plot fertilized with 75 kg UAN ha−1 year−1, and V4–plot fertilized with 100 kg UAN ha−1 year−1. The experimental plots were harvested once per year and the botanical composition, dry matter yield and forage quality were assessed. Our results showed important changes in forage quantity, quality and diversity as a result of UAN fertilization. Starting from the second experimental year the dominance/co-dominance ratio changed favoring the species from Poaceae family. Dry matter increased as a result of UAN fertilization but forage quality was negatively affected by the higher percentage of participation of species from other botanical families which have higher crude fiber content and lower crude protein. Based on our results we recommend moderate fertilization with UAN up to 50 kg UAN ha−1 year−1 for semi-natural grasslands located in soil-climatic conditions similar to those in our experiment.

Changing the degree to which animals feed is grinded can be done for hammer mills in several ways, namely: the use of sieves with different diameters, different hammers, different engine speeds.Grain milling energy consumption is in luenced by the type of material used, its moisture content, size and type of hammers, sieves holes etc.In the present study we determined the in luence of moisture and sieve mesh size on milling maize grain moisture of 11.1% and 17.6% using conventional hammer mill. Using th ree kinds of sieve apertures with a diameter of 4, 6 and 8 mm was determined from the speci ic grinding energy.