With a very diverse structure and small molecules, phytohormones are regulators of plant growth and development. Despite the fact that they are synthesized by plants in small quantities, they are highly active physiologically. According to their action, phytohormones can be divided into two categories, as either activators of plant growth and development or as inhibitors, with auxins and cytokinins belonging to the former group. Auxins are synthesized by plants in the apical meristems of shoots, but also in young leaves, seeds, and fruits. They stimulate the elongation growth of shoots and initiate the production of adventitious and lateral roots. Cytokinins, in turn, are formed in root tips and in unripe fruits and seeds. These hormones are responsible for stimulating the growth of lateral shoots, they also stimulate cytokinesis and, consequently, cell division. The aim of this review paper is to present the progress of the research on the effect of selected auxins and cytokinins on crops, considering the prospect of using them in plant growing methods.
Replicated three times, the research was conducted in the experimental field between 2011 and 2014. Three soil conditioners with the following trade names: UGmax, EkoUżyźniacz, and Humus Active Papka were used in the experiment, separately or together with NPK fertilisers. They were all used on plots sown with two species of grass, Dactylis glomerata of the Bora variety and Lolium perenne of the Info variety. The plant material from both grass species was tested for the concentration of ADL fraction (% DM), cellulose (% DM), and hemicellulose (% DM). It was found that the concentration of cellulose, hemicelluloses, and the ADL fraction was significantly higher in the biomass of Dactylis glomerata than in the biomass of Lolium perenne. The grass from the plot with the UGmax soil conditioner applied had the highest amount of cellulose and hemicellulose. The lowest amount of those organic compounds was found in the grass treated with UGmax together with mineral fertilisers and in plants treated with Humus Active, together with mineral fertilisers. However, the fertilisers and conditioners did not increase the ADL content in both grass species.
In 2013 a field experiment was set up in order to determine the effect of Ecklonia maxima extract on the development of the aboveground biomass of alfalfa (Medicago X Varia T. Martyn). The main experimental factor was a biostimulant based on the extract containing plant hormones. The extract was applied to the experimental units in the form of spraying. The following features were determined in the experiment: plant density, the number of shoots per square meter, dry matter weight per square meter, and the ratio of leaves to the entire biomass. The results were processed statistically with the analysis of variance, while differences between means were verified with Tukey's test (p ≤ 0.05). Furthermore, the Pearson linear correlation coefficient and the coefficient of determination were calculated in order to determine the relationship between the number of plants and shoots per area unit and biomass weight. Extract application led to an increase in shoot length and density, and the weight of dry matter in individual harvest, but it did not affect plant density and the ratio of alfalfa leaves. However, a decrease of plant density in consecutive years was observed.
The analysis of some physical properties of drained peat-moorsh soil layers. The paper presents the results of measurements of some physical properties for 14 drained fen peat-moorsh layers (degree of decomposition, bulk density, particle density, porosity and saturated moisture content). The soil samples were taken from north- -east, central and east part of Poland. These areas were drained in order to use as a grassland and meadows. The article presents obtained data of selected physical properties from several drained peatlands in Poland and shows the comparison of established results with relevant data published in literature.
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