ЗНАЧЕНИЕ КОЭФФИЦИЕНТА РАЗМНОЖЕНИЯ ПРИ ПРОИЗВОДСТВЕ СЕМЯН СОРТОВ ЯРОВОГО ЯЧМЕНЯ

Purpose. To determine the influence of the method of sowing and the quantitative placement of plants on the area on the formation of individual productivity and yield of Phaseolus vulgaris l. varieties. Methods. General scientific methods: hypothesis, experiment, observation and data analysis. Field research, measurement and weighting, and mathematical and statistical methods were used. Results. An increase in the density of sowing, due to the growth of competitive relationships between plants for life factors, regardless of the variety and sowing method, led to a decrease in the mass and number of seeds from one plant and the number of beans on it, as well as the mass of 1000 seeds. The maximum number of beans (13.9-14.6 pcs/plant) noted in the Bilosnizhka cultivar with wide-row sowing and a sowing density of 400-500 thousand pcs/ha. The specified variants provided the highest structural parameters of the crop and individual plant productivity: the number of seeds – 59.4-64.7 pcs/plant, the mass of 1000 seeds – 223-230 g, the mass of seeds per plant – 13.3- 14.9 g. Together with the sowing methods, the highest seed productivity was provided by the 600 thousand/ha plant density – 2.33-3.24 t/ha, and with a row spacing of 45 cm, the yield was 0.39-0.49 t/ha higher. The maximum seed productivity of Phaseolus vulgaris l. – at the level of 3.24 t/ha – was in the Bilosnizhka variety. Conclusions. The best parameters of the yield structure were observed in the Bilosnizhka variety in the variant of the wide-row sowing method (45 cm) and plant density of 400-500 thousand pcs/ha: the number of seeds – 59.4-64.7 pcs/plant, the mass of 1000 seeds – 223-230 g, the mass of seeds per plant – 13.3-14.9 g, the number of beans – 13.9-14.6 pcs/plant. The maximum seed productivity (2.72-3.24 t/ha) was provided by the sowing in 45 cm wide rows with a seeding density of 600 thousand pcs/ha. In all variants of the experiment, the highest seed yield was formed by the Bilosnizhka bean variety – 3.24 t/ha.

The aim of this study was to analyze the yield components of winter oilseed rape depending on the plant population in 2017/2018 growing season. Three plant populatios were considered in the study: 20, 40 and 60 plants m-2. At harvest several yield components were determined: plant height (cm), plant mass (g), height of the first fertile branch (cm), number of fertile lateral branches, number of pods per plant, length of the pod (cm), number of seeds per pod, mass of seeds per pod (g), number of seeds per plant, 1000 grain mass (g) and yield of seeds per plant (g). At the plant population of 40 plants m-2 the plants were the highest (153.4 cm), with the highest plant mass (295.3 g) and the number of lateral fertile branches (5.6 branches per plant). Furthermore, the plants from 40 plants m-2 had the highest number of pods per plant (716 pieces), the longest pods (6.5 cm) with the largest number of seeds per pod (21.0) and the number of seeds per plant (15 036 seeds). The highest and significant correlation coeficient was found between number of pods per plant and plant mass (r=0.890***) and than between the number of lateral branches and number of pods per plant (r=0.850***). Linear regression showed that for every centimeter increment of pod length the number of seeds increase for 4.8 seeds at 20 and 40 plants m-2 and for 5.5 seeds per pod at 60 plants m-2. Furthermore, regression analysis showed that for every centimeter pod length increment the seeds mass per pod increase on average of all plant population for 0.02 g.

Pecan is one of the most important horticultural nut crops in the world. It is a deciduous species native to the temperate zones of North America, introduced into the subtropical regions of Brazil during the 1870s. High quality seedlings are essential to establishing healthy and productive orchards, and selection of seeds is an important factor in this issue. In this study we evaluated the correlation between seed mass, emergence rate and morphometric traits of seedlings in the pecan cultivar Importada. A significant positive correlation (r > 0.81) between seed mass and plantlet height, stem diameter, emergence rate and number of leaves was observed. Our results suggest that seed mass can be used as a direct method for seed selection towards production of vigorous pecan seedlings. However, since an increase in seed mass is usually associated with a decrease in the number of seeds that a plant can produce per unit canopy, long-duration studies are recommended in order to evaluate the influence of seed selection on a plantation’s production.

This article presents the results of the study on the formation of pea seed yields under the influence of foliar fertilization at different backgrounds of mineral nutrition. The purpose of the study is to substantiate the methods of improving the cultivation technique of pea seeds based on the optimal combination of mineral nutrition backgrounds with the use of foliar fertilizers, the interaction of which ensures high yields. The following objectives were solved: 1. determination of the effect of different mineral nutrition backgrounds in combination with foliar fertilization on the formation of yield structure; 2. determination of the effect of different mineral nutrition backgrounds in combination with foliar fertilization on pea yield. The article deals with the influence of the studied methods on the main elements of productivity: number of beans on a plant, number of seeds in a bean, mass of seeds in a plant, 1000-seed mass. The pea yield as a function of foliar fertilization at different nutrition backgrounds is shown. In the conclusion, it is noted that foliar fertilization with Biostim Universal at a rate of 2.0 l/ha in the stemming + budding phase contributes to a higher grain yield in peas, regardless of the mineral nutrition backgrounds. Fertilization with N16P16K16 leads to higher yield growth. An increase in the fertilizer application rate – N32P32K32 – did not contribute to a further increase in yield. The highest yield is achieved when N16P16K16 is applied with subsequent foliar fertilization with Biostim Universal at a rate of 2.0 l/ha in the stemming + budding phases.

Relatively few studies conducted in natural plants populations focus on the relationship between seed size and their germination ability and seedling establishment. Maianthemum bifolium is a perennial herb that spreads vegetatively through rhizomatous growth and reproduces through seeds. However, this species is characterized as seed and microsite limited, and under undisturbed conditions seedlings are not noted. The studies were conducted in two populations of M. bifolium in six subsequent seasons. The mean seed mass was negatively correlated both per ramet as well as in the fruit with the number of seeds, and positively with its height and the number of flowers. The long-term mean annual production of seeds in the populations was 37 and 56 seeds per m2. The seeds from both populations had similarly high germination abilities that were approximately 90% under laboratory conditions, 60% in garden, and 55% in the natural habitat. Seeds from four size classes were sown and a positive correlation was noted between seedling establishment and the mass of the seeds from which they grew (rS = 0.64). Seedling survival was also significantly correlated with seed mass.

Evolution of low moisture stress tolerant genotypes of cotton is a dire need of the time for sustainable/increased production of cotton in Pakistan. A study was conducted to estimate the varietal differences and genetic control of various within boll yield components and fiber quality traits under normal and moisture stress conditions. Five parents viz; PB-39, MNH-886, MNH-147, CIM-598, BH-95 and their ten direct crosses were grown in field in split plot arrangement under randomized complete block design with two replications. Analysis of variance revealed significant differences between the two treatments (normal and moisture deficit) and among the fifteen genotypes for all the recorded traits including bolls number per plant, weight per boll, seed cotton yield per plant, GOT, seeds number per boll, seeds mass per boll, lint mass per boll, fiber length, fiber strength and fiber fineness. Treatment × genotype interaction was also significant for all the traits except fiber fineness. Variance due to GCA and SCA were significant for most of the traits; however magnitude of dominance variance was higher than additive variance indicating prevalence of non-additive genetic control for all the traits under both the conditions. The phenotypic expression of all the genotypes varied greatly under the two growing conditions.

The effects of the environment on the number and quality of the offspring produced by organisms is the fundamental concern of evolutionary ecology. For plants, the number and quality of their offspring may be limited by external environmental factors, such as pollination and seed predation, or internally by the availability of resources which, in turn, may be influenced by weather and soil conditions, herbivory, disease and competition. Each of these factors may vary over time and location. In response to these varying environmental conditions, plants may adjust their resource commitment to seed production by altering (i) the number (or gender) of flowers that differentiate, (ii) the number of ovules per flower, (iii) the number of fruits and seeds that abort, and (iv) the mass of the mature seeds (see, for example, Adams, 1967; Primack, 1978; Lloyd, 1980; Stephenson, 1981, 1984; Thomson, 1989). In the parlance of our colleagues who study animals, plants can potentially alter (i) clutch size (a clutch is defined as offspring in more or less the same developmental phase that are simultaneously drawing resources from the maternal plant), (ii) the interval between successive clutches, and/or (iii) the mass of the offspring at the termination of maternal care (Stearns, 1976; Burley, 1980).