The Effect of Various Grinding Aids on the Properties of Cement and Its Compatibility with Acrylate-Based Superplasticizer

The influence of grinding aids (pure triethanolamine and ethylene glycol) on the properties of cements, their compatibility with an acrylate-based superplasticizer and the rheological parameters of mortars were investigated. The presence of surfactants influences the standard properties of cements and the effectiveness of the superplasticizer. The results of the heat of hydration and setting time measurements indicate a delay in the hydration process and an increase in the induction period duration of the surfactant-doped pastes, in relation to the reference sample without grinding aids. Triethanolamine increases early-age compressive strength; the effect was observed for both standard and superplasticizer-containing mortars. The presence of grinding aids decreases the slump flow of mortars and increases rheological parameters such as yield stress (τ0) and viscosity (η).

The need for the vernalization duration of soft winter wheat collection samples

The need for vernalization is a duration-dependent effect of low, positive temperatures in order to ensure the plants' transition to generative development. If the requirement for the duration of germination is not met, the plant will not enter the stage of forming generative organs. The vernalization requirements of winter soft wheat samples of different geographical origins are determined. An assessment of the vernalization period duration influence on the severity of the elements of the yield structure is given. The research material consisted of 15 cultivars of soft winter wheat of various geographic origin. The samples were germinated in paper rolls, then vernalized in a climatic chamber at a temperature of 3–5 ºС for 60, 50, and 40 days. At the end of vernalization, 10 plants of each sample were planted in a greenhouse. The dates of the onset of phenological phases were noted: tube emergence, earing, flowering. To determine the main elements of the yield structure, a structural analysis of plants was carried out. With an increase in the vernalization period, a decrease in the interfacial periods from tube emergence to flowering was noted. The influence of the timing of vernalization was noted on the manifestation of the spike length trait. It was found that the total number of stems and the number of productive stems in almost all varieties decreases with an increase in the period of vernalization. Significant differences between collection varieties in the need for vernalization, due to both their geographical origin and the genotype of plants are revealed. In all the studied forms, with an increase in the period of vernalization, the rate of plant development increased to varying degrees, the total number of stems, the productive stem and the length of the spike decreased.

Quantitative Analysis of Winter Wheat Growth and Yields Responding to Climate Change in Xinjiang, China

The knowledge of climate change effects on variations of winter wheat yields are crucial for productions. Our objectives were to investigate the relationship between yield-related indices of winter wheat and the related climatic variables (selected using variance inflation factors) at the 20 sites of Xinjiang, China over 1981–2017. The background of climate and yield changes was analyzed from temporal and spatial respects. The number of independent climatic variables was selected with the variance inflation factor method to remove the multicollinear feature. The Pearson correlation was conducted between the first difference values of climatic variables and yield-related indices of winter wheat (namely plant height, growth period duration, 1000-kernel weight, kernel number per ear, biomass and yield) to find the key climatic variables that impacted winter wheat growth and yields. The multi-variate linear and nonlinear functions were established step by step using the selected key climatic variables. The best function was determined for each site (significant for p < 0.05). From the results, there were general wetter and warmer trends of the climatic variables. Correspondingly, shortened winter wheat phenology and increased growth and yields were observed for most sites. Still, the climatic trends had mixed effects on winter wheat yields. The effects of precipitation, mean air temperature and relative humidity on plant height and growth period duration agreed well. Different sites had different major climatic drivers for winter wheat growth or yields, and the best functions of growth and yields could be linearly or nonlinearly, mostly described by multi-variate functions. The winter wheat growth or yield indices were also found to be closely connected with the soil water content status at the eight sites. The relationship between winter wheat growth or yield and climate provided useful references for forecasting crop production and for projecting the impact of future climate changes.

Effect of different fattening period duration on meat productivity of domestic quails

The study was conducted with 224 domestic quails from the specialized meat-type WG line. The duration of fattening period and sex on productive traits, slaughter traits and meat quality of quails was evaluated. The study has shown that the longer duration of the fattening period in quails from the meat-type line WG was associated with lower production efficiency, with more reduction after the 35th day of life. The production efficiency in male quails was lower compared to that in females. The dispersion analysis demonstrated that the determination of 72.2% and 69.6% of dressed carcass weight and deboned meat weight, respectively, depended on fattening period duration (p<0.001). When fattening increased from 28 to 42 days, the amount of feed necessary for one bird increased by 73% and 87%, corresponding to increased costs by 64.5% and 77%. For production of 1 kg dressed quail carcasses, the necessary feed increased by 42.3-45.8% on a weight basis and by 35-37.7% on a cost basis. For production of 1 kg deboned quail meat, corresponding increases are by 42.1-49.5% and 34.8-41.2%, respectively. The period between 28 and 35 days of age was the most appropriate for planning slaughter of WG quails. During that period, the economic efficiency, although already declining, was still within acceptable limits and the increase in quantitative traits in both sexes – still relevant, making the produce more attractive for consumers. With age, the changes in colour characteristics of M. pectoralis superficialis result in darkening of meat (p<0.001). Thus, it assumes nuances specific rather for game meat. This effect is desirable, as it improves the commercial presentation of domestic quail meat in line with consumers’ attitudes.

Screening and monitoring of watermelon source material by components of the vegetation period in the conditions of the forest-steppe of Ukraine

Relevant in the selection of each crop, including watermelon is a comprehensive study of the source material to identify sources of valuable traits and include them in the selection process in order to expand the genetic diversity of the culture. According to the results of research, to create a new source material for heterosis selection of watermelon, screening and monitoring of the vegetation period duration (number of days from germination to ripening) and its components 118 (101 varieties, 17 hybrids) genotypes of watermelon in the forest-steppe of Ukraine have been conducted. Research methods are generally accepted: field experiment, observation, accounting, analysis, statistical. According to the results of determining the duration of the components of the vegetation period, the samples were divided into five groups of ripeness: early (65–80 days) – 80 (68 %), medium-early (81–85 days) – 14 (12 %), medium (86–95 days) – 18 (15 %), medium-late (96–105 days) – 4 (3 %) and late (106 days) – 2 (2 %). Variety-samples, selected by morphological and economically valuable characteristics, belong mainly (80 %) to early and medium-early. Only 6 % of genotypes belong to the medium-late and late-ripening groups. 52 samples with the smallest separate interphase periods were isolated. According to the results of the research, 8 sources with the high early ripeness were identified, the vegetation period of which was 66–70 days: Yellow early 108105 (66 days), Karapuz 108109, Surprise 108121 (67 days), Gift of the sun 108109, Lezheboka honey 108116, Thailand №1 108153 ( 69 days), Sweet Diamond 107874, Northern Lights 108127 (70 days). Sources are involved in the selection process

The Effect Mechanism and Model Optimization of Pulsed Light Dark Duration on Lettuce

Background: Despite its rapid development, the costs of crop artificial light source technology are still high. In addition, both the luminous efficiency and photosynthetic light supplement efficiency of the light source require further improvement. This study aims to improve the photosynthetic light supplement efficiency by altering the luminescence mode of the light source, transforming the conventional continuous supplementary light source into a pulse light source, and exploring how to further reduce energy consumption and improve the light supplement efficiency without influencing the light supplement effect of Lettuce.Results: For this purpose, Lettuce (Lactuca sativa L.) was selected as the experimental material to investigate the effects of varying the duty ratio, frequency and dark duration on the Pn (net photosynthetic rate) of leaves. The results revealed that Pn values under each duty ratio treatment increased with frequency and gradually stabilized to a level similar to that of continuous light. At higher duty ratios, the lettuce leaf Pn under pulse light reached a stable state at a lower frequency, with Pn leveling showing an overall upward trend with the decreasing dark period duration and a large increase in the early stage. For dark period durations lower than a certain value (0.000683594 s), variations in Pn among treatments were minimal, with a gradual increasing trend until no significant differences are observed with continuous light (CK); Under the D3 (weak light) condition, plants were easy to spindling(excessive growth)and exhibited narrow and slender leaves. Plants under the D2 condition (The duration period duration was 0.000465468s) presented the strongest roots and stems, with wide leaves and a compact growth. The following trend in Pn was observed across all duty ratios D2>D1 (0.000046547s)>CK>D3 (0.004654685s). Conclusions: The dominant influencing factor of the plant net photosynthetic rate was determined as the ratio of the frequency and duty ratio (i.e., dark period duration). Compared with continuous light, pulsed light is more beneficial to plant growth and utilization.

Optimizing Seed Germination and Seedling Growth in Different Kiwifruit Genotypes

The presence of dormant embryos in seeds and nonuniformity in seedling growth are the main limiting factors for kiwifruit propagation. Studies on the germination of hybrid genotypes are limited, especially at different ploidy levels. Low germination percentages and nonuniformity in seedling growth are two of the limiting factors of kiwifruit breeding, especially new and imported germplasm. The effect of cold moist stratification and growing substances on seed germination and seedling growth, respectively, on different kiwifruit seed populations were evaluated in this study. The effect of cold moist stratification (3, 4 and 5 weeks at 4 °C) and growing substrate composition (peat, perlite and coco peat) on seed germination and seedling growth of different Actinidia genotypes were assessed. In general, increasing stratification period duration often increased germination speed and uniformity. It was also found that increasing the ratio of peat moss improved the vegetative growth parameters of all kiwifruit seedlings. Stratification treatment, light and temperature fluctuation and consequently suitable substrate can accelerate and increase the production of seedlings and reduce seedling losses. It was also found that peat–perlite (1:1) medium was the best medium for kiwifruit seedling growth.

Timing Is Everything. Temporal and Spatial Niche Segregation in Curculio spp. (Coleoptera: Curculionidae) Associated with Oak Trees

Oak seed predatory weevils occurring in Poland are prone to increased interspecific competition due to the limited number of Quercus species, compared to southern Europe, in which they can develop. Therefore, analyses on the preferences of three weevil species for acorn sizes chosen for reproduction, as well as on reproductive period duration, were performed. Cafeteria-type experiments were set for females of three species associated with one oak species. Females were allowed to choose and oviposit in acorns of different sizes and growth stages. Research revealed statistically significant differences between the masses of acorns chosen for oviposition by females of Curculio glandium (the biggest), C. pellitus (medium), and C. venosus (the smallest). Studied weevils also differed in terms of the beginning of the reproductive period, which corresponded with the increasing mass of growing acorns. Moreover, C. glandium was observed to be the only species to perform radial egg galleries and lay a considerably higher and varied number of eggs. The results support the hypothesis of a strategy aimed at reducing interspecific competition between Curculio spp. in terms of limited host plant species number.