Germination and growth of primary roots of inoculated bean (Vicia faba) seeds under different temperatures

ArticleTemperature stress strongly affects legumes, rhizobia, and the efficiency of legume - rhizobia interaction. An experiment in 2016 was developed to test the seed germination in Petri dishes using different microorganism inoculation under several temperature treatments (4, 8, 12 and 20 °C) . The goal of t his study was to test the effect of rhizobium inoculation under low root zone temperature, and to examine whether the addition of mycorrhiza fungi could enhance rhizobia resistance to abiotic stress and improve faba bean ( Vicia faba ) germination. Four faba bean cultivars were selected for the experiment (‘Lielplatone’, ‘Fuego’, ‘Bartek’ and ‘Karmazyn’). Four different seed inoculation variants were included in this experiment – 1) with rhizobium inoculation; 2) with a commercial preparation containing mycor rhiza fungi; 3) inoculation with both rhizobium and the mycorrhiza fungi preparation; 4) control variant. The number of germinated seeds, the length of the primary root and the primary root weight ratio were determined. The effect of inoculation was found out to be dependent not only on the temperature treatment, but it also significantly varied between the bean cultivars. Variants where seeds were inoculated with both mycorrhiza and rhizobia resulted in the highest results (length and weight ratio of prima ry roots), comparing with other inoculation variants, regardless of temperature. Variants where seeds were treated only with rhizobia mostly showed the lowest results – both length and weight ratio of primary roots, especially under treatment of 4 °C . Faba bean inoculation with only rhizobia might not be efficient, when sowing seeds under a low temperature stress. Inoculation with both rhizobia and mycorrhiza fungi could be a potential solution, when the root zone temperature is still below the optimal temp erature

Impact of faba bean (Vicia faba L.) cultivation on soil microbiological activity

ArticleFaba bean (Vicia faba L.) is widely grown not only as an important protein source for food and feed, but as a component in different cropping systems to improve soil quality. Beans are grown using different soil management practices, moreover, legume seeds often are inoculated before sowing. Microorganisms, introduced in the soil as an inoculum, affect not only inoculated plants, but these microorganisms can remain in the soil for the next growing season and can also affect the subsequent crops. Seed inoculation can stimulate production of root exudates as well as change microbial diversity and structure. The aim of the present study was to estimate the soil microbiological activity in soils where faba beans were cultivated with different rhizobia inoculants obtained from collection of Latvia University of Life Sciences and Technologies. Another trial was established where faba beans were included in different crop rotations under two tillage systems. During both trials, soil microbiological activity was analysed. Soil respiration intensity was measured by changes of carbon dioxide. Soil enzymatic activity was assessed by dehydrogenase activity and fluorescein diacetate (FDA) hydrolysis intensity. The total number of bacteria, fungi and rhizobia was expressed as colony forming units (CFU) g-1 dry soil. Soil microbiological activity depended on the cultivated crop and the crop rotation. Faba bean inoculation method had less impact on the ratio between analysed microorganism groups than on the activity of soil enzymes

Development of symbiotic interactions in the faba bean (Vicia faba L.) roots

ArticleDouble-inoculation of faba bean (Vicia faba L.) seeds before sowing with rhizobium bacteria and mycorrhizal fungi is a known agronomic practice. It improves symbiotic nitrogen fixation and enhances legume supply with mineral elements and water. Effective symbiosis makes it possible to replace some of the required mineral fertilizer needed for plant growth with symbiotically fixed. This will ensure more environmentally friendly agricultural production. The formation of an effective symbiosis depends on a number of biotic and abiotic factors affecting the biochemical signals released by the partners. The biochemical mediator for symbiosis formation is flavonoids. The aim of this experiment was to test the effects of rhizobial and mycorrhizal inocula on symbiosis formation under different temperatures. Beans are an important source of protein for animal feed and human consumption. Four cultivars of faba beans were used - two V. faba var. minor Beck. -‘Fuego’ and ‘Lielplatone’, and two V. faba var. major Harz. - ‘Bartek’ and ‘Karmazyn’. The combination of microorganisms for seed inoculation influenced the frequency of root mycorrhization and abundance of arbuscules. The content of flavonoids in seed exudates correlated (r = 0.93) with germination temperatures. The use of mycorrhizal fungi alone or in combination with rhizobia reduced the amount of flavonoids in the bean seed exudate. In the pot experiment the amount and size of nodules significantly differed between cultivars. Use of mycorrhizal preparation mitigated the effect of inadequate germination temperature. Higher degree of mycorrhization and more intense formation of arbusculs formation was observed in the bean roots grown in vegetation pots in comparison with field ones. Local bred ‘Lielplatone’ had significantly better compatibility with microsymbionts in local agroclimatic conditions

Experimental analysis of IoT based camera SI-NDVI values for tomato plant health monitoring application

This paper reveals an IoT based camera design to capture SI-NDVI parameters and describes first obtained data analysis regarding luminary spectrum impact on readings in real greenhouse application. For experimental comparison, measurements of Encore, Strabena, Audiance, Bolzano, Forticia and Chocomate tomato plants, both for the ‘best’ and the ‘weakest’ plant sample, using IoT based camera solution and portable leaf spectrometer. First experimental results show that this approach can be applied for tomato plant monitoring, and reveals some ideas about possible precision improvements

Thermal decontamination of sewage sludge

Every year a huge amount of sewage sludge is formed at municipal wastewater treatment plants. Sewage sludge contains a sufficient amount of biogenic elements and organic components, which characterizes them as possible raw materials for the production of organic fertilizers. However, direct incorporation of these sediments into the soil is impossible due to the fact that, in addition to useful organic and mineral components, they contain pathogens, viruses and helminth eggs. The aim of the study was to optimise thermal disinfection conditions for preparing of safety sewage sludge fertilizer. Laboratory studies were carried out using sediments from wastewater treatment plants of some cities. During laboratory experiments, the conditions for thermal disinfection of sediments – the thickness of the sediment layer, the air temperature in the disinfection furnace, and the treatment time of the sediment – were determined. When conducting industrial tests of a conveyor-type sediment decontamination furnace, the operating conditions of the furnace were determined, i.e., the temperature regimes of the sludge heating zone, the decontamination zone and the cooling zone, and the optimum parameters of the sludge layer thickness on the conveyor and the conveyor speed were determined

Determination of tomato quality with hyperspectral imaging

Received: February 1st, 2023 ; Accepted: July 14th, 2023 ; Published: October 13th, 2023 ; Correspondence: [email protected] (Solanum lycopersicum L.) are a widely used vegetable in the human diet throughout the year, both fresh and in various processed products. Tomatoes contain compounds important to human health and are an important source of vitamins, antioxidants, and mineral elements. Performing biochemical analyses is an expensive, environmentally unfriendly and time-consuming process; therefore, a way to determine the biochemical composition of tomatoes using non-destructive methods is being sought. The study includes 45 varieties of tomatoes with different colors - red, pink, orange, brown, yellow, and bicolor tomato fruits. The content of dry matter, soluble dry matter, titratable acidity, lycopene, β-carotene, total phenol, and flavonoids was determined by standard biochemical procedure. Reflectance spectrums of tomato fruits were obtained with Remote Sensing Portable Spectroradiometer RS-3500 (Ltd. Spectral Evolution, Haverhill, MA, USA) at the wavelength 350–2,500 nm with a 1 nm interval. In order to determine the content of various biochemical parameters in tomatoes, the vegetation indices found in the literature were used, and new ones were developed. The research demonstrated that the developed vegetative indices allow to detect lycopene and β-carotene content non-destructively. For the determination of the dry matter, soluble solids and phenolic content, indices designed for detecting water content can be used, but their correlation coefficients with chemical methods are moderately high - 0.65, 0.56 and 0.57, respectively. It was found that the best correlation between biochemically detected parameters and vegetation indices is for lycopene > β-carotene > dry matter> total phenols = titratable acidity ≥ soluble solids > taste index > flavonoids

Evaluation of different lighting sources on the growth and chemical composition of lettuce

ArticleExperiment were carried out in Latvia University of Agriculture in plant growth room. Lettuce Lactuca sativa L. var foliosum cv. ‘Dubacek’ and L . sativa L. cv. ‘Michalina’ were grown under 4 types of lights (luminescence lamps, commercial light emitting diodes (LED) lamps (V - TAC premium series – for plant growing) and two different Lumigrow LED strips - dominant wavelength - blue or red with 14 h ph otoperiod and total photosynthetic active radiation (PAR) 100 μmol m - 2 s - 1 in all variants. Plant weight, length, amount of leaves were measured. Content of chlorophylls, carotenoids, phenols, flavonoids in lettuce was determined three times per vegetation period. In experiments were found that higher lettuce yield was under commercial LED (V - TAC premium series), but these plants contain less soluble sugars, pigments and phenols. Better plant quality was obtained with luminescence lamps. These lettuces have higher sugar, phenols and flavonoids content. Lettuce growth under blue dominate LED (LEDb) was delayed, but these plants contain higher chlorophylls content. The differences in plant growth, response to light and biochemical content b etween cultivars wer e detected

Possibilities of cucumber powdery mildew detection by visible and near-infrared spectroscopy

Received: July 16th, 2021 ; Accepted: November 6th, 2021 ; Published: February 1st, 2022 ; Correspondence: [email protected] are one of the most demanded and widely grown greenhouse vegetables. Important factors that influence quality and quantity of yield are diseases. Powdery mildew (caused by Podosphaera xanthii and/or Golovinomyces cichoracearum), is one of the most harmful cucumber diseases. Early detection of mildew via non-destructive methods can optimize schemes of fungicide application. The study aimed to find regularities in the reflected light spectra, indices described in the literature, and severity of mildew. Plants were grown in the polycarbonate greenhouse under artificial lighting in a 16 h photoperiod with PAR at the tips of plants 200 ± 30 µmol m-2 s-1. Leaf reflection spectra were obtained using spectroradiometer RS-3500 (Ltd. Spectral Evolution). Spectral range 350–2,500 nm, bandwidth 1 nm. The severity of cucumber mildew was evaluated using 10 point scale (0- no symptoms, … 9 - the plant is dead). The vegetation indices found in the literature have been calculated. The obtained results show that the calculated indices have different sensitivities. The strongest correlation between the degree of cucumbers infection with powdery mildew and the light reflectance spectrum was found in the green range of visible light around 550 nm. Disease-Water Stress Index-2 (DSWI-2), Structure Intensive Pigment Index (SIPI), and Normalized Difference Vegetation Index (NDVI) are the most suitable indices for determining powdery mildew in cucumbers. New indices for detection of powdery mildew have been created. None of the studied indices allows determining the powdery mildew at the early stages of disease development when powdery mildew severity is below 10%

Antioxidative Activity of Ferrocenes Bearing 2,6-Di-Tert-Butylphenol Moieties

The antioxidative activity of ferrocenes bearing either 2,6-di-tert-butylphenol or phenyl groups has been compared using DPPH (1,1-diphenyl-2-picrylhydrazyl) test and in the study of the in vitro impact on lipid peroxidation in rat brain homogenate and on some characteristics of rat liver mitochondria. The results of DPPH test at 20°C show that the activity depends strongly upon the presence of phenolic group but is improved by the influence of ferrocenyl fragment. The activity of N-(3,5-di-tert-butyl-4-hydroxyphenyl)iminomethylferrocene (1), for instance, was 88.4%, which was higher than the activity of a known antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) (48.5%), whereas the activity of N-phenyl-iminomethylferrocene 2 was almost negligible −2.9%. The data obtained demonstrate that the compounds with 2,6-di-tert-butylphenol moiety are significantly more active than the corresponding phenyl analogues in the in vitro study of lipid peroxidation in rat brain homogenate. Ferrocene 1 performs a promising behavior as an antioxidant and inhibits the calcium-dependent swelling of mitochondria. These results allow us to propose the potential cytoprotective (neuroprotective) effect of ditopic compounds containing antioxidant 2,6-di-tert-butylphenol group and redox active ferrocene fragment

Relationship between oral health status and cognitive functions

With global increases in the aging population, the number of patients with cognitive decline is greatly increasing, which has become a big social problem. The studies conducted previously suggest the possible relationship between oral health and cognitive status. It is well-known, that the oral cavity is an important component not only the maxillofacial region, but also acontributor of general health. In this article, we highlight the relationship among dentoalveolar system and the cognitive functions. Studies using functional magnetic resonance imaging revealed that during mastication there is activation of somatosensory cortical areas, the supplementary motor area, insula, and other areas including the striatum, thalamus and cerebellum. According to the results of the сlinical studies, patients with dementia have demonstrated poor oral hygiene, greater incidence of periodontal diseases and tooth loss. Accumulating evidence suggests that cognitive decline may be associated with masticatory dysfunction. Masticatory dysfunction, as an umbrella term, refers to a debilitating condition in which normal masticatory function is compromised due to structural factors (e.g., tooth loss) or functional factors (e.g., weaker biting force or poorer masticatory performance). The presented data support the hypothesis that there is a possible relationship between mastication, oral health status and cognitive functions, therefore maintenance and adequate restoration of the whole masticatory system are important for the prevention of cognitive decline. This problem requires further clinical interdisciplinary studies, assessing cognitive abilities and oral health