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  • Author: Tomasz Spiżewski x
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Summary

Three-year studies on the influence of temperature on vegetative growth and growth of broccoli heads (Brassica oleracea var. italica cv. Fiesta) were carried out at the Experimental Station “Marcelin” of Poznań University of Life Sciences in Poland. The relationship between temperature sum day-degree, number and area of leaves as well as head diameter was estimated. Likewise relationship between number and area of leaves and head diameter was established. The correlations were described using linear, curvilinear and segment linear regression. The relationship between temperature sum day-degree and number of leaves was linear, whereas the correlation between temperature and area of leaves and head diameter was curves function. On the basis of segment linear regression it was found that in the period when slow growth of heads was observed (the size of up to about 1.5 cm), the area of leaves increased the fastest. It occurred between the 24th and 27th day after planting. The fastest growth of broccoli heads was noted, when the plant had about 18 leaves and area 4900 cm2. In the period of rapid head growth, the increase of sum temperature of 100 day-degree resulted in head diameter increase by 3.5 cm.

Abstract

There are about 40 species in the Pleurotus genus, including those with high economic significance, i.e. P. ostreatus and P. pulmonarius. The fruiting bodies of oyster mushrooms are of high nutritional and health-promoting value. In addition, many species belonging to the Pleurotus genus have been used as sources of substances with documented medicinal properties, such as high-molecular weight bioactive compounds (polysaccharides, peptides and proteins) and low-molecular weight compounds (terpenoids, fatty acid esters and polyphenols). The bioactive substances contained in the mycelium and fruiting bodies of Pleurotus species exhibit immunostimulatory, anti-neoplastic, anti-diabetic, anti-atherosclerotic, anti-inflammatory, antibacterial and anti-oxidative properties. Their multidirectional positive influence on the human organism is the result of interaction of bioactive substances. Extracts from individual Pleurotus species can be used for the production of dietary supplements increasing the organism’s immunity. They are also used for the production of cosmetics. They can be added to functional foods as probiotics, or used as natural preservatives or ingredients of special foodstuffs for patients with specific diseases.

Abstract

Biostimulants are commonly used in horticulture, primarily to increase yield quantity and quality, as well as plant tolerance to stress. The purpose of the study was to determine the effect of amino acid-based biostimulants and amino acids in combination with Ascophyllum nodosum filtrate, applied during the growing season on the phenolic content in broccoli heads both after harvest and after long storage in a cold store. The seedlings were planted in mid-July, and heads were harvested from September to October in each year of the study. Ascophyllum nodosum filtrate at a concentration of 1% was used during seedling production. The plants were watered with biostimulants twice, in the fourth and fifth week after sowing. They were also sprayed with amino acid-based biostimulants (1.5 dm3 ha-1) three times, i.e. after the second, fourth and sixth week after planting. The biostimulants were not used in the control treatment. After harvest, the heads were stored for three weeks in a cold store at 1-2°C and 95% RH. Chemical analyses of total phenolic, caffeic, ferulic and sinapic acids, and of quercetin and kaempferol were carried out on samples of fresh broccoli and after the first, second and third week of storage. It was found that the application of biostimulants resulted in a significant increase in the total phenolic content, sinapic acid content, as well as quercetin content. Both in the control treatment and in the plants treated with the biostimulants, the concentration of all the tested phenolic compounds increased with the duration of storage.

Abstract

The study compared coal fly and bottom ashes for their ability to inactivate metals and lead to soil remediation. Soil was artificially contaminated with Cu, Zn, Pb and Cd at five degrees. Next, both ashes were added at five rates: 0, 0.5, 1.0, 1.5 and 2.0% and all treatments incubated. Data showed that for moderately contaminated soils, ash rates of 0.5 - 1.0% were efficient from 40 to 70% for Zn and Cd, and raised markedly to between 70 and 93% for Cu and Pb. For extremely contaminated soils, the rates of ashes at 1.0, 1.5 and 2% were much more efficient (60 - 80%). The use of fly and bottom ashes for metal inactivation and soil remediation should give greater consideration to the effect of pH and the type of heavy metals than the content of SiO2and Al2O3. Fly ash displayed superior inactivation and remediation effects to the bottom ash.

Abstract

Mn, as Fe, Zn, Cu and Ni is a heavy metal and also a necessary element all the living organisms. Excessive Mn nutrition causes a strong oxidative stress. The aim of the studies was to determination the effect of Se treatment (as sodium selenite Na2O4Se3) to alleviate the Mn stress of plants. Because of its sensitivity to oxidative stress induced by excessive concentrations of Mn a model plant was lettuce (Lactuca sativa L. ‘Sunny’). The studies were conducted in a controlled environment growth room in stable climate conditions: 16 h photoperiod; temperature light/dark 18.0 ±0.5°C/16.0 ±0.5°C; relative humidity 70-80%; quantum flux density 195-205 μmol m−2 s−1. Plants were grown hydroponically in nutrient solution characterized by excessive Mn content (19.2 mg dm−3) and different contents of Se (control; 0.77, 1.05, 1.33 mg dm−3). In all the combination were also tested different foliar sprays (distilled water and a 0.005% Se solution). Plants grown under conditions described above take up and transported Se from nutrient solutions into their leaves with a significant reduction of Mn concentration and changes in the plant nutrient status. With the increase in the concentrations of Se clearly narrowed quantitative relations in the leaves between this element and micro-metallic. Increasing Se levels in nutrient solution has a positive influence on the growth of plants, but Se foliar treatment generally decreases plant yield. The study shown that Se application may lead to alleviation of Mn stress of plants, with simultaneous reduce in Mn concentration in leaves - which may be of practical importance also in the cultivation of more economically important species.