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Interactive effects of adaptation technology, based on no-till sowing into the mulch of cover crop residues, and nitrogen nutrition on photosynthetic performance of maize under drought stress
Opoku, Emmanuel ; Holub, Petr ; Findurová, Hana ; Veselá, Barbora ; Klem, Karel
The aim of this study was to evaluate the interactive effect of adaptation technology based on no-till sowing into cover crop mulch and nitrogen nutrition on photosynthetic performance of maize under short term drought stress induced by rain-out shelters. The experiment was established in two locations in the same climatic condition but differing in soil fertility. The negative effect of drought on CO2 assimilation rate was modulated by nitrogen nutrition. However, while nitrogen nutrition led to alleviating effect at the location with higher fertility, the opposite effect was found at the site with lower fertility. Adaptation technology had only a minor impact on photosynthetic response to drought, but it generally increased CO2 assimilation rate at the site with higher soil fertility and decreased at the site with lower soil fertility. We can conclude that adaptation technology, despite of assumptions, did not significantly change the resilience of maize to drought, and probably longer use of such technology is required to improve soil water retention and thus also balanced supply of water to plants. \nAt the same time, we did not find a negative impact of adaptation technology on photosynthesis which can be related to cooler soil during maize emergence and slower mineralization, although the use of adaptation technology seems to be more effective in soils with higher fertility.
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Atmospheric CO2 concentration, light intensity and nitrogen nutrition affect spring barley response to drought and heat stress
Findurová, Hana ; Veselá, Barbora ; Opoku, Emmanuel ; Klem, Karel
The aim of this study was to compare physiological responses of two spring barley varieties,\ndiffering in their oxidative stress tolerance, to drought and heat stress after pre-treatment under different\nirradiation regimes, CO2 concentrations, and nitrogen fertilisation levels. High light intensity, elevated\nCO2, and additional UV radiation increased flavonoid accumulation. Moreover, more flavonoids were\ninduced in oxidative stress-sensitive variety Barke. Combined drought and heat stress caused a large\ndecline in CO2 assimilation, whereas heat stress alone caused only minor changes. Under combined\nstress, plants grown under low light intensity and no UV irradiation performed the best despite their\nhigher initial water use efficiency and lower flavonoids content.
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Comparison of Moringa yields in tropical areas and green house in temperate zones
Opoku, Emmanuel
Moringa oleifera je rostlina s vysokou užitnou hodnotou, která slouží jako potrava pro lidi i krmivo pro zvířata. Známá je taky v tradiční medicíně. Hlavním cílem této práce bylo porovnání výnosů moringy vypěstované ve skleníkových podmínkách mírného a tropického pásma. Studie byla provedena v Techimanu v Ghaně a na skleníkových plochách Mendelovy univerzity v Brně v České republice. Počet vzejitých rostlin byl odečítán po 7, 12, 17 a 22 dnech. Nejvyšší počet semen vyklíčil po 7 dnech v tropech, naopak nejnižší počet vyklíčených semen byl v tuto dobu zaznamenán ve skleníku. Výška semenáčků byla odečítána po 7, 21 a 35 dnech, v průměru činila 20,63 cm v tropickém a 29,14 cm v mírném pásmu. Klíčivost v tropech byla 35 % a ve skleníku 25,8 %. Ze získaných dat můžeme usuzovat, že je moringa schopná se úspěšně přizpůsobit podmínkám tropického i mírného pásma.
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