Effects of Foliar Spray Application of Selected Micronutrients on the Quality of Bush Tea

Abstract

<jats:p>Bush tea (<jats:italic>Athrixia phylicoides</jats:italic> DC.) is a herbal beverage and medicinal plant indigenous to South Africa. The aim of the study was to provide the baseline for foliar spray application of micronutrients to enhance the quality of bush tea. A trial was conducted to determine the effect of micronutrients on the quality of bush tea. Four separate trials for boron (B), iron (Fe), zinc (Zn), and copper (Cu) were laid out in a completely randomized block design. Treatments consisted of an unsprayed control and single foliar sprays of B, Fe, Zn, and Cu, with 10 replicates. The levels of each element were unsprayed control, 50 mL·L<jats:sup>−1</jats:sup>, 100 mL·L<jats:sup>−1</jats:sup>, and 150 mL·L<jats:sup>−1</jats:sup>. Parameters recorded were leaf tissue B, Fe, Zn, and Cu, and total polyphenol, total antioxidant, total flavonoids, and total tannin contents. Results from this study demonstrated that foliar application of B did not induce significant response in terms of total polyphenol content after B application. There was a quadratic response for total flavonoids (167 mg·g<jats:sup>−1</jats:sup>), with most of the total flavonoids reaching maximum at 100 mL·L<jats:sup>−1</jats:sup>. Foliar application of Fe exhibited a quadratic response, with most of the total polyphenols (45.1 mg·g<jats:sup>−1</jats:sup>) reaching maximum at 100 mL·L<jats:sup>−1</jats:sup>. All treatments showed a linear response for total antioxidant, total flavonoids, and total tannin contents. Treatments elicited a quadratic response for total polyphenols (70.6 mg·g<jats:sup>−1</jats:sup>), total antioxidants (78.3 mg·g<jats:sup>−1</jats:sup>), total flavonoids (148.9 mg·g<jats:sup>−1</jats:sup>), and total tannin contents (78.3 mg·g<jats:sup>−1</jats:sup>) after foliar Zn application, reaching maximum at 100 mL·L<jats:sup>−1</jats:sup>. Foliar application of essential elements in bush tea led to a significant increase in the Zn, Fe, Cu, and B content; application at 100 mL·L<jats:sup>−1</jats:sup> is recommended for improved chemical composition of bush tea. A further trial with treatment combinations is required to determine chemical responses of bush tea.</jats:p>

AGRONOMIC YIELD AND ESSENTIAL OIL PROPERTIES OF PURPLE CONEFLOWER (Echinacea purpurea L. MOENCH) WITH DIFFERENT NUTRIENT APPLICATIONS

“…Therefore, if the edaphic conditions are not suitable, the plant will not absorb these elements optimally. Therefore, foliar application of micronutrients is readily available to the plant and is spent on physiological activities (Khathutshelo et al, 2016). In the present results, the increasing effect of foliar application of micro and macro elements was evident in the production of E. purpurea flowers.…”

Influence of Plasma-Activated Water on Foliar and Fruit Micronutrient Content and Plant Protection Efficiency

“…Boynton reports on the use of iron sulfate on pineapple already at the beginning of the XX century to overcome iron deficiency resulting from the oversupply of magnesium [1]. The significance of foliar fertilizing with Horticulturae 2024, 10, 55 2 of 15 micronutrients for enhancing plant productivity and stress resistance has been repeatedly emphasized [2][3][4][5][6][7][8]. This is especially true for calcium foliar supply for improving the storability of apple fruits [9].…”

СОДЕРЖАНИЕ НЕКОТОРЫХ БИОЛОГИЧЕСКИ АКТИВНЫХ ВЕЩЕСТВ И ХИМИЧЕСКИХ ЭЛЕМЕНТОВ В ЛЕКАРСТВЕННОМ СЫРЬЕ Echinacea purpurea (L.) Moench ПОД ВЛИЯНИЕМ ЭССЕНЦИАЛЬНОГО МИКРОЭЛЕМЕНТА Cu

“…(34) отмечают хелатирующую способность танинов в отношении меди, что обусловливает их антиоксидантную активность. Положительное влияние меди также связано с тем, что она служит ключевым компонентом многих биологических соединений и играет важную роль в биосинтезе вторичных метаболитов, в том числе танинов (35). Полученные данные согласуются с сообщениями о том, что концентрации дубильных веществ напрямую зависят от количества питательных веществ, в частности Cu и Mn, которые служат кофакторами ферментов, участвующих в разложении фенола и биосинтезе лигнина.…”