The objective of this study was to evaluate the effects of the Ca:Mg ratio, magnetic field (MF), and mycorrhizal amendment on the yield and mineral composition of rose geranium. The experiment was structured as a 3 × 2 factorial experimental design, with three levels of the Ca:Mg ratio (2.40:6.78, 4.31:4.39, and 6.78:2.40 meq·L−1), 6.78 Ca:2.40 Mg meq·L−1 denoted by “High-Ca:Low-Mg,” equal proportion of Ca and Mg (4.31 Ca:4.39 Mg meq·L−1) represented by “EP-Ca:Mg,” and 2.32 Ca:6.38 Mg meq·L−1 denoted by “Low-Ca:High-Mg,” two levels of MF (no MF, denoted by “0 MF,” and 110 mT, denoted by “1 MF”) and split treatments of mycorrhizae (zero mycorrhizae denoted by “0 Myco,” and 20 mL mycorrhizae denoted by “1 Myco”) were used in this study. The results show that the plant height and branch dry mass were significantly (P < 0.05) affected by the Ca:Mg ratio. No significant effect of Ca:Mg ratio, MF, or mycorrhizae on the number of leaves, foliar mass, leaf dry mass, or yield was detected. Phosphorus, K, S, Fe, and B accumulation in the stem were unaffected, as were leaf N, P, K, Ca, S, Fe, B, and Cu. However, some agronomic attributes (plant height, number of branches, root length, and chlorophyll content) and mineral composition (Stem-N) were optimized when the 1 MF exposed nutrient solution was used with about equal proportions of Ca and Mg. This Ca:Mg ratio in the nutrient solution, together with the exposure of rose geranium plants to 1 MF, yielded positive results. The findings of this study can be applied to improve the production of rose geranium by enhancing the growth and mineral concentration of this crop.
Neo Edwin Nyakane, Moosa Mahmood Sedibe, and Elisha Markus
Patience Seyram Akakpo, Moosa Mahmood Sedibe, Bello Zaid, Zenzile P. Khetsha, Mokgaputsiwa P. Theka-Kutumela, and Fhatuwani N. Mudau
Potassium (K) is an essential nutrient in plant metabolism, ionic balance, and stress resistance. In this study, the effects of K on agronomic attributes and on mineral and primary metabolite content in African potato were determined. K was administered hydroponically at four concentrations (4.00, 6.00, 8.00, and 10.00 meq·L−1) using Steiner’s universal nutrient solution. Chlorophyll content (CHL), leaf area (LA), fresh corm mass (FCM), number of roots (NR), root fresh weight (RFM), and root dry mass (RDM) were measured 18, 32, and 40 weeks after transplanting. Mineral analysis data were collected at 18 weeks, and primary metabolite data were collected at 32 weeks. Significant effects of K were observed after 18 weeks, and all test concentrations had a positive effect on yield. Calcium and boron significantly accumulated in the corm at 4.00 meq·L−1 K. Alanine and malic acid were the only metabolites affected by K concentrations. More minerals accumulated in the corm at 4.00 meq·L−1 K, whereas at 10.00 meq·L−1 K, more minerals clustered in the leaf. K applied at 4.00 meq·L−1 is recommended when growing African potato using a nutrient solution to improve corm mineral and metabolite accumulation.