Methods of potassium contents evaluation in the substrate solution and gerbera leaves

Abstract

Several authors report that potassium (K) is the nutrient absorbed in greater amounts by gerbera plants. Thus, objective of determining the concentration of Kin the solution of substrates for growing potted gerbera, quantified by the Cardy Horiba C-131 and an atomic absorption spectrophotometer, correlating them with each other and with the plant leaf content. The experiment was carried out in a greenhouse. The experimental design was in randomized complete blocks using a 5×2 factorial scheme (5 substrates/2 cultivars) and four replications. Cherry and Red gerbera cultivar seedlings with four final leaves were transplanted into pots, filled with the substrates and acclimated for 30 days. After acclimation, the K content in the substrate solution extracted by the “PourThru” methodology was evaluated every two weeks using the Cardy Horiba C-131 portable ion meter and an atomic absorption spectrophotometer, as well as the K content in the leaves of gerbera plants. The solution of the commercial substrate had higher concentrations of K in relation to the others in the two forms of measurement, which is directly related to the high initial contents of the nutrient in this substrate. This is directly related to the high initial K contents in the substrate. Greater values of K were obtained for the cultivar Red, both in the solution and in the leaves. The K concentration of the substrate solution cultured with gerbera plants quantified by the Cardy Horiba C-131 and atomic absorption spectrophotometry correlated significantly with each other and showed a low correlation with the content of this nutrient in the plant tissue.

Nitrogen and calcium fertilization on the growth and development of gerbera cultivated in pots for cut flowers

“…At the dose of 0.02 g Ca L -1 substrate, a maximum K content of 21.27 g kg -1 was verified, which was followed by a decrease, as the doses of Ca increased (Figure 1D). These leaf K contents determined were below that indicated by Ludwig et al (2019), which were above 40.8 g kg -1 , depending on the cultivar or substrate used.…”

Soil management in integrated rose production system

“…Therefore, we may infer that 'Carola' rose bushes accumulate the same amount of macronutrients and micronutrients, with the exception of P, when submitted to different doses of chemical fertilizer, indicating that the use of high amounts of fertilizers is not necessary for the production of 'Carola' rose stems within a year. In addition, nutrient accumulation may differ in other types of roses under the same experimental conditions, as detected in gerberas (Ludwig et al, 2019) Table 6. Macronutrient and micronutrient accumulation in flower stems of 'Carola' roses according to the different percentages of chemical fertilization, regardless of the presence or absence of green fertilization.…”

“…The number of stems per plant was determined from harvests performed three times a week during a cultivation year, as well as their length from the base to the apex; flower bud length; base of stalk and bud diameters; and fresh mass of leaves, stems, and flower buds. Subsequently, the flower stems were washed in drinking water and distilled water, placed in paper bags, and dried in an oven with an air circulation and renewal system at 65°C until a constant weight was reached, to determine the dry mass and for chemical analysis (Malavolta et al, 1997). For soil analysis, samples were removed according to the different treatments tested, a year after these were applied.…”