Redistribution of potassium, boron, iron, magnesium and calcium in apple trees determined by an indirect method

Abstract

The intensity of the process of redistribution of the elements potassium, boron, iron, magnesium and calcium was determined by following the rate of accumulation of these elements into the fruits of apple (Malus domestica Borkh.) trees. The determination is based on the assumption that the process of primary distribution via the xylem becomes relatively unimportant with respect to supply along the phloem during the period of fruit growth. Thus a decreasing rate of accumulation for a phloem‐immobile and xylem‐mobile element will be seen during this period of growth, while an element which is mobile in both pathways will give a linear rate of accumulation when the supply by the root does not alter too much. In addition, the ratios of the contents in fruits and leaves were used as an indicator of the relative mobility in redistribution. In these experiments with apple, potassium and boron showed a high mobility. Magnesium and especially calcium showed a much lower mobility in redistribution than in the primary rate of supply. Iron was intermediary. The results, especially for boron and magnesium, are in contradiction to some of the data in the literature. Further studies are needed before these contrasting results can be explained.

Adubação Foliar Na Qualidade E Produtividade De Abacaxi

“…Thus, the B absorption, via leaf application, can be influenced by different factors: species (Goor & Lune 1980), concentration of the application solution, leaf cuticle permeability, relative air humidity, leaf age (Shu et al 1994), and also amount of applications. Basso & Suzuki (2001) reported that there are usually no problems of B deficiency in soils well provided with organic matter and pH less than 7, differing from the results observed in the present study.…”

The retranslocation of boron is influenced by the nutritional status of cherry tomato plants

“…In this context, the translocation of this element may confer better tolerance to deficiency or toxicity (BROWN;SHELP, 1997). However, depending on the species, it is considered a low mobile or immobile element in phloem (VAN GOOR;LUNE, 1980;BROWN;SHELP, 1997). In summary, B translocation involves active efflux channels and pumps with specific expression patterns depending on internal and external factors (LEAUNGTHITIKANCHANA et al 2013).…”

Mobilidade do boro em plantas de abacaxi

“…Estes compostos são itóis (álcoois de açúcar) como: sorbitol (macieira), manitol (brócolis) e dulcitol (Dordas et al, 2001). Os itóis são considerados compostos de estoque formados durante o processo fotossintético e transportados pelo floema em plantas superiores, sendo utilizados na nutrição heterotrófica e na osmorregulação (Loescher et al, 1995). O B se moveria, portanto, ligado a esses itóis.…”