Postbloom Humic- and Fulvic-based Zinc Sprays Can Improve Apple Zinc Nutrition

Abstract

<jats:p>Zinc supplied as a fulvic-based Zn compound was absorbed and retranslocated to unsprayed new growth as effectively as zinc sulphate in apple seedlings of low Zn status grown hydroponically in the greenhouse. Similarly, fulvic- and humic-based compounds were as effective as zinc sulphate at improving short-term growth and Zn uptake into new tissues in Zn-deficient apple seedlings, with the best growth occurring at spray concentrations of Zn at 500 mg·L<jats:sup>-1</jats:sup>. Under field conditions, Zn concentration of peeled and washed `Jonagold' apples at harvest was increased, without phytotoxicity, by two or four postbloom sprays of fulvic Zn. It is therefore possible to use this material safely as an effective Zn-source after bloom. However the mobility of the foliar-applied Zn is limited and any yield response by treated apple orchards of marginal Zn nutrition is unlikely to occur in the short term (within two growing seasons).</jats:p>

Zinc Sulfate and Sugar Alcohol Zinc Sprays at Critical Stages to Improve Apple Fruit Quality

“…However, studies about the effects on fruit quality of different forms of foliar Zn applied at different stages of apple tree growth are very few. foliar spray of fulvic-and humic-based Zn compounds was equally or more effective than ZnSO 4 at being absorbed by vegetative apple seedling tissue (Neilsen et al, 2005), but whether the sugar alcohol zinc is effective has not been clear. Recently, sugar compounds containing Zn have been advocated for use with little information to support their use.…”

Role of the foliar fertilization treatments on quality attributes of sweet cherry fruits (Prunus avium)

“…The important role of zinc, which functions as a cofactor in the structure and function of many enzymes (Jeffery et al, 1984;Hacisalihoglu et al, 2003;Andreini and Bertini, 2012), in various processes such as photosynthesis, carbohydrate metabolism and regulation of phytohormones (Hacisalihoglu et al, 2001;Krämer and Clemens, 2006;Alloway, 2008;Broadley et al, 2007;Gupta et al, 2011) can justify the influence of zinc on fruit quality characteristics in the study. As a matter of fact, Rodríguez et al (2005); Neilsen et al (2005); Khayyat et al (2007); Zhang et al (2013) have reported that zinc application can significantly improve fruit yield and quality in date palm, oranges and apples.…”

“…Zinc deficiency causes decrease in leaves, shoots and photosynthesis rate and hence, it affects yield and quality on fruit trees (Wang and Jin, 2005;Yan et al, 2010). Foliar zinc treatment in date palm, oranges and apples can significantly increase the zinc concentration, fruit yield and quality (Rodríguez et al, 2005;Neilsen et al, 2005;Khayyat et al, 2007;Zhang et al, 2013).…”

EFFECT OF BIO-STIMULANT AND SOIL AMENDMENT ON VEGETATIVE GROWTH, YIELD AND FRUIT QUALITY OF Pyrus communis cv. 'LE CONTE' PEAR TREES.

“…Using commercial products containing humic acid in pear production are very rarely reported in the literature, but some investigations have been conducted with these products in different fruits like orange and grapefruit (Alva andObreza, 1998), lemon (Sànchez-Sànchez et al, 2002), apple (Neilsen et al,. 2005) and date palm (Elboray et al, 2006).…”