Foliar Spraying of Solanum tuberosum L. with CaCl2 and Ca(NO3)2: Interactions with Nutrients Accumulation in Tubers

Abstract

Calcium is essential for plants, yet as its mobility is limited, the understanding of the rate of Ca2+ accumulation and deposition in tissues of tubers, as well as the interactions with other critical nutrients prompted this study. To assess the interactions and differential accumulation of micro and macronutrients in the tissues of tubers, Solanum tuberosum L. varieties Agria and Rossi were cultivated and, after the beginning of tuberization, four foliar sprayings (at 8–10 day intervals) with CaCl2 (3 and 6 kg ha−1) or Ca(NO3)2 (2 and 4 kg ha−1) solutions were performed. It was found that both fertilizers increased Ca accumulation in tubers (mostly in the parenchyma tissues located in the center of the equatorial region). The functioning of the photosynthetic apparatus was not affected until the 3rd application but was somewhat affected when approaching the end of the crop cycle (after the 4th application), although the lower dose of CaCl2 seemed to improve the photochemical use of energy, particularly when compared with the greater dose of Ca(NO3)2. Still, none of these impacts modified tuber height and diameter. Following the increased accumulation of Ca, in the tubers of both varieties, the mean contents of P, K, Na, Fe, and Zn revealed different accumulation patterns. Moreover, accumulation of K, Fe, Mn, and Zn prevailed in the epidermis, displaying a contrasting pattern relative to Ca. Therefore, Ca accumulation revealed a heterogeneous trend in the different regions analyzed, and Ca enrichment of tubers altered the accumulation of other nutrients.

Calcium Biofortification of Rocha Pear Fruits: Implications on Mineral Elements, Sugars and Fatty Acids Accumulation in Tissues

“…However, in the tissues of Rocha pear fruits, an opposite trend was found since K mobilization and accumulation occurred preferable outside the core zones from harvest and during storage (Table 1). This tendency was also found in apples [35,46,47] and tubers [48] after spraying with CaCl 2 and with Ca(NO 3 ) 2 , and in pears [17] with CaCl 2 . Although Fe, Mn and Cu have a low mobility in plant tissues, while Zn keeps an intermediate translocation [43,[48][49][50][51], the increasing contents of Ca in pear Rocha fruits did not have a negative impact on micronutrients accumulation (Figure 2), and still with storage their concentrations prevailed outside the core zones (Table 1).…”

“…This tendency was also found in apples [35,46,47] and tubers [48] after spraying with CaCl 2 and with Ca(NO 3 ) 2 , and in pears [17] with CaCl 2 . Although Fe, Mn and Cu have a low mobility in plant tissues, while Zn keeps an intermediate translocation [43,[48][49][50][51], the increasing contents of Ca in pear Rocha fruits did not have a negative impact on micronutrients accumulation (Figure 2), and still with storage their concentrations prevailed outside the core zones (Table 1). Nevertheless, the interactions between Ca and Zn, Mn, Fe and Cu seem to depend on plant genotypes and growth conditions.…”

“…Concerning grapes, synergistic and antagonistic interactions were also found between Zn and Ca accumulations in the varieties 'Castelão' and 'Moscatel', respectively [50]. Additionally, in two varieties of tubers, the increasing accumulation of Ca triggered by Ca(NO 3 ) 2 and CaCl 2 foliar spraying presented different accumulation trends of Fe and Zn [48].…”

Assessment of Physicochemical Parameters in Two Winegrapes Varieties after Foliar Application of ZnSO4 and ZnO

“…At harvest, Zn concentration of randomized grapes was determined (i.e., after being washed, dried at 60 °C until constant weight, and grounded in an agate mortar). Then, an acid digestion procedure was performed with a mixture of HNO 3 − :HClO 4 (4:1) [ 94 ], followed by filtration. Measurements were carried out in triplicate, using an atomic absorption spectrophotometer model, the Perkin Elmer Analyst 200 (Waltham, MA, USA), fitted with a deuterium background corrector and using the AA WinLab software program Version 32.…”

Foliar Mn and Zn Treatments Improve Apple Tree Nutrition and Help to Maintain Favorable Soil pH

“…There was no foliar application of macronutrients including N, in particular, to avoid the inhibition of N uptake via the roots (see [45,46]). In Figure 1, the results of the two treatments are presented, which showed the largest effect (the results for other treatments can be found in the Supplementary Materials).…”