Impact of Source and Timing of Calcium and Nitrogen Applications on `Atlantic' Potato Tuber Calcium Concentrations and Internal Quality

Abstract

<jats:p>Three Ca sources and two application schedules were compared for their effectiveness for increasing tissue Ca concentrations in 170 to 284 g field-grown tubers of `Atlantic' potato (<jats:italic>Solanum tuberosum</jats:italic> L.). Additional observations were made of internal physiological defects. Paired measures of tissue (periderm and nonperiderm) Ca concentration and internal quality (±hollow heart, ±internal brown spot) were made on individual tubers produced in plots fertilized with N at 224 kg·ha<jats:sup>-1</jats:sup> and Ca at either 0 or 168 kg·ha<jats:sup>-1</jats:sup>, supplied from either gypsum, calcium nitrate or NHIB (9N-0P-0K-11Ca, a commercial formulation of urea and CaCl<jats:sub>2</jats:sub>). Application of N and Ca at emergence and hilling (nonsplit) was compared to application at emergence, hilling, and 4 and 8 weeks after hilling (split). Tuber yield and grade were unaffected by treatments. Split Ca application (from either calcium nitrate or NHIB) increased mean tuber nonperiderm tissue Ca concentrations and the percentage of tubers with an elevated Ca concentration in both years compared with non-Ca-supplemented controls. Split Ca application also resulted in greater increases in Ca in nonperiderm tissue than nonsplit Ca application in 1994. Although the correlation coefficient between Ca level in periderm and nonperiderm tissue of &gt;400 individual tubers was highly significant in both study years, linear regression analyses suggested the Ca level in the two tissues were poorly related. Split application was associated with a 37% reduction in the incidence of internal tuber defects, relative to nonsplit application in 1994. Calcium application did not affect tuber internal quality based on means analysis, but chi-square analysis suggested that Ca concentration and internal quality of individual tubers may be related. The incidence of internal defects was 16.4% in tubers with nonperiderm tissue Ca &gt;100 μg·g<jats:sup>-1</jats:sup> dry weight compared to 10.6% in tubers with nonperiderm tissue Ca &gt;100 μg·g<jats:sup>-1</jats:sup> dry weight. These data suggest that 1) it is feasible to increase tuber Ca levels by field applications of moderate amounts of Ca, 2) tuber quality is impacted by N and Ca application schedule, and 3) Ca concentrations in tuber periderm and nonperiderm tissues may be controlled independently.</jats:p>

Exchangeable Soil Calcium May Not Reliably Predict In-season Calcium Requirements for Enhancing Potato Tuber Calcium Concentration

“…This increase in tuber Ca concentration varied among cultivars and among seasons at both locations but appears to have no relationship with soil Ca. Our recent studies have shown that in-season application of Ca can increase tuber Ca concentration and improve tuber quality (Palta 1996;Kleinhenz et al 1999;Ozgen et al 2006;Karlsson et al 2006). Frequently asked questions include: when should supplemental Ca be applied and at what soil test Ca level should these applications be made to provide adequate Ca for tuber quality?…”

“…The soils in these two areas are loamy sand and silt loam, respectively, and the soil at our experimental sites tested at 285 to 563 and 530 to 1,340 mg kg −1 of exchangeable Ca, respectively. In spite of these high soil test values, we have been able to increase the tuber Ca concentration and reduce tuber internal defects as well as reduce black spot bruising by in-season application of 168 kg ha −1 Ca during the tuber bulking period (Kleinhenz et al 1999;Ozgen et al 2006;Karlsson et al 2006). The objective of the present study was to determine the relationship between exchangeable soil Ca and tuber Ca, with and without in-season Ca fertilization.…”

“…The control plots received split doses of nitrogen using the method described above. Both sources of Ca (calcium nitrate, and a mixture of calcium chloride and calcium nitrate) have been found to be effective in increasing tuber Ca concentration and improving tuber internal quality (Ozgen et al 2006;Kleinhenz et al 1999;Karlsson et al 2006).…”

“…Several studies have recently documented that in-season Ca application in Wisconsin soils can increase tuber Ca concentration and reduce internal defects such as internal brown spot and hollow heart (Kleinhenz et al 1999;Ozgen et al 2006) and black spot bruise incidence ). This response of in-season Ca application has been found in soils that otherwise contain soil exchangeable Ca over 300 mg kg −1 , which is generally considered sufficient for potato production.…”

Impact of Zebra Chip Disease on the Mineral Content of Potato Tubers

“…It is evident from the published data that the mineral composition of potato tubers plays an important role in the tuber's overall health including protection against numerous potato-related diseases (Kleinhenz et al 1999;Mondy and Ponnampalam 1986;Bretzloff 1971;Lambert et al 2005;Davies 1998). Conversely, diseases can influence greatly the mineral composition of potatoes ultimately leading to diminished tuber nutrition and crop loss (Chandra and Mondy 1981;Krištůfek et al 2000;Hoveland et al 1954;Ulrychová and Limberk 1968).…”