589 Calcium Application at Preemergence and during Bulking May Improve Tuber Quality and Grade

in HortScience
Authors:
Christopher GunterDepartment of Horticulture, University of Wisconsin, 1575 Linden Dr., Madison, WI 53706

Search for other papers by Christopher Gunter in
ASHS
Google Scholar
PubMed
Close
,
Senay Ozgen
Search for other papers by Senay Ozgen in
ASHS
Google Scholar
PubMed
Close
,
Bjorn Karlsson
Search for other papers by Bjorn Karlsson in
ASHS
Google Scholar
PubMed
Close
, and
Jiwan Palta
Search for other papers by Jiwan Palta in
ASHS
Google Scholar
PubMed
Close

An increase in calcium concentration of potato tuber tissue has been shown to reduce soft rot severity and the incidence of internal physiological defects. Higher tuber calcium also seems to increase sprout vigor and maintain apical dominance by reducing subapical necrosis and sprout tip death. Preemergent applications of calcium at a rate of 0 and 26.5 kg·ha–1 from ammonium nitrate (PreAmNit), ammonium nitrate plus calcium nitrate (PreCaN), or calcium chloride plus calcium nitrate plus urea (PreCUC). A group of post-emergent split calcium nitrate plus calcium chloride plus urea (PostCUC) applications beginning with hilling and proceeding at 3, 6, and 8 weeks after hilling were also made at a rate of 56 kg·ha–1 calcium at each application time. From visual ratings of stand quality taken 64 days after hilling, we found plants receiving a preemergent application of nutrients or PostCUC had higher stand ratings than paired control plots. Internal tuber quality ratings revealed less internal brown spot in the PostCUC application in 168–364-g tubers. Yield of 112–168-g tubers was greatest from plants treated with PreCaN or PreCUC followed by PostCUC. PreAmNit plots had higher culls than the PreCUC plots. The non-split ammonium nitrate control (all nitrogen by hilling) produced a higher number of B-sized tubers than the PostCUC treatment. Also the PreAmNit+PostCUC had more B-sized tubers than PreCaN+PostCUC. In general the PostCUC treatment produced fewer small tubers and more large tubers than other treatments. These results suggest application of a small amount of calcium prior to emergence but after the sprouts have begun to develop improves seed performance. Furthermore these data show that supplemental calcium application during the season may improve tuber grade.

  • Collapse
  • Expand