212-5 Impact of Gypsum on Yield and Tuber Rot for White Potatoes in the Mid-Atlantic.

Poster Number 702

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Gypsum Use: Impact On Agricultural Productivity and Soil/Water Quality
Tuesday, October 18, 2011
Henry Gonzalez Convention Center, Hall C
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Mark S. Reiter, Catherine Fleming, Steve Rideout and Josh Freeman, Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA
Calcium (Ca) and sulfur (S) may significantly impact white potato (Solanum tuberosum) tuber quality and yield in the Mid-Atlantic. Eastern Shore of Virginia soils are naturally deficient in S and S depositions have decreased due to reductions in acid rain; warranting additions of S fertilizer. Similarly, sandy loam soils often test low for Ca and soil test values continue to decrease as lime use is reduced due to proper fertility management, a desired low pH for potato production, and reductions in acid rain. Studies indicated that use of S and Ca containing products, such as gypsum, not only increased yield but reduced tuber rot and increased tuber quality.  A field trial was initiated on a Bojac sandy loam using ‘Superior’ white potatoes in summer 2010. Gypsum was applied at 454, 907, 1361, and 1841 kg ha-1, giving effective S application rates of 188, 376, 564, and 753 kg S ha-1 and Ca application rates of 252, 504, 756, and 1008 kg Ca ha-1. Sulfur rates comparable to the gypsum application were also applied using elemental sulfur along with separate treatments of 0, 28, 56, and 112 kg S ha-1. Erwinia carotovora ss. carotovora and Pythium sp. occurred naturally in this trial causing tuber rots in the field. Potato tubers were harvested and graded for marketability using a mechanized potato harvester. In 2010, no Ca or S treatment significantly decreased tuber rot (average = 12.9%), increased marketable yield (average = 19,143 kg tubers ha-1), nor increased total yield (average = 21,535 kg tubers ha-1). This study will be continued in summers 2011 and 2012 to determine if S and Ca fertilization would increase tuber yields and reduce tuber rots for Mid-Atlantic sandy loam soils.   
See more from this Division: ASA Section: Environmental Quality
See more from this Session: Gypsum Use: Impact On Agricultural Productivity and Soil/Water Quality