Potassium Rate And Source Effects On Potato Yield Quality And Petiole Potassium Levels

Author : Robin L. McBride
Publisher :
ISBN 13 :
Total Pages : 158 pages
Book Rating : 4.:/5 (126 download)

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Download or read book Potash Fertilizer Effects on Yield, Hollow Heart, and Nutrient Levels in Potato Tubers and Petioles written by Robin L. McBride and published by . This book was released on 1985 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Potash rate and source effects on tuber yield and quality (hollow heart, size, and processing quality), and nutrient (K, Ca, Mg, and C1) concentrations in petioles and tubers were evaluated in three experiments, two in the Columbia Basin in Oregon (McDevitt and Levy) and one in Central Oregon (Powell Butte). The Powell Butte experiment included additional variables of rate and time of N application. The effects of KC1 and K2SO4 were compared at 83 and 249 lb K/A rates. Rates of K ranged from 0 to 581 lb/A with some treatments applied at planting only, while in other treatments the applications were split. Potash fertilizers increased total yield, yield of 6+ oz tubers, and decreased the incidence (%) of hollow heart (HH) and brown center (BC) in the Powell Butte and McDevitt experiments. Yields were increased with all rates of K in the Powell Butte experiment; from 18.3 T/A total yield and 6.0 T/A 6+ oz tubers in the K check treatments up to 25.6 T/A total yield and 12.6 T/A 6+ oz tubers for high K rates. In the McDevitt experiment, yields were increased only at high K rates (35.8 T/A total yield and 26.4 T/A 6+ oz tubers for the 581 lb K/A vs 33.4 T/A total and 20.8 T/A 6+ oz tubers for the check treatment). Hollow heart and brown center were reduced with potash fertilizers at the Powell Butte and McDevitt experiments with greater reductions when KC1 was used as compared to K2SO4. Time and rate of N variables established in the Powell Butte experiment also showed an effect on hollow heart; N applications at planting reduced HH and BC as compared to mid-season (July 7) applications when N rates were 120 lb N/A or more. In the Levy experiment, with higher initial soil K and C1 levels, K and C1 did not increase yields or reduce HH and BC. Potassium levels in petioles from check plots in the McDevitt experiment were above suggested critical levels and remained high throughout the season. In the McDevitt and Powell Butte experiments, potash fertilization increased petiole K with KC1 treatments being more effective in increasing K concentrations than comparable rates of K2S04. Petiole Ca levels also were lower in the K2SO4 treatments. Levels of total cations (meq/l00g dw) were higher in petioles from KC1 treatments than from comparable K2S04 treatments. Potash increased K levels in tubers with Ca and Mg also being increased with high K rates. Competitive interactions between K and Ca or Mg were not found. Potassium source did not significantly affect Ca and Mg levels in tubers and there was no relationship between these nutrients and the incidence of hollow heart and brown center. Low K levels in tuber centers and stem ends were found in K check and K2SO4 treatments, however, suggesting some relationship to the disorder. Petiole C1 levels correlated well (r=0.9) with C1 applied. Low concentrations of N03-N were associated (r=-0.9) with high C1 concentrations in petioles without reductions in yield. Concentrations of C1 in petioles correlated well (r=0.9) with C1 found in tubers throughout the season. Tubers from high KC1 treatments had lower specific gravities than tubers from check and low K treatments without affecting processing quality.