Sweetpotato (Ipomoea batatas L.) response to incremental application rates of potassium fertilizer in Mississippi

Authors: HARVEY, LORIN - Mississippi State University; SHANKLE, MARK - Mississippi State University; MORRIS, CALLIE - Mississippi State University; HALL, MARK - Mississippi State University; Chatterjee, Amitava; HARVEY, KELSEY - Mississippi State University

Submitted to: Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2022
Publication Date: 9/9/2022
Citation: Harvey, L.M., Shankle, M.W., Morris, C.J., Hall, M.A., Chatterjee, A., Harvey, K.M. 2022. Sweetpotato (Ipomoea batatas L.) response to incremental application rates of potassium fertilizer in Mississippi. Horticulturae. 8(9). https://doi.org/10.3390/horticulturae8090831.
DOI: https://doi.org/10.3390/horticulturae8090831

Interpretive Summary: Potassium plays an important role in sweet potato production. Due to increasing fertilizer price, it is important to develop application recommendations that considering grower profit. A field experiment was conducted to study the storage root yield of sweet potato under seven potassium rates in Mississippi. We found that a medium application rate of potassium fertilizer of 132 pounds potassium per acre can maximize profit in Mississippi. Our study showed that consideration of economic profit will reduce unnecessary application of potassium fertilizer and save money for the grower. These results are useful to farmers and researchers interested in potassium fertilizer need of sweet potato.

Technical Abstract: A field experiment was conducted to study sweet potato (cultivar Beauregard) storage root yield under seven potassium (K2O) application rates in Mississippi for four growing seasons. Growing season had a significant influence on leaf tissue nutrient concentration and storage root yield. Leaf tissue K concentration was significantly greater (P<0.10) at 269 kg K2O/ha than 0, 67, and 135 kg K2O/ha but the tissue K concentration was similar between 336 and 404 kg K2O/ha. Four-year average of the total marketable yield was highest at 135 kg K2O/ha, which was the only treatment significantly greater than the control. Incremental K application did not influence No. 1 yield. Assuming the cost of K fertilizer at $0.85/kg for K2O and price of sweetpotato at $0.52/kg, a quadratic fit between economic return and cost of K fertilizer revealed that K application rate of 148 kg K2O/ha may optimize the economic return.