Tuesday, November 6, 2007 - 9:00 AM
167-1
‘Crenshaw' Creeping Bentgrass Green Responses to Various Levels of Liquid or Granular Potassium.
Turf Quality during the summer often declines for Creeping Bentgrass grown on golf greens within the transition zone of the US . Applications of potassium have long been recommended for its ability to reduce high heat and drought stress with little regard for soil levels of K, Ca or Mg. The objective of this two year study was to determine the ability of either liquid (K2o/derived from Potassium Carbonate) or granular (K2O derived from Potassium Sulfate) sources of K to suppress high heat injury during the summer months in conjunction with supplemental Ca, Mg or both in calcareous golf greens. Liquid and granular K was supplied at an annual rate of 195.28 kg K /ha, split into 12 applications every two weeks from June to October in 2006 and 2007. Treatments of Ca and/or Mg were each applied at a rate of 48.82 kg Mg /ha annually in 5 equal applications during the previously stated months. Data collection included visual turfgrass quality (TQ) rated every two weeks from 1-9 (1 = brown, dead turf, 7 = acceptable turf, and 9 = perfect, green turfgrass) based on color, density, and overall stand health. Root mass by dry weight, root and leaf tissue nutrient concentrations and chlorophyll were collected three times each year in the beginning, middle and end of the study. Additionally, clipping yields and soil moisture were collected monthly. Results from the first year show that liquid applications of potassium lowered TQ ratings and clipping yields, however provided the greatest amount of K for leaf tissue nutrient content measurements. Data show that applications of calcium alone were more beneficial than magnesium with or without calcium.
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