Abstract
Tomato (Lycopersicon esculentum Mill. cv. Sunny) was grown with the full‐bed polyethylene mulch‐seepage (modified furrow) irrigation system for three seasons to evaluate the effects of potassium (K) sources and K rates on fruit yields and leaf K concentrations. Soil in the experimental area was an Eau Gallie fine sand (sandy, siliceous, hyperthermic Alfic Haplaquods) that varied from 12 mg kg‐1 (very low) to 56 mg kg‐1 (medium) K by Mehlich I extraction prior to planting. Potassium sources, potassium chloride (KC1), potassium nitrate (KNO3), and potassium sulfate (K2SO4) were evaluated at 0, 90, 180, 270, and 360 kg kg‐1 K rates. Nitrogen (N) was applied at 270 kg kg‐1 and P at 43 kg kg‐1 with all K rates. Yields of extra‐large and marketable total yields in one season were higher (P<0.05) with potassium nitrate (KNO3) than with KC1. Maximum yields were produced from 270 to 360 kg K kg‐1, regardless of pre‐plant soil K concentrations. In the shoots, K concentrations increased with increasing K rates. At 90 and 180 kg K kg‐1 application rates, K concentrations in the shoots were <2% and the plants and fruits had K‐deficiency symptoms.
Notes
Florida Agricultural Experiment Station Journal Series No. R‐06457.