PT  - JOURNAL ARTICLE
AU  - A. N. Kasimatis
AU  - L. Peter Christensen
TI  - Response of Thompson Seedless Grapevines to Potassium Application from Three Fertilizer Sources
AID  - 10.5344/ajev.1976.27.3.145
DP  - 1976 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 145--149
VI  - 27
IP  - 3
4099  - http://www.ajevonline.org/content/27/3/145.short
4100  - http://www.ajevonline.org/content/27/3/145.full
SO  - Am J Enol Vitic.1976 Jan 01; 27
AB  - In a replicated trial in a K-deficient area in a Fresno County Thompson Seedless vineyard, vine responses were compared to annual light (0.2 kg K per vine), to single heavy (1.0 kg K per vine) applications of K2SO4, KCl, and KNO3, and to repeated applications of a KNO3 foliar spray. Evaluations made annually for 5 years were based on chemical analyses of petioles collected during bloomtime and on visual grading of the vines for leaf symptoms of K deficiency in midsummer. The severity of foliar symptoms of K deficiency varied markedly from year to year. All treatments except the KNO3 foliar spray improved vine grades significantly over those of the untreated control. Tissue levels of K were lowest for the control and for the foliar spray treatments, highest for the heavy-rate K fertilizers, and intermediate for the annual treatments. Higher, though not damaging, levels of chloride resulted from both the single heavy and the annual light applications of KCl.