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Potassium Uptake by Cotton in Relation to Verticillium Wilt 1
Author(s) -
Hafez A. A. R.,
Stout P. R.,
DeVay J. E.
Publication year - 1975
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1975.00021962006700030019x
Subject(s) - verticillium wilt , verticillium dahliae , chloropicrin , fumigation , agronomy , lint , fertilizer , soil water , human fertilization , verticillium , malvaceae , potassium , biology , chemistry , horticulture , ecology , organic chemistry
Increasing evidence of a close relationship between K‐nutrition of cotton plants ( Gossypium hirsutum L.) and verticillium wilt ( Verticillium dahliae Kelb) development was observed in certain K‐deficient soils in San Joaquin Valley, California. Therefore, a K uptake field experiment on verticillium‐infected K‐deficient soil with 270 kg K/ha fertilized and unfertilized plots were conducted on both (420 liter/ha) chloropicrin (trichloronitromethane) fumigated and non‐fumigated treatments. The uptake of fertilizer K was traced by the “reverse‐tagging” procedure in which the indigenous soil‐Rb was used as a tag for K. In this instance the fertilizer Rb/K ratio was about 0.01 of the Rb/K ratio of the labile K in the upper foot of the soil profile. Cotton plants grown on fumigated soil absorbed 62% of their leaf K from the fertilizer source versus 48% for the non‐fumigated soils. Also it was observed that in the unfertilized plots, fumigation induced shifts in Rb/K ratio in plant tissues, which is explained by the differences in the Rb/K ratios in the upper and lower soil horizons coupled with reduced uptake efficiencies when roots in the upper soil horizons are infected with verticillium wilt. K‐fertilization alone resulted in a significant decrease in verticillium wilt. In both fumigated and non‐fumigated plots, yields of cotton lint responded significantly to K‐fertilization. However, corrections of K deficiency symptoms of cotton leaves required a combination of soil fumigation with chloropicrin and K‐fertilization.