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Soil Conditions and the Take‐All Disease of Wheat
Author(s) -
Garrett S. D.,
Mann Harold H.
Publication year - 1948
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1948.tb07388.x
Subject(s) - agronomy , take all , biology , crop , plough , straw , crop residue , crop rotation , field experiment , nitrogen , legume , agriculture , fungus , botany , chemistry , ecology , organic chemistry
In a field experiment on the control of take‐all at the Woburn Experimental Station, winter wheat was followed by two consecutive crops of spring‐sown barley. Samples of the barley crop were taken from the forty‐eight plots of the experiment in 1945 and 1946, for estimation of root Disease Rating, and grain yields were also recorded. A comparison of six autumn treatments of the stubble has shown that treatments affecting the available nitrogen content of the soil exercised a predominant effect upon incidence of take‐all in the following crop. Two effects of nitrogen applied in autumn have been distinguished: (1) an immediate effect, in assisting survival of Ophiobolus graminis in infected root and stubble residues; (2) a deferred effect, in promoting disease escape of the following crop. The ploughing in of straw in autumn was found to increase the incidence of take‐all, presumably because the adverse deferred effect of decomposing straw in locking up available nitrogen and withholding it from the following crop. outweighed its beneficial immediate effect in helping to starve out O. graminis , by depriving the fungus of nitrogen. The autumn growth of undersown trefoil ( Medicago lupulina ) on the stubble land seenled to be entirely beneficial; active growth of the legume appeared to assist in starving out O. graminis , and nitrogen was released by decomposition of the trefoil in the soil after spring ploughing in time to benefit the barley crop immediately following.