02269naa a2200349 a 450000100080000000500110000800800410001910000170006024501050007726000090018252013410019165000140153265000110154665000110155765000180156865000170158665000100160365000130161365000120162665000180163865000090165665000100166565300110167565300120168665300240169865300120172265300270173465300120176165300210177370000210179477301040181514588641996-11-26       1991    bl ---       0--  u    #d1 aMEHTA, Y. R.  aThe effects of tillage practices and crop rotation on the epidemiology of some major wheat diseases.  c1991  aIn nontraditional, warmer areas, instability in wheat productivity is due to constraints such as drought stress, soil acidity, and low fertility. Inappropriate management practices such as no crop rotation can also hinder wheat production in that they have a direct influences on the severity of some major diseases. Foliar disease severity, especially of tan spot, is increased due to the over-summering of the pathogen in wheat residues. Because of changes in cultivation practices, this disease has become increasingly important in several tropical and subtropical regions of the world, where earlier it was not important or else was not reported. Root rot dseases like common root rot, rhizoctonia, sclerotium, and take-all are also more severe in no tillage than inthe conventional cultivation systems. Normally, the severity of such diseases is dependent on the amount of rainfall during the early part of the crop cycle. In most cases, crop rotation is extremely important in restricting such diseases to low levels. Where changes in crop rotation are not possible, deep tillage systems should offer a potential compromise, like plowing once a year after the soybean crop or once in 2 or 3 years, depending upon the disease and its severity. Nevertheless, in general, an integrated disease management approachs in most desirable.  aAustralia  aBrazil  acotton  acrop rotation  aepidemiology  awheat  aAlgodão  aDoença  aEpidemiologia  aSoja  aTrigo  aBrasil  aDisease  aPyrenophora tritici  aRotacao  aSemeadura convencional  aSoybean  aTillage practice1 aGAUDENCIO, C. A.  tIn: SAUNDERS, D.A., ed. Wheat, for the nontraditional, warm areas. Mexico: CIMMYT, 1991. p.266-283.