Influence of Cultural Practices on Incidence of Foot Rot in Winter Wheat

consequence in the plots each year, and no supplemental inoculum of P. herABSTRACT Herrman, T., and Wiese, M. V. 1985. Influence of cultural practices on incidence of foot rot in potrichoides was added. winter wheat. Plant Disease 69:948-950. The three preplant tillage systems evaluated in this study were 1) conCrop rotation, preplant tillage, cultivar selection, nitrogen fertilization, and benomyl application ventional (moldboard plow, disc, were evaluated for their individual and interactive effects on foot rot (Pseudocercosporella harrow, and John Deere 8250 drill), 2) herpotrichoides) and seed yield in winter wheat. Preplant tillage had a significant and direct effect reduced (chisel planter designed at the on disease incidence. Conventional tillage (plow and disc) consistently supported significantly University of Idaho [19]), and 3) no-till higher foot rot levels than reduced-tillage and no-till treatments. Cultivars Daws and Stephens (John Deere 1500 Power-Till Drill). The supported higher and lower foot rot levels, respectively, than either Luke or Nugaines. The effect of three crop rotations evaluated were 1) rotation on disease incidence was inconsistent and nitrogen levels between 101 and 135 kg/ha had winter wheat/spring pea, 2) w no significant effect. In 1981, seed yield was influenced significantly by tillage, cultivar, and winter wheat/spring pea, a benomyl treatments. Benomyl application elicited significantly higher yields with all cultivars wheat/spring wheat/spring pea, and 3) under reduced tillage but not under no-till. In 1982, benomyl/rotation/tillage, winter wheat/alfalfa + red clover + benomyl/ tillage/ cultivar, and benomyl/ rotation/ cultivar interactions with yield were significant. spring pea/ alfalfa + red clover. Conventional tillage and benomyl application supported the highest yields. Results indicate that Winter wheat cultivars employed in the reduced-tillage practices can limit both soil erosion and foot rot incidence, but these advantages study were Nugaines (CI 13968), must be weighed against possible yield reductions. Stephens (CI 17596), Luke (CI 14586), and Daws (CI 17149). Seeding was done during mid-October each year and Yield suppression in winter wheat yield in the subsequent wheat crop than seeding depth was maintained between (Triticum aestivum L.) from foot rot when the straw was more completely 2.5 and.4 cm. Fertilizer (27-12-0-4)was caused by Pseudocercosporella herburied with a moldboard plow. Although applied at 101 kg of N/ha on all winter potrichoides (Fron) Deighton may reach foot rot incidence and severity were not wheat plots in autumn. Additional 50% in the Palouse region of eastern measured, Cook and Waldher surmised nitrogen (34-0-0) at rates of 17 and 34 Washington and northern Idaho (5,12,22). that resultant foot rot levels were related kg/ha was applied in spring to create Although such practices as late fall to plant size rather than to tillage. Brooks subplots receiving 101, 118, or 135 kg of seeding and spring application of and Dawson (3) reported less foot rot in N/ha. Subplot dimensions were 2.4 8.4 m, fungicide partially control foot rot no-till than in conventionally tilled plots, and each treatment was replicated four (4,6,12,13,17,20,22), the associated risk Neither of these studies, however, times. of overwinter soil erosion and the cost of compared tillage against both foot rot In 1981, foot rot incidence and wheat fungicide application are undesirable. In incidence and yield or examined a range yield were evaluated under the three recent years, up to 70% of the wheat of conventional tillage, reduced tillage, rotations; under three nitrogen levels; acreage in the Palouse receives a foliar and no-till practices. among the cultivars Daws, Nugaines, and application of fungicide in early spring to To date, the possible interaction of Stephens; and under reduced and no reduce foot rot development (M. V. fungicide, crop rotation, preplant tillage, preplant tillage with and without a Wiese and D. M. Gerten, unpublished). cultivar, and nitrogen variables as benomyl spray. Conventional tillage Short periods between successive determinants of foot rot and yield levels plots were unavailable in 1981 because of wheat crops (short rotations) tend to has not been evaluated. Such information equipment malfunction during seeding. favor foot rot development, whereas long could be useful to improve wheat In 1982, nitrogen was held constant at 118 rotations (two or more years between management practices and to identify kg/ha and cultivars Nugaines, Stephens, wheat crops) appear to limit inoculum management alternatives that best limit Daws, and Luke under the three tillage and disease development (10,12,15). foot rot and soil erosion while sustaining systems and three rotations with and Nitrogen, while promoting plant growth, or augmenting yield. The primary without benomyl fungicide were evaluated may also promote a favorable microenobjective of this research, therefore, was for disease incidence and yield. vironment for foot rot development to measure foot rot incidence in winter In 1981, benomyl was applied • eight (5,21). wheat as influenced by preplant tillage. of 10 rows of wheat (about 16 in ) across