Wheat scab is common in Argentina mainly durum wheat and some bread varieties. The epidemics occur every 5 to 7 years. During the 2007, 2008, and 2009 growing seasons, three trials were conducted at the INTA Balcarce Experimental Station. Each plot had six rows of 5？m long, spaced 0.15？m apart and was set up in a randomized complete block design with four replications. Trifloxystrobin plus cyproconazole was sprayed at Z3.1 stage. Treatments were sprayed at Z6.1 stage with tebuconazole, prochloraz, and metconazole to improve scab control. Artificial inoculations were made in Z6.1. Severity of Septoria leaf bloth and leaf rust was assessed in boot stage (Z3.9). Scab severity was rated at early dough stage (Z8.3). Yields were recorded each year. Fungicide only applied at Z3.1 stage did not reduce field scab severity but reduced the seeds infection and increased the yields. Early fungicide spray produced yield increase at about 22% and a decrease in seed infection of up to 40%. Yields increased in a 55.3% and in a 19.6% when compared with the inoculated and not inoculated check, respectively. The purpose of this study was to evaluate the effect of foliar disease control on scab, crop yield, and seed health. 1. Introduction Head blight (scab) caused by Fusarium graminearum Schwabe (teleomorph Gibberella zeae (Schw.) Petch) occurs in humid wheat producing areas of the world [1, 2]. In Argentina, it is common in durum wheat and some bread wheat cultivars depending of susceptibility to the pathogen . Very destructive outbreaks occurred in 1978, 1985, 1993, 2000, 2001, and 2002 growing seasons [4–6]. Damage has been significant in south east of Buenos Aires province. The disease attacks the heads and then seedling of small grains, but it is the most conspicuous and does the most damage when infecting the wheat heads. In Argentina, the use of foliar fungicides on wheat is common, and it has increased considerably . Near 30% of the crop area in SE of Buenos Aires is sprayed to control of foliar disease like rust and leaf blotch . The control of scab by fungicide applications should be a preventive action because if fungicide applications are done when the symptoms appear, the disease control efficiency would be extremely low. Therefore the use of fungicide to control wheat scab is low compared with the use of fungicide for controlling foliar disease. Yields can be improved with the use of fungicides, but yield increments vary extremely according to disease severity, fungicide efficiency, timing spray, and number of applications [9, 10]. Fungicide sprays
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J. D. Mantecón and J. H. Bariffi, “Fungicides sprays on durum wheat for control of Fusarium head blight in Argentina, 2003,” American Phythopathological Society, Fungicide and Nematicide Test, vol. 60, CF019, 2005.
S. Montiel, J. D. Mantecón, and J. H. Bariffi, “Effect of fungicide applications on grain quality, yield and incidence of Fusarium head blight of wheat, 2003,” American Phythopathological Society, Fungicide and Nematicide Test, vol. 60, CF022, 2005.
J. D. Mantecón and J. H. Bariffi, “Effects of fungicide applications and timing of sprays on Fusarium head blight and yield of wheat, 2004,” American Phythopathological Society, Fungicide and Nematicide Test, vol. 61, CF018, 2006.
J. D. Mantecón and J. H. Bariffi, “Fungicide applications for the control of Fusarium head blight on durum wheat, 2004,” American Phythopathological Society, Fungicide and Nematicide Test, vol. 61, CF019, 2006.