Sensitivity of Cercospora beticola isolates from Serbia to carbendazim and flutriafol

Cercospora beticola, causal agent of Cercospora leaf spot (CLS) of sugar beet, is primarily controlled by fungicides. Benzimidazole and demethylation inhibiting fungicides, including carbendazim and flutriafol, have been widely used in Serbia. Since these fungicide groups have a site-specific mode of action, there is a high risk for developing resistance in target organisms, which is the most important limiting factor in Cercospora leaf spot chemical control. A rapid identification of flutriafol and carbendazim resistance can help researchers in examining the potential of different fungicide resistance management practices, as well as in selection of fungicides for use in the areas where resistance has occurred. One hundred single-conidia isolates were collected from 70 representative locations of the sugar beet production region in Serbia. Evaluation of the isolates' sensitivity was based on the reduction of mycelial growth on medium amended with 1.25 μg mL⁻¹ flutriafol and 5 μg mL⁻¹ carbendazim. Resistance to flutriafol and carbendazim was detected in 16% and 96% of the tested isolates, respectively. All isolates resistant to flutriafol were resistant to carbendazim as well, which is the first report of a double resistance to fungicides in C. beticola. Detection of the isolates resistant to flutriafol and carbendazim using Cleaved Amplified Polymorphic Sequence (CAPS) markers confirmed the results of the in vitro tests. The efficacy of carbendazim, flutriafol, azoxystrobin, and tetraconazole at commercially recommended doses was evaluated in field trials where sugar beet plants in plots were inoculated with a mixture of isolates either sensitive and/or resistant to flutriafol and carbendazim. Carbendazim and flutriafol efficacy was very low in plots inoculated with isolates resistant to these fungicides. Presented results will contribute to development of a pathogen population sensitivity monitoring strategy that could be used for an effective CLS management in the region.     

Sensitivity of Cercospora sojina isolates to quinone outside inhibitor fungicides

Frogeye leaf spot, caused by Cercospora sojina, causes yield reductions to soybean (Glycine max) grown worldwide. Quinone outside inhibitor (QoI) fungicides have been effective in managing frogeye leaf spot, but the risk of selecting C. sojina strains with resistance to this class of fungicides is considered high. A QoI fungicide resistance monitoring program was initiated, in which sensitivities to azoxystrobin, pyraclostrobin, and trifloxystrobin were determined in C. sojina isolates collected prior to QoI fungicide use on soybean (baseline group) and C. sojina isolates collected from soybean fields in 2007, 2008 and 2009. For the baseline group, the mean effective fungicide concentration at which 50% of the conidial germination was inhibited (EC₅₀) was determined to be 0.01287, 0.00028 and 0.00116 μg ml⁻¹ for azoxystrobin, pyraclostrobin and trifloxystrobin, respectively. When mean EC₅₀ values of 2007, 2008 and 2009 C. sojina isolates were compared to baseline C. sojina EC₅₀ values, a small but statistically significant (P ≤ 0.05) shift towards less sensitivity was observed for trifloxystrobin in 2009. Although small (<1.5-fold), this shift in sensitivity indicates a risk of selecting for C. sojina strains with reduced sensitivity to QoI fungicides, and fungicide sensitivities should continue to be monitored in the future.     

江苏省油菜菌核病菌对多菌灵的敏感性

为监测目前油菜菌核病菌对多菌灵抗性现状，对从江苏省各地采集的油菜菌核病病原菌菌株以及海安、苏州和高淳三地的油菜菌核病病原菌田间群体菌株进行了多菌灵的敏感性测定。结果表明，江苏省油菜菌核病菌对多菌灵的抗药性已经产生，不同地区菌株对多菌灵的抗性比率不同。在苏州的田间菌株群体中抗性菌株的比率达到28.12%，而在高淳等地的菌株中没有检测到抗性菌株的存在。抗性菌株都表现为高抗，其EC50 >100µg／ml。对抗性菌株的β-微管蛋白基因进行PCR扩增和酶切的结果表明，所有抗性菌株的β-微管蛋白基因的198位都发生突变，从而导致油菜菌核病菌对多菌灵抗性的产生。从江苏省范围来看，继续使用多菌灵防治油菜菌核病菌可能会导致抗性频率上升、抗性范围扩大。     

Characterization of fungicide resistant isolates of Phaeoacremonium aleophilum infecting grapevines in Spain

Fungicide resistance in Phaeoacremonium aleophilum, one of the most frequent fungal pathogens associated with grapevine trunk diseases, was investigated and found to exist in some isolates of the pathogen against a commercial formulation, Escudo^®. The effect of this compound and its two active substances, carbendazim and flusilazole, was first evaluated on the mycelial growth of P. aleophilum. Escudo^®-resistant isolates were estimated at a frequency of 24% in Spanish vineyards. Then, the two active substances were used individually to test their effect on mycelia growth of twelve single-spore cultures originating from six Escudo^®-resistant isolates. Flusilazole (DMI-triazole) did not inhibit mycelia growth of any single-spore cultures of P. aleophilum. Carbendazim (benzimidazole) used alone allowed the growth of the same single-spore cultures that were also resistant to Escudo^®. AFLP characterization of sensitive and resistant single-spore cultures showed genetic diversity within P. aleophilum isolates but no AFLP markers were associated with resistance. New primers set (L2/R1) were designed to partially amplify the exon 6 of the beta-tubulin gene of P. aleophilum. Two different point mutations resulted in glycine (GGC) or lysine (AAA) replacing the glutamic acid (GAG) at codon 198 of the beta-tubulin gene in some of the resistant single-spore cultures studied. Resistant single-spore cultures of P. aleophilum were shown to have different aggressiveness levels as sensitive single-spore cultures by inoculation of wood segments of Vitis vinifera in the presence and absence of fungicide.     

Sensitivity of wheat and rice to low levels of atmospheric ethylene

Ethylene (C2H4) gas is produced throughout the life cycle of plants and can accumulate in closed growth chambers to levels 100 times higher than in outside environments. Elevated atmospheric C2H4 can cause a variety of abnormal responses, but the sensitivity to elevated C2H4 is not well characterized. We evaluated the C2H4 sensitivity of wheat (Triticum aestivum L.) and rice (Oryza sativa L.) in five studies. The first three studies compared the effects of continuous C2H4 levels ranging from 0 to 1000 nmol mol-1 (ppb) in a growth chamber throughout the life cycle of the plants. A short-term 1000 nmol mol-1 treatment was included in which exposure was stopped at anthesis. Yield was reduced by 36% in wheat and 63% in rice at 50 nmol mol-1 and both species were virtually sterile when continuously exposed to 1000 nmol mol-1. However, the yield reductions were much less with exposure that stopped at anthesis, suggesting the detrimental effect of C2H4 on yield was greatest around the time of seed set. Two additional studies evaluated the differential sensitivity of two wheat cultivars (Super Dwarf and USU-Apogee) to 50 nmol mol-1 C2H4 at three CO2 levels [350, 1200, 5000 micromoles mol-1 (ppm)] in a greenhouse. Yield of USU-Apogee was not significantly reduced by C2H4 but the yield of Super Dwarf was reduced by 60%. Elevated CO2 did not influence the sensitivity to C2H4. A difference in the C2H4 sensitivity of USU-Apogee between greenhouse and growth chamber trials suggests that C2H4 sensitivity is dependent on the environment. Collectively, the data suggest that relatively low levels of C2H4 could induce anomalous plant responses by accumulation in greenhouses and growth chambers with inadequate ventilation. The data also suggest that C2H4 sensitivity can be reduced by both genetic and environmental manipulations.     

Sensitivity to iprodione, difenoconazole and fludioxonil of Rhizoctonia cerealis isolates collected from wheat in China

Since the 1980s wheat sharp eyespot (WSE) caused mainly by Rhizoctonia cerealis has become one of serious diseases of wheat in China. In this study, the sensitivity of 89 R. cerealis isolates to different fungicides was evaluated using mycelial growth inhibition assays. The results showed that all R. cerealis isolates tested were sensitive to iprodione, difenoconazole and fludioxonil with mean EC₅₀ (effective concentration that results in 50% of mycelial growth inhibition) values of 0.419, 0.062 and 0.033 μg/ml, respectively. To evaluate the risk of fungicide resistance in R. cerealis, an attempt was made to induce resistant mutants in the laboratory. Although difenoconazole- and fludioxonil-resistant mutants were not obtained, we obtained seven independently iprodione-resistant (IR) mutants from 89 parental isolates. The EC₅₀ values for these IR mutants were greater than 100 μg/ml, whereas those for the original wild-type counterparts were less than 1 μg/ml. After having been subcultured on PDA for 10 generations, the IR mutants did not show any decrease in resistance to iprodione. Additionally, these IR mutants also showed resistance to fludioxonil but remained sensitive to difenoconazole. Osmotic sensitivity tests showed that the IR mutants were hypersensitive to osmotic stress generated by NaCl. Inoculation tests showed that all the IR mutants lost their ability to infect the host plant. Taken together, these results indicate that the current population of R. cerealis is sensitive to these fungicides and a fitness cost is associated with iprodione-resistant mutants of R. cerealis in both osmotic stress and pathogenicity. The information obtained in this study is useful in monitoring and managing fungicide resistance in R. cerealis populations in China.     

Towards a more rational approach to fungicide design

Whereas insignificant progress has been made in the chemical control of viruses, mycoplasmas and bacteria, the control of fungal diseases has been significantly improved by the recent introduction of more potent chemicals. However, the shortcomings of these chemicals, the changing background of world agriculture and the decreasing success rate call for more rational approaches in fungicide research. The increasing research efforts in the basic biochemistry of target organisms and host-parasite interactions hold promise for the design of new types of chemicals for plant protection.     

Physical and chemical parameters,Fusarium verticillioides growth and fumonisin production in kernels of nine maize genotypes

Fusarium verticilloides synthesizes fumonisins (FBs) in the field and during faulty storage of maize. FBs are worrisome because of their toxicological effects. Nine maize genotypes differing in physical grain properties, phytochemical profiles, and chemical compositions were evaluated. Kernels were tempered to 18% moisture and purposely contaminated with F. verticilloides to assess differences in mold growth and FBs. The genotype significantly influenced counts with mean values ranging from 12.9 CFU/mLx10⁴ for the highly susceptible Blue Don Goyo to only 1.0 CFU/mLx10⁴ for the Pob84C3 genotype. The concentrations of FBs in these two genotypes were 6.85 and 0.3 ppm, respectively. Popcorn kernels showed a relatively high level of Fusarium counts (7.0 CFU/mLx10⁴) but low concentrations of FBs (1.4 ppm). The large-sized Cacahuacintle and Don Goyo kernels, which had the lowest test weights and highest 1000 kernel weight (TKW) showed the highest occurrence of CFU likely due to their low proportion of pericarp, bound phenolics (coumaric), diferulic acids and bound antioxidants. Correlations indicated that mold counts did not correlate (r² = 0.6, P = 0.08) with FBs. However, grain thickness, hardness, TKW and bound phenolics were related to Fusarium counts. This research demonstrated that contrasting maize genotypes showed different susceptibilities to Fusarium growth and FBs contamination.     

Genetic diversity of rice sheath blight isolates (Rhizoctonia solani AG-1 IA) from different rice cultivars

Rhizoctonia solani AG 1 IA, the non specific, soil borne, and plant casual agent of rice sheath blight, occurring world widely in rice fields, has become a major disease to rice. In this study,relationships among R. solani AG 1 IA isolates, collected from different rice cultivars were reported.     

Aggressiveness variation of Fusarium graminearum isolates from Argentina following point inoculation of field grown wheat spikes

Aggressiveness variation among isolates of Fusarium graminearum from Argentina was analyzed by following disease development on point inoculated spikes of field grown wheat. Two aspects of the capacity of the isolates to induce disease were observed: (i) the infection efficiency reflected by the ability to produce symptoms and evaluated as the number of symptomatic spikes over the inoculated ones; and (ii) the size of the lesion provoked, which is reflected by the number of symptomatic spikelets over its total number. One hundred and twelve isolates were found to induce significantly different levels of disease severity, reflecting variation in aggressiveness. Differences were also found between the isolates for the thousand kernel weight (TKW) and the area under the disease progress curve (AUDPC) and the correlations between disease severity, AUDPC, and TKW were highly significant. Based on disease severity, isolates were clustered as low, medium and highly aggressive and both lesion size and infection efficiency were significantly different between these groups. The movement of the pathogen in the spike occurred primarily downwards the point of inoculation. Movement toward the upper portion was related with the aggressiveness of the isolates and the premature ripening of the spike appeared to be a function of isolate aggressiveness. In this work point inoculation allowed us to study not only the aggressiveness of a large collection of F. graminearum isolates but also to analyze the development of Fusarium head blight symptoms in large numbers of spikes under conditions similar to those in which this disease naturally occurs.     

新昌县稻米消费嫌籼喜粳演变趋势及其对我们的启示

新昌地处浙江东部 ,为山区小县 ,现拥有人口43万 ,耕地1.6万hm2 ,其中水田1.1万hm2。近年社会经济发展很快 ,“八五”时期从浙江省17个贫困县之一发展成为浙江省经济中等发达县 ;经“九五”努力 ,1998年又被评为省定小康县 ;经国家统计局农村社会经济调查总队综合测评结果 ,2001年跻身全国百强县 (市 )行列。2002年农民人均纯收入达4930元 ,城镇居民人均可支配收入达11683元 ,分别比2001年增加293元和1263元。当地传统上以消费籼米为主 ,其中稻米严重短缺的20世纪50年代以前 ,为中晚籼米 ;进入60年代因水稻改制成功 ,主要消费转向早籼米 ;从…     

A dynamic risk assessment model (FUMAgrain) of fumonisin synthesis by Fusarium verticillioides in maize grain in Italy

Fumonisin contamination of maize grain starts in the field. Forecasting Fusarium infection and fumonisin synthesis could allow operators in the field to control contamination during the growing season and to make the best agronomic decisions for high quality yields while respecting the limits imposed by the European Union.A research project to develop a decision support system for the control of field-phase fumonisin contamination began in Italy in 2003. This paper presents a preliminary version of the engine of the decision support tool: FUMAgrain, a dynamic risk assessment model developed with data from the north of Italy. The structure of FUMAgrain is based on the pathosystem formed by maize, F. verticillioides and Ostrinia nubilalis (European Corn Borer). The elements of the pathosystem are simulated by three sub-models: (i) maize development, (ii) F. verticillioides infection and fumonisin synthesis, (iii) European Corn Borer wounding activity on maize grain. Inputs to the model are (i) planting date, (ii) hourly meteorological data including temperature, relative humidity, wind speed and rain intensity, (iii) information on the phenological development of the hybrid planted (flowering and dry-down), and (iv) information about the chemical treatment against European Corn Borer. FUMAgrain gives an initial risk alert at the end of flowering based on the meteorological conditions during this phase. A second alert follows maturation when an assessment is made from (i) maize grain moisture, (ii) European Corn Borer damage to the ear, and (iii) fumonisin synthesis risk. Following calibration and validation with data FUMAgrain demonstrated its good capability to simulate fumonisin synthesis in maize grain in Italy (calibration: R² = 0.70; validation: R² = 0.71) and its usefulness for determining the optimal harvest date while respecting grain safety levels required by the international market and limiting moisture content, hence drying costs.     

Differential response of Cucumis melo to Fusarium oxysporum f. sp. melonis race 1.2 isolates

Fusarium wilt incited by Fusarium oxysporum f. sp. melonis (Fom) causes severe losses in melon crops. Four physiological races of Fom have been identified: 0, 1, 2 and 1.2. In most cases, resistance to race 1.2 has been described as recessive, polygenic and not race specific. However, some evidence of race-specific effects within melon resistance to race 1.2 has been reported. In this work, we study these effects and assess whether they are due to race-specific resistance. Seeds were obtained from 14 melon accessions that exhibit some level of resistance to race 1.2, and from the lines ‘Charentais-Fom1’ (resistant to races 0 and 2), ‘Charentais-Fom-2’ (resistant to races 0 and 1), and ‘Dinero F₁’ (with partial resistance to Fom race 1.2). Melon seedlings were artificially inoculated using two different procedures: ‘continuous shaking’ and ‘tray immersion’. Symptom severity was assessed on leaves using a rating scale from 0 (no symptoms) to 4 (death of the plant). Symptoms were recorded weekly over the four-week period following the first appearance of symptoms and the area under the disease progress curve (AUDPC) was calculated. Six Fom isolates (3 from pathotype Y and 3 from pathotype W) were used in the inoculation. The less aggressive ‘tray immersion’ procedure seems to be more appropriate for detecting the typically small resistance factors of this type of polygenic partial resistance. ‘Kogane Nashi Makuwa’, ‘BG-5384’, ‘Shiro Uri Okayama’, ‘C-211’ and the control, ‘Dinero F₁’, showed a high level of resistance to all Fom isolates. However, some genotype × isolate effects were also detected. ‘Baza’, when inoculated with isolate Fom 9302, and ‘Korça, when inoculated with Fom 37mls.1.2W, showed resistance levels similar to that of ‘Dinero F₁’; this effect was not observed when ‘Baza’ and ‘Korça’ were inoculated with other isolates. These results are characteristic of race-specific resistance and offer evidence for the presence of this type of resistance to Fom race 1.2 in melons.     

Characterisation and functional properties of Australian rice protein isolates

Albumin, globulin, glutelin and prolamin fractions were isolated from an Australian rice variety (cv. Langi) and characterised by yield, protein content and molecular weight profile using both capillary electrophoresis (SDS-CE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The influence of pre-extraction enzymatic hydrolysis of starch and heating to 70 °C was also investigated, as was the extraction of the glutelin fraction without prior removal of the albumin and globulin fractions. Pre-extraction treatment affected mainly the albumin fraction, increasing dry matter yield but reducing protein content. SDS-CE was able to separate the protein fractions over a wider molecular weight range than SDS-PAGE, and the peaks from SDS-CE showed slightly higher molecular weight compared to equivalent bands from SDS-PAGE. The glutelin fraction extracted without prior removal of albumin and globulin fractions had different characteristics compared to those obtained by conventional extraction methods. Pre-extraction hydrolysis of starch did not significantly affect the emulsifying, foaming and gelling properties of extracted protein. Although rice glutelin had poor solubility, emulsifying and foaming properties in aqueous systems, it had good gelling properties which could be important for food applications.     

Sensitivity to fluopicolide of wild type isolates and biological characteristics of fluopicolide-resistant mutants in Pseudoperonospora cubensis

Cucurbit downy mildew caused by the oomycete pathogen Pseudoperonospora cubensis is a devastating disease that is distributed worldwide and affects cucumber in open fields and greenhouses. Fluopicolide, which was a novel systemic fungicide and was released in 2008, it is very effective in controlling downy mildew on cucumber and grape, potato late blight and pepper Phythophthora blight and reduces the loss caused by the diseases, but so far the potential for P. cubensis to develop resistance to fluopicolide has not been investigated. Hence, a laboratory study was undertaken to assess the risk of P. cubensis developing resistance to fluopicolide. Baseline sensitivity to fluopicolide was determined by using 75 P. cubensis isolates collected from cucumber-growing greenhouses in Hebei province, where no fluopicolide had been used for control of cucumber downy mildew before. Values of effective concentrations for 50% inhibition (EC₅₀) of sporulation ranged from 0.02 to 0.40 μg ml⁻¹ and were distributed as a unimodal curve, indicating that all 75 isolates were sensitive to fluopicolide. Sporangia of nine sensitive isolates were ultraviolet (UV)-irradiated, and four fluopicolide-resistant mutants were acquired at a mutation frequency of 7.4 × 10⁻⁷. Seven mutants resistant to fluopicolide were obtained from seven isolates by sporangia adaptation on fluopicolide-treated leaves of cucumber. The EC₅₀ values for all eleven fluopicolide-resistant mutants ranged from 3.37 to 13.06 μg ml⁻¹ with mean resistance factors of 7.9–118.0. After 10 sporangia transfers on fungicide-free leaves of cucumber, all eleven resistant mutants remained resistant to fluopicolide with mean resistance factors of 8.2–81.3. Seven resistant mutants from the selection for resistance and one resistant mutant from UV mutagenesis exhibited stable resistance; however, the other three resistant mutants from UV irradiation became significantly less resistant. Compared to their respective sensitive parents, the eleven resistant mutants exhibited diversity in latent period, infection frequency, lesion extension and sporulation ability. Five out of the eleven resistant mutants exhibited prolonged latent period and three out of the eleven resistant mutants provided decreased infection frequency (IF) compared to their respective parents, indicating that in some cases, resistance mutation might affect the latent period and IF of P. cubensis. There were significant differences in pathogenicity and ability to produce sporangia, but this seemed not to be caused by resistance mutation. No cross-resistance was detected between fluopicolide and azoxystrobin, metalaxyl, dimethomorph, or cymoxanil. In all, there could be a moderate to high risk of field populations of P. cubensis developing resistance to fluopicolide, and populations of P. cubensis should be monitored regularly for their shift of sensitivity over years of application.     

Management of mango malformation disease based on a novel strategy of timing of fungicide applications combined with sanitation

Mango malformation disease (MMD) caused by Fusarium mangiferae severely affects the crop and is widely distributed in almost all mango-growing regions worldwide. Since malformed inflorescences do not bear fruit, MMD is a major constraint to crop production in affected areas. No effective management methods have been reported to date. The airborne nature of dissemination and infection of buds suggest that protection of buds from infection when inoculum prevails may be a plausible method for disease control from season to season. Various fungicides were assessed for their ability to control the pathogen under laboratory, greenhouse and field conditions. Prochloraz was the most effective fungicide in inhibiting F. mangiferae in vitro with a 0.01 μg mL⁻¹ concentration required for 50% fungal growth inhibition. In greenhouse trials, protective and curative activity exceeding 90% was achieved when the fungicide was applied up to 14 days prior or post inoculation. Field experiments conducted over a number of seasons in different regions in Israel indicate that combined sanitation with timely applications of prochloraz resulted in a significant reduction in MMD disease severity and incidence, as well as a significant increase in yield in treated plots. It is assumed that long-term treatment by removal of infected panicles (the main source of inoculum) combined with timely sprays will result in disease reduction annually achieving negligible levels of malformation in treated orchards, in time.     

Economic returns from fungicide application to control foliar fungal diseases in winter wheat

Fungicides are commonly applied to control foliar fungal diseases of winter wheat in the central Great Plains of the United States and often are routinely recommended. However, economic benefits from fungicide application in winter wheat have rarely been quantified in this region. A total of eight field experiments were conducted in 2006 and 2007 in Nebraska, USA to quantify yield increases from fungicide applications to control foliar fungal diseases in winter wheat. Experiments were conducted at the same four locations (Mead, Clay Center, North Platte and Sidney) in both years. The fungicides used were azoxystrobin + propiconazole, pyraclostrobin, propiconazole, azoxystrobin and trifloxystrobin + propiconazole applied at varying rates and growth stages. Average wheat prices were calculated from data provided by the United States Department of Agriculture (USDA) Agricultural Marketing Service. Average fungicide and fungicide application costs were obtained through surveys of local retailers, chemical manufacturers and commercial applicators. These prices and costs were used to calculate net returns from fungicide treatments. The probability of a positive net return was 0.60, 1.00 and 0.80 in 2006 (dry, low disease severity), 2007 (wet, moderate to high disease severity) and both years combined, respectively. Net returns ranged from $−101 ha⁻¹ to $172 ha⁻¹ in 2006 and from $60 ha⁻¹ to $294 ha⁻¹ in 2007. Net returns were at least two times the total cost ($2 return on $1 investment) in 4 out of 60 or 6.7% of treatments in 2006 and 51 out of 60 or 85% of treatments in 2007. In 2006, the best net returns occurred at Mead and Clay Center and resulted from the treatments 1) azoxystrobin + propiconazole applied at Zadoks growth stage (GS) 31 (first node detectable) at a rate of 0.58 l ha⁻¹ and 2) azoxystrobin + propiconazole applied at GS 31 at a rate of 0.58 l ha⁻¹ and again at GS 37 (flag leaf just visible) at the same rate. In 2007, the treatments that resulted in the best net returns were 1) azoxystrobin + propiconazole applied at GS 39 (ligule/collar of flag leaf just visible) at a rate of 1.02 l ha⁻¹, 2) pyraclostrobin applied at GS 39 at a rate of 0.66 l ha⁻¹, 3) propiconazole applied at GS 39 at a rate of 0.29 l ha⁻¹, and 4) trifloxystrobin + propiconazole applied at GS 39 at a rate of 0.73 l ha⁻¹. For the same fungicide applied at the same rate at GS 31 and GS 39 in 2007 (wet, moderate to high disease severity), the GS 39 application generally resulted in a higher net return than the GS 31 application. Averaged across treatments and locations, net returns were $6 ha⁻¹ and $183 ha⁻¹ in 2006 and 2007, respectively. The results from this study indicate that foliar fungicide application to winter wheat can be profitable in years with moderate to high disease severity; however, net loss can result if fungicides are applied in years with low disease severity.