Yield Loss In Winter Wheat Research Articles

Predicting potential winter wheat yield losses caused by multiple disease systems and climatic conditions

Yield losses in field crops are most commonly predicted by using regression models that include either biotic or abiotic factors as predictor variables. Knowing that yield loss is a complex trait, the potential capability of regression models for predicting yield losses by using models containing both biotic and abiotic factors as predictors were estimated in this study. Biotic factors considered in regression models were: leaf rust, powdery mildew, septoria tritici blotch and tan spot occurrence on the varieties Barbee and Durumko known to have various degrees of susceptibility to obligate parasites and leaf blotch diseases. Among abiotic factors, monthly averages of temperature, relative humidity and total rainfall taken from November to June for growing seasons 2006–2013 were used as predictors. In 2014, yellow rust became the predominant pathogen over leaf rust, thus 2014 and 2015 were excluded from regression models and analyzed separately. Since a high correlation was found between abiotic and biotic factors, partial least squares regression, stepwise regression and best subsets regression were applied. Best subsets regression revealed that models consisted of both biotic and abiotic factors were more precise in estimating regression coefficients and predicting future responses. The potential yield loss predictions, conducted using these models, were regressed with actual yield losses, and high coefficients of determination (R2 = 79% for Barbee; and R2 = 63% for Durumko) were obtained. It was also evident that using more predictors in regression models does not necessarily mean that the model would have a higher potential in making yield loss predictions. This study confirms that the relationship between a disease scoring scale and yield loss is not straightforward and higher potentials for yield loss predictions were given due to the regression models using abiotic and biotic predictor variables.

Quantifying the spatial variation in the potential productivity and yield gap of winter wheat in China

Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential for estimating the food production capacity and improving agricultural policies to ensure food security. Gradually descending models and geographic information system (GIS) technology were employed to characterize the spatial variability of potential yields and yield gaps in winter wheat across the main production region of China. The results showed that during 2000–2010, the average potential yield limited by thermal resource (YGT) was 23.2 Mg ha−1, with larger value in the northern area relative to the southern area. The potential yield limited by the water supply (YGW) generally decreased from north to south, with an average value of 1.9 Mg ha−1 across the entire study region. The highest YGW in the north sub-region (NS) implied that the irrigation and drainage conditions in this sub-region must be improved. The averaged yield loss of winter wheat from nutrient deficiency (YGN) varied between 2.1 and 3.1 Mg ha−1 in the study area, which was greater than the yield loss caused by water limitation. The potential decrease in yield from photo-thermal-water-nutrient-limited production to actual yield (YGO) was over 6.0 Mg ha−1, ranging from 4.9 to 8.3 Mg ha−1 across the entire study region, and it was more obvious in the southern area than in the northern area. These findings suggest that across the main winter wheat production region, the highest yield gap was induced by thermal resources, followed by other factors, such as the level of farming technology, social policy and economic feasibility. Furthermore, there are opportunities to narrow the yield gaps by making full use of climatic resources and developing a reasonable production plan for winter wheat crops. Thus, meeting the challenges of food security and sustainability in the coming decades is possible but will require considerable changes in water and nutrient management and socio-economic policies.

Yield reduction risk based on WOFOST model and water stress for winter wheat in Henan Province, China

The main wheat production area in Henan Province was classified into five regions based on observed wheat production data, historical meteorological data and soil data from thirty sites du-ring 1981 to 2014. The changes in the risk of yield loss of winter wheat under water stress condition in each region were calculated with WOFOST model. From 1981 to 2014, the yield reduction rate of winter wheat showed an increasing trend at all the sites with the increase rate of 2.8%-5.0% per 10 years. The yield reduction rate decreased from north to south in Henan Province. The event of yield reduction rate over 20% occurred about once every 10 years in southern Henan Province, and once every 2 years at Xinxiang, Fengqiu and Puyang in northern Henan Province. The event of yield reduction rate over 50% occurred about once every 3 years at Xinxiang and Zhengzhou but was rare in southern Henan Province. The highest hazard areas were mainly distributed in north and middle parts of Henan Province, the lowest hazard areas were distributed at Lushi in western Henan Pro-vince, Nanyang in southwestern Henan Province, Xinyang in southern Henan Province and south part of Zhumadian, the medium hazard areas were distributed in the other regions of Henan Province.

Winter wheat yield loss in response to Avena fatua competition and effect of reduced herbicide dose rates on seed production of this species

Avena fatua is one of the most abundant and competitive grass weed species in cereal cropping systems worldwide. Despite its main occurrence in summer annual cereals, A. fatua is suspected to cause significant yield losses in winter wheat as well. Five yield loss experiments were conducted over the course of five years to investigate the impact of A. fatua on winter wheat yield. Two additional field studies were conducted to assess the efficacy of two ALS-inhibiting herbicides as well as of two ACCase-inhibiting herbicides at variable dose rates on A. fatua seed production. Avena fatua caused significant winter wheat yield losses of up to 40% at densities of approximately 250 plants m−2. Winter wheat yield losses did not differ between years and sites. Relative A. fatua biomass was a better predictor for winter wheat yield loss as A. fatua density and biomass. Three out of four herbicides showed high efficacy against A. fatua, even at reduced dose rates, but A. fatua seed production was not directly related to herbicide efficacy. Seed production was rather influenced by the mode of action and the competitiveness of the winter wheat stand. The results showed that A. fatua can be a serious threat for winter wheat production in the local conditions, leading to high yield losses if not controlled. We did not find a general potential for reducing herbicide dose rates for the control of A. fatua in winter wheat due to variable effects on A. fatua seed production. The potential is highly dependent on the winter wheat competitiveness and herbicide mode of action.

Modelling of low input herbicide strategies for the control of wild oat in intensive winter wheat cropping systems

Weeds are causing significant yield losses in intensive winter wheat cropping systems worldwide. Prospective weed control strategies aim to reduce herbicide inputs in order to diminish the environmental, food safety and operator risks. The objective of this study is to make a long-term comparison of herbicide saving weed control strategies in intensive winter wheat cropping systems. The herbicide saving weed control strategies are compared with emphasis on herbicide input, crop yield, economic net return and weed population dynamics. The modelling approach is based on existing models for calculation of crop yield loss, herbicide dose-response, weed seed bank development and economic net return. The model is parametrised for wild oat in winter wheat. Field experiments were conducted for model parameter estimation. Three herbicide saving weed control strategies were compared, namely the economic threshold strategy as well as two reduced herbicide dose strategies. The two reduced dose strategies differed in their intensity of dose reduction and thus in their risk for potential efficacy failure. The modelling results could show that, depending on the risk level, reduced dose strategies can decrease herbicide inputs by 21% respectively 59%, compared to the economic threshold method. Differences between the three herbicide saving weed control strategies regarding yield and economic net return were negligible. From the consumer and environmental safety point of view, the high potential for herbicide input reduction makes the reduced herbicide dose methods favourable. However, the benefit for farmers is questionable due to the absence of an actual economic benefit and the enhanced risk of efficacy failure and herbicide resistance development.

Reduction of Winter Wheat Yield Losses Caused by Stripe Rust through Fungicide Management

AbstractStripe rust of winter bread wheat (Triticum aestivum L.) causes substantial grain yield loss in Central Asia. This study involved two replicated field experiments undertaken in 2009–2010 and 2010–2011 winter wheat crop seasons. The first experiment was conducted to determine grain yield reductions on susceptible winter wheat cultivars using single and two sprays of fungicide at Zadoks growth stages Z61–Z69 in two farmers’ fields in Tajikistan and one farmer's field in Uzbekistan. In the second experiment, four different fungicides at two concentrations were evaluated at Zadoks growth stage Z69. These included three products from BASF – Opus (0.5 l/ha and 1.0 l/ha), Platoon (0.5 l/ha and 1.0 l/ha) and Opera (0.75 l/ha and 1.5 l/ha) – and locally used fungicide Titul 390 (0.5 l/ha and 1.0 l/ha). One and two sprays of fungicides did not differ significantly (P > 0.05) in increasing grain yield. Stripe rust reduced grain yield and 1000‐kernel weight (TKW) from 24 to 39% and from 16 to 24%, respectively. The benefits from the two concentrations of the same fungicide did not consistently resulted in significantly higher grain yield, suggesting that the lower concentrations could be more cost effective. Our study provides important information about the selection of fungicides, spray concentrations and number of spray to control stripe rust and increase grain yield. The findings could play an important role in developing stripe rust management approaches such as fungicide rotation and strategic fungicide applications in Central Asian countries.

Effect of controlled traffic system on machine fuel saving in annual two crops region in North China Plain

Energy saving was one of the main benefits of controlled traffic system. Research on the energy conservation mechanism of controlled traffic system with medium and small scale agricultural machinery was conducted in the North China Plain, to quantify the energy benefits of controlled traffic system. Two treatments were included: zero tillage with controlled traffic (NTCN) and zero tillage with random traffic (NT). Results showed that controlled traffic system can increase soil compaction in traffic lane and reduce soil compaction in crop zone. Controlled traffic system can reduced machinery field working force significantly through lower tire rolling resistance from relatively harder permanent track, and lower tine opener working resistance from softer soil in crop zone. Compared with NT, NTCN reduced traction force by 14.6%, 13.3% and 13.3% at subsoiling, wheat and maize no-till planting. Consequently, fuel consumption was reduced in all machine operation in controlled traffic system. Compared with NT, two years total fuel consumption in NTCN was significantly reduced by 19.79L/ha (23.7%). Besides, controlled traffic increased total annual yield and WUE by compensating yield loss in winter wheat through the yield benefit in summer maize, even though 30% of the field was occupied by the permanent traffic lanes. Although these results were preliminary, it was indicated that controlled traffic system was fuel saving system in small and medium machinery condition in North China Plain.

Effect of Wheel Traffic on Crop Performance in North China Plain

Controlled traffic system was an effective solution to soil compaction, thus to promote sustainable development. The objective was to evaluate the effect of small and medium machinery wheel traffic on soil conservation and crop performance in annual two-crop region in North China Plain. Three treatments were included, zero tillage with Controlled Traffic (NTCN), zero tillage with random Traffic (NT) and traditional tillage treatment with random traffic (CK). Based on the two-year controlled traffic experiment in North China Plain, it was illustrated that controlled traffic system NTCN reduced soil bulk density in 0-30 cm soil layer in crop zone by applying permanent wheel track. Due to the avoiding of compaction, crop performance was enhanced. Both winter wheat and summer maize yield components value were increased in NTCN, compared with NT and CK. Even 30% of the field was occupied by the permanent traffic lanes, controlled traffic still increased total annual yield and WUE by compensating yield loss in winter wheat from the yield benefit in summer maize. It was indicated that controlled traffic system improved soil structure, promoted crop performance and induced higher annual crop yield in the annual two crops region in North China Plain. Although these results are preliminary, it was indicated that controlled traffic system was a valuable farming system in small and medium machinery condition in North China Plain.

Physiological Responses of Hard Red Winter Wheat to Infection by Wheat streak mosaic virus.

Wheat streak mosaic virus (WSMV) causes significant yield loss in hard red winter wheat in the U.S. Southern High Plains. Despite the prevalence of this pathogen, little is known about the physiological response of wheat to WSMV infection. A 2-year study was initiated to (i) investigate the effect of WSMV, inoculated at different development stages, on shoot and root growth, water use, water use efficiency (WUE), and photosynthesis and (ii) understand the relationships between yield and photosynthetic parameters during WSMV infection. Two greenhouse experiments were conducted with two wheat cultivars mechanically inoculated with WSMV at different developmental stages, from three-leaf to booting. WSMV inoculated early, at three- to five-leaf stage, resulted in a significant reduction in shoot biomass, root dry weight, and yield compared with wheat infected at the jointing and booting stages. However, even when inoculated as late as jointing, WSMV still reduced grain yield by at least 53%. Reduced tillers, shoot biomass, root dry weight, water use, and WUE contributed to yield loss under WSMV infection. However, infection by WSMV did not affect rooting depth and the number of seminal roots but reduced the number of nodal roots. Leaf photosynthetic parameters (chlorophyll [SPAD], net photosynthetic rate [Pn], stomatal conductance [Gs], intercellular CO2 concentration [Ci], and transpiration rate [Tr]) were reduced when infected by WSMV, and early infection reduced parameters more than late infection. Photosynthetic parameters had a linear relationship with grain yield and shoot biomass. The reduced Pn under WSMV infection was mainly in response to decreased Gs, Ci, and SPAD. The results of this study indicated that leaf chlorophyll and gas exchange parameters can be used to quantify WSMV effects on biomass and grain yield in wheat.

基于干热风危害指数的黄淮海地区冬小麦干热风灾损评估

基于干热风危害指数的黄淮海地区冬小麦干热风灾损评估

Quantification of agricultural drought occurrence as an estimate for insurance programs

Temporal irregularities of rainfall and drought have major impacts on rainfed cropping systems. The main goal of this study was to develop an approach for realizing drought occurrence based on local winter wheat yield loss and rainfall. The domain study included 11 counties in the state of Washington that actively grow rainfed winter wheat and an uncertainty rainfall evaluation model using daily rainfall values from 1985 to 2007. An application was developed that calculates a rainfall index for insurance that was then used to determine the drought intensity for each study year and for each study site. Evaluation of the drought intensity showed that both the 1999–2000 and 2000–2001 growing seasons were stressful years for most of the study locations, while the 2005–2006 and the 2006–2007 growing seasons experienced the lowest drought intensity for all locations. Our results are consistent with local extension reports of drought occurrences. Quantification of drought intensity based on this application could provide a convenient index for insurance companies for determining the effect of rainfall and drought on crop yield loss under the varying weather conditions of semi-arid regions.

Understanding the development and management of stripe rust in central Alberta

The occurrence of stripe rust (Puccinia striiformis Westend.) of cereal in central Alberta was first documented nearly a century ago. Since the late 1990s, outbreaks of wheat stripe rust caused by P. striiformis f. sp. tritici (Pst) were frequently reported and barley stripe rust caused by P. striiformis f. sp. hordei (Psh) was regularly observed. The major source of stripe rust inoculum for Alberta is considered to be from the Pacific Northwest (PNW) region of the USA. However, this pathogen was found to have the potential to survive on winter wheat in central Alberta and then spread to other winter and spring cereals the following growing season. During 2007–2011, 165 field collections of stripe rust samples were identified to forma specialis and pathotype using wheat and barley differentials. Overlapping virulence was observed in both Pst and Psh isolates that were virulent on highly susceptible wheat and barley cultivars and lines. Potential hybridization between the two formae speciales is considered to be the source of isolates capable of overcoming multiple wheat and barley resistance genes. The predominant Pst races were similar between central Alberta and the PNW, while the predominant Psh races appeared to be different between the two regions. Wheat genes in differential lines were found to show more resistance in central Alberta trap nurseries than in southern Alberta and the PNW. Low to moderate disease pressure in central Alberta was sufficient to cause significant yield losses in susceptible spring wheat cultivars, while there was limited to no yield reduction in resistant or intermediate cultivars in this region. Winter wheat is generally more susceptible than spring wheat and, thus, yield losses in winter wheat are more likely to occur than susceptible spring wheat in this region. Considerably more two-row hulled barley lines were resistant than six-row and hulless lines screened in international nurseries. For management of this disease, an integrated approach is discussed in relation to central Alberta conditions.

Physiological, proteomic and transcriptional responses of wheat to combination of drought or waterlogging with late spring low temperature.

Spring low temperature events affect winter wheat (Triticum aestivum L.) during late vegetative or reproductive development, exposing plants to a subzero low temperature stress when winter hardening is lost. The increased climatic variability results in wheat being exposed to more frequent adverse impacts of combined low temperature and water stress, including drought and waterlogging. The responses of potted wheat plants cultivated in climatic chambers to these environmental perturbations were investigated at physiological, proteomic and transcriptional levels. At the physiological level, the depressed carbon (C) assimilation induced by the combined stresses was due mainly to stomatal closure and damage of photosynthetic electron transport. Biochemically, the adaptive effects of early moderate drought or waterlogging stress were associated with the activation of antioxidant enzyme system in chloroplasts and mitochondria of leaf under low temperature. Further proteomic analysis revealed that the oxidative stress defence, C metabolism and photosynthesis related proteins were modulated by the combined low temperature and water stress. Collectively, the results indicate that impairment of photosynthesis and C metabolism was responsible for the grain yield loss in winter wheat under low temperature in combination with severe drought or waterlogging stress. In addition, prior mild drought or waterlogging contributed to the homeostasis of oxidative metabolism and relatively better photosynthesis, and hence to less grain yield loss under later spring low temperature stress.

A stomatal ozone flux–response relationship to assess ozone-induced yield loss of winter wheat in subtropical China

Stomatal ozone flux and flux–response relationships were derived for winter wheat (Triticum aestivum L.) grown under fully open-air ozone fumigation. A stomatal conductance (gsto) model developed for wheat in Europe was re-parameterized. Compared to European model parameterizations, the main changes were that the VPD and radiation response functions were made less and more restrictive, respectively, and that the temperature function was omitted. The re-parameterized gsto model performed well with an r2 value of 0.76. The slope and intercept of the regression between observed and predicted gsto were not significantly different from 1 to 0, respectively. An ozone uptake threshold of 12 nmol m−2 s−1 was judged most reasonable for the wheat flux–response relationship in subtropical China. Judging from both flux- and concentration-based relationships, the cultivars investigated seem to be more sensitive to ozone than European cultivars. The new flux–response relationship can be applied to ozone risk assessment in subtropical regions.

Relationship between Incidence of Cephalosporium Stripe and Yield Loss in Winter Wheat

Cephalosporium stripe (caused byCephalosporium gramineum) can be a serious disease of winter wheat (Triticum aestivumL.) in the Pacific Northwest of the USA. Effects of Cephalosporium stripe on yield, test weight, protein, and kernel characteristics were examined using 12 winter wheat varieties in field plots inoculated and not inoculated with the pathogen. Averaged over varieties, inoculation decreased yield, test weight, kernel weight, and kernel diameter; grain protein and the standard deviations of kernel weight and kernel diameter were increased by inoculation. Grain yield of the susceptible check was reduced by as much as 41% with addition of inoculum. The most resistant and the most susceptible varieties performed similarly for yield in the two environments, while varieties with intermediate levels of resistance were sometimes inconsistent. There was a linear relationship between yield and % whiteheads (sterile heads caused by disease) in one environment and a curvilinear relation in the other.

Models for Predicting Potential Yield Loss of Wheat Caused by Stripe Rust in the U.S. Pacific Northwest

Climatic variation in the U.S. Pacific Northwest (PNW) affects epidemics of wheat stripe rust caused by Puccinia striiformis f. sp. tritici. Previous models only estimated disease severity at the flowering stage, which may not predict the actual yield loss. To identify weather factors correlated to stripe rust epidemics and develop models for predicting potential yield loss, correlation and regression analyses were conducted using weather parameters and historical yield loss data from 1993 to 2007 for winter wheat and 1995 to 2007 for spring wheat. Among 1,376 weather variables, 54 were correlated to yield loss of winter wheat and 18 to yield loss of spring wheat. Among the seasons, winter temperature variables were more highly correlated to wheat yield loss than the other seasons. The sum of daily temperatures and accumulated negative degree days of February were more highly correlated to winter wheat yield loss than the other monthly winter variables. In addition, the number of winter rainfall days was found correlated with yield loss. Six yield loss models were selected for each of winter and spring wheats based on their better correlation coefficients, time of weather data availability during the crop season, and better performance in validation tests. Compared with previous models, the new system of using a series of the selected models has advantages that should make it more suitable for forecasting and managing stripe rust in the major wheat growing areas in the U.S. PNW, where the weather conditions have become more favorable to stripe rust.

Winter Wheat Response to Preplant Applications of Aminocyclopyrachlor

Field studies were conducted in Wyoming and Nebraska in 2007 through 2009 to evaluate winter wheat response to aminocyclopyrachlor. Aminocyclopyrachlor was applied at rates between 15 and 120 g ai ha−1 6, 4, and 2 mo before winter wheat planting (MBP). Redroot pigweed control was 90% with aminocyclopyrachlor rates of 111 and 50 g ha−1 when applied 4 or 2 MBP. Aminocyclopyrachlor at 37 g ha−1 controlled Russian thistle 90% when applied 6 MBP. At Sidney, NE, winter wheat yield loss was > 10% at all aminocyclopyrachlor rates when applied 2 or 4 MBP, and at all rates > 15 g ha−1 when applied 6 MBP. At Lingle, WY, > 40% winter wheat yield loss was observed at all rates when averaged over application timings. Although the maturing wheat plants looked normal, few seed were produced in the aminocyclopyrachlor treatments, and therefore preharvest wheat injury ratings of only 5% corresponded to yield losses ranging from 23 to 90%, depending on location. The high potential for winter wheat crop injury will almost certainly preclude the use of aminocyclopyrachlor in the fallow period immediately preceding winter wheat.

A model to simulate yield losses in winter wheat caused by weeds, for use in a weed management decision support system

The ‘within-season’ module of the Weed Manager decision support system (DSS) predicts the effect of twelve UK arable weeds on winter wheat yields and profitability. The model and decision algorithm that underpin the DSS are described and their performance discussed. The model comprises: (i) seedling germination and emergence, (ii) early growth, (iii) phenological development, (iv) herbicide and cultivation effects and (v) crop yield loss. Crop and weed emergence are predicted from the timing and method of cultivation, species biology, and the weather. Wheat and weeds compete for resources, and yield losses are predicted from their relative leaf area at canopy closure. Herbicides and cultural control methods reduce weed green area index, improving crop yield. A decision algorithm identifies economically successful weed management strategies based on model output. The output of the Weed Manager model and decision algorithm was extensively validated by experts, who confirmed the predicted responses to herbicide application were sufficiently accurate for practical use. Limited independent data were also used in the validation. The development of the module required integrating novel and existing approaches for simulating weed seedling establishment, plant development and decision algorithm design. Combining these within Weed Manager created a framework suitable for commercial use.

Genetic analysis of tolerance to photo-oxidative stress induced by high light in winter wheat (Triticum aestivum L.)

High light induced photooxidation (HLIP) usually leads to leaf premature senescence and causes great yield loss in winter wheat. In order to explore the genetic control of wheat tolerance to HLIP stress, a quantitative trait loci (QTL) analysis was conducted on a set of doubled haploid population, derived from two winter wheat cultivars. Actual values of chlorophyll content (Chl), minimum fluorescence level (Fo), maximum fluorescence level (Fm), and the maximum quantum efficiency of photosystem II (Fv/Fm) under both HLIP and non-stress conditions as well as the ratios of HLIP to non-stress were evaluated. HLIP considerably reduced Chl, Fm, and Fv/Fm, but increased Fo, compared with that under non-stress condition. A total of 27, 16, and 28 QTLs were associated with the investigated traits under HLIP and non-stress and the ratios of HLIP to non-stress, respectively. Most of the QTLs for the ratios of HLIP to non-stress collocated or nearly linked with those detected under HLIP condition. HLIP-induced QTLs were mapped on 15 chromosomes, involving in 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 4A, 4D, 5B, 6A, 6B, 7A, and 7D while those expressed under non-stress condition involved in nine chromosomes, including 1B, 1D, 2A, 2B, 3B, 4A, 5A, 5B, and 7A. The expression patterns of QTLs under HLIP condition were different from that under non-stress condition except for six loci on five chromosomes. The phenotypic variance explained by individual QTL ranged from 5.0% to 19.7% under HLIP, 8.3% to 20.8% under non-stress, and 4.9% to 20.2% for the ratios of HLIP to non-stress, respectively. Some markers, for example, Xgwm192 and WMC331 on 4D regulating Chl, Fo, Fm, and Fv/Fm under HLIP condition, might be used in marker assistant selection.

Impact of Preceding Crop and Cultural Practices on Rye Growth in Winter Wheat

Improving crop vigor can suppress growth of weeds present in the crop. This study examined the impact of preceding crop and cultural practices on rye growth in winter wheat. Preceding crops were soybean, spring wheat, and an oat/dry pea mixture. Two cultural treatments in winter wheat were also compared, referred to as conventional and competitive canopies. The competitive canopy differed from the conventional in that the seeding rate was 67% higher and starter fertilizer was banded with the seed. The study was conducted at Brookings, SD. Rye seed and biomass production differed fourfold among treatments, with winter wheat following oat/pea being most suppressive of rye growth. Rye produced 63 seeds/plant in winter wheat with a competitive canopy that followed oat/pea, contrasting with 273 seeds/plant in conventional winter wheat following spring wheat. Yield loss in winter wheat due to rye interference increased with rye biomass, but winter wheat was more tolerant of rye interference following oat/pea compared with the other preceding crops. Regression analysis indicated that winter wheat yield loss at the same rye biomass was threefold higher following spring wheat or soybean compared with oat/pea as a preceding crop. Winter wheat competitiveness and tolerance to rye can be improved by increasing the seeding rate, using a starter fertilizer, and growing winter wheat after an oat/pea mixture.