Influence of wild oat plant density on spring wheat yield

Abstract

Wild oat (Avena fatua L.) is the most serious weed infesting cereal fields in Latvia. To predict possible yield loss at different wild oat densities field trials were established in four consecutive years, each year in a different spring wheat field in the southern part of Latvia. Growth dynamics and biomass of both crop and wild oat and grain yield were measured. Yield loss model developed by Cousens (1985) and exponential decay model were fitted to the data from each year. Grain yield and biomass of both spring wheat and wild oat significantly differed between the years. The average grain yield of spring wheat in all treatments was 4443.38-7127.02 kg ha -1 . The targeted wild oat density was 0, 1, 2, 4, 8, 16, 32, 100, 200 and 500 plants m -2 . The achieved density in the field trial reached from 0 to 332-466 plants m -2 . The emergence of wild oat seedlings lasted for 35 to 56 days after sowing, depending on the year. The initial hypothesis that low wild oat plant density may cause grain yield loss of spring wheat was supported by the results of the field trials. There was substantial variation in model parameters among the years of the trials, 5% yield loss was estimated to result from wild oat density ranging from 3 to 54 plants m -2 in different years. The variation of spring wheat yield loss and wild oat competitiveness might be explained by different meteorological conditions in the years 2013-2016 and different nutrient supply in the trial fields. Further research is necessary to find the most influential factors that determine yield loss caused by wild oat. The results are important to raise awareness of the harm caused by wild oat in cereals in the Baltic region.

Fifth survey on weed flora in spring cereals in Finland

“…However, P. annua was characteristic only in conventional production in terms of frequency (48%) and average density (25 plants m -2 ) compared with organic production (11% and 1 plant m -2 ). The success of P. annua is in line with observations in the Nordic and Baltic countries (Tørresen et al 2006, Andreasen and Stryhn 2008, Nečajeva et al 2018) linked with moist soil conditions, adaptation to compact soil, successful overwintering and substantial phenotypic and genotypic variability (Warwick 1979). Increased area of reduced tillage in survey fields since the 1990s has likely favoured P. annua, as reported earlier in Norway (Tørresen et al 2003).…”

“…In conventional production, the declining trend of E. repens biomass began in the late 1990s (Salonen et al 2013) as a consequence of common use of glyphosate, which has been the most sold herbicide in Finland for more than two decades (Tukes 2023). In comparison, a similar decline in E. repens was observed earlier in Denmark (Andreasen and Stryhn 2008) and Latvia (Nečajeva et al 2018), and also associated with increased use of glyphosate.…”

The impact of seed burial depths and post-emergence herbicides on seedling emergence and biomass production of wild oat (Avena fatua L.): Implications for management

“…Wild oat causes 20–76% yield losses in wheat crop depending upon the severity and duration of infestation. Different studies have reported that wild oat severely hampers yield components of wheat crop in different regions of the world [ 11 , 21 – 24 ]. High temperature reduces seed viability and seed germination percentage of wild oat [ 25 ].…”