Influence of the Relative Time of Emergence of Wild Oat (Avena fatua) on Yield Loss of Barley (Hordeum vulgare) and Wheat (Triticum aestivum)

Abstract

Multiple regression analysis of data from field experiments conducted in Alberta at two locations between 1972 and 1983 indicated that there was a significant relationship between yield loss of barley (Hordeum vulgareL.) and wheat (Triticum aestivumL.) and relative time of emergence of wild oat (Avena fatuaL. ♯ AVEFA). At a given wild oat density, percent yield loss increased the earlier wild oat emerged relative to the crops and gradually diminished the later it emerged. However, the magnitude of the yield loss for both species varied with the year. Regression equations based on data pooled over years and locations were developed to provide an estimate of yield loss of barley and wheat due to relative time of wild oat emergence and wild oat density. The information should be considered when barley and wheat losses due to wild oat are being assessed.

Redução de doses de herbicidas no controle de plantas daninhas em cultivo de cevada sob condições climáticas temperadas

“…As also reported by some researchers, earlier application timings provide higher grain yields (O´Donovan et al, 1985;FernandezQuintanilla et al, 2000and Barros et al, 2005, 2008. Even though the highest grain yields tended to be achieved with the highest doses for both herbicides at the first application timing, herbicide doses lower than the recommended (intermediate doses) were sufficient at both application timings to avoid significant yield losses, which is in accordance with Fernandez-Quintanilla et al (2000), Navarrete et al (2000) and Barros et al (2005Barros et al ( , 2007Barros et al ( , 2008.…”

“…The results achieved in these experiments also show that the success of reduced herbicide doses depends on an early application timing, when the weeds are more sensitive to herbicides, which is in accordance with O´Donovan et al (1985) and Barros et al (2005Barros et al ( , 2007Barros et al ( , 2008. The H2 herbicide (amidosulfuron + Iodosulfuron -methyl) showed some difficulties in controlling Lavatera cretica L., Values followed by the same letter or letters are not significantly different at a 5% level (Duncan´s multiple range test) Figure 1.…”

Effect of Temperature and Soil Moisture on Time of Emergence of Tomatoes and Four Weed Species

“…Crop yield losses decline when weed emergence is delayed after sowing (Nieto et al 1968;Weaver 1984a). Year-to-year variation in crop yield losses at constant weed densities has been attributed to variation in weed size, which is thought to be in part a function of time of weed emergence (Spitters and Aerts 1983;Kropff et al 1984;O'Donovan et al 1985). However, the number of ASM levels in the present study was not adequate to detect a critical level.…”

An Automatic Random Forest-OBIA Algorithm for Early Weed Mapping between and within Crop Rows Using UAV Imagery

“…Although some researchers have achieved interesting results in terms of weed detection and herbicide savings based on on-the-go weed detection systems and field surveys [56][57][58], they are time consuming and costly. It could delay the The optimization of weed management practices relies on timing weed control [51], as weed presence in the early crop season is a key component of the weed-crop competition and further yield loss [52,53]. Thus, it is essential to maintain a weed-controlled environment for the crop at these initial growth stages [54], making quick weed detection a crucial tool for preventing yield losses.…”