Sensitivity of barley varieties to weather in Finland

Abstract

SUMMARYGlobal climate change is predicted to shift seasonal temperature and precipitation patterns. An increasing frequency of extreme weather events such as heat waves and prolonged droughts is predicted, but there are high levels of uncertainty about the nature of local changes. Crop adaptation will be important in reducing potential damage to agriculture. Crop diversity may enhance resilience to climate variability and changes that are difficult to predict. Therefore, there has to be sufficient diversity within the set of available cultivars in response to weather parameters critical for yield formation. To determine the scale of such ‘weather response diversity’ within barley (Hordeum vulgare L.), an important crop in northern conditions, the yield responses of a wide range of modern and historical varieties were analysed according to a well-defined set of critical agro-meteorological variables. The Finnish long-term dataset of MTT Official Variety Trials was used together with historical weather records of the Finnish Meteorological Institute. The foci of the analysis were firstly to describe the general response of barley to different weather conditions and secondly to reveal the diversity among varieties in the sensitivity to each weather variable. It was established that barley yields were frequently reduced by drought or excessive rain early in the season, by high temperatures at around heading, and by accelerated temperature sum accumulation rates during periods 2 weeks before heading and between heading and yellow ripeness. Low temperatures early in the season increased yields, but frost during the first 4 weeks after sowing had no effect. After canopy establishment, higher precipitation on average resulted in higher yields. In a cultivar-specific analysis, it was found that there were differences in responses to all but three of the studied climatic variables: waterlogging and drought early in the season and temperature sum accumulation rate before heading. The results suggest that low temperatures early in the season, delayed sowing, rain 3–7 weeks after sowing, a temperature change 3–4 weeks after sowing, a high temperature sum accumulation rate from heading to yellow ripeness and high temperatures (⩾25°C) at around heading could mostly be addressed by exploiting the traits found in the range of varieties included in the present study. However, new technology and novel genetic material are needed to enable crops to withstand periods of excessive rain or drought early in the season and to enhance performance under increased temperature sum accumulation rates prior to heading.

Can barley (Hordeum vulgare L. s.l.) adapt to fast climate changes? A controlled selection experiment

“…It seems likely that higher temperatures will lead to diminished efficiency in seed filling as increased temperatures and heat stress accelerate plant development and shorten developmental phases, resulting in early maturation and decrease in yield (Barnabas et al 2008;Hatfield et al 2011). Especially the plant's reproductive stage is sensitive to high temperature, and optimum temperature for yield is generally lower than optimum for vegetative growth (Hatfield et al 2011). Hakala et al (2012 in a study of Finnish barley cultivar trials from year 1976 to 2004 documented that when temperatures were high-more than 28°C-over several days just before and after heading in barley, yield was substantially depressed.…”

“…High genetic diversity may enhance the environmental adaptation potential of a cultivar (Hakala et al 2012), however, it is often anticipated that the recurrent breeding leading to modern crops have reduced their genetic variation and thus their adaptability. In barley-the crop under study here-the genetic variation has been analyzed e.g.…”

Climate change and crop diversity: farmers’ perceptions and adaptation on the Bolivian Altiplano

“…Yet field observations confirm that farmers in this community continue to use traditional risk management strategies, such as planting some of their plots to a mixture of local potato varieties (chalis). Maintaining crop and variety portfolios with different traits and tolerances provides response diversity that mitigates losses from weather and market shocks (di Falco and Perrings 2003;Halloy et al 2005;di Falco and Chavas 2009;Perez et al 2010;Hakala et al 2012;McDowell and Hess 2012;Kahiluoto et al 2014). Most households in all the communities cultivated several potato varieties, including non-bitter and hardy bitter varieties.…”

Recent warming across the North Atlantic region may be contributing to an expansion in barley cultivation

“…In Finland, for example, high (≥ 25°C) and very high (≥ 28°C) temperatures around heading were associated with significant yield losses over a 40-year period (Hakala et al 2012). In the NAR, temperatures above 25°C can occur in July or August in most of coastal Norway and Newfoundland.…”