Climate Change Impacts on Corn Phenology and Productivity

Adaptation Strategies to Improve the Resistance of Oilseed Crops to Heat Stress Under a Changing Climate: An Overview

Temperature is one of the decisive environmental factors that is projected to increase by 1. 5°C over the next two decades due to climate change that may affect various agronomic characteristics, such as biomass production, phenology and physiology, and yield-contributing traits in oilseed crops. Oilseed crops such as soybean, sunflower, canola, peanut, cottonseed, coconut, palm oil, sesame, safflower, olive etc., are widely grown. Specific importance is the vulnerability of oil synthesis in these crops against the rise in climatic temperature, threatening the stability of yield and quality. The natural defense system in these crops cannot withstand the harmful impacts of heat stress, thus causing a considerable loss in seed and oil yield. Therefore, a proper understanding of underlying mechanisms of genotype-environment interactions that could affect oil synthesis pathways is a prime requirement in developing stable cultivars. Heat stress tolerance is a complex quantitative trait controlled by many genes and is challenging to study and characterize. However, heat tolerance studies to date have pointed to several sophisticated mechanisms to deal with the stress of high temperatures, including hormonal signaling pathways for sensing heat stimuli and acquiring tolerance to heat stress, maintaining membrane integrity, production of heat shock proteins (HSPs), removal of reactive oxygen species (ROS), assembly of antioxidants, accumulation of compatible solutes, modified gene expression to enable changes, intelligent agricultural technologies, and several other agronomic techniques for thriving and surviving. Manipulation of multiple genes responsible for thermo-tolerance and exploring their high expressions greatly impacts their potential application using CRISPR/Cas genome editing and OMICS technology. This review highlights the latest outcomes on the response and tolerance to heat stress at the cellular, organelle, and whole plant levels describing numerous approaches applied to enhance thermos-tolerance in oilseed crops. We are attempting to critically analyze the scattered existing approaches to temperature tolerance used in oilseeds as a whole, work toward extending studies into the field, and provide researchers and related parties with useful information to streamline their breeding programs so that they can seek new avenues and develop guidelines that will greatly enhance ongoing efforts to establish heat stress tolerance in oilseeds.

Climate Trends and Consumption of Foods and Beverages by Processing Level in Mexican Cities

Background: Little is known about the potential impact of climate change on food systems and diet. We aimed to estimate the association of changes in rainfall and temperatures with consumption of unprocessed and processed foods among residents of Mexican cities by climate region.

Methods: We analyzed 3,312 participants of the 2012 Mexican National Health and Nutrition Survey with dietary intake and sociodemographic information linked to historical rainfall and temperature data collected by the Mexican National Weather Service. We classified foods as unprocessed, processed, or ultra-processed. We performed multilevel linear regression to estimate the association of annual change in rainfalls (for each 0.5 mm decrease) and temperatures (for each 0.1°C increase) at municipality level over the past 5 years with consumption of processed and unprocessed foods measured as the contribution to total energy intake. We investigated whether associations differed by climate region (tropical, temperate, and arid).

Results: Each 0.5 mm annual decrease in precipitation was associated with lower consumption of unprocessed foods and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake −0.009% (95% CI: −0.019, < −0.001) and 0.011% (95% CI: 0.001, 0.021), respectively]. Each 0.1 degree Celsius annual increase in temperature was also associated with lower consumption of unprocessed and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake was −0.03 (95% CI: −0.05, −0.01) and 0.03% (95% CI: <0.01, 0.05)]. When stratified by climate region these associations were only observed in tropical regions.

Conclusions: Decreases in rainfalls and increases in temperature were associated with lower consumption of unprocessed foods but higher consumption of ultra-processed foods, especially in tropical regions. Previous studies have established how food production affects the climate, our study suggests that climate change could, in turn, reinforce modern food production, closing a vicious circle with clear negative implications for planetary health.

Management options for mid-century maize (Zea mays L.) in Ethiopia

This simulation study was carried out to assess the impact of climate change and adaptation strategies on maize production across 22 locations in Ethiopia using Decision Support System for Agrotechnology Transfer - Cropping System Model (DSSAT-CSM) CERES-Maize. Three maize varieties, i.e., [BH-660 (late maturing), BH-540 (medium maturing) and Melkasa-1 (short maturing)] along with three planting dates [early (25-Apr), normal (25-May) and late (25-Jun)], four N fertilizer rates (64, 96, 128 and 160 kg N/ha) and three water levels [rainfed (no irrigation), two irrigations (each 30 mm at time of flowering and 5 d after flowering with total = 60 mm) and five irrigations (each 30 mm at time of flowering to early grain-filing, which were applied every five days in total = 150 mm)] were evaluated as the adaptation strategy. The mid-century (2040-2069) temperatures and solar radiation were extracted from multiple model means across the Coordinated Regional Climate Downscaling Experiment (CORDEX) models under the highest Representative Concentration Pathway (RCP8.5). Maize productivity was evaluated assuming that maize was grown on shallow sandy loam soils. Yield of an early, medium and late maturing maize were changed by -13 to -8%, -10 to +4% and + 3 to +13%, respectively, relative to the baseline period (1980-2005). The days to maturity decreased by about 16%. Under rainfed condition, N application up to 64, 128 and 160 kg/ha significantly improved yield for early, medium and late maturing varieties, respectively. Relatively high yield and low inter-seasonal yield variability were simulated for BH-660 and Melkasa-1 when planted on 25-Apr and 25-May, respectively, for most locations. Application of two (60 mm) and five (150 mm) irrigation levels improved yield in drier locations. In conclusion, this study provides potential adaptation options under the future climate in maize producing regions of Ethiopia.

The fingerprints of climate warming on cereal crops phenology and adaptation options

Growth and development of cereal crops are linked to weather, day length and growing degree-days (GDDs) which make them responsive to the specific environments in specific seasons. Global temperature is rising due to human activities such as burning of fossil fuels and clearance of woodlands for building construction. The rise in temperature disrupts crop growth and development. Disturbance mainly causes a shift in phenological development of crops and affects their economic yield. Scientists and farmers adapt to these phenological shifts, in part, by changing sowing time and cultivar shifts which may increase or decrease crop growth duration. Nonetheless, climate warming is a global phenomenon and cannot be avoided. In this scenario, food security can be ensured by improving cereal production through agronomic management, breeding of climate-adapted genotypes and increasing genetic biodiversity. In this review, climate warming, its impact and consequences are discussed with reference to their influences on phenological shifts. Furthermore, how different cereal crops adapt to climate warming by regulating their phenological development is elaborated. Based on the above mentioned discussion, different management strategies to cope with climate warming are suggested.

Pheromone responses of Ostrinia nubilalis (Hübner) from north of its range in Europe

The European corn borer (ECB), Ostrinia nubilalis Hbn. (Lepidoptera: Crambidae) has recently become very harmful to maize in the North of its range in Europe, primarily in Belarus. Conventional pheromone-trapping methods however show very low effectiveness. Our electrophysiological study did not reveal any impairment in peripheral sensitivity, but flight-tunnel responses were low. The reason for such discrepancy could lie in breeding of the Z race of moth coming with maize from south with local populations of the pest.