Assessing the response of maize phenology under elevated temperature scenarios

Abstract

The objective of this study was to simulate the development of maize in elevated temperature scenarios at Santa Maria, RS, Brazil. The developmental cycle of maize was simulated with the Wang and Engel (WE) model with genotype-dependent coefficients for the cultivar BRS Missões. The developmental cycle was divided into vegetative phase (from emergence to silking), and reproductive phase (from silking to physiological maturity). Twelve sowing dates throughout the year were considered, resulting in emergences on the day 15 of each month all year round. Climate scenarios used were synthetic time series of 100 years of current climate and with increase in mean air temperature of +1, +2, +3, +4, and +5, with symmetric and asymmetric increases in daily minimum and maximum temperatures. As temperature increased, the number of years in which crop was killed by frost decreased, indicating that if global warming will confirm, the growing season for maize grown in subtropical environment will be longer by the end of this century. Maize vegetative and reproductive development was delayed or hastened depending upon the emergence time of the year, and if the increase in air temperature is symmetric or asymmetric, indicating complex Genotype x Environment interactions and high vulnerability of maize development to climate change. Keywords: Development, temperature increase, global warming, climate change, agriculture, IPCC.RESUMO: RESPOSTA FENOLÓGICA DO MILHO EM CENÁRIOS DE AUMENTO DE TEMPERATURA O objetivo deste trabalho foi simular o desenvolvimento da cultura de milho em cenários de aumento de temperatura em Santa Maria, RS, Brasil. O ciclo de desenvolvimento do milho foi simulado com o modelo de Wang e Engel (WE) com coeficientes dependentes do genótipo, para a cultivar BRS Missões. O ciclo de desenvolvimento foi dividido em fase vegetativa (da emergência ao espigamento) e fase reprodutiva (do florescimento até a maturidade fisiológica). Foram consideradas doze datas de semeadura, resultando a emergência no dia 15 de cada mês durante todo o ano. Os cenários climáticos utilizados foram séries sintéticas de 100 anos do clima atual e com aumentos na temperatura média do ar de +1, +2, +3, +4 e +5, com aumentos simétricos e assimétricos na temperatura mínina e máxima diária. Com o aumento da temperatura, diminuiu o número de anos em que a cultura foi morta pela geada, indicando que, se o aquecimento global se confirmar, o calendário do cultivo do milho será maior até o final deste século. O desenvolvimento vegetativo e reprodutivo do milho foi retardado ou acelerado dependendo da época de emergência da cultura ao longo do ano, e se o aumento na temperatura do ar é simétrico ou assimétrico, o que indica uma complexa interação Genótipo x Ambiente, bem como, alta vulnerabilidade do desenvolvimento do milho à mudança climática. Palavras-chave: Desenvolvimento, aumento de temperatura, aquecimento global, mudança climática, agricultura, IPCC.

Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops

“…For maize, temperature is one of the main factors responsible for altering its phenology. Moreover, the growth of this crop can be affected by the lack of water, which is very characteristic during the second cropping period (Streck, Silva, & Langner, ). On the other hand, sorghum phenology, especially flowering, can be altered by changes in photoperiod (Buso, Morgado, Silva, & França, ).…”

Effect of sowing time on the growth and yield of sweet corn (Zea mays L.) cultivated during fall-winter period in Subtropical climate

“…On the other hand, temperature, solar radiation, photoperiod and rainfall vary randomly around seasonal average tendencies, so that the greatest challenge is adjusting the ideal time for sowing (Tsimba et al, 2013a). The proper positioning of the sowing time (ST) becomes even more challenging because of the climatic change (Laux et al, 2010;Folberth et al, 2012;Liu et al, 2012), those are more rigorous in less developed countries and tropical regions (IPCC, 2013), especially for the corn crop because it is very vulnerable to climatic change (Streck et al, 2012). Waha et al (2013a) studied in Sub-Sahara Africa (40º N to 40º S and 20º W to 60º E), founded that the regions are much more influenced where the second season is grown (sowing in the second half of the wet season).…”

Modelling Management Strategies to Mitigate the Effects of Alterations of Temperature and of Co2 Concentration on Maize

“…In practice, fewer cardinal days are spent to achieve the thermal sums required in each phenological phase of maize, causing the shortening of the cycle, which by its turn, reduces the opportunity for the plant to accumulate and translocate photoassimilates to the grains (Bergamaschi and Matzenauer, 2014) and, evidently, affects yield (Cruz et al, 2011). In a modeling study conducted in Santa Maria, RS, Brazil, it was also found that the vegetative development of maize is accelerated due to the increase of temperature (Streck et al, 2012).…”

“…The increase in temperature, above 23 o C, causes a reduction in maize yield, which is even more accentuated when the daily values exceed 30 o C (Lobell et al, 2011). Several factors contribute to this yield reduction, among which, the increase of maintenance respiration, the reduction of soil moisture (Levis et al, 2018;Lizaso et al, 2018;Andrea et al, 2019) and the acceleration of vegetative development (Streck et al, 2012), which leads to the shortening of the maize cycle. In practice, fewer cardinal days are spent to achieve the thermal sums required in each phenological phase of maize, causing the shortening of the cycle, which by its turn, reduces the opportunity for the plant to accumulate and translocate photoassimilates to the grains (Bergamaschi and Matzenauer, 2014) and, evidently, affects yield (Cruz et al, 2011).…”