Resposta de cultivares de feijão à alta temperatura do ar no período reprodutivo

Abstract

RESUMO O rendimento de grãos do feijão é afetado pela ocorrência de alta temperatura do ar, durante o período reprodutivo. Sendo assim, foi objetivo do trabalho avaliar a variabilidade genética do feijão para tolerância à alta temperatura do ar durante o período de pré-floração (R5) à formação de vagens (R7

Common bean in highly variable weather conditions, on sandy soils, and food security in a subtropical environment

“…), because high temperature influences the abscission of flowers and pods, seeds per pod, and low seed mass (Hoffmann Júnior et al. ). However, bean is more affected by high temperature in the pre‐flowering (Shonnard and Gepts ), flowering (Balardin et al.…”

“…), and pod filling (Shonnard and Gepts ) stages, and abscission rate of reproductive organs can reach 50 to 70% of blooming flowers (Hoffmann Júnior et al. ). Negative effects on common bean growth and yield may be more severe with larger time where temperature remains above 30°C during the day, maximum temperature, and number of consecutive days with critical temperature (Barbano et al.…”

“…1B), the optimum temperature for common beans (Balardin et al 2000). Critical air temperature (30°C) (Hoffmann Júnior et al 2007) occurred in 13 consecutive days at 15:00 h, between 35 to 47 days after emergence. A comparison between daily rainfall and average daily air temperature showed that air temperature decreased after rainfall event, indicating the cooling effect of rainfall.…”

“…Critical air temperature (30°C) (Hoffmann Júnior et al 2007) occurred at 15:00 h in 40 days, 13 of them were consecutive days between 35 to 47 days after emergence (reproductive period) (Fig. 1B).…”

“…Temperatures above 30°C during the day provide negative effects on growth and development of common bean (Massignam et al 1998), because high temperature influences the abscission of flowers and pods, seeds per pod, and low seed mass (Hoffmann Júnior et al 2007). However, bean is more affected by high temperature in the pre-flowering (Shonnard and Gepts 1994), flowering (Balardin et al 2000), and pod filling (Shonnard and Gepts 1994) stages, and abscission rate of reproductive organs can reach 50 to 70% of blooming flowers (Hoffmann Júnior et al 2007). Negative effects on common bean growth and yield may be more severe with larger time where temperature remains above 30°C during the day, maximum temperature, and number of consecutive days with critical temperature (Barbano et al 2001).…”