Heat Stress during Late Vegetative Growth of Maize: Effects on Phenology and Assessment of Optimum Temperature

Abstract

Prediction of phenology is based on thermal time (TT) computation, which requires the correct definition of base (TB) and optimum (TO) temperatures. Most information on these traits came from controlled environments using a wide range of mean air temperatures (TX), including TX > TO and TX < TB These conditions are rarely found in field environments. We assessed the effect on development of day‐time temperatures above TO during late‐vegetative growth of maize (Zea mays L), and established a model based on TT computation on a per hour (TTh, in °C h) rather than per day basis (TTd) for TO estimation. Field experiments included two temperature regimes (TC: control; TH: heated) between V11 and tasseling of TC We registered temperature at ear level, and dates of anthesis and silking. We computed developmental rates (DR), TTh above 8°C during treatment period (TTh1) and between V11 and silking (TTh2), a stress index based on the quotient of differences in TTh (ΔTTh) between TH and TC (SI = ΔTTh2/ΔTTh1), and TO Heat stress caused a delay in flowering events, and a decline in DRs. Estimated TB was higher (12.7°C) than normally used in computations. Estimated TO was within the expected range (36°C > TO > 30°C), independently of TB Stressful temperatures promoted a delayed in silking, identified as an increase of at least 2.14°C h in TTh for each degree above TO Estimated TO differed between growing seasons (P = 0.04), suggesting possible variation due to climatic effects.

Comparative response of maize and rice genotypes to heat stress: status of oxidative stress and antioxidants

“…Previous studies report inhibition due to heat stress in growth and yield of rice (Jagadish et al 2007;Mohammed and Tarpley 2009) and maize (Karim et al 2001, Crafts-Brandner andSalvucci 2002;Sinsawat et al 2004;Cicchino et al 2010). To the best of our knowledge, there is no report about the comparative response of maize and rice to similar degree of high temperature that would indicate their relative sensitivity to heat stress, if any.…”

Yield of forage, grain and biomass in eight hybrids of maize with different sowing dates and environmental conditions

“…Heat stress reduced maize grain weight due to proportional losses in grain composition (starch, protein and oil contents) and due to its direct effect during the grain-filling period, which caused a cessation of grain filling (43)(44) . Moreover, heat stress reduced maize grain yield due to its negative effect on plant growth and development by increasing the abortion of fertilized structures (45,46) . The differences observed among hybrids on grain and corn ear yield was due to the timing of male and female flowering and individual weight of the corncob and grain.…”

Response of maize and olive to climate change under the semi-arid conditions of southern Spain

“…The heat stress reduction factor using T can performed better than that using T air when the critical threshold temperature determined in Cicchino et al (2010a) was used.…”

“…Rattalino Edreira et al (2011,2012,2013) indicated that reduction in yield is explained by both a reduction in RUE (-3 to 33 % of Another aspect of crop growth and development known to be affected by high temperatures is phenology. Thus, there is evidence to suggest that high temperatures delay flowering (Cicchino et al, 2010a …”

“…These functions are included in crop models to be applied at field and larger scales. Cicchino et al (2010aCicchino et al ( , 2010b. Briefly, the cultivar used was the temperate hybrid Nidera AX 842 MG, classified as 119 for relative maturity (Peterson et al, 1973).…”