Modeling Preemergent Maize Shoot Growth: II. High Temperature Stress Conditions

Abstract

High soil temperatures are a significant constraint to crop establishment. Exposure of preemergent maize (Zea mays L.) to temperatures in excess of 40°C stops shoot elongation and may also damage the seedling, reducing subsequent shoot growth in the physiological temperature range (9 to 40°C). At present, there is little quantitative understanding of the effects of high temperature stress on preemergent maize shoot growth. Consequently, existing maize emergence or preemergent maize shoot growth models are restricted to the physiological temperature range. The work described in this paper quantified the effect of supramaximum temperatures (temperatures greater than 40°C) on maize shoot growth, and in particular on its component parts, the coleoptile and first internode. The major impact of supramaximum temperatures on shoot growth was due to a severe reduction in the first internode growth rate, which was correlated with the maximum temperature reached during the day. We also found that, under diurnally varying temperature conditions, coleoptile growth ceased only at 45°C, rather than at 40°C as found previously in constant temperature experiments. Inhibition of shoot growth due to high temperature damage was alleviated when seedlings were grown in the physiological temperature range for 33 h. Based on these findings, a model was developed that can predict shoot growth of seedlings exposed to supramaximum temperatures. The model successfully predicted shoot growth of seedlings exposed to supramaximum temperatures as a part of the diurnal cycle. The model was unable, however, to predict seedling recovery from high temperature damage.

Correlation and path coefficient analysis for grain yield and its attributing traits of maize inbred lines (Zea mays L.) under heat stress condition

“…Effect of heat stress was most prominent on plant and ear height reduction might be result of the effect of heat stress on internal -nodal elongation. This research finding was supported by (Weaich et al, 1996 andCairns et al, 2012).…”

Maize Production in a Changing Climate

“…During the autotrophic phase of germination, plant energy is directly affected by soil temperature (Stone, 2001). High temperature reduces both seedling percentage and growth (Weaich et al, 1996a). In maize, seedling growth is maximized at a soil temperature of 26 °C and above this temperature, root and shoot mass both decline by 10 % for each degree increase until 35 °C when growth is severely retarded (Walker, 1969).…”

Heat stress in crop plants: its nature, impacts and integrated breeding strategies to improve heat tolerance

“…The coleoptile growth is completely halted in maize at 45°C (Weaich et al. , Akman ). Similarly, HS leads to an enhancement in respiration and reduction in photosynthesis in maize (Crafts‐Brander and Salvucci ), which often causes pollen sterility and inflicts kernel development (Schoper et al.…”

“…In case of maize, impaired protein synthesis in embryo led to the inhibition of germination at temperatures beyond 37°C (Riley et al 1981). The coleoptile growth is completely halted in maize at 45°C (Weaich et al 1996, Akman 2009). Similarly, HS leads to an enhancement in respiration and reduction in photosynthesis in maize (Crafts-Brander and Salvucci 2002), which often causes pollen sterility and inflicts kernel development (Schoper et al 1987a,b, Cheikh andJones 1994).…”