Maize Leaf Development Biases Caused by Air–Apex Temperature Differences

Abstract

tures during short periods of the maize life cycle (Cellier et al., 1993; Ben-Haj-Salah and Tardieu, 1996). How-Accurate determination of leaf appearance rate is required in crop ever, none of them quantified the effect of the bias on simulation models to estimate canopy development and ultimately maize development. The differences between air and crop yield. Most crop simulation models use air temperature for thermal time calculations to estimate leaf appearance rate, although the meristem temperature support the evidence of biases near soil temperature is more closely related to the growing apex when air temperature is used in thermal time calculatemperature than air temperature before stem elongation. A field tions instead of apex temperatures and highlight the experiment was conducted in 1996 at East Lansing, MI, to determine importance of choosing the appropriate temperature to the effect of soil, air, and apex temperatures on maize (Zea mays L.) most accurately simulate phenology. leaf development. Maize leaf tip appearance dates and leaf numbers The phyllochron, time between the appearance of were observed on four sowing dates to provide variations in the successive leaves on a shoot, is usually expressed in units thermal regime of developing plants. Solar irradiance and temperature of TT per leaf tip (McMaster and Wilhelm, 1995). The of the air (1.5 m height), apex, and soil (1-, 3-, and 5-cm depths) phyllochron provides a convenient method to describe were recorded on 0.5-h (half-hourly) intervals. The daily average soil plant vegetative development and aids in understanding temperature at the 3-to 5-cm depth was reasonably close (ϩ0.6؇C in average) to the daily average apex temperature for use as a surrogate and modeling crop development. Measurements of the for apex temperature to increase the accuracy of maize development phyllochron for maize were reported to vary between simulation in the sowing to ninth leaf tip stage. Thereafter, the air 30 and 50ЊCd (degree days) per leaf tip using base temtemperature was sufficiently accurate to estimate plant development.peratures ranging from 6 to 9ЊC. A summary of results Using apex temperatures from leaf 3 to 9, this study indicated that from the literature (Table 1) provides phyllochron inforthe phyllochron was near 55؇C d (degree days) per leaf tip appearance. mation derived from field and controlled environment The consistent bias between air and apex temperature from sowing experiments, from diverse sites, and for a broad range to V6 found in this study clearly indicates the necessity of using the of maize cultivars. In all of these studies estimates were right temperature in thermal time calculations for accurate maize done using air temperature with no corrections for possidevelopment simulation.ble air-apex temperature biases.Accurate phyllochron values are required in crop simulation models to estimate canopy development and Có rdoba, Argentina; and J.T. Ritchie, Crop and Soil Sciences Dep., Michigan State Univ., East Lansing, MI 48824.

Effect of high temperature on photosynthesis and transpiration of sweet corn (Zea mays L. var. rugosa)

“…Vinocur and Ritchie (2001) indicated the necessity of using the apex temperature in thermal time calculations for an accurate understanding of maize development. A decreased leaf P N at high temperatures is believed to be largely due to reduced efficiency in photosystem 2, rather than an increase in maintenance dark respiration or a decrease in leaf area (Prange et al 1990).…”

Soil Temperature and Precipitation Affect the Rooting Ability of Dormant Hardwood Cuttings of Populus

“…Although some rooting takes place at soil temperatures below 10°C DOMISCH et al, 2001;VINOCUR and RITCHIE, 2001;PAVEL and FER-ERES, 1998;FENNELL et al, 1990), successful rooting is sustained only at soil temperatures above this threshold (LANDHÄUSSER et al, 2001;WAN et al, 1999;HANSEN, 1986;JENKINSON, 1980). KESTER (1970) stated the minimum temperature in a 24-hour period often governed rooting.…”

Simulation of Tillage Systems Impact on Soil Biophysical Properties Using the SALUS Model

“…SALUS predicts plant development rate using the model developed by Vinocur and Ritchie (2001) to predict meristematic temperature from soil and air temperature to predict the phenology in early stages of plant development when the meristem of the plant is 1-2 cm below the soil surface (i.e. in maize and wheat).…”

“…in maize and wheat). In light of the previous consideration, SALUS includes the Vinocur and Ritchie (2001) modification of the soil temperature model of CERES to account for the presence of crop residues.…”