Temperature response function for leaf appearance rate in wheat and corn

1999 ◽  
Vol 79 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Y. W. Jame ◽  
H. W. Cutforth ◽  
J. T. Ritchie

The ability to predict leaf appearance would enhance our capability of modeling plant development and the rate of leaf area expansion. Many crop models use the constant thermal time for successive leaf tip appearance (which is often termed a phyllochron) as one model parameter to predict total number of leaves and date of anthesis. However, many researchers have found that phyllochron is not constant, but is dependent upon environment. The problem could be related to the simplified assumption that the daily leaf appearance rate is linearly related to temperature (and hence, phyllochron is constant, independent of temperature). In reality, the temperature response function for the development of a biological system is nonlinear. Thus, we fitted daily leaf appearance rate–temperature relationships obtained from growth room studies for both wheat (Triticum aestivum) and corn (Zea mays L.) to a nonlinear beta function with 0 °C as the base temperature and 42 °C as the upper critical temperature. The function described the relationships very well over the full range of temperatures for plant development. Other variables that are used to describe the duration and rate of leaf appearance, such as calendar days, phyllochron, and thermal rate of leaf appearance, are related to the daily leaf appearance rate, eliminating the need to develop various mathematical functions to independently describe the response of these variables to temperature. Because of the nonlinear nature of the temperature response function, we demonstrated that more accurate determinations of daily leaf appearance rates can be achieved by calculating rates over relatively short periods (i.e., hourly) and summing these to get the mean daily rate. Many environmental factors other than temperature also affect leaf appearance rate. However, once the proper temperature response function for leaf appearance rate is determined, it is much easier to determine when and how other factors are involved to modify the leaf appearance rate under a given environment.Key words: Temperature, leaf appearance rate, phyllochron, wheat, corn, beta function

2004 ◽  
Vol 34 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Nereu Augusto Streck

Response functions used in crop simulation models are usually different for different physiological processes and cultivars, resulting in many unknown coefficients in the response functions. This is the case of African violet (Saintpaulia ionantha Wendl.), where a generalized temperature response for leaf growth and development has not been developed yet. The objective of this study was to develop a generalized nonlinear temperature response function for leaf appearance rate and leaf elongation rate in African violet. The nonlinear function has three coefficients, which are the cardinal temperatures (minimum, optimum, and maximum temperatures). These coefficients were defined as 10, 24, and 33ºC, based on the cardinal temperatures of other tropical species. Data of temperature response of leaf appearance rate and leaf elongation rate in African violet, cultivar Utah, at different light levels, which are from published research, were used as independent data for evaluating the performance of the nonlinear temperature response function. The results showed that a generalized nonlinear response function can be used to describe the temperature response of leaf growth and development in African violet. These results imply that a reduction in the number of input data required in African violet simulation models is possible.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 498D-498
Author(s):  
J.T. Baker ◽  
D.I. Leskovar ◽  
V.R. Reddy ◽  
F.J. Dainello

A temperature experiment with two cultivars of muskmelon (`Gold Rush' and `Mission') was conducted in growth chambers to determine how main vine leaf appearance rates responded to temperature. We identified three cardinal temperatures for leaf appearance rate: the base temperature (10 °C) at which leaf appearance rate was zero, an optimum temperature where leaf appearance rate was at a maximum (34 °C) and an upper threshold temperature (45 °C) where leaf appearance rate returned to zero. Using these three cardinal temperatures, we constructed a simplified thermal unit accumulator for hourly measurements of air temperature. Main vine plastochron interval (PI), thermal time to harvest and final yield was determined for three cultivars of muskmelon (`Explorer', `Goldrush', and `Mission') grown in the field over six transplanting dates. The PI was calculated for each cultivar-transplanting date combination as the reciprocal of the slope of main vine node number vs. accumulated hourly thermal units (Tu). The PI was significantly affected by both cultivar and transplanting date. Final yield was sharply reduced in the last two planting dates, presumably due to high temperature stresses impacting reproductive development. As air temperatures warmed during the field experiment, the time interval from transplanting to 10% final harvest were reduced by between 21 to 28 days among the three cultivars and the first four transplanting dates. Our goal was to construct a simple muskmelon phenology model that could be run with easily obtainable weather station data and used by growers to quantify phenological development and aid in projecting harvest dates. We also wanted to test whether main vine node number was a useful description of vegetative development for muskmelon.


2020 ◽  
Author(s):  
Priyanka A. Basavaraddi ◽  
Roxana Savin ◽  
Luzie U Wingen ◽  
Stefano Bencivenga ◽  
Alexandra M. Przewieslik-Allen ◽  
...  

AbstractEarliness per se (Eps) genes are reported to be important in fine-tuning flowering time in wheat independently of photoperiod (Ppd) and vernalisation (Vrn). Unlike Ppd and Vrn genes, Eps have relatively small effects and their physiological effect along with chromosomal position are not well defined. We evaluated eight lines derived from crossing Paragon and Baj (late and early flowering respectively), vernalisation insensitive, to study the detailed effects of two newly identified QTLs, Eps-7D and Eps-2B and their interactions under field conditions. The effect of both QTLs were minor but their effect was modulated by the allelic status of the other. While the magnitude of effect of these QTLs on anthesis was similar, they are associated with very different profiles of pre-anthesis development which also depends on their interaction. Eps-7D affected both duration before and after terminal spikelet while not affecting final leaf number (FLN) so Eps-7D-early had a faster rate of leaf appearance. Eps-2B acted more specifically in the early reproductive phase and slightly altered FLN without affecting the leaf appearance rate. Both Eps-7D and 2B affected the spike fertility by altering the rate of floret development and mortality. The effect of the latter was very small but consistent in that the -late allele tended to produced more fertile florets.


1974 ◽  
Vol 25 (1) ◽  
pp. 1 ◽  
Author(s):  
JR Syme

Three Mexican cultivars of high yield potential were compared in four field sowings with three Australian varieties of similar flowering time. The cultivars had different numbers of leaves on the main stem, associated mainly with differences in rate of leaf appearance rather than duration of leaf production. The Mexican cultivars produced leaves more quickly throughout growth, and this was repeated under glasshouse conditions. A fast rate of leaf appearance was associated with more spikelets and with faster tillering. Analysis of parental, F1, F2 and backcross populations of one cross showed leaf production rate to be under polygenic control with moderate heritability.


1997 ◽  
Vol 77 (1) ◽  
pp. 23-31 ◽  
Author(s):  
G. K. Hotsonyame ◽  
L. A. Hunt

Rate of leaf appearance is a characteristic that can impact on the rate of development of a crop canopy. For wheat (Triticum aestivum L.), it is generally thought to be constant within a sowing date, but to vary among sowing dates. Such variation has been variously attributed to differences in the rate of change of photoperiod, the absolute photoperiod, or the mean air temperature. This study was undertaken to provide further information on the photoperiod and temperature effects on rate of leaf appearance in wheat. Field studies were conducted at Elora, Ontario at five sowing dates under natural and extended (20 h) photoperiod conditions. Two genotypes each of spring and winter wheat were grown under 0 and 150 kg ha−1 nitrogen fertilization. The results indicated that variations in rate of leaf appearance were not due to rate of change in photoperiod or absolute photoperiod at emergence. The change in rate of leaf appearance during a growth cycle was constant when mean air temperature during growth varied in a narrow range (less than 10 °C), but varied when there were wider ranges (over 10 °C) of temperature variation. Rate of leaf appearance was lower for the September seeding, at which time temperatures were around 5 °C, but were quite similar for May, June, July and August seedings even though temperatures ranged from approximately 15 °C (May) to 23 °C (June). The results suggested that the leaf appearance rate–temperature response curve is curvilinear, as found in some growth room studies, and supported work indicating that the phyllochron would depend on the temperature at the time of measurement. Key words: Wheat, photoperiod, temperature, nitrogen, sowing date, leaf appearance rate


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka A. Basavaraddi ◽  
Roxana Savin ◽  
Luzie U. Wingen ◽  
Stefano Bencivenga ◽  
Alexandra M. Przewieslik-Allen ◽  
...  

AbstractEarliness per se (Eps) genes are reported to be important in fine-tuning flowering time in wheat independently of photoperiod (Ppd) and vernalisation (Vrn). Unlike Ppd and Vrn genes, Eps have relatively small effects and their physiological effect along with chromosomal position are not well defined. We evaluated eight lines derived from crossing two vernalisation insensitive lines, Paragon and Baj (late and early flowering respectively), to study the detailed effects of two newly identified QTLs, Eps-7D and Eps-2B and their interactions under field conditions. The effect of both QTLs was minor and was affected by the allelic status of the other. While the magnitude of effect of these QTLs on anthesis was similar, they are associated with very different profiles of pre-anthesis development which also depends on their interaction. Eps-7D affected both duration before and after terminal spikelet while not affecting final leaf number (FLN) so Eps-7D-early had a faster rate of leaf appearance. Eps-2B acted more specifically in the early reproductive phase and slightly altered FLN without affecting the leaf appearance rate. Both QTLs affected the spike fertility by altering the rate of floret development and mortality. The effect of Eps-2B was very small but consistent in that -late allele tended to produce more fertile florets.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 810B-810
Author(s):  
D. Scott NeSmith

Different planting dates were used to study the influence of thermal time on leaf appearance rate of four summer squash (Cucurbita pepo L.) cultivars. During the first year (1991), thermal time or growing degree days (GDD) were calculated using a base temperature of 8C and a ceiling temperature of 32C for several planting dates. Leaf numbers per plant were determined every 2 to 3 days. Leaves that were beginning to unfold with a width of 2 cm or greater were included in the counts. The relationship between leaf number and GDD was established from the initial data set, and data from subsequent years were used for model validation. Results indicated that single equation could be used to predict leaf appearance of all four cultivars in response to thermal time. The response of leaf appearance to GDD was curvilinear, with a lag over the first five leaves. After five leaves, the increase in leaf number per plant was linear with increased GDD. Segmented regression with two linear functions also fit the data well. With this approach, leaf 5 was the node, and a separate linear function was used to predict the leaf number below five leaves and above five leaves. The results of this model should prove to be useful in developing a model of leaf area development, and eventually a crop growth model, for summer squash.


2010 ◽  
Vol 90 (4) ◽  
pp. 399-402 ◽  
Author(s):  
H. Wang ◽  
H. Cutforth ◽  
R M DePauw ◽  
T. McCaig ◽  
G. McLeod ◽  
...  

The rate of leaf appearance [LAR (d-1)] was observed for two older (Marquis and Neepawa) and two newer (AC Barrie and AC Elsa) Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) cultivars grown in a semiarid environment on the Canadian prairies for four years. Although the newer cultivars significantly increased yield LAR did not change when compared with the older cultivars. A simulation model developed by Jame et al. (1998a), and using coefficients for Neepawa determined from a previous study adequately predicted LAR for all four cultivars.Key words: Wheat, leaf appearance rate, temperature, daylength, model


1998 ◽  
Vol 25 (7) ◽  
pp. 829 ◽  
Author(s):  
G. D. Bonnett

Leaf appearance rate is a major determinant of canopy establishment, radiation interception and therefore yield. The effect of genotype on leaf appearance rate in sugarcane is largely unknown. Leaf appearance rate was recorded for the mainstems of pot grown sugarcane plants of nine commercial varieties, over 10 months in Townsville, Australia. Bi-phasic linear, polynomial and power-law models were fitted to data describing leaf appearance with thermal time. The bi-phasic model (previously used for sugarcane) had a single large change in phyllochron for which no biological explanation is apparent. Polynomials were less likely to predict leaf appearance accurately outside the range of fitted data. The power-law model gave a continuously increasing thermal time between the appearance of successive leaves (phyllochron) and was used to compare the varieties. An increasing phyllochron for the first 15 leaves could be explained, in part, by the increasing length of lamina each successive leaf had to grow through. However, an explanation for an increasing phyllochron throughout ontogeny has yet to be found. The rate of leaf appearance was significantly different between the varieties. After 5000˚Cd the number of leaves predicted to have appeared ranged from 35 to 46. These variety specific parameters make an important contribution to describing how different varieties produce leaf area.


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