Change in Maize Final Leaf Numbers and Its Effects on Biomass and Grain Yield across China

Abstract

The final leaf number is an important morphological characteristic of maize (Zea mays L.) and is therefore an important input parameter in some maize crop models. In this study, field experiments were conducted from 2013 to 2016 at 23 sites across China, which were located between latitudes of 26°30′ and 46°45′ N, focusing on five modern maize cultivars, in order to determine the amplitude of variation in mean leaf numbers between each cultivar, identify differences between the mean leaf numbers of cultivars under different climatic conditions, and clarify the effects of the differences in final leaf numbers on aboveground dry matter (DM) and grain yield. The results showed that the mean final leaf numbers increased in the order of XY335 < NH101 < ZD909 < ZD958 < DH11 among the five cultivars, with the wide distribution ranges of final leaf numbers being 17.0–23.3 (DH11), 16.7–22.3 (ZD958), 16.7–22.0 (ZD909), 16.7–22.3 (NH101), and 17.0–22.0 (XY335) across all locations. In addition, leaf numbers above and below the primary ear showed the same trends with the mean final leaf numbers for the same cultivars. Many climatic factors were found to significantly affect the final leaf numbers across four maize-growing regions in China, and the result of stepwise regression indicated that the influences of photoperiod and temperature, in particular, were greater than other climatic factors for these cultivars. Finally, there were found to be significant and positive relationships between the final leaf number and (1) the maximum leaf area index (LAImax), (2) DM at both silking and physiological maturity, and (3) grain yield for the same cultivars across all locations. The results of this study are of great importance for guiding future trans-regional maize cultivation and further model calibration.

The effects of photoperiod and temperature-related factors on maize leaf number and leaf positional distribution in the field

“…Moreover, variations in TLN was primarily attributed to variations in LB. The degree of variation in LA was smaller than that of the LB or TLN, which has also been reported in earlier papers (Warrington and Kanemasu, 1983;Tollenaar, 1999;Liu et al, 2020). In contrast to the patterns we observed for variation in LA and LB in conventional maize, Subedi and Ma (2005) reported greater variation in LA than in LB for leafy hybrid maize.…”

“…For instance, when the same variety of maize was planted at different latitudes, the resulting TLN varied by 5 or more leaves (Liu et al, 2020). Changes in leaf number are important as they affect key growth and developmental processes, leaf area, and the overall canopy morphology of maize plants, which affects plant biomass accumulation and yield; as such, leaf number can be used to assess regional adaptations among different maize cultivars (Allen et al, 1973;Ellis et al, 1992;Bonhomme et al, 1994;Lafitte and Edmeades, 1997;Li et al, 2016;Liu et al, 2020). Leaf number is also a useful metric for modeling maize phenology and ontogeny (Bonhomme et al, 1991;Birch et al, 1998b).…”

“…Environmental factors affect the leaf initiation rate and duration, two important traits that ultimately determine the final leaf number (Tollenaar and Hunter, 1983). Many researchers have investigated variations in leaf number between different maize cultivars in response to environmental factors, such as photoperiod and air temperature (Russell and Stuber, 1983;Tollenaar and Hunter, 1983;Warrington and Kanemasu, 1983;Ellis et al, 1992;Liu et al, 2020), diurnal temperature range (Bonhomme et al, 1991), rate of changing daylength (Bonhomme et al, 1991), and incident photosynthetic photon flux density (Tollenaar, 1999).…”

“…Most studies investigating changes in maize leaf number in response to environmental factors have been focused on field experiments in multiple locations or altering sowing dates (Bonhomme et al, 1991;Birch et al, 1998a;Giauffret et al, 2000;Liu et al, 2020), however some studies have also used controlledenvironment cabinets to more tightly dissect the effects of different environmental factors on maize leaf number (Allison and Daynard, 1979;Chen et al, 2015;Francis et al, 1969;Stevenson and Goodman, 1972;Tollenaar, 1999), and a few others used combined field based and climate controlled experiments (Russell and Stuber, 1985;Mungoma and Pollak, 1991). However, between field based and controlled-environment experiments, controlled-environment studies consistently obtain lower photothermal ratios (the ratio between the daily amount of light and daily temperature), and the correlation between controlled-environment and field phenotypic data is very low (Poorter et al, 2016).…”

The influence of siam weed compost and inorganic fertiliser applications on tomato performance

“…The leaf acts as a source from which photosynthates are translocated to the harvestable target organs. The same was also evident from the investigation of Liu et al (2020), stating that the final grain yields in maize had a relationship with total leaf areas.…”