Can Growing Degree Days and Photoperiod Predict Spring Wheat Phenology?

Abstract

Wheat (Triticum aestivum) production in the rainfed area of Pothwar Pakistan is extremely vulnerable to high temperature. The expected increase in temperature due to global warming should result in shorter crop life cycles, and thus lower biomass and grain yield. Two major factors control wheat phenological development: temperature and photoperiod. To evaluate wheat development in response to these factors, we conducted experiments that created diverse temperature and daylength conditions by adjusting the crop sowing time. The study was conducted during 2013-14 and 2014-15 using five spring wheat genotypes, four sowing times, at three sites under rainfed management in Pothwar, Pakistan. Wheat crops experienced more cold days with early sowing, but later sowing dates resulted in higher temperatures, especially from anthesis to maturity. These treatments produced large differences in phenology, biomass production, and yield. To investigate whether growing degree days (GDD) and photoperiod algorithms could predict wheat phenology under these changing conditions, GDD was calculated based on the method proposed by Wang and Engel while photoperiod followed the approach introduced in the APSIM crop growth model. GDD was calculated separately and in combination with photoperiod from germination to anthesis. For the grain filling period, only GDD was calculated. The observed and predicted number of days to anthesis and maturity were in good agreement, showing that the combination of GDD and photoperiod algorithms provided good estimations of spring wheat phenology under variable temperature and daylength conditions.

The fingerprints of climate warming on cereal crops phenology and adaptation options

“…Globally, the climate warming and other stresses are contributing towards yield losses and advocating the necessity of changing the crop calendar (Fig. 2) 57,[88][89][90][91] . This necessity for changing the crop calendar is mainly because of changes in the timing of plant phenological stages or events that respond to temperature (Fig.…”

Rising Atmospheric Temperature Impact on Wheat and Thermotolerance Strategies

“…High temperature enforces the plant to complete the growing degree days earlier, which results in early maturity and shorter life cycle of plant, lesser biosynthetic products accumulation, and ultimately poor grain development [ 32 , 53 , 54 ]. Vernalization ( VRN1, VRN2 ) and the photoperiodic ( PPD-A1, PPD-D1 ) sensitive gene determines the developmental phases at volatile temperature events and triggers earliness in wheat by limiting various growth phases [ 55 , 56 ].…”

The chaos in calibrating crop models

“…The number and identity of simulated stages varies with the model, and may include both observable stages (for example anthesis) and stages that are model constructs (for example, start of linear phase of grain filling). The most important inputs that determine spring wheat phenology are daily temperature and photoperiod (Aslam et al, 2017), while for winter wheat it is also important to include the process of vernalization, i.e. the effect of low winter temperatures on development (Li et al, 2013).…”