Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops

Abstract

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water‐use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water‐use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water‐use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree‐days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water‐use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.

Adapting to heat stress by sowing summer grain crops early in late winter: Sorghum root growth, water use, and yield

“…As expected, lower ambient temperatures for the late winter and spring sown crops delayed crop emergence and flowering, though still the late winter sown crop flowered earlier than the spring and summer alternatives reducing the likelihood of heat stresses around flowering (Kapanigowda et al 2013; Barbosa et al, 2020). This was also reflected in lower values for the estimated seed set (Singh, et al, 2015).…”

Grain sorghum hybrids under drought stress and full‐irrigation conditions in the Brazilian Semiarid

“…In Brazil, grain sorghum has been mainly grown in the off‐season as a succession crop to soybean, when the risk for corn planting increases, especially in the Cerrado biome (Barbosa et al., 2020; Tardin et al., 2013). In Cerrado regions, the sowing occurs after February, when the rain season decreases, making post‐flowering drought stress a common occurrence (Menezes et al, 2015).…”

Optimizing forage production in double‐annual cropping systems under irrigated Mediterranean conditions

“…Therefore, the harvest index is reduced when maize sowing is delayed (Pampana, Ercoli, Masoni, & Arduini, 2009). High temperatures during the vegetative growth period influenced the growth rate more than the development rate, resulting in taller plants with more biomass at an equivalent developmental stage (Barbosa et al., 2020; Dobben, 1962). Accordingly, the faster growth reduced the proportion of grain (Table 5), which also has a negative effect on forage quality (Bunting, 1968; Deinum & Struik, 1986).…”