Crop growth and relative growth rates of old and modern wheat cultivars

Abstract

An analysis of the dynamics of green area index (GAI), dry matter (DM), relative growth rate (RGR) and crop growth rate (CGR) based on growing degree days (GDD) is presented for a historical series of wheats commercially released in Western Australia. Relative to the old cultivars, modern wheats were characterized by a greater RGR during the vegetative phase. This was achieved at a lower initial GAI, which persisted as the season progressed and was associated with a higher CGR at anthesis and greater grain yield at the end of the season. In the old cultivars, a greater GAI during the mid season declined rapidly as temperatures and soil moisture stress increased in spring, resulting in a lower GAI at anthesis. Together with lower CGR at anthesis this resulted in less dry matter and grain yield at final harvest. The higher grain yield of modern wheat cultivars was achieved with a high RGR during the vegetative phase and greater CGR from ear emergence to harvest.

Root and shoot growth, water use and water use efficiency of spring durum wheat under early-season drought

“…The slowest increase in RGR under stress was observed for the latest cultivar, i.e. Keyperounda, confirming previous results for wheat [15].…”

Physiological Attributes of Transplant <i>Aman</i> Rice (Cv. Brri Dhan52) as Affected by Tiller Seedlings and Urea Super Granules

“…Haloi and Baldev (1986) observed higher RGR at initial stage of crop growth. Karim and Siddique (1991) stated that higher RGR was obtained at vegetative phase. RGR increased with increasing the number of tiller seedlings hill -1 (Table 3).…”

Growth analysis of winter wheat cultivars as affected by nitrogen fertilization / Wachstumsanalyse von Winterweizensorten in Abhängigkeit von Stickstoffdüngung

“…A better understanding of crop yield physiology would help to achieve the rates of yield improvement required in the near future. Various authors have published the results of growth analysis on various crops in terms of different management practices and cultivar comparisons, including maize (e.g., Bullock et al, 1993), wheat (Davidson and Campbell, 1984;Barneix, 1990;Karimi and Siddique, 1991;Ozturk et al, 2006;Neugschwandtner et al, 2015), triticale (Royo and Blanco, 1999), Bermuda grass (Silva et al, 2016), soybean (Clawson et al, 1986;Yusuf et al, 1999;Hu and Wiatrak, 2012), potato (Oliveira et al, 2016), sugar beet (Hoffman and KlugeSeverin, 2011) and peas (Silim et al, 1985;Munier-Jolain et al, 2010;Neugschwandtner et al, 2013). However, few studies appear to have been made on the effect of agronomic treatments on the growth and productivity of wheat at both the individual plant and plant stand levels.…”