Net Photosynthetic Rates, Relative Leaf Growth Rates, and Leaf Numbers of 22 Races of Maize Grown at Eight Temperatures¹

Abstract

Twenty‐two races of maize (Zea mays L.) and one selection of teosinte (Euchlaena mexicana Schrad) were grown under natural daylight in eight glasshouses where day/night temperatures were maintained from 15/10 to 36/31 C. Differences were found among temperatures and races in net photosynthetic rates, relative leaf growth rates, and leaf numbers. At low temperatures, high altitude races had relatively higher leaf growth rates and dry weights at harvest. At high temperatures high altitude races had relatively lower net photosynthetic rates. Leaf numbers increased with increasing temperatures.

Differences between spring wheat cultivars in early growth

“…We consider a range of 5-10% to be realistic for genotypes in breeding nurseries. This estimate is based on C0 2 assimilation measurements of single leaves at high light published by DUNCAN & HESKETH (1968), PEARCE et al, (1969, EVANS & DUNSTONE (1970), KHAN & TSUNODA (1970a, CRISWELL & SHIBLES (1971), DANTUMA (1973), ASAYet al (1974, KISHITANI & TSUNODA (1974), FISCHER et al (1981, AUSTIN et al (1982), MAHON (1983), EVANS et al (1984), andYAMAUCHI &YOSHIDA (1985). Values of Amax change with conditions for growth during leaf development and with leaf age.…”

Chemical composition of 24 wild species differing in relative growth rate

“…The process of CO 2 fixation is a prerequisite for plant growth and has received considerable attention from (eco)physiologists, who have analysed inherent variation in relative growth rate (RGR; Duncan & Hesketh 1968;Dijkstra & Lambers 1989;Poorter, Remkes & Lambers 1990). However, it is only the first step in a series of biochemical reactions that leads to the construction of biomass.…”

Agro physiological characteristics of quality protein maize genotypes as influenced by irrigation and plant population in a semi arid Region of Nigeria

“…The leaf area obtained from the individual leaves was added and divided by the number of plants sampled to obtain LAI. The leaf area per plant was then multiplied by the number of plants/m 2 and divided by the land area covered by the plant (Duncan and Hasketh, 1968).…”