Abstract

DIAZ-LOPEZ, Ernesto et al. Radiation-use efficiency, net assimilation rate and thermal integral as a function of phosphorus in maize (Zea mays L.). Agrociencia [online]. 2013, vol.47, n.2, pp.135-146. ISSN 2521-9766.

Phosphorus is an essential macroelement for plants and along with environmental factors, such as radiation and temperature influences the growth and yield of crops such as maize (Zea mays L.). The aim of this study was to compare the effect of six levels of phosphorus (0, 40, 80, 120, 160 and 200 kg P₂O₅ ha^-1 on radiation-use efficiency, net assimilation rate and heat units of the maize cultivars Amarillo Almoloya, Cacahuacintle and Cóndor, in tip irrigation conditions in the Cerrillo Piedras Blancas, Estado de Mexico. The experiment was a randomized complete block design with a factorial arrangement; the 18 treatments were combinations of three cultivars and six levels of phosphorus. Data were analyzed with an ANOVA and treatment means with the HSD test (p<0.05). Analysis of results indicated that Cacahuacintle responded better to the study environment with 80 kg P₂O₅ ha^-1, since it had higher yield (7136.7 kg ha^-1), radiation-use efficiency (RUE; 0.33 MJ m^-2) and net assimilation rate (NAR, 0.023 g m^-2 day^-1) than the other cultivars. It was concluded that phosphorous affect RUE, corn growth and yield with low (0 and 40 kg ha^-1) and high doses (160 and 200 kg ha^-1).

Keywords : cultivars; open pollination; agronomic yield; heat units; Zea mays.