HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Capristo, P. R. Articles by Andrade, F. H. Search for Related Content PubMed Articles by Capristo, P. R. Articles by Andrade, F. H. Agricola Articles by Capristo, P. R. Articles by Andrade, F. H. Related Collections Crop Growth and Development Maize Management

Corn

Ecophysiological Yield Components of Maize Hybrids with Contrasting Maturity

Unidad Integrada INTA Balcarce, Facultad de Ciencias Agrarias UNMP, CC 276, 7620 Balcarce, Provincia de Buenos Aires, Argentina

^* Corresponding author (fandrade{at}balcarce.inta.gov.ar)

Received for publication December 19, 2006. The length of the growing cycle is one of the most important traits determining hybrid adaptability to the environment. The objective of this work was to study the development, dry matter accumulation, grain yield, harvest index, and sink–source relationship of 11 maize (Zea mays L.) hybrids with contrasting maturity. The durations of the cycle from emergence to flowering varied from 537 to 781 growing degree days and from emergence to physiological maturity from 1221 to 1656°Cd. Cumulative biomass from emergence to flowering increased linearly with hybrid cycle length. Long-season hybrids showed the highest cumulative interception but the lowest radiation use efficiency (RUE) during reproductive growth. Total aboveground biomass increased from 1624 to 2422 g m^–2 with hybrid maturity class, and grain yields were lowest for short-season hybrids (832 g m^–2) and similar between mid and long-season hybrids (avg. = 1256 g m^–2). Increases in maturity class were associated with increases in grain number (from 2432 to 5078 grains m^–2) and reductions in individual grain growth rate (from 9.1 to 4.9 mg grain^–1 d^–1). The sink–source relationship and the apparent reserve remobilization increased with hybrid maturity class. These results indicate that grain yield of short-season hybrids would be more limited by the capacity of the reproductive sinks during grain filling than their long-season counterparts. Hybrids Ax 840 and Experimental have a short developmental time from emergence to flowering but a long developmental time from flowering to physiological maturity. This resulted in the largest values of radiation interception during reproductive growth and in the greatest grain yields and harvest indexes.

Abbreviations: DAF, days or growing degree days after flowering • EGFD, effective grain filling duration • GGR, grain growth rate • GW, grain weight • PAR, photosynthetically active radiation • RUE, radiation use efficiency