Yield responses to narrow rows depend on increased radiation interception

FERNANDO H. ANDRADE, PABLO A. CALVIÑO, ALFREDO CIRILO, PABLO A. BARBIERI

AGRONOMY JOURNAL

ASA

Lugar: Madison, WI; Año: 2002 p. 975 - 980

0002-1962

The response of grain yield to narrow rows can be analyzed in terms of the effect on the amount of radiation intercepted by the crops. The objective of this work was to study the effect of row spacing on grain yield and radiation intercepion (RI) during the critical period for grain set in three crop species. Ten experiments were conducted with maize (Zea mays L.), sunflower (Helianthus annus L.) or soybean [Glycine max (L.) Merr.] under irrigation or under driland conditions without severe drought during flowring and grain filling. The treatments consisted of two row distances combined with other factors such as plant density, cultivar, defoliation, etc. Grain yield responses to decrease distance between rows were inversely proportional to RI achieved with the wide row control treatment during the critical period for grain number determination (r2= 0.62, 0.54, and 0.86 for maize, soybean and sunflower, respectively). Moreover, when row spacing was reduced, grain yield increases and RI increases during the critical periods for grain set were significantly and directly correlated in the three crop species (r2= 0.71, 0.64, and 0.94 for maize, soybean and sunflower, respectively). For the conditions of these experiments, grain yieldincrease in response tonarrow rows was closely related to improvement in light interception during the critical periods for grain set.