Defoliation affects soybean yield depending on the time and level of reduction of light interception

GREGORUTTI, V.C.; CAVIGLIA, O.P.; SALUSO, A.

AUSTRALIAN JOURNAL OF CROP SCIENCE

SOUTHERN CROSS PUBL

Año: 2012 vol. 6 p. 1166 - 1171

1835-2693

Light interception during the critical period in soybean may be a better index of the injury level by defoliation than the insect population or the percentage of defoliation. Our aim was to simulate the effects of time and levels of defoliation on soybean seed yield, its numerical components and light interception during the critical period. The study was conducted in Paraná (31.5ºS; 60.3ºW), Argentina. We evaluated a combination of defoliation levels (0, 33, 66 and 100%) and two times of defoliation during soybean development (pod initiation and beginning of seed filling, i.e. R3 and R5, respectively). We measured radiation interception during the linear seed filling period (R5.5), seed yield and its components. Total defoliation performed at R3 reduced seed yield more than that performed at R5 (P