Interference and control of wild sunflower (Helianthus annuus L.) in spring wheat (Triticum aestivum L.) in Northeastern Mexico
Rosales Robles, E.; Salinas Garcia, J.R.; Sanchez de la Cruz, R.; Rodriguez del Bosque, L.A.; Esqueda Esquivel, V.
Cereal Research Communications 30(3/4): 439-446
ISSN/ISBN: 0133-3720 Accession: 003821387
Field studies were conducted in northeastern Mexico in 1992 and 1993 to determine the effect of wild sunflower density (0, 1, 2, 4, 8, 16 and 32 plants/m2) on its own growth and interference in spring wheat CIANO T-79, and the effectiveness of triasulfuron (at 10.1 and 15 a.i./ha) and thifensulfuron (at 18.8 g a.i./ha) on wild sunflower chemical control. Full-season interference of wild sunflower at 2, 4, 8, 16, and 32 plants/m2 decreased spring wheat grain yields by 27, 49, 60, 71 and 75%, respectively, compared to weed-free plots. Wild sunflower was more competitive with spring wheat at low densities and intraspecific interference was evident at 12 plants/m2.