Herbicidas para el control de Spermacoce tenuior L. en papaya (Carica papaya)

Abstract

In order to assess the effectiveness of pre and post-emergence herbicides for the control of Spermacoce tenuior and other weeds in papa ya, a field test was conducted in 2007, in a commercial field of the "Pococí" hybrid, located in Guápiles, Limón, Costa Rica. A first phase of the study consisted of six post-emergent treatments (1. Glyphosate 24 SL, 2. Glyphosate 68 SG , 3. Glip hosate 24 SL + carfentrazone 24 EC , 4. Glyphosate 68 SG + carfentrazone 24 EC , 5. Glip hosate 24 SL + metsulfuron methyl 60 WG, 6. Gliphosate 24 SL + oxyfluorfen 24 EC). A second phase consisted of three pre-emergent treatments (1. Oryzalin 75 WP, 2. Oxyfluorfen 12 EC, 3. Acetoclor 90 EC) distributed in a randomized complete block design in both phases. The percentage of weed ground cover, height and stem thickness of papa ya plants were measured before and after herbicide app lication. Post-emergence app lications of glyphosate (0.94 kg i.a./ha) + metsulfuron (16 g i.a./ha) showed the best weed control from the second until the sixth week after app lication (WAA ) without affecting the crop. Oryzalin app lied as a preemergent (3 kg i.a./ha) showed the best control of Spermacoce tenuior until 14 WAA under the planting row and around the plants. No phytotoxicity was observed. (English) [ABSTRACT FROM AUTHOR]