Spontaneous plants and weed identified in five times in pineapple crop in Maquiné, Rio Grande do Sul, Brazil

Abstract

identifying weed that compete with pineapple crop allows us to improve weed control more efficiently and with less environmental costs. between aug./1997 and oct./1999 and of mar./05 dec./2005, at FePagro litoral norte, maquiné-rs, (lat. 29°54’ s, long. 50°19’, alt.46 m, rain. 1659 mm, chernossolo Háplico typical Órtico), two field assays were carried out in the same area. The spontaneous plants were identified before the plantation (aug./97 and mar./2005) and the weed three (nov./97), six (aug./05) and nine months later (dec./05). in the two assays, in the five dates, 74 spontaneous and/or weed were identified that belong the 25 botanical families: 17 Poaceae-23%, 21 asteraceae-28%, 4 cyperaceae-5%, 4 Fabaceae-5%, 3 oxalidaceae-4%, 2 rubiaceae-3%, 2 convolvulaceae-3%, 2 commelinaceae-3%, Polygonaceae-3% and the remain belong to others 16 families. Cynodon dacfilon-5, Paspalum notatum-5, Vernonia polianthes-4 and Sida rhombifolia-4 were more frequently identified. The soil management increased the percentage of annual plants in the first-7% and the second assay-48%. Poaceae and asteraceae summed 67%, 53%, 52%, 52%, 49% of the identified species, respectively, in aug./97, nov./97, mar./05, aug./05 and dec./05. in the respective dates, due to influences of time of year, applied treatments and soil and cu