Germination Characteristic of Rhizomes of Major Monocotyledonous Weeds in Coconut Plantations of Sri Lanka

Abstract

Panicum maximum, Panicum repens, Imperata cylindrica, Pennisetum polystachion and Cyperus rotundus are five rhizomatous grass weeds that exist and are problematic in the coconut lands of Sri Lanka.Rhizomatous weeds are the most difficult to control because of their vegetative reproduction by underground propagules. Therefore chemical and biological techniques have failed to control these weeds to acceptable levels. Experiments were conducted to investigate the impact of depth of burial, duration of sun drying or duration of air drying rhizomes of the selected weed species on germination. Depth of burial reduced germination of all species. Burying rhizomes at depths less than 10 cm inhibited germination of P. maximum and P. polystachion. Burying depths below 30～40 cm inhibited germination of all species.Sun drying or air drying rhizomes for durations less than 5 days inhibited germination of P. maximum and P. polystachion. Germinations of all species were inhibited by sun drying rhizomes for 15 days or air drying rhizomes for 20 days. Sun drying of rhizomes of all species for five days reduced the moisture content to a greater extent than air drying. The results indicated that burying rhizomes at the depthsbelow

Manejo De Plantas Daninhas Em Frutíferas Tropicais: Abacaxizeiro, Bananeira, Coqueiro, Mamoeiro E Maracujazeiro

“…A roçada da parte aérea das plantas daninhas também é um método frequentemente utilizado principalmente nas entrelinhas das culturas, pois considera-se uma prática eficiente (CONSTANTIN, 2011). Porém, em alguns casos, a eficiência é contestada, pois plantas de propagação vegetativa podem apresentar rebrota rápida, exigindo várias operações durante o ano, como é o caso do capim-amargoso e tiririca (SENARATHNE; SAMARAJEEWA; PERERA, 2003;RONCHI et al, 2008;SANGAKKARA, 2009;BANDARA;SANGAKKAR, 2012). O revolvimento do solo com implementos como grades e enxadas rotativas nas entrelinhas da cultura, são práticas mecânicas que promovem controle eficiente de algumas plantas daninhas, mas, no que diz respeito à conservação do solo, não se trata do método mais sustentável (CARVALHO, 2000).…”