Alternatives to methyl bromide soil fumigation for vegetable and floriculture production
Location: Subtropical Plant Pathology Research
Title: Differential effect of organic and plastic mulches on Cyperus rotundus suppression and Citrullus lanatus (watermelon) fruit yield
| Morales Payan, Jose Pablo - UNIV. OF PUERTO RICO |
| Marquez-Mendez, Pedro - UNIV. OF PUERTO RICO |
| Shabana, Yasser - UNIV. OF FLORIDA |
| Charudattan, Raghavan - UNIV. OF FLORIDA |
| Klassen, Waldemar - UNIV. OF FLORIDA |
Submitted to: International Weed Science Society
Publication Type: Abstract Only
Publication Acceptance Date: October 11, 2011
Publication Date: June 23, 2008
Citation: Morales Payan, J., Marquez-Mendez, P., Shabana, Y., Charudattan, R., Rosskopf, E.N., Klassen, W. 2008. Differential effect of organic and plastic mulches on Cyperus rotundus suppression and Citrullus lanatus (watermelon) fruit yield. International Weed Science Society.
Cyperus rotundus (Purple nutsedge) [PN] is commonly referred to as one of the worst weeds of the world. In Puerto Rico, PN is among the most troublesome weeds in production systems where synthetic herbicides are not utilized. Alternative methods for PN management, such as mulching, may be valuable tools for organic production in PN-infested soils. Field research was conducted in Isabela, PR, to assess PN suppression by black and IRT plastic mulches and eight organic mulches and its impact on Citrullus lanatus (watermelon) yield in a production system managed according to organic regulations. The organic mulches were hays of Paspalum notatum (Bahiagrass), Imperata cylindrica (cogongrass), Vigna unguiculata (cowpea), Pennisetum glaucum(millet), Cyperus rotundus (purple nutsedge), Sorghum bicolor (sorghum), Crotalaria juncea (sunnhemp), and Secale cereale (rye). Mulches were placed on the soil beds the same day Citrullus lanatus (watermelon) cv Crimson Sweet was planted. The original PN density was 100 tubers per m². The crop was managed using organic production practices. PN able to grow through the mulches grew unchecked until crop harvesting. Plastic mulches suppressed PN almost completely, but also caused drastic suppression of crop growth and yield. PN biomass was suppressed by as much as 20% in Crotalaria- and Vigna-mulched plots, resulting in significant crop yield loss as compared to the weed-free crop. Imperata cylindrica and Cyperus rotundus mulches reduced PN shoot biomass by as much as 80%, resulting in higher crop yields than in PN-infested plots. These results confirm the importance of PN management in this organic crop and the differential suppression efficacy of the mulches tested.