Alternatives to methyl bromide soil fumigation for vegetable and floriculture production
Location: Subtropical Plant Pathology Research
Title: Use of organic mulch as an alternative to the plastic mulch-methyl bromide system for suppressing purple and yellow nutsedges in tomato production
| Shabana, Y. - UNIV. OF FLORIDA |
| Charudattan, R. - UNIV. OF FLORIDA |
| Abou Tabi, A. H. - UNIV. OF FLORIDA |
| Klassen, W. - UNIV. OF FLORIDA |
| Morales-Payan, J. P. - UNIV. OF PUERTO RICO |
Submitted to: International Weed Science Congress
Publication Type: Abstract Only
Publication Acceptance Date: October 11, 2011
Publication Date: June 23, 2008
Citation: Shabana, Y., Charudattan, R., Abou Tabi, A., Klassen, W., Rosskopf, E.N., Morales-Payan, J. 2008. Use of organic mulch as an alternative to the plastic mulch-methyl bromide system for suppressing purple and yellow nutsedges in tomato production. International Weed Science Congress.
Cyperus rotundus and C. esculentus (purple and yellow nutsedges, respectively) are among the most serious weed problems in many cropping systems in Florida and other parts of the world. They have been reported to cause yield losses of 20-89% in various horticultural crops. Production systems based on plastic mulch and methyl bromide soil fumigation are used for nutsedge suppression in many conventional vegetable cropping systems. When methyl bromide has been totally phased out, the losses due to nutsedges are expected to increase in conventional horticultural crops. Organic production will continue to suffer due to a lack of effective weed control measures. Thus, 10 organic hays (shoot straw of bahiagrass, cogongrass, cowpea, millet, nutsedge, sorghum Sudangrass, sunnhemp, rye, corn, and sugarcane bagasse), four green mulches (cowpea, millet, sorghum Sudangrass, and sunnhemp), and two plastic mulches (black and IRT) were tested for their efficacy in suppressing purple and yellow nutsedge growth in a raised bed tomato (cv. Tygress) field. The beds were fumigated with methyl bromide prior to treatment establishment and a randomized complete block design was used with four replications. Tomato seedlings were transplanted in a single row in all plots at a rate of six tomato seedlings per plot with 18” plant spacing. The following day, nutsedge tubers were seeded, with yellow and purple nutsedge tubers seeded alternately at 1' depth and 3' space in two lines parallel to tomato rows (one line on each side with 2' spacing from tomatoes). Only the plot of weed-free control treatment in each block was not seeded with nutsedge. After seeding the nutsedge tubers, the hays and green or plastic mulches were spread in each plot. The black plastic mulch consistently reduced nutsedge emergence and growth more than the organic mulches and the IRT plastic mulch. All green organic mulches, except the green sunnhemp, were more suppressive to nutsedge emergence and growth than hay mulches. Among the organic mulches, the greatest suppressive effect on nutsedge was found when using green sorghum, green millet, and congongrass hay followed by green cowpea and bahiagrass hay. Sugarcane bagasse, corn hay, green sunnhemp, and yellow nutsedge hay provided the least nutsedge suppression. Although cogongrass hay did not enhance the total yield, it influenced the proportion of larger fruits. The highest yield of extra large tomatoes per plant was obtained when cogongrass hay was used as mulch. However, the use of black plastic increased the total yield and the proportion of larger fruit.