|Abdul Baki, Aref|
Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 6/6/2005
Publication Date: 10/1/2005
Citation: Abdul Baki, A.A., Klassen, W., Bryan, H.H., Codallo, M., Hima, B.L., Wang, Q.R., Li, Y., Lu, Y.C., Handoo, Z.A. 2005. A biologically-based system for winter production of fresh-market tomatoes in south florida. Proceedings of Florida State Horticultural Society. 118:153-159. Interpretive Summary: In almost all areas where winter tomatoes and peppers are grown in south Florida, the soil is fumigated with methyl bromide/chloropicrin before planting the vegetables to control nematodes, pathogens, and nutsedge. This treatment adds to the production cost and may not be needed where infestations with these pests are light to moderate. This research reports on a tomato production system that uses three nematode-resistant cover crops (cowpea, velvetbean, and sunn hemp), in a cropping rotation without soil fumigation. The cover crops are planted in summer, mowed, and incorporated into the soil before transplanting the tomatoes in the fall. A standard soil fumigation treatment with methyl bromide/chloropicrin was also included each year. The results of three years suggest that in the alkaline limestone-derived soils of Miami-Dade county where the nematode and nutsedge populations are usually light to moderate, yields and net returns of tomatoes following the cover crops, without soil fumigation, were equal to or sometimes better than those in the soil fumigated treatment. However, these conclusions are limited to the alkaline limestone derived soils of Miami-Dade County and may not apply to sandy soils of north Florida. Users of this research are vegetable growers in south Florida, extension specialists, organic vegetable growers, and the public.
Technical Abstract: A three year-experiment was conducted near Homestead, Florida to evaluate the feasibility of using a biologically-based system for winter production of fresh-market tomatoes (Lycopersicon esculentum Mill.) in south Florida fields with light to moderate infestations of the root knot nematode, Meloidogyne incognita, and yellow nutsedge, Cyperus esculentus. The experiments were conducted at two locations: the Tropical Research and Education Center (TREC) at Homestead in 2001/02 and 2002/03 and at Pine Island Farms (PIF), 20 miles northeast of Homestead, in 2004. The system consisted of a cropping rotation in which nematode-resistant cover crops [cowpea (Vigna unguiculata cv. Iron Clay), velvetbean (Mucuna deeringiana), and sunn hemp (Crotalaria juncea cv. Tropic Sun)] were followed by ‘Sanibel’, a nematode-resistant tomato cultivar in 2001/02, ‘Leila’ , a nematode-susceptible cultivar in 2002/03, and ‘Agri 6153’, a Fusarium and Verticillium-resistant, nematode-susceptible indeterminate cultivar developed for vine-ripe production in 2003/04. There were two cover crop treatments (cowpea and velvetbean) and a standard methyl bromide/chloropicrin (MC-33) treatment in 2001/02. A third cover crop treatment using sunn hemp was added in 2002/03. In 2003/04, two cover crop treatments (velvetbean and sunn hemp), a fallow (no cover crop), and a MC-33 treatment preceded by a summer sorghum sudangrass cover crop were used. Each treatment was replicated four times in all years. Biomass production by the velvetbean, cowpea, and sunn hemp crops averaged 14.8, 8.5, and 11.6 Mg ha -1, respectively. Suppression of root-knot (Meloidogyne incognita) nematode by the cover crops could not be rigorously determined because of a very low density nematode population at TREC and low-to-moderate populations at PIF. Marketable tomato yields in all treatments and in all years were above average annual yields in Miami-Dade County. Yields were highest in 2003/04 because the crop was healthy and favorable prices encouraged eight harvests. In contrast, yields were low in 2002 due to a heavy infection by foliar pathogens. In 2001/02, there was no significant difference in extra-large fruit yield among the treatments but the MC-33 treatment had higher yield of large fruits than the cowpea and velvetbean treatments thus resulting in a higher total marketable yield than both cover crop treatments. The total marketable yield in the velvetbean treatment was next highest. In 2002/03, the cowpea treatment had significantly higher yield of extra-large fruits than the MC-33 and the velvetbean treatments and significantly higher total marketable yield than all other treatments. In 2003/04, sorghum sudangrass/MC-33, velvetbean, and sunn hemp treatments had equal marketable yields in all fruit-size grades and were significantly higher than the fallow treatment. Economic analysis shows that all treatments resulted in positive net returns in all years. Returns in 2003/04 were the highest of all study years due to high yields and high market prices. Among the cover crops, sunn hemp produced the highest tomato yields and net returns of all treatments over the two years it was used.