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Tomato spotted wilt (TSW) is caused by a Tospovirus [tomato spotted wilt virus (TSVW)] and is vectored by thrips. TSW is a major impediment to tomato production worldwide and has been identified as the most significant limitation in the southeastern United States. The objectives of this study were to quantify the impact of polyethylene mulch type (black, metalized, Heat stripe, and Sonoco printed) and insecticide (alternating applications of spinosad and methamidophos) on midafternoon soil temperature under the mulch, reflected photosynthetic photon flux (PPF), vegetative growth, flower number, incidence of TSW, yield, and fruit quality of āFL-47ā tomato (Solanum lycopersicum L.). Midafternoon soil temperature during April and May (10-cm depth) averaged 2 to 4 Ā°C higher under black mulch compared with the other mulches. The reflectance of PPF was highest for metalized mulch (up to two-thirds of PPF in full sunlight) followed by Heat stripe, Sonoco printed, and black mulch. In the presence of a full plant canopy, PPF reflectance was greatly reduced. The incidence of TSW [as determined visually and confirmed by enzyme-linked immunosorbent assay (ELISA)] was very high in 2002 and relatively low in 2003. Stem weight was significantly reduced in the black mulch treatment; however, plant height, leaf weight, or total numbers of flowers were not influenced by mulch type. For both years, the incidence of TSW on black mulch was significantly greater than that of the other mulch treatments for most sampling dates. The application of insecticides reduced percentage TSW on the last two sampling dates in both years. In 2002, but not 2003, yield per hectare was affected by mulch type. In both years, mulch type did not influence yield per plant and percentage marketable fruit, and insecticide applications increased yield per hectare, yield per plant, and percentage marketable fruit.
Studies were conducted at three locations in Florida to evaluate the effects of kasugamycin alone, in alternation, or as a tank-mix partner with copper bactericides and other fungicides against bacterial spot of tomato. In greenhouse trials, kasugamycin, formulated as KasuminĀ® 2L, reduced bacterial spot severity by up to 37.5% compared with a non-treated control. Little advantage in disease control was observed by mixing kasugamycin with other fungicides. Kasugamycin was assessed in six field trials. In the four field trials that tested kasugamycin alone, it was as effective as the standard copper + mancozeb treatment for the control of bacterial spot. In four trials, no benefit was observed in applying kasugamycin as a mixture with copper + mancozeb, and only one of three trials did alternating kasugamycin with copper + mancozeb improve bacterial spot control over either the copper + mancozeb standard or kasugamycin alone. Although kasugamycin was effective for the control of bacterial spot in greenhouse and field trials, rapid development of resistance in field populations of X. perforans may shorten the effective use of this antibiotic.