科研之友
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摘要
Fresh market tomato is an important and valuable crop in Florida, accounting for 630 million dollars farm-gate value, which was 45% of the total value of the U.S. crop in 2010. In order to maintain or increase its productivity, labeled herbicide alternatives to methyl bromide are important to limiting seed production of weeds emerging between the raised plasticulture beds. A study was conducted inside a greenhouse where carfentrazone was applied as a drench at 0.03125x, 0.0625x, 0.125x, 0.25x, 0.5x, 1x, 2x, 4x, and 8x and as a subsurface irrigation at 0.0625x, 0.125x, 0.25x, 0.5x, 1x, 2x, 4x, 8x, and 16x rates. The 1x rate equaled the maximum labeled rate of carfentrazone (35.1 g ai ha(-1)) that would be applied to an area of 0.360 m(2). Both the drench and subsurface trials showed an increase in plant injury and reduced growth as the rate of carfentrazone increased. The drench trial, however, was observed to have higher visible injury and greater growth reduction (based on plant measurement) than the subsurface trial, when comparing similar rates. For the 1x rate of carfentrazone in the drench trial vs. the subsurface trial, injury was 66 and 24.5%, respectively. For the 1x rate the tomato plants had estimated growth, based on the curves fit for the data, of 4.8% vs. 39.9% for the drench and subsurface trials, respectively. The subsurface trial better represents what happens in the field when carfentrazone root uptake injury is observed since it is normally observed to be around 10 % or less. This still leaves a level of concern; once a 10 % injury level in the subsurface trial was estimated to have reduced tomato growth, fruit weight, and total shoot dry weight by 33, 15, and 9.5%, respectively.
- 出版日期2013-9
