Control of horsenettle [Solanum] regeneration from root fragments with chlorpropham
2005
Ito, K.(Kyoto Univ. (Japan)) | Ito, M. | Huseyin, O. | Tanaka, S. | Miura, R. | Anzai, T.
In order to establish chemical control of horsenettle (Solanum carolinense L.) in crop fields, six commonly used prememergence herbicides, atrazine, alachlor, butamifos, trifluralin, pendimethalin and chlorpropham were examined for efficacy on horsenettle regeneration from its root fragments. Chlorpropham was found most effective: no fragment sprouted for 44 days after one-hour dipping in a 229 ppm solution that was almost 100 times lower than the concentrations normally applied in fields (Table 1). Effects of chlorpropham applied preemergence with soil incorporation were then determined in a corn field (soil: loam) where root fragments of horsenettle had been buried. Growth of emerged shoots from the fragments placed at 5-10 cm depth was considerably reduced at 0.46 kg/ha and the higher rates, but the herbicide did not affect emergence itself even at a rate of 1.37 kg/ha (Figs. 1,2,3 and 4). On the contrary, for the fragments placed at 20-25 cm depth, emergence was inhibited but growth was only slightly affected by chlorpropham. Chlorpropham efficacy on the regeneration from root fragments varied greatly between soil types, being most effective in sandy loam, followed by volcanic, clay loam and loam soils in that order (Fig 5). Soil incorporated chlorpropham at 1.37 kg/ha almost completely suppressed sprouting from root fragments for 47 days in sandy loam soil, 27 days in volcanic soil and 15 days in clay loam and loam soils. The prominent control effects of chlorpropham seem to be attributed to its inhibition of cell division at meristematic regions and its ready diffusion through soil pores due to high vapor pressure, which tends to make an uniform and rather deeper layer of the herbicide when soil incorporated.
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