Application Effects of Several Herbicides in Spring Proso Millet Area in Northern Hebei Province

According to the ecological environment and current status of weeds in northern Hebei Province,five herbicides were screened out to test weed control efficacy and crop safety. The result showed that Gaolaotou was more economic and effective when spraying in soil on the sowing day at the dose of 2 250 m L/hm;.

Primary Research on Screening of Herbicides in Summer Sowing Broomcorn Millet Field

[ Objective] The paper was to select the suitable herbicides for summer sowing breomcom millet and reduce labor costs. [ Method ] More than 20 kinds of herbicides commonly used in fields had been preliminarily screened, and six kinds of herbicides were selected for further field herbicidal effect experiment. [ Re- suit] The herbicidal effects of 2,4-D butylate, MCPA-Na, tribenuren, 2,4-D isooctyl ester and monosulfuren plus prepasine against Pharbitis nil （ lAan. ） Choisy, Amaranth mangostanus L. and Portulaca oleracea L. were greater than 70%, and the weed control effect on fresh weight by leaf and stem spray of tribenu- ran and MCPA-Na were greater than 96% after herbicide application for 20 d. [ Concluslon] The study provides the guidance for production of breomcom millet.

Application of pre-emergence herbicides in poplar nursery production

In addition to pests and diseases, weeds are a major problem in poplar nursery production. The possibilities of herbicide application in juvenile poplar growth were researched, taking into account that weeds are one of the main limiting factors. The following pre-emergence herbicides were tested： acetochlor, S-metolachlor, metribuzin,oxifluorfen, and dimethenamid during two vegetation seasons at two locations, which differed by the soil physicochemical characteristics. The study results show that the number of weeds on sample plots was significantly reduced by the tested herbicides when compared to control plots. The highest reduction in the number of weeds was achieved using the herbicides acetochlor and metribuzin. However, metribuzin showed a phytotoxic effect on sandy soil. Metribuzin application is recommended only on the soils with higher contents of organic matter, where the phytotoxic effect was absent. Acetochlor, S-metolachlor, oxifluorfen, and dimethenamid were not phytotoxic to poplars and can be used for weed suppression in the production of poplar plants.

Effect of Herbicides Used in Horticulture (2,4-D, Glyphosate and Nicosulfuron) on Snails <i>Achatina fulica</i>(Bowdich, 1720)

2,4-Dichlorophenoxyacetic (2,4-D), glyphosate, and nicosulfuron, because of their modes of action and selectivity, are the most widely used herbicides in Ivorian horticulture. Fuels toxicity was the reason of many debates in the world because of their massive and uncontrolled use. They are frequently blamed for the reduction of soil fertility and terrestrial biodiversity observed in agricultural areas. In view of the debates raised by their toxicities, the use of these herbicides requires the greatest caution and clear information on the real risk incurred by the edaphic fauna by conducting ecotoxicity studies. The present study aims to evaluate the effect of 2,4-D, glyphosate and nicosulfuron herbicides on the growth and reproduction of Achatina fulica snails in microcosm. To do this, we treated each plot on which snail microcosms were placed with 2,4-D, glyphosate or nicosulfuron herbicides according to the manufacturer’s recommendations. The results showed for all the herbicides used, that after 28 days of exposure, the growth of juvenile snails was slowed down. The number of eggs laid per pair was reduced in adult snails. The egg hatchability test revealed a reduction in egg hatchability. In addition, each effect was dependent on the herbicide used. Thus, toxicity was found to be greater according to the following order: nicosulfuron ? glyphosate ? 2,4-D. From the results obtained, we concluded that 2,4-D, glyphosate, and nicosulfuron treatments under field conditions are a potential threat to the sustainability of snail species and therefore to soil life. The intensity of the effect depends on the toxicity of the herbicides used.