A study was conducted to detect the effect of water extracts from different parts such as root, bark, branch and leaf, of adult larch, Larix gmelini, trees on growth of Manchurian walnut, Juglans mandshudca, seedlings...A study was conducted to detect the effect of water extracts from different parts such as root, bark, branch and leaf, of adult larch, Larix gmelini, trees on growth of Manchurian walnut, Juglans mandshudca, seedlings and the allelopathy between the two tree species. Four concentrations （100 g. kg i, 50 g. kg^-1, 25 g. kg^-1 and 12.5 g. kg^-1） were prepared for each kind of extracts. Result showed that the water extracts with low and moderate concentrations accelerated the growth of collar diameter and increased biomass and root/shoot ratio of walnut seedlings. The water extracts from branches and barks with low and moderate concentrations accelerated the height growth of the seedlings, while those from leaves and roots slightly decreased the height growth of seedlings. The fact that application of water extracts of larch improved the growth of Manchurian walnut attributes possibly to the allelopathy between the two tree species.展开更多
[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg...[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg/kg） on plant height, biomass, root-shoot ratio and chlorophyll content of P. hydridum. [Results] Low level of atrazine stress （20 and 50 mg/kg） showed no significant effects on plant height and biomass of P. hydridum. Moderate level of atrazine stress （100 and 200 mg/kg） did not show significant effect on plant height, but did on the biomass of P. hydridum. Biomass of P. hydridum stressed by 100 and 200 mg/kg of atrazine was decreased by 34.1% and 36.4% compared with control, respectively. High level of atrazine stress （500 mg/kg） brought significant decrease in plant height（by 40.6%） and biomass（20.0%） of P. hydridum. All levels of atrazine stress showed no significant effects on root-shoot ratio and chlorophyll content of P. hydridum. [Conclusion] Pennisetum hydridum has strong tolerance to atrazine stress.展开更多
There are a limited number of postemergence (POST) herbicides available for weed management in mung bean production in Ontario. Five field studies were conducted in 2010, 2011 and 2012 near Exeter, Ontario and in 2011...There are a limited number of postemergence (POST) herbicides available for weed management in mung bean production in Ontario. Five field studies were conducted in 2010, 2011 and 2012 near Exeter, Ontario and in 2011 and 2012 near Ridgetown, Ontario to determine the tolerance of mung bean to fomesafen, bentazon, bentazon + fomesafen and halosulfuron applied POST at the 1X and 2X proposed manufacturer’s recommended rate. Bentazon caused 5%-29%, 4%-31%, and 2%-18% injury, fomesafen caused 3%-17%, 1%-7%, and 0%-6% injury, bentazon + fomesafen caused 6%-40%, 4%-37%, and 1%-20% injury, and halosulfuron caused 13%-65%, 8%-75%, and 5%-47% injury in mung bean at 1, 2, and 4 weeks after treatment (WAT), respectively. At Exeter, fomesafen had no adverse effect on height of mung bean but bentazon, bentazon + fomesafen and halosulfuron decreased mung bean height as much as 5% compared to the untreated control. At Ridgetown, there was no decrease in mung bean height due to the herbicides applied. Fomesafen had no adverse effect on shoot dry weight of mung bean but bentazon, bentazon + fomesafen and halosulfuron decreased shoot dry weight of mung beans as much as 43%, 47%, and 57%, respectively. Fomesafen, bentazon, bentazon + fomesafen and halosulfuron had no adverse effect on the seed moisture content and seed yield of mung bean with the exception of halosulfuron applied POST at 70 g ai ha-1 which increased seed moisture content 0.4% at Exeter and 1.4% at Ridgetown and decreased yield 16% at Exeter compared to the untreated control. Based on these results, there is not an adequate margin of crop safety for bentazon, bentazon + fomesafen and?halosulfuron applied POST in mung bean. However, there is potential for fomesafen applied POST at the proposed manufacturer’s rate of 240 g ai ha-1 in mung bean production.展开更多
基金This paper was supported by National Natural Science Foundation of China （No. 30400341） and Heilongjiang Provincial Science Foundation （No. C0320）Acknowledgement I thank Dr. YAN Xiu-feng for his help and guidance.
文摘A study was conducted to detect the effect of water extracts from different parts such as root, bark, branch and leaf, of adult larch, Larix gmelini, trees on growth of Manchurian walnut, Juglans mandshudca, seedlings and the allelopathy between the two tree species. Four concentrations （100 g. kg i, 50 g. kg^-1, 25 g. kg^-1 and 12.5 g. kg^-1） were prepared for each kind of extracts. Result showed that the water extracts with low and moderate concentrations accelerated the growth of collar diameter and increased biomass and root/shoot ratio of walnut seedlings. The water extracts from branches and barks with low and moderate concentrations accelerated the height growth of the seedlings, while those from leaves and roots slightly decreased the height growth of seedlings. The fact that application of water extracts of larch improved the growth of Manchurian walnut attributes possibly to the allelopathy between the two tree species.
基金Supported by Natural Science Foundation of Yunnan Province(2010CD058)~~
文摘[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg/kg） on plant height, biomass, root-shoot ratio and chlorophyll content of P. hydridum. [Results] Low level of atrazine stress （20 and 50 mg/kg） showed no significant effects on plant height and biomass of P. hydridum. Moderate level of atrazine stress （100 and 200 mg/kg） did not show significant effect on plant height, but did on the biomass of P. hydridum. Biomass of P. hydridum stressed by 100 and 200 mg/kg of atrazine was decreased by 34.1% and 36.4% compared with control, respectively. High level of atrazine stress （500 mg/kg） brought significant decrease in plant height（by 40.6%） and biomass（20.0%） of P. hydridum. All levels of atrazine stress showed no significant effects on root-shoot ratio and chlorophyll content of P. hydridum. [Conclusion] Pennisetum hydridum has strong tolerance to atrazine stress.
文摘There are a limited number of postemergence (POST) herbicides available for weed management in mung bean production in Ontario. Five field studies were conducted in 2010, 2011 and 2012 near Exeter, Ontario and in 2011 and 2012 near Ridgetown, Ontario to determine the tolerance of mung bean to fomesafen, bentazon, bentazon + fomesafen and halosulfuron applied POST at the 1X and 2X proposed manufacturer’s recommended rate. Bentazon caused 5%-29%, 4%-31%, and 2%-18% injury, fomesafen caused 3%-17%, 1%-7%, and 0%-6% injury, bentazon + fomesafen caused 6%-40%, 4%-37%, and 1%-20% injury, and halosulfuron caused 13%-65%, 8%-75%, and 5%-47% injury in mung bean at 1, 2, and 4 weeks after treatment (WAT), respectively. At Exeter, fomesafen had no adverse effect on height of mung bean but bentazon, bentazon + fomesafen and halosulfuron decreased mung bean height as much as 5% compared to the untreated control. At Ridgetown, there was no decrease in mung bean height due to the herbicides applied. Fomesafen had no adverse effect on shoot dry weight of mung bean but bentazon, bentazon + fomesafen and halosulfuron decreased shoot dry weight of mung beans as much as 43%, 47%, and 57%, respectively. Fomesafen, bentazon, bentazon + fomesafen and halosulfuron had no adverse effect on the seed moisture content and seed yield of mung bean with the exception of halosulfuron applied POST at 70 g ai ha-1 which increased seed moisture content 0.4% at Exeter and 1.4% at Ridgetown and decreased yield 16% at Exeter compared to the untreated control. Based on these results, there is not an adequate margin of crop safety for bentazon, bentazon + fomesafen and?halosulfuron applied POST in mung bean. However, there is potential for fomesafen applied POST at the proposed manufacturer’s rate of 240 g ai ha-1 in mung bean production.
