共查询到19条相似文献，搜索用时 171 毫秒
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施用杀菌剂可引起土壤中铜的积累，增加铜的生物有效性和对植物的毒性。文中对河北省怀来县环官厅水库不同位置的4个葡萄园土壤剖面中铜组分的积累和分布进行了分析。研究结果表明：1)研究区域长期使用含铜杀菌剂已经造成了葡萄园表层土壤铜积累。2)怀来县因气候原因，葡萄在冬季需下架深埋，不同的深埋方式对土壤产生的扰动程度不同，进而影响铜在土壤剖面中的分布。3)研究区域内土壤中的铜主要以铁锰氧化态和强有机结合态存在。4)土壤中钙镁离子、黏粒和有机质含量与不同形态铜含量存在相关关系。钙镁离子的存在以及土壤中黏粒的增加能够降低水溶态铜和碳酸盐结合态铜含量，促进土壤中的铜向稳定形态转变，同时有机肥的施用在一定程度上能降低铜的生物有效性。 相似文献
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警惕长残留性除草剂对后茬作物的伤害苏少泉（东北农业大学１５００３０）１什么是长残留性除草剂目前农业生产中应用的除草剂品种很多，大多数品种使用后在短时期内便分解失效，它们在土壤中的残留期不超过半年，一般不会伤害后茬作物。但有少数品种使用后在土壤中的残留... 相似文献
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为了确保杀虫单在甘蔗上的安全科学使用,本研究分别于2015和2016年度在海南和广西开展了9%杀虫单颗粒剂在甘蔗和土壤中的残留消解试验和最终残留试验。残留消解试验结果表明,杀虫单在甘蔗植株中的半衰期为17.3～30.1 d,在土壤中的半衰期为1.7 d;最终残留试验结果表明,杀虫单在甘蔗蔗梢、蔗茎和土壤中的最终残留皆低于LOQ(0.02 mg/kg)。综上,在甘蔗苗期按照3 375 g/hm~2沟施9%杀虫单颗粒剂1次,甘蔗蔗梢和蔗茎中杀虫单的最终残留低于我国的限量标准,对人类的暴露风险较低;而且土壤中杀虫单残留对非靶标生物蚯蚓的环境风险也较低。 相似文献
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壬菌铜和吡唑醚菌酯在苹果和土壤中的残留及消解动态 总被引：2，自引：2，他引：0
建立了同时测定苹果及其土壤中壬菌铜和吡唑醚菌酯残留的分散固相萃取-高效液相色谱-串联质谱（DSPE-HPLC-MS/MS）方法,并采用该方法研究了24%吡唑醚菌酯·壬菌铜微乳剂在苹果和土壤中的残留及消解动态。其中壬菌铜以硫化钠为破络剂,将其转化为壬基酚磺酸后进行检测。样品用乙腈提取,同时加入硫化钠,经N-丙基乙二胺（PSA）净化后,采用C18色谱柱,以甲醇-水为流动相梯度洗脱分离,于多反应监测模式下经正负离子同时扫描进行定性,基质匹配标准曲线外标法定量。结果表明:在0.1~10 mg/kg添加水平下,壬菌铜在苹果及土壤中的回收率范围为92%~103%,相对标准偏差（RSD）为1.3%~5.1%;在0.01~1 mg/kg添加水平下,吡唑醚菌酯在苹果及土壤中的回收率范围为96%~105%,RSD为2.4%~4.6%。苹果及土壤中壬菌铜和吡唑醚菌酯的最低检测浓度（LOQ）分别为0.1和0.01 mg/kg。2014-2015年,中国宁夏、北京和山东两年三地的田间残留试验表明:壬菌铜在苹果和土壤中的消解半衰期分别为2.7~5.4和2.0~5.8 d,吡唑醚菌酯在苹果和土壤中的消解半衰期分别为4.3~8.3和3.6~10.2 d;采用24%吡唑醚菌酯·壬菌铜微乳剂,分别按推荐剂量（有效成分300 mg/kg）和推荐剂量的1.5倍（有效成分450 mg/kg）于苹果幼果期施药,最多施药4次,距末次施药14 d时,壬菌铜在苹果中的最大残留量为0.31 mg/kg,远低于日本规定的最大允许残留限量（MRL）值（5 mg/kg）,吡唑醚菌酯在苹果中的最大残留量为0.27 mg/kg,低于中国规定的MRL值（0.5 mg/kg）。 相似文献
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农田土壤中的农药残留对农产品安全的影响研究进展 总被引：4，自引：0，他引：4
农田土壤中的农药污染是威胁农产品安全的重要因素之一。在病虫草害的化学防治过程中,田间施用的农药最终会进入土壤环境并在其中转化积累,导致农田土壤环境污染。农作物能够通过根部吸收将土壤中的农药转运至植物体的各个器官和组织中,造成农产品中的农药残留,影响农产品质量和安全。本文系统地综述了土壤中农药残留进入植物体的途径,指出了可能影响土壤中农药进入植物体的内外因素,着重强调了其对农产品安全存在的潜在威胁,并针对农田土壤污染的治理和此类食品安全问题的防范提出了合理的建议。最后展望了未来研究应该关注的问题和方向。 相似文献
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浙八味中药材中农药残留调查及控制对策 总被引：1，自引：0，他引：1
通过对浙八味主产区的调查.发现有些中药材依然受到土壤中的滴滴涕、六六六农药残留的污染.麦冬中滴滴涕(或同系物)残留量较高,主要因过去曾长期、大量使用滴滴涕、六六六,导致种植麦冬的部分土壤中滴滴涕(或同系物)残留量仍较高(最高达1.6mg/kg);在部分中药材和土壤中检测出痕量的六六六残留.仙居白术2个样品和土壤中五氯硝基苯的残留较高,其他部分中药材中检测到很低量的毒死蜱、违禁高毒有机磷农药甲胺磷、氯菊酯等农药残留.除了滴滴涕、六六六外,造成中药材中其他农药残留的原因均为药农违规使用农药. 相似文献
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The effects of two mixtures of resistant and susceptible apple cultivars on the development of scab caused by Venturia inequalis were observed in an experimental orchard over four years, initially for two years without fungicides against scab, and subsequently for two years with a moderate fungicide schedule. The row-by-row and within-row mixtures included a susceptible cultivar and a resistant cultivar in equal proportions. Without fungicides, the results showed a significant reduction of disease incidence over both years (7·3 to 21·3%), and severity in the second year (35·4%) in the within-row mixtures, compared to the monoculture of the susceptible cultivar. The best results were obtained when the within-row mixture was associated with moderate fungicide treatments; in this case the reduction in disease incidence reached 75·1% on leaves and 69·7% on fruits during the growth phase. The characteristics of the Venturia inaequalis / Malus × domestica pathosystem and the results obtained in this experiment suggest a moderate but not negligible ability of cultivar mixtures for reducing epidemics of the disease. 相似文献
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L. Jamar B. Lefrancq C. Fassotte M. Lateur 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(4):481-493
In a field experiment conducted over two growing seasons, the effectiveness and phytotoxicity of inorganic fungicides such
as sulphur, lime sulphur, copper, silicon and Armicarb (a new formulation of potassium bicarbonate) was compared with water
for the control of primary apple scab infections in Belgium on high, medium and low scab-susceptible cultivars (cvs ‘Pinova’,
‘Pirouette’ and ‘Reinette des Capucins’, respectively). In order to drastically reduce the amount of fungicide applied in
the orchard, two approaches were used: (1) a strategy involving spraying during the infection process, before fungal penetration
and (2) a tunnel sprayer machine for treatment applications. Under field conditions highly favourable for disease, low rates
of elemental sulphur (31.8 and 38.6 kg ha−1 year−1 in 2005 and 2006, respectively) combined with low rates of copper (2.1 kg ha−1 year−1 in both years) provided the best scab control and reduced scab severity on the fruits of cv. ‘Pinova’ by 97 and 98% compared
with water control in 2005 and 2006, respectively. Lime sulphur was much more effective than wettable sulphur and appeared
to be efficient at temperatures below 10°C, but its effectiveness against apple scab decreased if the treatments were applied
12–24 h later than in the ‘during-infection’ spray strategy. Armicarb used alone significantly reduced apple scab severity
on the leaves and fruits of the three cultivars compared with the water control. Its effectiveness was as good as wettable
sulphur applied using the same timing and dosage. Silicon reduced apple scab on fruits very slightly, but not on leaves. The
amounts of wettable sulphur, lime sulphur, copper, silicon and potassium bicarbonate used in this experiment to control apple
scab were not phytotoxic, did not increase fruit russet, did increase the yield of each cultivar and did not affect summer
density of the beneficial Typhlodromus pyri. The potential and limitations of ‘during-infection’ spraying as a protection strategy against apple scab in organic farming
are discussed. 相似文献
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Moshe Reuveni Dov Prusky 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(4):349-357
The sterol biosynthesis inhibitors bromuconazole and difenoconazole and tank mixes of each fungicide with captan were applied
to apples and evaluated as controls for moldy-core and fruit decay caused by Alternaria alternata. Effectiveness of a mixture of bromuconazole and captan in controlling colonization by the fungus was also evaluated. Decay
formation by A. alternata on mature detached fruits was partially inhibited by bromuconazole at 0.5 μg ml−1 and was completely inhibited at 50 μg ml−1; it was significantly affected by either bromoconazole at 5 μg ml−1 or captan at 1,250 μg ml−1, and was completely inhibited by their mixture. In general, three foliar applications of bromuconazole or difenoconazole
in the field, during the bloom period, reduced the numbers of infected fruits by 40–60% compared with untreated control trees.
However, tank mixes of either fungicide with captan improved control of moldy-core in fruits at harvest. Tank mixtures of
bromuconazole and captan also significantly reduced the percentage of fruits colonized by A. alternata when sampled at various days after full bloom. Artificial inoculations in the orchard at full bloom did not change the inhibitory
effects of the tank mixtures. Large-scale demonstration trials in commercial orchards supported these findings. The inhibitory
effects of tank mixes on decay development in detached fruits, and on moldy-core in the field indicate that a control programme
based on mixtures of either bromuconazole or difenoconazole with captan during the bloom period can effectively reduce moldy-core
on Red Delicious apples. 相似文献
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The effect of various fungicides on Glomerella cingulata, the causal agent of a serious rot of olive fruits, was evaluated both in vitro and in the field. The following fungicides were tested: copper oxychloride, Bordeaux mixture, ziram, myclobutanil, hexaconazole, metiram, bitertanol and benomyl. Field trials were carried out in Calabria (southern Italy) for 2 years on two olive cultivars, Ottobratica (susceptible) and Sinopolese (resistant). The minimum effective concentrations of bitertanol, hexaconazole, myclobutanil, benomyl, metiram, ziram, and copper oxychloride on mycelial growth in vitro were < 5, < 50, < 50, < 1000, < 1000, < 1000, < 1000 μg ml?1, respectively. The ED90 values for conidial germination were 0.01, 0.02, 50, 50, 1000, 1000, and 1000 μg ml?1 of benomyl, ziram, myclobutanil, copper oxychloride, bitertanol, hexaconazole and metiram, respectively. In field trials, Bordeaux mixture and copper oxychloride proved to be the most effective products; however ziram, myclobutanil, bitertanol, metiram, and hexaconazole reduced the incidence of fruit rot significantly. 相似文献
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稻瘟是全国性的水稻病害,近年来在东北地区随着水稻生产的提高而加重危害,特别是1953及1954两年在东北南部移栽地区危害很重,局部地方个别田块,甚至颗粒不收,已经成为东北水稻生产上急待解决的主要问题之一。 相似文献
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对柑桔溃疡病苗化学治疗试验结果指出:病苗在1000～2000单位/毫升链霉素+1:100酒精的混合药液中浸1～3小时,便能把病苗治好。处理过的果苗,生长仍然良好。病苗在1:1000～1500的升汞水+1:100酒精的混合药液中1～3小时,也有同样的治疗效果,但苗木生长略差,死亡率略高。用链霉素、升汞水或波尔多液喷射经剪掉病枝叶,或不剪掉病枝叶的病苗,均不能把病苗完全肃清。对柑桔溃疡病的防治,许多国家(如南非、美国等),认为只有毁灭病株,才有可能彻底消灭病原。有时病菌能潜伏数年,如南非有一果园在1918年毁灭病株,1924年重种,当年又发生病害。因此,毁灭病株后,需要连续数年检查,证实无病,才能复种。 相似文献
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Cazorla FM Arrebola E Sesma A Pérez-García A Codina JC Murillo J de Vicente A 《Phytopathology》2002,92(8):909-916
ABSTRACT Bacterial apical necrosis of mango, elicited by Pseudomonas syringae pv. syringae, limits fruit production in southern Spain and Portugal. Examination of a collection of P. syringae pv. syringae isolates for copper resistance showed that 59% were resistant to cupric sulfate. The survey of a mango orchard revealed an increase in frequencies of copper-resistant bacteria after repeated treatments with Bordeaux mixture. These data suggest that selection of copper-resistant strains could be a major reason for control failures following management with copper bactericides. Most copper-resistant isolates harbored plasmids, although the majority of them contained a 62-kb plasmid that also was present in copper-sensitive strains. The 62-kb plasmids were differentiated by restriction enzyme analysis and hybridization to copABCD DNA. The most frequently found copper-resistant plasmid type (62.1) was transferable by conjugation. Southern blot hybridizations showed that genetic determinants partially homologous to copABCD were present in all the copper-resistant strains examined, and usually were associated with plasmids; these determinants were not detected in copper-sensitive strains. The selective pressure exerted by copper bactericide sprays on the diversity of copper resistance determinants in bacterial populations of mango is discussed. 相似文献
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性信息素迷向丝对不同果树梨小食心虫的防控效果 总被引：1，自引：0，他引：1
2017年在宁夏果园开展了性信息素迷向丝(北京中捷四方生物科技公司生产的长效迷向丝,有效成分占30%)对为害不同果树的梨小食心虫的防控效果研究。试验地共5.5 hm~2,栽植有成龄苹果树、梨树和李树。试验区按树种设置3个处理区,3个对照区。处理区在边缘区域每株树平均悬挂3条迷向丝,内部区域隔树悬挂,每树悬挂1条迷向丝,悬挂高度为距离地面2 m。调查各树种全年诱蛾量、诱蛾下降率、蛀果率等指标,研究迷向丝对不同果树上梨小食心虫的防控效果,分析苹果、梨和李树分区域集中栽培下梨小食心虫为害特点。研究结果显示:3个处理区的诱蛾下降率均达96%以上,果实膨大期蛀果下降率均达50%以上,成熟期蛀果下降率均达57%以上,说明性信息素迷向丝对3种果树区域的梨小食心虫防控效果明显且稳定;不同果树区域梨小食心虫发生高峰期一致;梨园中诱捕的梨小食心虫成虫最多,说明其具有寄主选择性;李园蛀果率明显高于苹果园和梨园,李果实成熟采摘后成虫诱捕量减少,同时期苹果园与梨园成虫诱捕量增加,说明梨小食心虫具有迁移为害特性。 相似文献
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1985年在广西隆安县从未施过Bt菌剂的柑桔园中喷洒Bt菌剂(Bt5a5b).1986年对该园的土壤和柑桔叶片取样分析,结果表明,施菌区土壤及叶片的Bt(H5a5b)检出率均高于不施菌剂的对照区。1987年检测果园的鳞翅目害虫,施菌区活虫的Bt检出率为51.4％,其中Bt(H5a5b) 占60.2％,死虫的Bt检出率为81.3％,其中Bt(H5a5b)占67.1％。对照区活虫Bt检出率为20.5％,其中Bt(H5a5b)占34.3％,死虫的Bt检出率为35.7％,其中Bt(H5a5b)占10％。说明施用菌剂两年后,果园中仍残留一定量的Bt,对害虫有致死的作用。 相似文献