Field Control Effects and Crop Safety Assessment of Triazole Fungicides on Apple Rust

In order to provide a reference basis for efficient prevention and control of apple rust,apple rust(Gymnosporangium yamadai)was used as the test material,the field control effects of six triazole fungicides with different concentrations and different application times on apple rust,and the safety of application in different periods on the crop were investigated in field trials.The results showed that the control effect and safety of myclobutanil were excellent.In the prevention test,the effects of myclobutanil 40%EC 2000 times and 4000 times dilutions in protecting apple leaves from G.yamadai infection reached more than 98%at 10 d after the second spraying in the fruitlet stage,and in the treatment test,the control effects of inhibiting the spread of leaf lesions were 90.89%and 87.17%at 16 d after the fourth spraying in the fruit expansion stage,respectively.The results of the crop safety test showed that when applying the triazole fungicides with different concentrations from the red bud stage to the fruit expansion stage of apple trees,there were no adverse effects on the leaves,branches,flowers and fruit,as well as no rust or deformity on the fruit surface.When spraying the fungicides from the red bud stage to the fruit expansion stage,except that the single fruit weights in the treatment of the 10%difenoconazole DC 2000 times and myclobutanil 40%EC 4000 times dilutions were reduced without a significant difference from the control,and the values of other treatments were all reduced by more than 9%compared with the control.When applying the fungicides during the fruit expansion period,none of the tested fungicide treatments had a significant effect on the fruit growth.

Control Effects of Bacillus subtilis DJ-6 and Pyraclostrobin Alone and in Combination Against Fusarium oxysporum

[Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 and pyraclostrobin alone or in combination at five ratios against Fusarium oxysporum were detected by mea-suring mycelium growth rate in laboratory tests. The growth promotion and disease control effect of combined or single use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000, 1∶2 000 and 1∶3 000 dilutions were detected in field trials. [Result] The EC50 values of combined use of B. subtilis DJ-6 and pyra-clostrobin at ratios of 1∶1, 1∶2, 1∶3, 1∶4 and 1∶5 against F. oxysporum were 5.311 5, 4.008 6, 3.570 6, 3.350 9 and 3.218 9 μg/ml, with the synergistic ratios （SR） of 2.28, 1.77, 1.53, 1.64, 1.11, among which the synergetic effect at 1∶1 was the best. The fungicidal activity of pyraclostrobin was greater than that of B. subtilis DJ-6 in laboratory tests. Field trials revealed that al the 1∶1 000, 1∶2 000 and 1∶3 000 dilu-tions of 20% pyraclostrobin·2×1011 cfu/g B. subtilis DJ-6 WP in combination, 1∶1 000 dilution of 1 ×1012 cfu/g B. subtilis DJ-6 WP and 1∶2 000 dilution of 250 g/L pyra-clostrobin EC promoted the growth of strawberry by increasing plant height, leaf petiole, leaf blade area and stem diameter. Among them, the treatments with 1∶1 000 and 1∶2 000 of 20% pyraclostrobin · 2×1011 cfu/g B. subtilis DJ-6 WP in combina-tion had better effects than other treatments. The control effects of al the treat-ments were measured 30 and 80 d after fungicide application. The control effects of 1∶1 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combina-tion were up to 100% and 93.11%, which were higher than those in al other treat-ments. The second highest control effects were found in the treatment with 1∶ 2 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination, they were 92.49% and 86.49%, higher than those in other treatments except the 1∶1 000 dilution of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 in combination. The control effects of 1∶3 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination were 82.61% and 72.42%, higher than those in treatment with 1∶1 000 dilution of 1×1012 cfu/g B. subtilis DJ-6 WP, but lower than those in treat-ment with 1∶2 000 dilution of 25% pyraclostrobin EC. [Conclusion] Al the results re-vealed that the combination use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000 to 1∶2 000 dilution had better control effect against strawberry Fusarium wilt.

Oscillation of Dzyaloshinskii–Moriya interaction driven by weak electric fields

Dzyaloshinskii–Moriya interaction(DMI) is under extensive investigation considering its crucial status in chiral magnetic orders, such as Néel-type domain wall(DW) and skyrmions. It has been reported that the interfacial DMI originating from Rashba spin–orbit coupling(SOC) can be linearly tuned with strong external electric fields. In this work, we experimentally demonstrate that the strength of DMI exhibits rapid fluctuations, ranging from 10% to 30% of its original value, as a function of applied electric fields in Pt/Co/MgO heterostructures within the small field regime(< 10-2V/nm). Brillouin light scattering(BLS) experiments have been performed to measure DMI, and first-principles calculations show agreement with this observation, which can be explained by the variation in orbital hybridization at the Co/MgO interface in response to the weak electric fields. Our results on voltage control of DMI(VCDMI) suggest that research related to the voltage control of magnetic anisotropy for spin–orbit torque or the motion control of skyrmions might also have to consider the role of the external electric field on DMI as small voltages are generally used for the magnetoresistance detection.

Monolithic integration of an AlGaN/GaN metal-insulator field-effect transistor with an ultra-low voltage-drop diode for self-protection

In this paper, we present a monolithic integration of a self-protected AlGaN/GaN metal-insulator field-effect transistor （MISFET）. An integrated field-controlled diode on the drain side of the AlGaN/GaN MISFET features a self- protected function for a reverse bias. This diode takes advantage of the recessed-barrier enhancement-mode technique to realize an ultra-low voltage drop and a low turn-ON voltage. In the smart monolithic integration, this integrated diode can block a reverse bias （〉 70 V/μm） and suppress the leakage current （〈 5 × 10-11 A/mm）. Compared with conventional monolithic integration, the numerical results show that the MISET integrated with a field-controlled diode leads to a good performance for smart power integration. And the power loss is lower than 50% in conduction without forward current degeneration.

Preparation of 55% MCPA-isooctyl and Ametryn EC and Its Field Efficacy

[ Objective] The purpose was to supply experimental base for preparing new types of high efficient and safe mixture herbicide for sugarcane field. [ Method ] The associated function of MCPA-isooctyl and ametryn on Digitaria sanguinalis and Celosia argentea was evaluated by co-tox. icity coefficient method by potting experiment. [ Result] When active ingredient of MCPA-isooctyl and ametryn was mixed in the proportion of 9： 5, there was obvious synergistic effect on D. sanguinalis and C. argentea, while the co-toxicity coefficients reached 156.24 and 140.40. Proportion method and bisection method were used to confirm the optimum proportion of various ingredients in mixture of MCPA-isooctyl and ametryn, and the optimum proportion was as follows： 35.4% MCPA-isooctyl, 19.6% ametryn, 10.0% emulsifier and the rest were solvents. The stability test indicated that each index of this EC was consistent with standard for pesticide EC. Field efficacy test of 55% MCPA-isooctyl and ametryn EC showed that most weeds in sugarcane field could be effectively controlled with the dose range of 1 073 -2 310 g （a. i. ）/hm^2. [ Conclusion ] Mixture product of ametryn and MCPA-isooctyl with high content was successfully developed, which had the advantages including high efficiency, broad spectrum, good economy and convenient utilization, etc.

480g/L异[口恶]草松EC对水稻田千金子的田间防除效果评价

为明确480 g/L异[口恶]草松EC对水稻田千金子的田间防除效果,采用田间药效试验方法评价了其在田间的综合表现,旨在为水稻田千金子防除提供解决思路。结果表明,480 g/L异[口恶]草松EC在使用剂量为40、50、60、70 m L/667m^(2)时,其对水稻田千金子防除效果较好,药后30 d千金子株防效及鲜重防效均可达80%以上,且对作物安全,优于20%氰氟草酯EC、10%[口恶]唑酰草胺EC、5%五氟磺草胺SC和25%二氯喹啉酸SC。建议以60 m L/667m^(2)的推荐剂量于杂草分蘖前均匀喷雾。

两种药剂组合防治多斑柞跳象的田间药效试验

为有效防控柞园害虫多斑柞跳象,在小区试验基础上进行田间药效试验。结果表明,“蚕敌一扫光+乐果”对潜叶幼虫有较好的防效,可达90%左右;“敌克+敌克1号”“蚕敌一扫光+乐果”对当代成虫均有较好的防效。柞园防治多斑柞跳象可根据柞园实际情况选择药剂组合,潜叶幼虫期无蚕柞园推荐使用“蚕敌一扫光+乐果”组合;当代成虫期无蚕柞园用“蚕敌一扫光+乐果”,有蚕柞园用“敌克+敌克1号”进行防治。

哈茨木霉和地衣芽孢杆菌对梨锈病的田间防治效果

为明确哈茨木霉和地衣芽孢杆菌对梨锈病的田间防治效果,选择1×10^(9) cfu/g哈茨木霉可湿性粉剂(WP)、2×10^(8) cfu/g地衣芽孢杆菌可湿性粉剂(WP)、35%咪鲜胺·乙蒜素可溶液剂(SL)、20%苯醚甲环唑水乳剂(EW)、25%吡唑醚菌酯悬浮剂(SC)开展田间药效试验。结果表明,1×10^(9) cfu/g哈茨木霉可湿性粉剂300倍液和2×10^(8) cfu/g地衣芽孢杆菌可湿性粉剂600倍液对梨锈病的病斑大小及锈孢子器的形成均具有显著的抑制作用。哈茨木霉、地衣芽孢杆菌施药后30 d,梨锈病的病斑直径较对照分别减小41.2%、30.9%;形成锈孢子器的病斑数量较对照分别减少50.0%、44.9%。2022、2023年哈茨木霉对梨锈病施药后15 d的防效分别为46.7%、73.3%,施药后30 d的防效分别为59.3%、71.9%;地衣芽孢杆菌对梨锈病施药后15 d的防效分别为54.7%、60.1%,施药后30 d的防效分别为61.7%、62.4%。试验结果表明,哈茨木霉和地衣芽孢杆菌对梨锈病均具有较好的防治效果,为充分发挥药效,建议在发病前或发病初期使用。

霍尔效应实验教学设计及内容拓展探索

从霍尔效应的发现及历史发展出发,介绍了磁感应强度、载流子浓度及迁移率的测量原理,进而拓展引入了前沿科学研究内容——光场调控霍尔效应及动力学演化过程。教学内容由浅入深、由古及今,引发学生的思考,拓宽学生的视野,使学生对霍尔效应有一个全面的认识,为培养追求卓越、引领未来的领军人才奠定基础。

植保无人机喷施封闭除草剂对稻田杂草的防效研究

为探究植保无人机喷施除草剂对直播稻田杂草防效,采用50%丁草胺乳油、26%噁草酮悬浮剂、350 g/L异噁草松微囊悬浮剂、300 g/L丙草胺乳油4种封闭除草剂,在飞行高度2 m和3 m,用水量22.5、45.0 L/hm^(2)条件下设置不同处理,考察播前施药结合水层管理及播后干封对水稻安全性及对直播稻田不同种类杂草的防除效果。结果表明,26%噁草酮悬浮剂2个用水量处理的成苗率和苗高显著低于其余处理,播后30 d各处理水稻分蘖数均显著高于空白对照,各处理5株苗茎基宽与空白对照无差异。药后15 d,3种除草剂供试浓度下高用水量处理对稗草、千金子、多花水苋、异型莎草等杂草的防效均优于低用水量;播前水封与播后干封效果整体上差异不大。药后40 d,整体上各处理防效均降低,26%噁草酮悬浮剂、350 g/L异噁草松微囊悬浮剂在高用水量时对稗草的株数防效显著优于低用水量,3种药剂在高用水量时对千金子的株数防效均显著高于低用水量,鲜重防效与株数防效趋势基本一致。3种药剂不同飞防参数下对异型莎草和多花水苋的防效有差异,且效果较差。同一药剂在用水量45 L/hm^(2)和飞行高度3 m时对不同杂草的防效优于用水量22.5 L/hm^(2)和飞行高度2 m处理。不同除草剂对不同种类杂草的防效存在差异,高用水量播前施药结合水层管理对不同杂草的防效均优于播后干封处理。后期应适时进行茎叶处理,以提升施药对田间杂草的治理效果。

释放烟蚜茧蜂防治烟田烟蚜的生态效应评估技术

【目的】建立烟田规模化释放烟蚜茧蜂生物防治烟蚜的生态效应评价技术,为规模化释放天敌昆虫生物防治害虫的生态安全性评估提供科学依据。【方法】以2016—2017年云南省保山市隆阳区和大理白族自治州弥渡县长年释放烟蚜茧蜂防治烟蚜的烟田和未释放烟蚜茧蜂的烟田为试验地,系统开展释放烟蚜茧蜂烟田生物多样性指标分析及烟农问卷调查,筛选生态效应评价指标,构建基于层次分析法的释放烟蚜茧蜂防治烟蚜生态效应评价模型。【结果】构建了基于释放烟蚜茧蜂对烟田生物多样性的影响、对其他种类蚜茧蜂及蚜虫天敌的影响、烟蚜茧蜂的适生性/适应力、定殖可能性、存在可能性、对人畜健康及植物安全的影响、蚜茧蜂种群扩散与建立的可能性共计7个目标层、19个准则层和76个指标层构成的规模化释放烟蚜茧蜂防治烟蚜的生态效应评估技术及模型。应用该模型计算的2016年弥渡县和隆阳区烟田释放烟蚜茧蜂的生态效应值分别为2.65和2.51;2017年两地烟区释放烟蚜茧蜂烟田的生态安全值分别为2.56和2.50,与2016年的生态效应评价结果一致。【结论】本研究构建的模型可用于烟田释放烟蚜茧蜂防治烟蚜的生态效应评估。

不同土壤处理除草剂对棉田杂草防除效果及安全性

为筛选出适宜本地区土壤处理的除草剂。通过大田小区试验,采用土壤封闭处理,对比分析了7种土壤处理除草剂对棉花安全性和杂草防除的效果。结果显示,与对照相比,不同药剂处理对‘冈棉11号’出苗率和第一果枝结位均没有显著性差异,但鲜重、株高和果枝数有增加趋势,表明试验药剂对棉花安全。田间药效结果显示,复配剂50%扑草净可湿性粉剂(WP)+33%二甲戊灵乳油(EC)、50%扑草净WP+960 g/L精异丙甲草胺EC和50%扑草净WP+50%乙草胺EC对禾本科和阔叶杂草均具有较好防效,45 d平均鲜重防效分别为83.32%、84.08%、80.57%,与单剂处理均存在极显著差异,且持效期较长,建议3种复配剂作为土壤处理除草剂用于棉田杂草防除。

5种除草剂对宁夏入侵生物刺苍耳的防控效果初探

本研究旨在筛选出适合在宁夏地区防控刺苍耳的除草剂,通过田间试验测定了2-甲基-4-氯二甲胺盐、氯氟吡氧乙酸、苯嘧·草甘膦、硝磺草酮、苯唑草酮5种除草剂对刺苍耳的株防效和鲜重防效。通过单因素方差分析及差异显著性检验,统计株防效。研究结果显示,在5种除草剂中,60%2-甲基-4-氯二甲胺盐AS 750 mL/hm^(2)、200 g/L氯氟吡氧乙酸EC 900 mL/hm^(2)、40%苯嘧·草甘膦OD 1500 mL/hm^(2)对刺苍耳防效显著,21 d防效分别为96.62%、98.31%、100%;鲜重防效结果显示,200 g/L氯氟吡氧乙酸EC 900 mL/hm^(2)、40%苯嘧·草甘膦OD 1500 mL/hm^(2)防控效果最好,21 d防效分别为93.94%、100%。综合以上防效结合作物种类,在荒地、林地、沟渠等防除刺苍耳,可选择灭生性除草剂苯嘧·草甘膦,在小麦、玉米等禾本科作物田防除刺苍耳,可优先选用氯氟吡氧乙酸类除草剂。本研究解过为筛选出高效防除药剂,及刺苍耳的防除提供了理论依据与数据支持。

生防菌对芒果叶部炭疽病的生防效果研究

生物防治是芒果胶孢炭疽病防控的主要措施之一。为了系统性评价生防菌的防控效果,为生防菌剂的生产应用提供指导,本文采用离体叶片针刺法,室内评价了18种生防菌对‘贵妃’‘台农1号’两个芒果主栽品种叶部炭疽病的防护、治疗和兼防兼治效果。结果表明,生防菌对两个主栽品种的芒果叶部病害的防效具有一致性,18种生防菌均具有防护、治疗和兼防兼治的作用,其中对‘贵妃’芒果效果较好的是S8(蜡质芽孢杆菌菌剂)、S3(枯草芽孢杆菌菌剂),对‘台农1号’芒果效果最好的是S3;田间防治芒果叶部炭疽病试验表明,S8、S9(枯草·纳豆·地衣芽孢杆菌·硝化细菌)效果较好,防效超过90%,可以应用于芒果叶部胶孢炭疽病的生物防治中。

9.5%丙嗪嘧磺隆悬浮剂对移栽水稻田稗草和鸭舌草的防效及安全性研究

2020和2021年在江西省南昌市进行了9.5%丙嗪嘧磺隆SC在15~60 g a.i./hm^(2)处理下及对照药(苄嘧磺隆和五氟磺草胺)的大田杂草防效试验,并评估其对水稻安全性和产量的影响。结果表明,9.5%丙嗪嘧磺隆SC对移栽水稻田稗草和鸭舌草均具有良好的防除效果,60 g a.i./hm^(2)剂量处理后,对稗草的株防效高达92.40%~98.91%,对鸭舌草的株防效为82.62%~89.15%。所有处理对水稻均无药害产生,并实现增产。因此,新型除草剂丙嗪嘧磺隆可有效防除移栽水稻田稗草和鸭舌草,有较好的应用价值。

多种药剂对豇豆蚜虫田间防治效果比较

为寻找高效安全药剂用以防治豇豆蚜虫,保障豇豆质量安全和农户种植效益,2023年开展了豇豆蚜虫田间药剂筛选试验。对比分析表明:防治豇豆蚜虫以10%啶虫脒可湿性粉剂300 g/hm2处理的速效性最好,药后1 d的平均防效可达82.32%;其次是50%氟啶虫酰胺水分散粒剂150 g/hm2处理;速效性最差的是60%吡蚜酮水分散粒剂180 g/hm2处理,药后1 d的平均防效仅为21.97%。4种供试药剂处理的持效期均较长,药后10 d、15 d的平均防效均保持在99%以上。

滴灌条件下诱抗剂对向日葵列当田间防治效果的研究

【目的】探究施用植物诱抗剂对田间向日葵列当的防治效果,为综合防控列当提供新思路。【方法】利用滴灌系统田间施用锦苗标靶、甲壳素枯草芽孢杆菌、锦苗标靶与甲壳素枯草芽孢杆菌混合及清水(CK),在4个不同调查时间点(7月20日、8月10日、8月15日、9月30日)调查内蒙古乌兰察布市四子王旗、包头市固阳县的向日葵列当寄生率和寄生程度,研究两种植物诱抗剂对列当寄生向日葵生产指标和产量的影响。【结果】滴灌锦苗标靶,两地向日葵列当寄生程度与CK相比均显著降低(P<0.05),分别降低2.95、6.27、3.97与1.11、4.99、4.08;两地向日葵株高和产量均显著增加(P<0.05),株高分别增加39.15、36.97、20.66、22.50 cm,产量分别增加892.80、984.00 kg/hm^(2)。滴灌甲壳素枯草芽孢杆菌,列当寄生程度在不同调查时间点与CK相比都显著增加(P<0.05),两地寄生程度分别增加5.71、3.77、1.91与1.36、14.12、13.03,向日葵各项生长指标与CK相比无显著差异(P>0.05)。锦苗标靶与甲壳素枯草芽孢杆菌混合滴灌,两地列当寄生率和寄生程度与CK相比均显著降低(P<0.05),寄生率分别降低79.60%、31.80%、19.00%与36.67%、81.00%、35.67%,寄生程度分别降低7.25%、9.69%、8.80%与1.33%、6.01%、5.61%;向日葵株高、花盘直径和产量与CK相比均显著增加(P<0.05),株高分别增加23.08、33.49与14.08、11.33 cm,花盘直径分别增加6.18、4.44 cm,产量分别增加796.80、835.20 kg/hm^(2)。【结论】锦苗标靶和滴灌相结合能够作为一项措施整合到向日葵列当绿色防控技术体系中对列当进行有效防控。

5种杀虫剂对温室番茄烟粉虱的药效试验

烟粉虱为刺吸性害虫,其繁殖能力强、种群数量庞大,群聚为害,叠代发生,在北京温室严重为害番茄。为此,选用5种杀虫剂对温室番茄烟粉虱开展田间药效试验。试验结果表明,各处理在药后1、3、7 d的校正防效分别为55.41%~74.94%、73.63%~90.28%、84.12%~96.03%,有逐步提升的趋势,说明各处理药剂的持效性与稳定性未衰减。药后7 d,5种杀虫剂均表现出良好的防效,其中,22%螺虫·噻虫啉悬浮剂和20%呋虫胺可溶性粉剂的防效最好,分别为96.03%和91.96%,显著高于其他处理。

氟啶虫酰胺复配剂对烟粉虱田间防治方案探索

为了明确氟啶虫酰胺复配制剂对烟粉虱的防治效果,为其生产应用提供理论依据,2022年7—9月在杭州市参照田间药效试验准则,进行了相关田间药效试验。试验表明,24%阿维·氟啶悬浮剂(SC)750~1 000倍液混用助剂(冬青油)300~500倍液可以有效防治茄子、番薯的烟粉虱(成虫、若虫、卵);高虫口密度下不建议使用22%氟啶·氟啶脲SC 750倍液混用助剂300倍液防治番薯烟粉虱(成虫、卵)。24%阿维·氟啶SC混用助剂是一种理想的烟粉虱防治方案,具有较好的应用与推广价值。

0.15%噻呋酰胺颗粒剂防治小麦纹枯病田间效果试验

小麦纹枯病是一种土传病害,防治难度较大,在我国黄淮海麦区有逐年加重发生的趋势。本文以目前常用药剂作为对照药剂,小麦播种量为150 kg/hm^(2),研究了0.15%噻呋酰胺颗粒剂(载体中氮-磷-钾为18-12-10)作底肥撒施对小麦纹枯病的田间防效。结果表明,与25 g/L咯菌腈悬浮种衣剂300 mL/hm^(2)、60 g/L戊唑醇悬浮种衣剂225 mL/hm^(2)进行种子处理相比,0.15%噻呋酰胺颗粒剂525 kg/hm^(2)作底肥撒施,在病株防效、病指防效和增产率方面效果相当,均优于3%苯醚甲环唑悬浮种衣剂750 mL/hm^(2)进行种子处理。说明0.15%噻呋酰胺颗粒剂作底肥撒施能有效防治小麦纹枯病,在大田生产中有广阔的应用前景。