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Cold plasma, an ionized gas produced by applying an electrical current to air, can be used to produce plasma-activated water (PAW), which has excellent antimicrobial properties. In this study PAW was applied to conidia of Colletotrichum alienum to investigate its impact on conidial germination in vitro. PAW was produced by treating tap, deionized, or distilled water with cold plasma for 30 or 60 min to produce PAW30 or PAW60, each of which was then incubated for up to 24 hr with a conidial suspension of C. alienum in a ratio of 1:1, 1:2, or 1:3 (conidial suspension:PAW), and the percentage germination measured. The greatest reduction in germination occurred when conidia were incubated with PAW60 produced from deionized water or distilled water, for all ratios. For PAW30, deionized water was the most effective for all three ratios, and on this basis, deionized water was selected for all further experiments. PAW produced from smaller volumes of water and at shorter distances from the cold plasma source was more effective at reducing germination. Treatment of conidia with acidified water was not as effective as PAW at inhibiting germination. Nitrates and nitrites were present in the PAW in varying concentrations and may have contributed to the inhibition of germination. PAW retained activity and reduced germination even after storage for 15 days. These findings demonstrate the potential of PAW as a novel treatment for postharvest fungal pathogens.  相似文献   
3.
Weeds and weed control are major production costs in global agriculture, with increasing challenges associated with herbicide‐based management because of concerns with chemical residue and herbicide resistance. Non‐chemical weed management may address these challenges but requires the ability to differentiate weeds from crops. Harvest is an ideal opportunity for the differentiation of weeds that grow taller than the crop, however, the ability to differentiate late‐season weeds from the crop is unknown. Weed mapping enables farmers to locate weed patches, evaluate the success of previous weed management strategies, and assist with planning for future herbicide applications. The aim of this study was to determine whether weed patches could be differentiated from the crop plants, based on height differences. Field surveys were carried out before crop harvest in 2018 and 2019, where a total of 86 and 105 weedy patches were manually assessed respectively. The results of this study demonstrated that across the 191 assessed weedy patches, in 97% of patches with Avena fatua (wild oat) plants, 86% with Raphanus raphanistrum (wild radish) plants and 92% with Sonchus oleraceus L. (sow thistles) plants it was possible to distinguish the weeds taller than the 95% of the crop plants. Future work should be dedicated to the assessment of the ability of remote sensing methods such as Light Detection and Ranging to detect and map late‐season weed species based on the results from this study on crop and weed height differences.  相似文献   
4.
Juvenile hormone (JH) is an insect-specific hormone that regulates molting and metamorphosis. Hence, JH signaling inhibitors (JHSIs) and activators (JHSAs) can be used as effective insect growth regulators (IGRs) for pest management. In our previous study, we established a high-throughput screening (HTS) system for exploration of novel JHSIs and JHSAs using a Bombyx mori cell line (BmN_JF&AR cells) and succeeded in identifying novel JHSIs from a chemical library. Here, we searched for novel JHSAs using this system. The four-step HTS yielded 10 compounds as candidate JHSAs; some of these compounds showed novel basic structures, whereas the others were composed of a 4-phenoxyphenoxymethyl skeleton, the basic structure of several existing JH analogs (pyriproxyfen and fenoxycarb). Topical application of seven compounds to B. mori larvae significantly prolonged the larval period, suggesting that the identified JHSAs may be promising IGRs targeting the JH signaling pathway.  相似文献   
5.
  【目的】   本研究调查了养分专家系统 (Nutrient Expert, NE) 推荐施肥在西北旱地冬小麦生产上的应用效果,以明确该方法在西北旱地小麦推荐施肥中的可行性。   【方法】   在陕西渭北旱塬两年共布置15个田间试验,所有试验均设置两个处理:养分专家系统推荐施肥 (NE) 和农户习惯施肥 (FP)。在小麦成熟期采集小麦样品和0—100 cm土层土壤样品,测定植株氮磷钾养分含量和土壤硝态氮含量,调查分析小麦产量及其构成要素、经济效益和肥料偏生产力。   【结果】   NE推荐的N施用量平均为158 kg/hm2,较FP处理 (N 192 kg/hm2) 减少了18%;P2O5施用量平均为62 kg/hm2,较FP处理 (134 kg/hm2) 减少了54%;而K2O用量为40 kg/hm2,较FP处理 (28 kg/hm2) 增加了43%。NE处理的冬小麦平均籽粒产量为5171 kg/hm2,与FP处理 (5111 kg/hm2) 籽粒产量接近,经济效益提高了7.8%,氮肥偏生产力提高25.1%,磷肥偏生产力提高了139.8%。与FP相比,NE处理的土壤0—100 cm土层硝态氮残留量无显著差异。   【结论】   相比农户习惯施肥,基于养分专家系统推荐的施肥方案减少了18%的氮肥和54%的磷肥用量,增加了43%的钾肥用量,冬小麦产量保持稳定,氮肥和磷肥的偏生产力和经济效益均显著提升,具有较好的化肥减施和增收效果,可在旱地冬小麦生产中推广应用。  相似文献   
6.
Studies have shown that the three subunits of β-conglycinin are the main potential allergens of soybean sensitive patients.And β-conglycinin has adverse effects on nutrition and food processing.So solation and production of lines with lower β-conglycinin content has been the focus of recent soybean breeding projects.Soybean lines with deficiency in one or all subunits of β-conglycinin have been obtained.An effective and rapid system to identify such mutations will facilitate genetic manipulation of the β-conglycinin subunit composition.Here,two segregating F_2 populations were developed from crosses between Cgy-1/cgy-1 (CC),an α′-lacking line (Δα′),and DongNong 47 (DN47),a wild-type (Wt) Chinese soybean cultivar with normal globulin components,and Cgy-2/cgy-2 (CB),an α-lacking line (Δα),and DN47.These populations were used to estimate linkage among the cgy-1 (conferring α′-null) and cgy-2 (α-null) loci and simple sequence repeat (SSR) markers.Seven SSR markers (Sat_038,Satt243,Sat_307,Sat_109,Sat_231,Sat_108 and Sat_190) were determined to co-segregate with cgy-1,and six SSR markers (Satt650,Satt671,Sat_418,Sat_170,Satt292 and Sat_324) co-segregated with cgy-2.Linkage maps being composed of seven SSR markers and cgy-1 locus,and six SSR markers and the cgy-2 locus were then constructed.It assigned that the cgy-1 gene to chromosome 10 at a position between Sat_307 and Sat_231,and the cgy-2 gene to chromosome 20 at a position between Satt650 and Satt671.These markers should enable map-based cloning of the cgy-1 and cgy-2 genes.For different subunit-deficiency types[α′-null,α-null and (α′+α)-null types],the two sets of SSR markers could also detect of polymorphism between three normal cultivars and seven related mutant lines.The identification of these markers is great significance to the molecular marker-assisted breeding of soybean β-conglycinin subunits.  相似文献   
7.
为积极推进棉花减氮增效,实现农业提质增效和保护农田环境。以鲁棉1131、鲁棉37、鲁棉319、聊棉19为试验材料,设置氮磷钾配比肥施用量为0、225、300和375 kg/hm 2共4个处理,研究施肥用量对棉花农艺性状和产量的影响。结果表明:棉花株高随着施肥量的减少而降低;单株结铃数随着施肥量的减少而减少,而单铃重相反;同一品种衣分各处理间无明显差异;各品种随着施肥量的减少籽棉产量先升高后降低,各个品种均在施肥量225 kg/hm 2下达到最大值;霜前花率和籽棉收益也在施肥量225 kg/hm 2下达到最大值;净收益最高的是不施肥处理。综合认为,在鲁西南地区高肥力蒜套棉地块无需对棉花进行追肥,可为鲁西南地区蒜套棉减肥增效提供数据支撑。  相似文献   
8.
落叶果树冬季进入休眠期,果农田间管理时间长,农事操作方便,而在生产中,不少果农忽视了冬季这个果园管理的关键时期,造成树势衰弱、树形杂乱、病虫害严重。做好落叶果树冬季管理技术措施,对于增强树势,提高翌年果树产量、品质和效益起到关键性的作用。  相似文献   
9.
为探究微润灌溉下不同施肥运筹对大棚番茄生长的影响,将番茄定植于大棚内的种植箱中,设置施肥浓度分别为200 mg/L(N1:全生育期浓度为200 mg/L)、200~400 mg/L(N2:苗期浓度为200 mg/L,结果期、成熟期为400 mg/L)、400 mg/L(N3:全生育期浓度为400 mg/L)、400~800 mg/L(N4:苗期浓度为400 mg/L,结果期、成熟期为800 mg/L)、800 mg/L(N5:全生育期浓度为800 mg/L)5组不同处理,测定番茄全生育期的含水率、茎粗、株高、叶面积、产量及灌溉水分生产率等指标。研究表明:不同施肥浓度各处理土壤含水率差异不显著,N4、N5处理的番茄各项生长指标差异不显著且优于其余处理,说明施肥对土壤含水率影响较小,但随着施肥浓度的增加,番茄的产量及其余生长指标增长明显;施肥浓度前少后多的N4处理番茄长势及产量不弱于N5处理,因此苗期减少施肥、开花坐果期追肥与全生育期保持较高浓度施肥是微润灌溉水肥一体化种植番茄的有效施肥措施。  相似文献   
10.
地膜覆盖与施肥对秸秆碳氮在土壤中固存的影响   总被引:1,自引:0,他引:1  
【目的】作物秸秆不仅含有较高的有机碳,而且含有丰富的矿质营养元素。秸秆还田是东北黑土地区培肥土壤和农业可持续发展的重要技术措施。然而不同地膜覆盖(简称“覆膜”)及施肥方式下秸秆碳(C)和氮(N)在土壤中的固持特征还不是很明确。本研究通过定量分析秸秆碳对土壤有机碳(SOC)和秸秆氮对土壤全氮(TN)的贡献,探讨不同覆膜和施肥条件下秸秆碳和氮在土壤中固定的差异,以期为土壤肥力提升和东北黑土地保护提供依据。【方法】基于覆膜与施肥的长期定位试验,选择覆膜和不覆膜(裸地)栽培条件下不施肥(CK)、单施氮肥(N4)和有机肥配施氮肥(M2N2)处理,在表层(0—20 cm)土壤添加13C15N双标记秸秆后在田间原位培养150 d,测定SOC含量及其δ13C值、TN含量及其δ15N值,分析SOC中秸秆来源C(13C-SOC)、TN中秸秆来源N(15N-TN)和土壤碳氮比随时间的动态变化特征。【结果】施肥、覆膜及其它们的交互作用显著影响(P<0.05)13C-SOC和15N-TN含量。整个培养期间,M2N2处理秸秆碳对SOC的贡献率(13C-SOC/SOC)和秸秆氮对TN贡献率(15N-TN/TN)平均分别为10.48%和3.18%;施肥(N4和M2N2)处理13C-SOC/SOC和秸秆碳残留率在覆膜方式下平均分别为12.65%和37.14%,不覆膜方式下分别为12.08%和34.50%。同一栽培方式培养第150天,N4处理13C-SOC/SOC和秸秆碳残留率平均分别为14.33%和39.40%,其他施肥处理平均分别为11.77%和33.21%;CK处理15N-TN/TN平均为4.56%,分别比N4和M2N2处理高26.00%和44.53%。培养第150天,秸秆氮残留率在覆膜和不覆膜条件下CK处理最高,平均为10.03%;不覆膜N4处理最低,为7.87%。无论覆膜与否,N4处理13C-SOC与15N-TN比值为32—39,其他施肥处理均<30。【结论】秸秆碳氮在土壤中的固存对覆膜与施肥的响应敏感。单施氮肥有利于秸秆碳在土壤中的积累和有机碳的更新,不施肥处理秸秆氮对土壤氮库的固定起正反馈效应,而有机肥配施氮肥土壤碳氮的更新相对滞后。  相似文献   
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