玉米重大病虫害发生动态及未来发生趋势

2012年7月下旬以来。北方玉米主产区出现了较大范围降雨，天气条件对玉米中后期病虫害发生流行极为有利。大斑病、褐斑病等叶部病害为害突出．大斑病在华北和东北大发生态势明显．粘虫和玉米螟发生范围明显扩大。顶腐病和矮花叶病等病虫在部分地区为害加重。据国家气候中心预测，2012年8月份。东北大部、内蒙古中东部、华北、黄淮大部、西北东部、西南中北部降水较常年偏多，特别是吉林东南部、辽宁大部、河北大部、北京、天津、山东北部、四川西部偏多2-5成，未来天气对大斑病、茎腐病、穗腐病、玉米螟和粘虫等病虫害发生依然十分有利。大斑病在东北和华北北部春玉米区大流行、粘虫在局部地区集中为害的风险极高，茎腐病在华北、东北、西北、黄淮春、夏玉米区，穗腐病在黄淮和西南夏玉米区有偏重发生的可能；局部地区降水偏少、气温偏高。有利于玉米叶螨、双斑萤叶甲、矮花叶病等喜旱性病虫的发生。     

甘肃天水玉米病虫害发生种类及发生程度调查

2015 — 2017年连续3 a的系统调查表明,天水地区危害玉米的病虫害有15目19科31种,其中以玉米螟、玉米蚜、玉米大斑病、黏虫、玉米锈病、玉米小斑病和玉米瘤黑粉病为害最严重。玉米病虫害的发生时期、发生程度等与病虫害基数、温度、湿度、降水量因子相关。防治应以玉米螟、玉米蚜、玉米大斑病、玉米小斑病为重点。     

南繁玉米常见植保问题及措施

我国90%的玉米育种专家冬季都要在海南开展南繁工作,而南繁玉米容易遭受病虫害、草害、鼠害、气象灾害等,严重影响育种工作。介绍南繁玉米常发生的病害(玉米小斑病、南方锈病、苗期根腐病、细菌性茎腐病、茎腐病、穗腐病、线虫病)、虫害(蚜虫、甜菜夜蛾、苜蓿夜蛾、玉米螟)、鼠害、各种药害、草害、气象灾害、低温冷害的典型症状、发生原因及防治措施。     

桂西南地区辣木病虫害的主要表现及防治措施

受气候、栽培因素等影响,辣木极易发生病虫害,其中红蜘蛛、斑潜蝇、螟类、根腐病、果腐病及落叶病等病虫害对辣木的为害十分严重,如何防治病虫害成为辣木种植一大难题。基于此,介绍了桂西南地区辣木病虫害的主要表现,并通过合理种植、科学修剪、化学药剂施用和保护虫害天敌等措施进行病虫害防治。     

天水市冬油菜病虫害发生情况调查分析

为了加强甘肃省天水市冬油菜病虫害绿色防控,全面了解、掌握冬油菜病虫害发生种类、严重程度、为害特点等,天水市植保技术人员(市县植保部门)开展了冬油菜病虫害调查研究。调查结果表明:1)天水市为害冬油菜的病虫害有15目25科32种,以油菜菌核病、油菜霜霉病、油菜病毒病、油菜白锈病、油菜蚜虫、小菜蛾、油菜黑缝叶甲、油菜蓝跳甲、黄曲条跳甲为害最严重。2)油菜病虫害的发生时期、发生程度等与病虫越冬基数、温度、湿度、降雨量等因子相关。3)病虫害的防治应以油菜菌核病、油菜霜霉病、油菜蚜虫、小菜蛾为重点。     

浅谈玉米病虫害的综合防治技术

概述玉米在不同生长时期极易发生的病虫害及防治手段,并介绍玉米科学管水,合理施肥、施药的技术措施,讨论了玉米纹枯病、大斑病、小斑病、锈病和茎腐病常见病虫害的综合防治措施。     

潼南县玉米病虫草害种类及发生为害特点研究

2010—2012年,在重庆市潼南县的3个镇9个村开展了针对玉米有害生物的调查。结果表明,潼南县境内有玉米病害16种、虫害7种、草害67种。发生为害表现出玉米病虫草害种类多、玉米病虫草害发生面广、不同地理区域病虫草害种类及发生为害差别大等特点。建议病虫害主要防治地老虎、玉米螟、纹枯病、大小斑病、丝黑穗病及青枯病等,草害控防应在药剂防治的基础上加大人工除草的力度。     

早熟玉米新品种酒166选育报告

酒166是以自选系酒071为母本,以外引系701为父本组配而成的玉米新品种。2014 — 2015年在甘肃省玉米新品种早熟组区域试验中,酒166有9点(次)增产,2点(次)减产;2 a 11点(次)平均折合产量 10 440.0 kg/hm2,较对照品种金穗3号增产10.13%。2016年在甘肃省玉米新品种早熟组生产试验中,酒166平均折合产量9 367.5 kg/hm2,比对照品种金穗3号增产11.4%。酒166籽粒含粗蛋白93.3 g/kg、粗脂肪42.5 g/kg、粗淀粉736.2 g/kg、赖氨酸2.9 g/kg。抗轮枝镰孢穗腐病,中抗禾谷镰孢茎腐病,中抗红叶病。适宜在甘肃省高海拔早熟春玉米区种植。     

番茄筋腐病的识别与防治

番茄筋腐病又称条腐病或带腐病,主要危害番茄果实.近几年在重庆市万州区普遍发生,特别足九池乡黄梅村发生较重,如果不及时预防,将给菜农带来较大的经济损失,甚至绝收.现将番茄筋腐病的防治方法介绍如下.     

中晚熟玉米新品种酒623选育报告

酒623是以外引系6H为母本、自育系酒23为父本选育而成的中晚熟玉米新品种。在2014 — 2015年甘肃省中晚熟高密A组玉米区域试验中,2 a10点(次)平均折合产量16 402.5 kg/hm2,比对照品种先玉335增产6.6%。在2016年甘肃省中晚熟高密A组玉米生产试验中,5点平均折合产量15 406.5 kg/hm2,比对照品种先玉335增产4.6%。酒623抗穗腐病、丝黑穗病和瘤黑粉病,中抗茎基腐病和矮花叶病。籽粒含粗蛋白8.26%、粗脂肪3.61%、粗淀粉74.51%、赖氨酸0.21%。适宜在甘肃省中晚熟水地春玉米区种植。     

Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey

Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg^‐1 (mean 7.79 mg kg^‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg^‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg^‐1 (mean 166.5 mg kg^‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg^‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used.     

Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition

Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl₂)] and Se [0, 3, and 7 µM sodium selenite (Na₂SeO₃)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions.     

红壤区不同肥力水稻土根际硝化作用特征

通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。     

自由基在鸡肾病发生中的作用研究

肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据.     

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO₂ and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.     

Meta-analysis in the Selection of Groups in Varieties of Citrus

Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management.     

Effect of iron-quercetin complex on reduction of nitrite in in vitro and in vivo systems

This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions.     

旱地果园水肥管理模式研究进展

分析了旱地果园水肥管理模式的研究进展和存在问题,指出水肥胁迫尤其是水钾已成为旱区果树高产稳产优质化的主要限制因子。在系统探讨旱地果园水分管理、养分管理、综合管理以及果树叶营养综合诊断施肥标准的基础上,提出了旱地果园的高效水肥管理模式。     

Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs

The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance.     

东北黑土土壤磷的纬向分异

以中国东北的中纬度黑土区为样带,研究了有机磷浓度与有机质、全氮浓度的关系;全磷、有机磷、无机磷及有机磷和无机磷的比率与纬度分布的关系。结果表明,有机磷和有机质、全氮浓度具有良好的相关性,它们之间的相关系数分别为0.90和0.92,呈极显著正相关(P<0.01)。全磷、有机磷、无机磷、P_o/P_i在纬度上都存在不同程度的分异规律,即随着纬度的升高,其浓度或比率均有逐渐升高的趋势;其相关系数分别为0.68、0.77、0.26和0.60,相关分析表明,这些纬向分异规律都达极显著水平(P<0.01)。除了无机磷的纬向分异原因尚不明确之外,其他纬向分异的原因可能是由于黑土南北样带气候热量上的差异和人类活动的影响所致,从而造成南北样带之间有机质的矿化程度和速率产生差异。