36%"广灭灵"对地膜覆盖烤烟田间杂草的防效

为了有效地防除地膜覆盖的烟田杂草 ,于 2 0 0 0～ 2 0 0 1年进行了 36%“广灭灵”ME 4种用量(15、30、4 5、60mL/ 667m2 )、5 %“敌草胺”WP和清水 (对照 )喷施防除地膜覆盖烤烟田杂草的田间试验。结果表明 ,烟苗移栽大田后 ,喷施 36%“广灭灵”ME 4 5～ 60mL/ 667m2 ,药后 80d对单子叶和双子叶杂草防效均达 96.7%以上 ,而且对烟株无药害     

几种除草剂单剂与混配剂烟田除草效果初报

研究了几种除草剂单剂和混配剂对永定烟田杂草的防除效果。结果表明：广灭灵、广灭灵混配剂、果尔Ⅰ号混配剂对单子叶稗草、马唐、金色狗尾草及双子叶的蓼属、雀舌草、芫姿菊等烟田优势种杂草的防效达９０％以上；果尔、果尔Ⅱ号混配剂对单、双子叶杂草防效均为８０％以上；除草通、阿特拉津对双子叶杂草防效高达９９％，而对单于叶防效较差；敌草胺、地乐胺、拉索３种单剂防效不够理想。     

除草膜防除烤烟地杂草的研究

对除草膜防除烤烟地杂草的效应进行了研究 ,结果表明 :烟苗移栽大田后覆盖除草膜 30天、60天对烟田杂草防除效果为 96.5%～ 98.6% ,其中对禾本科杂草防效为 96.3%～ 98.9%。应用除草膜防除烟地杂草 ,对烟株的生长无不良影响。     

几种防治烟草普通花叶病药剂的田间药效

为给防治烟草普通花叶病的药剂选择提供依据 ,进行了“毒消”6 0 0倍、“病毒必克”5 0 0倍 (药剂 )和氨基酸 30 0倍、“丰农”5 0 0倍 (叶面肥 )田间防效试验。结果表明 ,烟株发病初期开始施药 ,“毒消”6 0 0倍在首次施药后防效达 73.2 4 % ,第 3次施药后各药剂防效下降并在停止施药后 30d病情发生反弹 ;烟株发病中期开始施药 ,首次施药后“病毒必克”5 0 0倍防效达 75 .90 % ,此后各药剂防效均下降 ;氨基酸30 0倍和“丰农”5 0 0倍防效较差     

50%敌草胺可湿性粉剂防除烟田杂草应用技术及药效评价

50 %敌草胺可湿性粉剂是江苏如东农药厂独家开发生产在烟草上获得唯一登记的广谱高效除草剂 ,具有高效、广谱、安全、持效期长的特点 ,经湖南、山东等省科研部门试验 ,防效显著。1　敌草胺的特性1 .1　商品名称　敌草胺1 .2　化学名称　 N,N-二乙基 - 2 - ( 1 -萘基氧 )丙酰胺1 .3　通用名称　napropamide1 .4　作用机理　敌草胺使用后 ,在土壤表面形成药物层 ,通过杂草的芽和叶面吸收 ,从而抑制杂草体内酶的合成 ,阻碍细胞分裂 ,进而使杂草的根芽不能生长而坏死。1 .5　防除对象　可以防除一年生单子叶杂草和许多重要的阔叶杂草 ,如稗草、…     

除草剂、除草膜防除烟田杂草试验

在云南昭通和曲靖进行了烟田除草试验 ,结果表明 ,相对于普通无色地膜覆盖栽培而言 ,除芽通、敌草胺和金都尔除草膜对烟田杂草的相对防除效果分别为 93.8%、6 1.2 %、4 3.7% ,方差分析证明各处理间差异达极显著水平     

甘蔗农业文摘(五)

敌草隆、阿来净防除蔗田杂草试验王长方等，甘蔗，1996，3（3），24～25应用敌草隆、阿来净除蔗田15种杂草，数4量防效在91、7-994%之间。鲜重防效为93、0%－99．8％。播后芽前施药防除禾本科余革效果明显优于苗期茎叶处理，防除种草、千金子效果分别提高16%、387％；但对其余杂草防交差异不明显。苗期施药，阿来净和敌草隆混用对种草的防效均显著高于两个单剂的防效；对千金子的效果也优于两种低浓度的各单效果。混用或播后芽前施药可提高对甘蔗的安全简。马格巴顿钻联甘蔗丐性杂交育种可行性研究—一江鹤基等，甘蔗，柏96，3（3），56～59…     

"高效氯氰菊酯"防治地老虎试验

为选择对地老虎有较好防效的农药,用10%"高效氯氰菊酯"EC(20mL/667m2,结合移栽水法)和90%"敌百虫"(80g/667m2,用毒饵法)将药剂施于烟苗根部周围土壤进行防治地老虎试验。施药后10、15、20、25、30和35d后调查田间烟株的被害情况,结果表明,"高效氯氰菊酯"对地老虎的防治效果较好,对烟草生长没有明显不利的影响。     

甘蔗地喷施几种除草剂防除杂草试验

通过试验结果表明,甘蔗地喷施几种除草剂,喷药后５０天内,对种子萌发的单、双子叶杂草有显著的防除效果,其中乙阿混剂防效９５.３４％,蔗田除草剂防效８８．５％,对多年生杂草有一定防效。试验还表明,芽前或芽后除草剂可根据天气、劳力情况灵活的喷施。甘蔗地喷施几种除草剂防除杂草试验     

化学除草对烟田杂草群落结构的影响

施用除草剂对烟田杂草进行了化学防除试验.结果表明,所用的除草剂均能有效地防除双予叶杂草,如茴茴蒜、西栖蓼和碎米荠等,平均防效均高于88%.随着除草剂的连年使用,引起烟田杂草群落结构的变化,原以茴茴蒜为主的杂草群落,演变为以马唐、稗草、胜红蓟、两栖蓼和茴茴蒜为主的单、双子叶混生杂草群落,并且马唐和稗草的发生量逐年增加.     

铁盐催化比色法测定葡萄籽提取物中的原花青素

建立了葡萄籽提取物中原花青素的测定方法———铁盐催化比色法 ,并探讨了影响催化比色的有关因素。经实验 ,最佳测定条件为 :体系含水量为 3%～ 4 % ,硫酸高铁铵浓度为0 6～ 0 8g/L ,加入 0 5mL浓盐酸使H+ 为 0 6mol/L ,在正丁醇介质中于沸水浴 (99± 1℃ )下反应 4 0min。本法最低检测限为 4 μg ,平均回收率 (n =3)随浓度增加而逐渐下降 ,加入浓度为 5 2 0 0～ 2 0 8 0 μg/mL的原花青素标准液时 ,回收率为 90 6%～ 10 9 5 % ,精密度 (RSD)为 2 13%～ 2 98% ,原花青素浓度在 2 6 0 0～ 4 16 0 μg/mL范围内与吸光值呈线性相关 (r =0 9993) ,符合测定要求。葡萄籽提取物样品经 6次分析 ,平均含量为 99 39% ,RSD为0 4 2 2 %。     

乳酸菌菌种的简便分离和培养

嗜热链球菌和保加利亚杆菌是酸乳制品的常用菌种,因其有共生关系,较难分离。用特殊的培养基如M17和MRS酸化培养基可以将此共生苗分离。本文介绍的培养基同样能起到分离的作用,且成分简单,取材方便。     

Quality changes and storage life of common carp (Cyprinus carpio) at various storage temperatures

The shelf life and freshness changes in pond-grown common carp (Cyprinus carpio L) during storage at 0–2°C, 5–6°C and room temperature (26–29°C) were investigated by sensory, microbiological, physical and chemical analyses. The effect of gutting on the shelf life during storage at 0–2°C was examined. Iodine/starch and potassium sorbate were examined for their effects on shelf life of whole fish stored at 0–2°C and 5–6°C. Sensory results indicated that the whole fish had a maximum shelf life of 24 to 25 days at 0– 2°C. The life of the fish to the point beyond which it would be unsuitable for sale (commercial shelf life) was 17 days at 0–2°C. Storage at 5–6°C shortened shelf life 2- to 2.5-fold. At room temperature (26–29°C), spoilage was evident after 13 h. Gutting the carp shortened its storage potential at 0–2°C. Iodine treatment of this species stored at 0–2°C and at 5–6°C did not extend shelf life. The maximum shelf life of sorbate-treated fish at 0–2°C and 5–6°C was extended by 1–2 days, commercial shelf life by 3–4 days. Total volatile basic nitrogen, pH and penetrometer analyses were not reliable indicators of changes in freshness during shelf life. Thiobarbituric acid values were not useful as rancid odours or flavours were not detected during storage.     

Pregnancy outcomes after change in dose delivery of prostaglandin F2α and time of gonadotropin-releasing hormone injection in a 5-day timed artificial insemination program in lactating dairy cows

We demonstrated that 50 mg of PGF_2α on d 6 successfully induced luteolysis in lactating dairy cows enrolled in a traditional 5-d Ovsynch-72 program [GnRH injection 5 d before (d 0; GnRH-1) and 56 (p.m. on d 7; GnRH-2) or 72 h (d 8; GnRH-2) after a 25-mg injection of PGF_2α (d 5 and 6 after GnRH injection); timed artificial insemination (AI) on d 8]. Our current objective was to determine pregnancy outcomes in lactating dairy cows after a 50-mg injection of PGF_2α on d 6 or a 25-mg injection of PGF_2α on d 5 and 6 in a 5-d Ovsynch program. Cows in herd 1 diagnosed not pregnant between 30 and 36 d since last AI were enrolled to receive either a 50-mg injection of PGF_2α on d 6 (1 × 50; n = 134) or a 25-mg injection of PGF_2α on d 5 and 6 (2 × 25; n = 139) after GnRH-1 (d 0), with GnRH-2 at 72 h after PGF_2α injection (d 5), concurrent with timed AI (d 8). Cows in herd 2 diagnosed not pregnant between 34 and 40 d were treated similarly: even-tagged cows received the 2 × 25 (n = 422) treatment, and odd-tagged cows received the 1 × 50 (n = 450) treatment, except that GnRH-2 was administered at 56 h. Blood collected from cows in herd 1 at d 0, 5, 6, and 8 was assayed for progesterone. Luteolysis was defined to occur when progesterone concentration was ≥1 ng/mL on d 5, and 72 h later (d 8) was either <0.5 ng/mL or <1 ng/mL. Progesterone concentrations did not differ between treatments on pretreatment d 0 and 5, but were greater in 1 × 50 than 2 × 25 cows on d 6 (4.7 ± 0.2 vs. 1.1 ± 0.2 ng/mL) and d 8 (0.43 ± 0.04 vs. 0.19 ± 0.04 ng/mL), respectively. Luteolysis was greater in the 2 × 25 versus 1 × 50 treatment when the cut point was 0.5 ng/mL, whereas no difference was detected when the cut point was <1 ng/mL on d 8. Lack of complete luteolysis was greater in cows classified as early cycle on d 0 or having a new corpus luteum after d 0 because progesterone concentration was greater on d 5 and 6 than for cows classified as late cycle on d 0 or cows having low progesterone on d 0 and 5. Pregnancy per AI at 30 to 40 d did not differ between 2 × 25 and 1 × 50 cows having luteolysis by d 8 or in all cows (37.2 vs. 33.3%) in herd 1, respectively, but differed in herd 2 (24.7 vs. 19.5%; no treatment by herd interaction). We conclude that incomplete luteolysis by d 8 was greater in 1 × 50 cows using a cut point of <0.5 ng/mL at AI. The difference in pregnancy outcome in herd 2 may have resulted from insufficient time for complete luteolysis before GnRH-2 at 56 h compared with GnRH-2 at 72 h (at AI) in herd 1.     

基于Trace Pro仿真的橙果品质光谱检测托盘参数设计与试验

为了实现橙果的内部品质可见/近红外光谱无损检测,采用Trace Pro软件对设计的橙果在线检测传送托盘模型进行光学仿真分析,参考仿真结果中的辉度/照度值,对值较高的托盘模型进行实物加工,结合实际光谱检测平台进行试验验证。仿真结果表明,成果传送托盘的最优外形参数为:外径80 mm、内横径55 mm,内纵径50mm、厚度20mm。采用不同材料对托盘进行加工,用于实际橙果可溶性固形物含量(SSC)检测,光谱数据经预处理后,建立偏最小二乘回归法(PLSR)的预测模型,其中亚克力托盘预测结果最优。为进一步优化检测模型,分别用遗传算法(GA)、稳定性竞争自适应重加权采样(SCARS)算法提取光谱特征波段,建立橙果SSC的PLSR的预测模型,其中SCARS算法特征提取方法最佳,预测决定系数R_(pre)~2为0.920 9;预测均方根误差(RMSEP)为0.468 3。     

Determination of fatty acids in broiler breast meat by near-infrared reflectance spectroscopy

The aim of this study was to develop near-infrared reflectance spectroscopy (NIRS) calibrations for determination of the fatty acids (FA) in broiler breast meat. A total of 144 breast meat samples were freeze-dried and divided into calibration set and validation set. Calibration models were developed for FA including C14:0, C16:0, C16:1n-7, C18:0, C18:1n-7, C18:1n-9, C18:2n-6, C18:3n-3, C18:3n-6, C20:0, C20:1n-9, C20:2n-6, C20:4n-6, C20:5n-3, C22:4n-6, C22:6n-3, C24:0 and C24:1n-9. Calibration models for FA groups were also developed. Calibrations based on the absolute FA content were more accurate than those based on the relative composition (%). The coefficients of determination of FA and FA groups (based on the absolute content) except C18:3n-6, C20:0, C20:2n-6 and C24:1n-9, were between 0.86 and 0.98 for calibration, and 0.83 and 0.97 for validation. The results indicate NIRS can be a feasible and rapid method for determination of FA with a mean concentration over 0.10 g/kg.     

A repeat national survey (ten years on) of muscle pH values in commercial bacon carcasses

Measurements of M. longissimus pH values at 45 min post mortem (pH(1)) were taken in a total of 5383 commercial bacon weight carcasses at fourteen bacon factories and meat plants in 1980/81. Comparable pH(2) values at 24 h post mortem were taken in a further 5150 carcasses. The overall mean pH(1) was 6·38 ± 0·29 (SD) with 12·8% of values less than 6·0. The overall mean pH(2) was 5·91 ± 0·18 with 0·6% of values greater than 6·5. Relationships between pH values and carcass weight, fat thickness and length were very low (maximum r = 0·05). Comparison of the results with a similar survey conducted in 1972/73 indicated that the proportion of carcasses with pH(1) values less than 6·0 has doubled (1972/73 result was 5·7%). The proportion of carcasses with high pH(2) values changed little.     

Effects of long chain fatty acids on lipid and glucose metabolism in monolayer cultures of bovine hepatocytes

The objectives were to determine the long-term (48 h) effects of specific long chain fatty acids on hepatic lipid and glucose metabolism in monolayer cultures of bovine hepatocytes. From 16 to 64 h after plating, hepatocytes from three 7- to 10-d-old calves were exposed to one of the following treatments: 1 mM palmitic acid (1 mM C16:0), 2 mM palmitic acid (2 mM C16:0), or 1 mM palmitic acid plus 1 mM of either stearic (C18:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), eicosapentaenoic (C20:5), or docosahexaenoic (C22:6) acid, or 0.5 mM each of eicosapentaenoic and docosahexaenoic acid (C20:5 + C22:6). The two treatments containing 2 mM of saturated fatty acids, 2 mM C16:0 and 1 mM C16:0 plus 1 mM C18:0, increased beta-hydroxybutyrate concentrations in the medium and [1-(14)C]palmitic acid oxidation to acid-soluble products compared with all other treatments. The treatment containing C22:6 increased total cellular triglyceride content and incorporation of [1-(14)C]palmitic acid into cellular triglycerides. The treatments containing C22:6 or C20:5 + C22:6 increased [1-(14)C]palmitic acid metabolism to phospholipids and cholesterol. The presence of C22:6 in the medium decreased metabolism of [2-(14)C]propionic acid either to glucose in the medium or to cellular glycogen. Overall, fatty acids differed in their effects on lipid and glucose metabolism in monolayer cultures of bovine hepatocytes with C22:6 eliciting the most profound changes.     

Interaction between milk allowance and fat content of the starter feed on performance of Holstein calves

Sixty-six Holstein male calves [42 ± 6.0 kg of body weight (BW) and 12 ± 3.1 d of age] were housed individually and allocated to 1 of 4 treatments following a 2 × 2 factorial complete randomized design to assess the potential interaction between milk replacer (MR) allowance and fat content in the starter feed. Thus, 4 treatments were evaluated: a low-fat (4.1% fat; LF) starter feed offered along with 4 L/d of MR (4LF), a high-fat (11.2% fat; HF) starter feed plus 4 L/d of MR (4HF), a LF starter feed offered with 6 L/d of MR (6LF), and an HF starter feed offered with 6 L/d of MR (6HF). Calves were fed either 4 or 6 L/d of MR (25% crude protein and 19.2% fat) in 2 offers (0800 and 1630 h) and had ad libitum access to either an LF or an HF starter feed (21.4 and 22.3% crude protein). Calves were weaned at wk 6 of study by halving the daily MR allowance for 1 wk. Individual MR and starter feed intakes were recorded daily and BW was determined weekly. A glucose tolerance test was performed on d 30 of study to evaluate the effects of increased energy provision on glucose metabolism. Apparent feed digestibility was measured for the last 5 d of study. Overall, fat content of starter feed had no effect on solid feed intake. However, during wk 8 of study (after weaning), calves in the LF treatment had greater starter feed intake than HF calves. Calves on 6 L/d of MR had greater BW than calves fed 4 L/d from the second week of study until weaning. After weaning, 6LF calves had lesser BW than 6HF calves. Calves on 6 L/d of MR had greater average daily gain than calves fed 4 L/d, and 6HF calves tended to have the greatest average daily gain. Glucose clearance rate tended to be lesser for HF than for LF calves. In conclusion, offering 6 L/d of MR increased growth performance before weaning and, when offering 6 L/d of MR, feeding a high-fat starter feed resulted in the greatest BW after weaning.     

青春双歧杆菌增菌培养基的优化

针对青春双歧杆菌的营养需要 ,采用正交实验优化基础培养基及增殖因子的用量。得出最佳基础培养基配比是 :大豆蛋白胨 1 2 % ,胰蛋白胨 0 6 % ,酪蛋白水解物 0 6 % ,牛肉浸膏 0 6 % ,葡萄糖 1 % ,低聚糖 0 5 % ,乳糖 0 5 % ,酵母浸出粉 0 7%。最佳增殖因子添加量是 :胡萝卜汁 1 5 % ,番茄汁 5 % ,肝浸液 1 5 % ,胱氨酸 0 0 5 %。最后使用优化出的增菌培养基配比测定生长曲线 ,同时测定 pH和滴定酸度的变化 ,确定增菌培养终止时间为 1 2h ,通过平板菌落计数 ,此时菌数可达 2 9× 1 0 9cfu/mL。