Application of imidacloprid controlled-release granules to enhance the utilization rate and control wheat aphid on winter wheat

During winter wheat production, aphids need to be controlled with pesticides for the entire growth period. Controlled-release technology has been regarded as an alternative method for the improvement of pesticide efficiency. This study investigated two types of imidacloprid controlled-release granule (CR-GR): 2% imidacloprid CR-GR and 0.2% imidacloprid pesticide-fertilizer controlled-release granule (PF-CR-GR) when wheat was sown in winter. The release performance, utilization rate, terminal residues in edible parts, control effect on aphids, and achieved winter wheat yield were evaluated for both laboratory experiments and field application. Imidacloprid PF-CR-GR released more quickly in aqueous medium than CR-GR because of its good water solubility. After CR-GR treatments, the concentrations in wheat roots and soil were similar throughout the entire sampling period, and the concentrations in shoots were about 10–20% of those in roots. Imidacloprid was better absorbed when CR-GR was used as root treatment, compared with foliar treatment. Field application showed that imidacloprid CR-GR and PF-CR-GR controlled aphids throughout the entire growth period of winter wheat and improved the wheat yield. These findings identified application of imidacloprid CR-GR and PF-CR-GR on winter wheat as an effective way to enhance the pesticide utilization rate and ensure adequate yield. This paper provides a theoretical basis for the scientific use of pesticides and guides scientific pesticide application.     

氯虫苯甲酰胺水分散粒剂对桃小食心虫的防治效果研究

本试验比较了不同浓度氯虫苯甲酰胺水分散粒剂对桃小食心虫的防治效果。结果表明:试验药剂35%氯虫苯甲酰胺水分散粒剂在水中分散性良好,700倍用药量(有效成分量为41.2 g/hm^2)防治桃小食心虫的速效性和持效性均良好,14 d后防效达到最大值,为99.1%。试验证明,氯虫苯甲酰胺水分散粒剂可用来防治果树桃小食心虫。     

不同配料颗粒秸秆施用对土壤速效养分及小麦生长的影响

我国西北地区气温较低，秸秆直接还田腐解慢、养分循环慢、当季利用率低、影响作物出苗，导致秸秆还田率不高。针对以上问题，本研究以小麦秸秆为原料，以硫磺粉（养分活化剂）和麦秸生物炭（养分吸附剂）为外源添加材料，制成秸秆颗粒。硫磺粉的添加质量比为3%（WS3）、5%（WS5）、10%（WS10），生物质炭的添加质量比为5%（WC5）、10%（WC10）、15%（WC15），以秸秆颗粒（WK）、剪碎秸秆（W，W6）及无秸秆（CK）为对照，通过盆栽试验探究了秸秆颗粒对土壤速效养分及小麦生长的影响。结果表明：秸秆颗粒较剪碎秸秆处理相比，能显著提高土壤速效养分及小麦生物量和植株全量氮、磷、钾含量，添加硫磺或生物炭的秸秆颗粒提升效果更明显。各处理土壤硝态氮含量以WS3处理最高，较W处理提高14.44%；铵态氮含量以WC5处理最高，较W处理提高40.93%；速效磷含量以WS10处理最高，较W处理提高23.42%；速效钾含量以WC5处理最高，较W处理提高9.05%；差异均达显著水平（P<0.05）。小麦生物量以WS5处理最高，较WK处理提高29.61%；全氮含量以WS10最高，较WK处理提高11.44%；全磷含量以WS10处理最高，较WK处理提高21.82%；全钾含量以WC15最高，较WK处理提高12.53%；差异均达显著水平（P<0.05）。综上可知，秸秆颗粒在西北地区实现秸秆还田和养分循环，维持土壤肥力等方面具有很大应用前景。     

HPLC法测定复方黄芪饲料添加剂中五种指标成分含量

试验旨在建立采用HPLC同时测定复方黄芪饲料添加剂中毛蕊异黄酮苷、甘草苷、刺芒柄花苷、毛蕊异黄酮、甘草酸5种指标成分含量的方法。试验采用Agela Venusic C18色谱柱(250 mm×4.6 mm,5μm),以乙腈-0.1%磷酸溶液为流动相,进行梯度洗脱,流速1.0 mL/min,柱温30℃。结果显示,复方黄芪中5种指标成分分离度良好,且在各自线性范围内线性良好,精密度、重复性、稳定性的相对标准偏差(RSD)均小于3%,平均回收率为95%~105%。3批样品中5种指标成分的含量均值分别为0.43、1.06、0.11、0.14、0.60 mg/g,5种指标成分的总量均值为2.34 mg/g,5种成分的含量较稳定,可作为复方黄芪饲料添加剂的质量控制指标成分。研究表明,试验建立的方法操作简便、准确,重复性好、灵敏度高,能够为复方黄芪饲料添加剂的质量控制提供参考。     

Starch granule size variation and relationship with tuber dry matter content in heritage potato varieties

Heritage potato varieties in Canada are historic old varieties collected from Canada and various countries before the formal establishment of the Canadian plant variety registration system and may be a valuable gene resource for beneficial traits in potato breeding and bioproducts development. Greater evaluation is the key for the enhanced use of these materials. It is unknown how much variation of starch granules occurs among Canadian heritage potato varieties. We analyzed the starch granule size of 14 potato heritage varieties held in the Canadian Plant Gene Resources collection over 2 years using a squeezed juice and microscopic method recently developed at the Potato Research Centre. The varieties demonstrated considerable variation in starch granule size and shape. The granules showed average lengths ranging from 18 μm in the variety Congo to 32 μm in ‘Russet Burbank’. The largest single granule measured from 64 μm in ‘Congo’ to 91 μm in ‘Crotte d’Ours.’ The granule sizes of the varieties showed a very high correlation (r = 0.975, P < 0.0001) between years. This high reproducibility suggests the existence of genetic factors in determining starch granule size. We also found that the starch granule size is positively correlated with tuber dry matter (in terms of specific gravity) in these heritage potatoes. The results demonstrated reproducible genotypic variation for starch granule size and shape in tubers with a significant correlation to tuber dry matter in these heritage potato varieties, and offers the possibility for and agronomic relevance of genetic modification of starch granules through selective breeding.     

农药新剂型——微乳粒剂配制的可行性研究

以三唑磷为模式农药,研究了一种外观为颗粒状、用水稀释后成微乳液的农药新剂型——微乳粒剂配制的可行性。以乳状液的中位径(D50)为因变量,各表面活性剂用量为自变量,采用混料均匀试验设计并结合偏最小二乘回归法筛选表面活性剂品种;用比例法与对分法优化各表面活性剂用量;采用旋转挤压造粒法造粒。将筛选获得的农乳500与农乳602号用于配制15%三唑磷微乳粒剂,其乳状液外观为淡蓝色透明状,分散相颗粒迁移速度为0,且不同水质(水硬度:0~3 420 mg/L,水温:10~50 ℃)下乳液稳定性均合格;乳状液D50为54.2 nm,粒径分布范围为15.7~122 nm,粒径增大速率为0.01%/min;乳状液在相对离心力10 730×g下离心5 min未发生相分离。结果表明:该三唑磷微乳粒剂的乳状液为微乳液,微乳粒剂可以成功配制。     

灌浆期高温对不同耐热性小麦籽粒淀粉积累的影响

为揭示小麦耐热机理,以3个耐热性不同的小麦品种(系)［44（耐热）、94（热敏感）和中国春（热敏感）］为材料,在开花后15 d至成熟进行胁迫（昼/夜温度37/17 ℃,14/10 h）,探究热胁迫对小麦灌浆时间、千粒重、籽粒淀粉含量、组成和淀粉颗粒的影响。结果表明,在高温胁迫处理后,耐热和热敏感小麦籽粒总淀粉含量均降低,直/支比分别下降和升高;与耐热品系44相比,2个热敏感小麦品种的A型淀粉颗粒粒径减小,中间型淀粉颗粒（8~14 μm）增多。这些结果说明,灌浆期高温胁迫抑制了小麦籽粒淀粉的积累,但不同耐热能力的品种（系）对高温胁迫的响应存在差异。     

Electron microscopic observations of sooty moulds on crape myrtle leaves

Sooty moulds on crape myrtle leaves were investigated using light and electron microscopy. The adaxial leaf surface was distinctly covered with soot‐like masses of dark brown hyphae and conidia. The main characteristics of the sooty moulds included stauroconidia, conidial clusters, hyphal degeneration and extracellular melanin depositions. Some conidia were round, measured ~10 μm in diameter, and mostly one‐septate; others were branched and multiseptate (stauroconidia). Based on their morphology, the sooty moulds were determined to consist of several component fungal species belonging to genera such as Antennaria, Metacapnodium and Tripospermum. Enclosed in electron‐dense melanin layers, hyphae and conidial clusters had concentric bodies exhibiting electron‐transparent cores and electron‐dense shells with fibrillar sheaths. Concentric bodies are hypothesized to function as multilayer lipid‐encapsulated nanobubbles or eukaryotic gas vesicles for cytoplasmic volume control. Intrahyphal hyphae possessed electron‐dense cytoplasm and lipid globules. These results suggest that sooty moulds are equipped with melanized cell walls, multicelled resting structures, hyphal regeneration, intrahyphal growth and gas vesicles to adapt to their xeric phylloplane environment. Condensed and elongated starch granules in the chloroplasts of mesophyll tissues may indicate the acclimation of the sooty leaf regions to light reduction and temperature increase.     

均匀设计法优选抗雏鸡白痢翁苋颗粒

利用均匀设计法及回归分析优选抗雏鸡白痢的中药组方翁苋颗粒.结合中兽药组方原则,将白头翁、马齿苋、苍术、陈皮等中药进行组方配伍,采用均匀设计法及回归分析,以不同配比的翁苋颗粒对鸡白痢沙门氏菌的体外抑菌效果作为考察指标,运用中兽医整体观念及体外抑菌活性评价筛选最优处方.采用腹腔注射鸡白痢沙门氏菌菌液的方法复制雏鸡白痢的病理模型,通过在饲料中添加一定比例的翁苋颗粒,于试验后统计有效率、治愈率.翁苋方28的组分配比为最佳处方,最优处方配比的翁苋颗粒高剂量组对雏鸡白痢的治愈率、有效率均为91.7%.该试验筛选出的优化复方制备处方翁苋颗粒能够有效防治雏鸡白痢.     

大颗粒尿素在农业生产中的推广应用

介绍了大颗粒尿素的特性,阐述了大颗粒尿素主要的生产技术及应用方式,分析了推广应用大颗粒尿素面临的主要问题,并提出了在农业生产中推广应用大颗粒尿素的措施。