37种杀虫剂混剂对稻纵卷叶螟的田间防治效果

为进一步明确现有杀虫剂对水稻稻纵卷叶螟的效果。2007年,在大田中,以喷雾施药法对37种杀虫剂混配剂进行了防治稻纵卷叶螟的田间试验。结果表明：用药20天后,对稻纵卷叶螟控制效果达90%以上的品种有11种;控制效果达80%～89%有23种;控制效果〈80%的仅3种。可以认为,合理的混配剂,可能是今后控制稻纵卷叶螟为害的最为经济有效品种。     

An optimization algorithm for calculating the critical parametersof multicomponent mixture refrigerants

Aiming to calculate the true critical parameters of refrigerant mixtures, the Helmholtz free energy stability criterion for thermal systems is adopted to establish a calculation thermodynamic model of the true critical parameters. A novel optimization alg     

The distribution of QTL additive and dominance effects in porcine F2 crosses

The present study used published quantitative trait loci (QTL) mapping data from three F2 crosses in pigs for 34 meat quality and carcass traits to derive the distribution of additive QTL effects as well as dominance coefficients. Dominance coefficients were calculated as the observed QTL dominance deviation divided by the absolute value of the observed QTL additive effect. The error variance of this ratio was approximated using the delta method. Mixtures of normal distributions (mixtures of normals) were fitted to the dominance coefficient using a modified EM‐algorithm that considered the heterogeneous error variances of the data points. The results suggested clearly to fit one component which means that the dominance coefficients are normally distributed with an estimated mean (standard deviation) of 0.193 (0.312). For the additive effects mixtures of normals and a truncated exponential distribution were fitted. Two components were fitted by the mixtures of normals. The mixtures of normals did not predict enough QTL with small effects compared to the exponential distribution and to literature reports. The estimated rate parameter of the exponential distribution was 5.81 resulting in a mean effect of 0.172.     

Long‐chain alcohols did not improve predictions of the composition of tall fescue and red clover mixtures over n‐alkanes alone

Feed intake and diet choice affect production efficiency in livestock. Plant waxes, in particular n‐alkanes, have been used as markers to predict intake and diet preferences. Still, when n‐alkane profiles of plants within mixed swards are similar, they alone may not produce reliable predictions. Including long‐chain alcohols (LCOHs) may help. In this study, the reliability of predicting forage mixtures was assessed using n‐alkanes and LCOH separately and in combination. Reliability was characterized as the regression of observed on predicted fescue proportion in forage mixtures and the Kulczyński similarity index. Two technicians performed extractions of n‐alkanes and LCOHs of pure red clover and ‘Fawn’ tall fescue, and nine mixtures of them. The concentrations of n‐alkanes C₂₇, C₂₉, C₃₁ and C₃₃ and alcohols C₂₆‐OH, C₂₈‐OH and C₃₀‐OH were compared among forage mixtures and between technicians. Technicians were consistent in their measures of n‐alkanes (P > 0·12), but differed in their measures of C₂₆‐OH and C₂₈‐OH (P < 0·002). Longer‐chained compounds were more consistently quantified. Forage delineations were not improved by C₂₆‐OH. With n‐alkanes alone, estimated and actual fescue proportions closely agreed. Including LCOH offered no improvement. Despite variation in measured concentrations between technicians, fescue and red clover mixtures were reliably predicted using n‐alkanes alone.     

36个农药单剂和33个混配农药的稳定性

研究了33个混配农药和32个农药单剂,在54±2℃贮存14d的热贮稳定性试验,以及4个农药单剂常温贮存的稳定性试验。结果表明,混剂中大部分农药成分的稳定性不如其单剂稳定。例如,高效氯氟氰菊酯单剂热贮是稳定的,但是在与吡虫啉混配时,高效氯氟氰菊酯的分解率为61.07%;阿维菌素与毒死蜱混配时,阿维菌素热贮分解率为100%,但是阿维菌素的单剂热贮也是稳定的。     

Does relative time of emergence affect stand composition and yield in a grass–legume mixture? Kura clover (Trifolium ambiguum)–meadow bromegrass (Bromus biebersteinii) and Kura clover–orchardgrass (Dactylis glomerata) mixtures

Establishing Kura clover (Trifolium ambiguum) in mixtures with grass species is challenging, because slow growth of clover seedlings results in low competitive ability. This study examined establishment success by altering time of seeding of the grass component to reduce competition with Kura clover seedlings. Two trials, one of Kura clover–meadow bromegrass (Bromus biebersteinii) and the other Kura clover–orchardgrass (Dactylis glomerata) mixtures were planted in Edmonton, Alberta. Grasses were seeded at the same time as the clover, or introduced when the clover reached one true leaf or three true leaves, in the autumn of the planting year or the following spring. Species composition varied significantly between treatments. When sown at the same time, Kura clover contributed 31 and 14% of yield in the establishment year when sown with meadow bromegrass and orchard grass, respectively. Delaying grass sowing until Kura clover had one or three leaves gave a higher percentage of Kura clover compared with planting at the same time. Autumn and spring grass sowing resulted in stands of 78 and 80% clover with meadow bromegrass, and 74 and 67% clover with orchardgrass. Altering the competitive advantage of the grass species to produce a more balanced mixture was successfully achieved by delaying seeding of the grass relative to Kura clover. A long interval before introducing the grass (autumn or following spring), was not successful as established Kura clover seedlings have an increased competitive ability.     

深绿木霉T95和球毛壳ND35混用对土传病害的防治效果

用深绿木霉T95和球毛壳ND35两种拮抗菌株以及两者的混合菌株对由瓜果腐霉Pa和立枯丝核菌Rs引起的猝倒病和立枯病的防治效果进行了初步研究。平皿对峙结果表明,对瓜果腐霉Pa抑制作用最大的为ND35+T95混合拮抗菌,生长抑制率为73.36%,高于拮抗菌ND35对瓜果腐霉Pa的生长抑制率47.87%。而对立枯丝核菌Rs的拮抗作用三者之间差异不显著。盆栽试验结果表明,在菜豆上ND35+T95混合菌株对猝倒病的防治效果高于单个菌株深绿木霉T95,但在黄瓜、番茄上差异不显著。田间试验结果表明,混合拮抗菌株ND35+T95组合对立枯病和猝倒病的防治效果分别为49.05%和60.37%,均高于单一拮抗菌株深绿木霉T95的防治效果,但与对照化学药剂恶霉灵相比存在一定的差异。     

Milk-production potential of different sward types in a temperate southern Australian environment

The milk-production potential of different sward types was measured in each of the four seasons of the year in a replicated experiment in south-west Victoria, Australia. Dairy cows were offered ad libitum allowances of a 'short-term winter' sward, based on Italian ryegrass (treatment STW), a 'long-term winter' sward, based on a winter-active tall fescue (treatment LTW), a 'long-term summer' sward, based on a summer-active tall fescue (treatment LTS) and a Control sward (perennial ryegrass) in four seasons (days in milk in parentheses): spring (November dairy cows, 124), summer (February, 227), autumn (May, 234) and winter (August, sixty-four). A 'short-term summer' sward, based on chicory and white clover (treatment STS), was also included in summer. There was a significant season × treatment interaction caused by a more gradual decline in milk yield from peak for cows grazing treatment LTS compared to the Control treatment in the transition period from spring to summer. In summer, cows grazing treatment STS produced more milk (1·41 kg fat plus protein per cow d⁻¹) than cows grazing all other treatments (0·92 kg per cow d⁻¹) because of the superior nutritive value of herbage of pre-grazing pasture and higher apparent dry-matter intakes. Swards based on alternative species to perennial ryegrass are capable of supporting milk production that is at least comparable over an annual cycle.     

Intellectual property in entomology: Analysis and perspective on recent trends in global patent publications

Intellectual property (IP) is an important consideration for entomological research and provides a means to capture value from new discoveries. Herein, we describe an analysis of more than 26 000 patent publications from 2007–2017 related to the field of entomology. These patents were divided among 8000 patent assignees; however, only 5% of the assignees had ≥10 patents. Corporations accounted for the largest share of patents (59%), with individuals (20%), academic institutions (17%) and government organizations (4%) making up the remaining segments. From 2007–2017 the number of entomological patents increased by 400%, with the largest number being from China. However, unlike patents from Europe, Japan or the US, which target a range of countries, the Chinese patents almost exclusively focus on China. Among the array of subjects covered are transgenic insects and plants, repellents, recombinant insect cells, with the highest proportion of patents focused on insecticides (39%), followed by insecticide mixtures (27%) and formulations (21%). The top 30 patent assignees included companies/institutions from China (18), Europe (3), Japan (6) and the US (3). Among the top 12 entities, IP from the US assignees was distributed across insecticides, mixtures and insecticidal traits while those from China were more focused on mixtures. However, given expanding IP numbers from China it is expected that in the future there will be a greater impact on new insecticides and related technologies. © 2020 Society of Chemical Industry