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1.
为了对离心分种器进行结构改进和参数优化以提高小麦小区播种机的分种均匀性,该文对小麦离心分种过程进行运动分析,得出小麦籽粒的运动受到离心分种器转速、分种面夹角和分种距离的影响;采用离散元仿真软件,建立仿真模型,以离心分种器转速、分种面夹角和分种距离为试验因素,以分种均匀性变异系数为试验指标,进行不同播量下的三因素三水平正交试验,研究各个因素对分种均匀性的影响规律,以获得较优的参数组合。仿真试验结果表明,在播量为2 000、3 000粒时影响分种均匀性的主次因素为离心分种器转速、分种距离和分种面夹角,在播量为1 000粒时为离心分种器转速、分种面夹角、分种距离;通过仿真试验和台架试验,确定离心分种器较优参数组合为离心分种器转速1 250 r/min、分种面夹角120°、分种距离17.5 mm,台架试验条件下3种播量的分种均匀性变异系数分别为5.18%、4.45%和3.98%,与仿真试验结果相差0.36%、0.14%和0.55%,两者基本一致,且籽粒破碎率为0.17%、0.13%和0.14%,具有较小的籽粒破碎。该研究可为小麦小区条播机的离心分种器优化改进以及分种性能提升提供参考。  相似文献   
2.
Botrytis cinerea, which causes grey mould, is a major pathogen of many crops. On strawberry, isolates of Trichoderma spp. can effectively control B. cinerea, but frequent application is necessary. Bees can be used to disseminate biological control agents to the target crop. We tested the ability of honey bees to disseminate Trichoderma harzianum T39 to control B. cinerea in strawberry in the field during the winter in Israel over two consecutive seasons. We used the recently developed ‘Triwaks’ dispenser for loading the bees with the T. harzianum inoculum. During both years, grey mould developed in late January in untreated control plots; at low to medium disease levels it was partially controlled by fungicide treatment, and was best controlled in bee-visited plots. At high disease levels neither chemical nor biological control was effective. To assess the spatial distribution of inoculum by bees, we sampled flowers up to 200 m from the hives and found effective levels of T. harzianum even at 200 m. The approach used in this study provides an effective control of grey mould in strawberry in conditions of low to medium grey mould incidence.  相似文献   
3.
Outbreaks of saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae) have been reported in Belgium and other European countries since 2010. Because of the sporadic nature of this pest, which can sometimes be very harmful to cereal crops, an effective monitoring tool is required, both to determine the optimal timing for insecticide applications, and to understand the enigmatic population dynamics of this insect. Following the recent identification of the major sex pheromone component of the saddle gall midge, non-2-yl butanoate, a slow-release dispenser was developed using rubber septa. The release rates of 5 mg and 10 mg-loaded dispensers were initially measured under laboratory conditions, and their effectiveness in terms of pheromone loading and use duration was assessed in the field. The experiments showed that sticky traps baited with 5 mg pheromone-loaded rubber dispensers, renewed every 6 weeks, are suitable for accurately monitoring male H. marginata flights.  相似文献   
4.
BACKGROUND: To date, in modern agriculture, biological control strategies are increasingly becoming the preferred pest management approach. However, the success of microbiological control agents (MCAs) largely depends on efficient dissemination into the crop. The pollinator‐and‐vector technology employs pollinating insects like bees for a better dissemination. In this study, a new dispenser for bumblebee workers of Bombus terrestris L. was developed. Binab‐T‐vector and Prestop‐Mix were used as two typical MCA products for dissemination. RESULTS: In a first series of experiments in the laboratory for optimisation, the newly developed dispenser was a two‐way type dispenser, 20 cm long, with two rectangular compartments and different entrance and exit holes. In addition, the amounts of MCA loaded on the workers were 10 times higher with the new dispenser as compared with the side‐by‐side passageway (SSP) dispenser. Typically, the highest amounts were recovered from the thorax and legs of the workers. In a second series of experiments under greenhouse conditions with the use of queen‐right B. terrestris hives, successful dissemination in strawberry flowers was obtained at different distances from the hive (0–8 m, 8–18 m and 18–21 m), and the workers inoculated the first, second and third flowers that were consecutively visited. In addition, the new dispenser caused no adverse effects on worker foraging intensity, whereas a dramatic reduction was scored with an SSP dispenser. Finally, the data suggested that it is necessary to refill the newly developed dispenser at 3 day intervals. CONCLUSIONS: The results demonstrated that, with the use of the newly developed dispenser, bumblebee workers carried high amounts of MCA, and this resulted in a successful dissemination of MCA into strawberry flowers. Copyright © 2010 Society of Chemical Industry  相似文献   
5.
为明确蓟马聚集信息素组分在2种常用载体中的释放规律,应用固相微萃取(SPME)和气相色谱-质谱联用技术测定不同聚集信息素剂量(1、10、100μg)和萃取时间(30、60、120 min)下SPME萃取头对载体中3种蓟马聚集信息素组分的萃取效率,筛选最佳萃取条件,并分析储藏温度对载体中蓟马聚集信息素组分释放速率的影响。结果表明,在橡胶塞和PVC管2种载体中,相同聚集信息素剂量下,与萃取30 min处理相比,萃取60、120 min时SPME萃取头对载体释放的3种聚集信息素组分的萃取效率或无显著差异,或随萃取时间增加而呈现降低趋势;相同萃取时间下,SPME萃取头对载体释放的3种聚集信息素组分的萃取效率均随剂量增加而显著增大。因此,测定载体中聚集信息素释放速率的最佳条件为萃取时间30 min、剂量100μg。室温25℃储藏条件下,橡胶塞和PVC管中3种聚集信息素组分的释放速率均在存储2 d时最高,之后随存放时间的延长而逐渐降低;-20℃储藏条件下,载体中3种聚集信息素组分的释放速率随着存放时间的延长相对稳定,56 d内释放速率均处于较高水平,且显著高于室温下储藏载体中聚集信息素组分的释放速率。表明-20℃储藏可有效减少载体中聚集信息素组分的损耗,即-20℃是聚集信息素载体储藏的适宜温度。  相似文献   
6.
Thirty-three dairy farms in the Norwegian counties of Østfold and Akershus in which cubicle sheds had been in use for at least one year and with a herd size of less than 60 cows, were contacted and asked to participate in a study. The study focused on heifers'' use of cubicles and concentrate dispenser just after being transferred from rearing accommodation to the milking herd. For each heifer, the farmer recorded cubicle use once nightly between 9 and 11 pm. The daily amount of concentrate released in the dispenser and the allotted daily ration were also recorded. The recording period was 15 consecutive days for cubicle use and 7 days for concentrate dispenser use. Cubicle refusal behaviour, i.e. lying outside the cubicles, was analysed by logistic regression using rearing accommodation of heifers, herd size, heifer age, and housing layout as independent variables, and herd as a clustering variable. On Day 2 after transfer, 34% of the heifers were showing cubicle refusal behaviour (N = 340). By Day 15 this percentage had dropped to 23. Cubicle refusal was lower throughout the whole period among heifers which used the cubicles on the 3 first days after transfer compared to those which did not. This tendency could also be detected several months later. The analysis showed cubicle refusal to be significantly associated with rearing accommodation (OR = 6.1, c.i.95%OR = 1.5–24.3, P = 0.01) and cubicle layout in the shed (OR = 0.2, c.i.95%OR = 0.0–0.7, P = 0.01). None of the tested variables were found to be significant for failure to use the concentrate dispenser, a behaviour which was less frequent than cubicle refusal. However, 8 percent of the heifers did not visit the dispenser at all throughout the 7 days of observation.  相似文献   
7.
During 1996–1998 mating disruption trials were conducted on all three generations of the grapevine mothLobesia botrana Den. et Schiff. (Lep., Tortricidae) in a 25-ha vineyard situated at Spata, Attiki, Greece. Shortly before the beginning of the first flight period ampoule-type pheromone dispensers were set up lining a 6.5-ha rectangular plot. Around the dispenser zone a protection belt was created whereBacillus thuringiensis (Bt) and selective insecticides were applied against the second and third generation larvae. The protection belt was 35 m wide and covered 3.5 ha. The rest of the vineyard was divided into the reference plot — where conventional insecticide treatments were implemented to control both carpophagous pest generations, and the untreated control plot — which measured 1 ha. Male catches within the dispenser zone were virtually zero. Nevertheless, no difference was apparent between the percentage of mated females from within and outside of the dispenser zone. Attractant was released from the dispensers throughout the season at a rather constant rate, but by the middle of the third flight period dispensers were found to be almost empty. During the 3 years of the survey pest pressure was often at exceptionally high levels. The effectiveness of the mating disruption technique (MDT) was found to vary with year and pest generation. MDT was used against the first (anthophagous) generation with rather poor results. In the following carpophagous generations results were comparable to control measures with insecticides used and sometimes slightly better. The density of the pest population in the pheromone-treated vineyard as compared with the untreated control, was reduced on average by 67% in the second and by 57% in the third generation. MDT therefore did not accomplish sufficient crop protection. http://www.phytoparasitica.org posting Dec. 19, 2003.  相似文献   
8.
2004—2006年,先后在重庆、广西、山西等地进行了灭虫药包及布撒器施药技术防治食叶害虫试验。试验表明,除白僵菌灭虫药包因天气影响而防治效果较低外,其他灭虫药包防治效果十分显著。应用该项技术可降低防治成本和防治作业劳动强度,扩大有效防治面积,提高防治效率和药剂覆盖度,保护环境和生物多样性。  相似文献   
9.
剂量控制是迷向技术防控梨小食心虫的关键,本文通过田间试验研究了新型材料装置固体迷向丝和高剂量自动信息素喷施系统对梨园梨小食心虫的防治效果和持效期,以期探讨新型材料和释放技术在害虫迷向中的应用。结果表明,性信息素在傍晚18:00―20:00对梨小食心虫的诱捕量占全天的93.7%,田间虫量监测以绿色粘胶诱捕器效果较好。常规化学防治处理区对梨小食心虫的平均诱蛾量为42.13头,平均蛀果率为2.64%,相对于常规化学防治处理区,新型材料固体迷向丝、高剂量自动信息素喷施系统处理区平均诱蛾量分别为1.00头、5.31头,对成虫的迷向率分别为91.84%~100%、70.86%~98.25%,平均为97.96%、91.41%,平均蛀果率分别为0.81%、0.95%,在8月采果期的蛀果防治效果分别达85.79%、77.16%,防控持效期可达6个月以上。  相似文献   
10.
The effect of a straw dispenser in farrowing crates was investigated to determine the extent to which the provision of small quantities of straw has an influence on both sows and piglets. Sows and suckling piglets are often housed in barren environments with limited opportunities to show behavior they are highly motivated to perform. Enriching the environment might be a solution; for example, by providing materials that can be manipulated. In this study, 20 sows received a straw dispenser with chopped straw (treatment group) and 20 other sows did not receive any enrichment (control group). The treatment group was split up in 2: in treatment group A, the straw dispenser was placed in front of the sow, above the feed trough; and in treatment group B, the straw dispenser was placed next to the sow. Sows from the treatment groups received the straw dispenser from arrival in the farrowing crate until weaning. The total straw use within the treatment group was very variable but did not differ before and after farrowing. Sows took on average 53.0 g (±8.85) straw from the straw dispenser during the whole period in the farrowing crate. The frequency of undesirable and stereotypical behavior performed by the sows did not differ between treatment and control groups, and the same is seen with nest-building behavior before farrowing. By positioning the dispenser in front of the sow, the frequency of lateral lying increased, which means the udder was exposed more toward the piglets. This was reflected in the higher frequency of udder activity, performed by piglets from this treatment group. By positioning the dispenser next to the sow, sows showed more ventral lying behavior, because of disturbance of lying behavior by piglets. Piglets from this treatment group also showed less udder activity and possibly because of this, more pain-related behavior. These piglets performed more playing behavior in the third week of life compared with other groups, but it cannot be stated with certainty that this is a positive effect. A lower weight gain and weaning weight were seen in piglets within treatment group B. Possible explanations are the higher level of activity among these piglets as the straw dispenser was positioned within their reach or decreased milk consumption because of decreased udder activity and increased ventral lying by the sows. It can be concluded that the straw dispenser has positive effects on the behavior and welfare of sows and piglets, but positioning the straw dispenser in reach of both sow and piglets is not preferred as it is associated with undesirable effects on behavior such as ventral lying in sows and pain-related behaviors in piglets.  相似文献   
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