scholarly journals Isolate locale ale baculovirului entomopatogenic ca o tehnologie de formulare inovatoare, care protejează biopesticidul din degradare a radiației ultraviolete

2021 ◽  
Author(s):  
Aurelia Stingaci ◽  
◽  
Leonid Volosciuc ◽  

This paper presents the conceptual conceptual vision a formulation technology for biopesticides in which the active ingredient (baculovirus) is an active coal. Importantly, this indgredient protects the sen-sitive viral DNA from degrading in sunlight, but dissolves in the alkaline insect gut to release the virus, which then infects and kills the pest. We show, using this ingredient, in both laboratory bioassays and field tests, that this can extend the efficacy of the biopesticide well beyond the few hours of existing virus formulations, potentially increasing the spray interval and reducing the need for high application rates. Are presented both theoretical foundations and practical applications and described the results oriented for implementation and functionality of organic agriculture in Republic of Moldova.

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1449
Author(s):  
Wenfeng Wang ◽  
Shaochan Duan ◽  
Haoran Zhu

In order to improve the durability of the asphalt pavement on a cement concrete bridge, this study investigated the effect of the modulus of the asphalt mixture at the bottom layer on the mechanical response of bridge pavement, along with a type of emerging bridge pavement structure. In addition, the design method and pavement performance of a high-modulus asphalt mixture were investigated using laboratory and field tests, and the life expectancy of the deck pavement structure was predicted based on the rutting deformation. The results showed that the application of a high-modulus asphalt mixture as the bottom asphalt layer decreased the stress level of the pavement structure. The new high-modulus asphalt mixture displayed excellent comprehensive performance, i.e., the dynamic stability reached 9632 times/mm and the fatigue life reached 1.65 million cycles. Based on the rutting depth prediction, using high-modulus mixtures for the bridge pavement prolonged the service life from the original 5 years to 10 years, which significantly enhanced the durability of the pavement structure. These research results could be of potential interest for practical applications in the construction industry.


2019 ◽  
Vol 19(34) (4) ◽  
pp. 103-112
Author(s):  
Mariusz Trojak ◽  
Barbara Kiełbasa ◽  
Daniela Popa ◽  
Aliona Sargo

Economic literature pays a great deal of attention to economic and financial efficiency, expressed in terms of competition, concentration, productivity and profitability. This paper provides an all-embracing framework for the various existing theories in this area and illustrates these theories with practical applications. Currently, changing the size of the production potential in agricultural units in the Republic of Moldova depends to a great extent on the influence of different trends in the modification of production resources: the reduction of labor resources and agricultural land, quantitative and qualitative changes in fixed assets, and in current assets, etc. The notion of resource potential means the totality of the volume of all resources (natural, labor, material, intellectual, information, etc.) on specific enterprises, territories, branches, regions. Evaluating a broad field of research, the paper describes profit maximizing food products and demonstrates how several widely-used products can be fit into this framework. The authors also present an overview of the current major trends in the food sector and relate them to the assumptions for food products, thereby displaying their relevance and timeliness. The results include a set of recommendations for future research on this topic. The design, methodology and approach of this research is to explain why efficiency can help obtain a profit surplus, and to measure this efficiency. For quality of methodology we apply a range of statistical methods, as well as the strategic capability of organisations – made up of resources and competences. One way to approach the stategic capability of an organisation is to consider its strengths and weaknesses (for example, where it has a competitive advantage, profit, efficiency or disadvantage). Based on our research and results, we sought to understand the concepts of financial effciency and to apply these concepts to practical situations. At the start of each analysis entrepreneurship plays an important role. Most organisations have to innovate constantly to obtain profit and efficiency for food products. They need to be first into a market, or simply a follower of customers in developing new products and services. Original studies in Moldova and Poland regarding farm concentration in terms of Gini Coefficient, Gini Index and Concentration Index of the utilized agricultural area. Original calculus formula to determine the Concentration Index of the UAA for the top 10% largest farms in Moldova and UK.


2018 ◽  
Vol 38 (02) ◽  
pp. 159-167
Author(s):  
E. Mazhawidza ◽  
B. M. Mvumi ◽  
U. Mazarura

AbstractEffects of pesticidal plant extracts on non-targeted species are rare. Direct topical and residual sprays of crude aqueous extracts of three pesticidal plants: Datura stramonium L. Bobgunnia madagascariensis Kirkbr. & Wiersema and Solanum delagoense L. were assessed in laboratory bioassays and on-station experiments against the ladybird beetle, Hippodamia variegata (Goeze). The plants are routinely used by smallholder vegetable farmers to control aphids, Brevicoryne brassicae L. attacking rape, Brassica napus L. The crude extracts of D. stramonium fresh leaves, S. delagoense fresh fruits and B. madagascariensis dried pods, were applied separately at 5, 10, 15, 20 and 25% w/v under laboratory conditions. Application rates of 20% and 25% w/v of the plant extracts were further evaluated on-station. Negative (tap water) and positive (dimethoate® (36% E.C)) controls were included for comparison. The mortality of H. variegata was recorded 24, 48 and 72 h post-exposure. In on-station experiments, treatments were applied fortnightly and live H. variegata adults were counted at 1, 7 and 14 days post-application. Mortality of H. variegata in laboratory bioassays increased with increase in post-exposure time and B. madagascariensis (25% w/v) caused the highest mortality. Based on LD50 values, B. madagascariensis extracts were most toxic (LD50, 30% w/v) followed by D. stramonium (LD50, 34% w/v) and S. delagoense (LD50, 49% w/v) 24 h post-application. In on-station experiments, the synthetic chemical significantly lowered (P < 0.05) H. variegata numbers compared to the negative control and plant extracts. The results showed that D. stramonium and S. delagoense extracts at the application rates used in the study were relatively safer to H. variegata than B. madagascariensis (25% w/v); hence, the former two plants can be included in integrated pest management programmes.


1994 ◽  
Vol 37 (3) ◽  
pp. 753-757
Author(s):  
E. D. Lowe ◽  
D. R. Buckmaster

1976 ◽  
Vol 108 (11) ◽  
pp. 1137-1144 ◽  
Author(s):  
J. N. All ◽  
D. M. Benjamin

AbstractAntifeedants for controlling larval feeding of several Neodiprion sawflies were evaluated in laboratory and field studies. Nine commercially available insect antifeedants and a hexane extract of the juvenile foliage of jack pine, Pinus banksiana Lambert, were tested on larvae of six species. In laboratory bioassays larvae exhibited varying sensitivity to antifeedants; generally species with monophagous or restricted oligophagous feeding habits were most sensitive. In the laboratory the Swaine jack pine sawfly, Neodiprion swainei Middleton, had severely restricted feeding, development, survival, and fecundity. Triphenyltin hydroxide was toxic to N. swainei and to European pine sawfly, N. sertifer (Geoffroy). In field tests certain antifeedants disrupted N. swainei feeding and development. The colonial behavior of larvae often was disrupted and solitary larvae fell from trees or wandered on twigs. Colony disruption by most antifeedants was temporary and many larvae resumed feeding.


HortScience ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Katherine B. Wing ◽  
Marvin P. Pritts ◽  
Wayne F. Wilcox

Blackening and decay of roots in association with plant stunting are common in perennial strawberry (Fragaria ×ananassa Duch.) plantings worldwide; this syndrome is commonly referred to as black root rot (BRR), although its causal agent(s) are not well characterized. We conducted a New York field survey that measured many physical and cultural factors in healthy and diseased fields to identify those most strongly associated with BRR. Factors significantly correlated with BRR symptoms were soil compaction, fine soil texture, absence of raised beds, high application rates of the herbicide terbacil, advanced age of planting, nonuse of the fungicide metalaxyl, and cumulative years of strawberry monoculture. Populations of Pratylenchus spp. were not associated with poor root health. The data suggest that most factors that compromise root growth may predispose strawberry plants to infection by site-specific BRR pathogens. Chemical names used: 3-tert-butyl-5-chloro-6-methyluracil (terbacil); N-(2,6-dimethylphenyl)-N-(methoxyacetyl) alanine methyl ester (metalaxyl).


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1125b-1125
Author(s):  
Allen D. Owings ◽  
Steven E. Newman

The action of foliar-applied uniconazole, paclobutrazol, dikegulac-sodium, ancymidol, 6-BA, GA4+7, and 6-BA + GA4+7 On container–grown Photinia × fraseri was studied over a one year period. Vegetative growth habit was evaluated at three month intervals. Shoot dry weight and histological examination of stern anatomy in the apical meristematic region was conducted at experiment termination.Several plant growth regulators, primarily uniconazole, 6-BA, 6-BA + GA4+7, and dikegulac-sodium, stimulated lateral branching. Linear increases in lateral branching occurred as application rates increased. High application rates of uniconazole and paclobutrazol created an asymmetrical growth habit and decreased dry weight accumulation.


Sign in / Sign up

Export Citation Format

Share Document