scholarly journals Flower strips increase the control of rosy apple aphids after parasitoid releases in an apple orchard

2022 ◽  
Author(s):  
Kévin Tougeron ◽  
Louise Ferrais ◽  
Pauline Gardin ◽  
Marc Lateur ◽  
Thierry Hance

Mass releases of two parasitoid species, Aphidius matricariae and Ephedrus cerasicola, may provide an alternative measure to pesticides to control the rosy apple aphid Dysaphis plantaginea in organic apple orchards. As a proof of concept study, we tested if the presence of flower strips between apple tree rows could improve the action of three early parasitoid releases—and of other naturally present aphid enemies—on the control of aphid colonies and number of aphids per tree. Apple trees located at different distances from parasitoid release points were monitored in plots with and without flower strips in an organic apple orchard over two years, along the season of aphid infestation (March to July). Our case study demonstrated that the presence of flowering plant mixes in the alleyways of an apple orchard improved the biological control of D. plantaginea, with an effect size of 33.4% less aphids in plots with flower strips, compared to plots without flower strips, at the infestation peak date. We also showed a negative effect of higher distance to parasitoid release points on aphid control, but our results at the infestation peak date suggest that the presence of flowers could marginally compensate for the detrimental effect of distance, probably by improving the persistence and dispersal capacities of natural enemies. Despite high variations in aphid population dynamics between years, we conclude that combining flower strips with early parasitoid releases in apple orchards is promising for biological control of the rosy apple aphid, although the method merits to be further refined and repeated in more orchards.

2021 ◽  
Author(s):  
Louise Ferrais ◽  
Kevin Tougeron ◽  
Pauline Gardin ◽  
Thierry Hance

Alternative measures to pesticides to control the rosy apple aphid Dysaphis plantaginea are being developed. Naturally occurring predators and parasitoids often fail to reduce aphid abundance below the economic threshold in orchards, because they are active too late after the aphid first infestation. We tested the efficiency of mass release of two parasitoid species, Aphidius matricariae and Ephedrus cerasicola, early in the season to match the presence of aphid fundatrix (sensitive stages). In this trial focusing on an organic apple orchard, three releases were done either every week or every two weeks to test the effect of the release frequency, during two consecutive years. The number of aphid colonies and aphid number per tree were monitored from late March to late May. Degree-days necessary for parasitoid emergence in the field after release were calculated. We show that a sufficient level of aphid control by parasitoids is reached during the first month of the survey, but control mostly fails during the second part of the monitoring session, for both release treatments, and compared to the neem oil control treatment. The relative effects of release frequencies were different between years probably because of interannual differences in aphid population dynamics and initial infestation in orchards. The field survey and the degree-day model suggest that parasitoid releases, at either frequency, are promising candidates for biological control of the rosy aphid, although the method still needs proper calibration. This conclusion needs to be reinforced by repeating the study in more orchards, but our case study lays the first empirical basis that will help to develop future control methods of aphids by parasitoid releases in apple orchards. We argue that releases should be done one to two weeks before first aphid detection to account for long development times of parasitoids at relatively low temperatures.


PLoS ONE ◽  
2011 ◽  
Vol 6 (11) ◽  
pp. e26694 ◽  
Author(s):  
Blas Lavandero ◽  
Christian C. Figueroa ◽  
Pierre Franck ◽  
Angela Mendez

1993 ◽  
Vol 125 (5) ◽  
pp. 967-969 ◽  
Author(s):  
David R. Clements ◽  
Rudolf Harmsen

Effective management of the interactions within the mite community is critical to biological control of economically damaging phytophagous mites such as Panonychus ulmi Koch (Tetranychidae) (Clements and Harmsen 1990). Although much is known about the potential role of phytoseiid mites in controlling P. ulmi (Dover et al. 1979), mites from at least seven other families may be present in apple orchards (Thistlewood 1991). Stigmaeid mites are predators which may play a beneficial role in biological control in conjunction with phytoseiids (Clements and Harmsen 1992). Eriophyid mites are phytophagous but seldom cause economic damage, and may compete with tetranychids and provide alternative food for predators of tetranychids (Croft and Hoying 1977).


2017 ◽  
Vol 9 (4) ◽  
pp. 262 ◽  
Author(s):  
Bismark Addai ◽  
Adjei Gyamfi Gyimah ◽  
Wendy Kumah Boadi Owusu

Savings among individuals in the informal sector is imperatively expedient if they are to have any decent and comfortable living conditions at retirement as savings in the informal sector become the obvious substitute for formal pensions. However, much is not known regarding the savings habits of informal sector, particularly, the fishing communities in Ghana. Apparently, this study investigates into the determinants of savings habit of the informal sector in Ghana, using the case of the Gbegbeyishie Fishing community. The data for the study was obtained through administering questionnaires and interviewing targeted respondents. A 120 sample size was randomly drawn from Gbegbeyishie fishing community in Ghana. This study employs the probit model in estimating the determinants of savings in the informal sector. SPSS and STATA statistical packages were employed in descriptive analysis and estimation of the probit model respectively.It is glaring in this study that age, gender and income are statistically significant conditions for savings in the informal sector. It is also evincing in this study that Age has a significant negative effect on savings and aging decreases the propensity to save by 0.1577656. On the other hand, income has statistically significant positive effect on savings and that a one unit change in the income variable increases the propensity to save by 0.1292502. Also, the probability for a male, all other factors held constant, to save is higher than for a female to save and being a man increases the propensity to save by 0.2024894. The study also revealed that the main hindrance to savings in the Gbegbeyishie Fishing Community is Low income.As a result, the authors recommend that men and married people should be targeted whiles paying little attention to the aged in stimulating savings among fishing communities in Ghana. Educational programs could also be organized for the workers in the informal sector as most of the workers have no education which could hinder their income earning capacity and for that matter savings. Further research could also be engineered to consider macro-economic conditions for savings habit in Ghana.


Facilities ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shang Gao ◽  
Sui Pheng Low ◽  
Hua Qian Gong

Purpose The purpose of this study is to investigate the effects of the activity-based workspace (ABW) on employee belonging. Place attachment theory (PAT) is used as a proxy to understand and measure the belongingness of employees to their physical workplaces. Design/methodology/approach A case study of a bank’s newly retrofitted ABW office is conducted, providing fresh perspectives on the effect of ABW on employee belonging. A questionnaire survey was used to understand employee belongingness. Surveys are conducted with employees of the bank (n = 100) who experienced the transition from the conventional open-plan office with designated seats to an ABW, to understand and compare the change in employee belonging after the transition, by studying the level of belonging achieved in the space before and after. Findings The results showed that there was a positive sense of belongingness amongst employees working in the ABW space, as per the PAT framework and an increased sense of belongingness compared with the previous conventional open-plan office. However, ABWs were found to also have a negative effect on employees’ sense of control and security. Originality/value Maslow’s hierarchy of needs indicates that a feeling of belonging is fundamental to humans. The need for belonging is also applicable in the workplaces of today’s progressive corporate organisations, where there is increased pressure and incentive to appeal to and retain talent. This research was conducted in response to the huge growth in interest in activity-based working across the corporate real estate community. As there has been no prior research done in the area of the emotional need for belongingness in ABW.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abraham Gyamfi Ababio ◽  
Arthur Gnonsio Mangueye

Purpose Improving tax compliance would drive the needed development in Ghana. Small and medium scale enterprises (SME) constitute a sizable proportion of the Ghanaian economy but its contribution to tax revenue is below expectation. This study aims to determine whether SME's perception of state legitimacy affects tax compliance. Design/methodology/approach A structured questionnaire was administered to 200 SMEs randomly drawn from Dodowa in the Shai-Osudoku District of Greater Accra Region. Descriptive statistics and the Probit model with sample selection were used to analyse the data. Findings The study found that SME's perception of government legitimacy exerts a significant negative effect on reducing profit to avoid tax liability (ß = −0.0305, p < 0.05). Other factors such as education and fear of fines and penalties were also found to reduce the likelihood that the firm would reduce profit to avoid high tax liability. Still, tax knowledge had a positive effect on this behaviour. Practical implications This study would help deepen policymakers' knowledge of how to improve tax compliance among SMEs in Ghana. Originality/value The originality of this work is that it explicitly models the role of fiscal exchange theory in explaining tax compliance among SMEs in Ghana by using robust methodology.


2015 ◽  
Vol 4 (2) ◽  
pp. 102
Author(s):  
Muhiuddin Haider ◽  
Milind Patel ◽  
Priyanka Bhattacharjee ◽  
Maariya Bassa

Biodiversity is the variability of between genetics, species, or ecosystems of living organisms within a specific region. Biodiversity is essential for sustaining healthy living networks and systems because it allows for a variety of food sources, medicine, and biological control, while also playing a significant role in atmospheric regulation, nutrient cycling, and pollination. Loss of biodiversity and ecosystem change increases the risk of the emergence or spreading of infectious diseases and global pandemics such as the Avian Influenza (AI H5N1). Biotechnology is one solution for reducing, and ultimately eliminating, the transmission of avian influenza. Traditional methods of treating infected animals, such as common vaccines, are temporary solutions that have no effect on the biodiversity of an ecosystem. Methods in animal biotechnology such as artificial insemination, embryo transfer, and <em>in vitro </em>fertilization have led to developments of cheaper, safer, and more effective vaccines. Livestock that have been treated for H5N1, as well as those that are healthy and have never been infected have proven to increase the diversity, leading to the elimination of specific issues. Similar effects are attainable if these animal biotechnology methods were to be used on poultry infected with the avian influenza virus.


2005 ◽  
Vol 54 (3-4) ◽  
pp. 389-402 ◽  
Author(s):  
Péter Tamás Nagy

In a three-year study carried out at the Debrecen-Pallagi nursery of the University of Debrecen, the nutrient contents, humus content and pH of the soil were determined in integrated and organic apple orchards established on brown forest soil with thin interstratified layers of colloid and sesquioxide accumulation. The organic orchard was only given organic manure (50 t/ha) in spring 2000 and 2002, while the integrated orchard was treated with 250 kg/ha complex NPK fertilizer (16.5-16.5-16.5) every year between 1997 and 2003 after the leaves had fallen. An additional 50 kg/ha N active agent as NH 4 NO 3 was applied every year, while 4 t/ha lime fertilizer (carbonation mud) was provided in autumn 2002 and 25 t/ha organic manure in November 2003. In 2004 no fertilizer was given to either orchard. The available forms of N (NO 3- , NH 4+ , organic N and total N) and P (ortho-, organic and total-PO 43- ) were determined after extraction with 0.01 M CaCl 2 , while the Ca, Mg and microelement (Mn, Cu, Zn) content of the soil was extracted with NH 4 -acetate +EDTA (Lakanen-Erviö extractant). Potassium was measured in both extractants. The results showed that the inorganic, organic and total soluble nitrogen in the soil were significantly higher (P = 0.05) in the integrated orchard than in the organic one. It was found that the quantity and ratio of the organic N fraction was comparable with that of the inorganic N forms. The ortho- phosphate and total P fractions were significantly higher (P = 0.05) in the integrated apple orchard than in the organic orchard, while there was no significant difference in the organic P quantity. The potassium data showed that both the integrated and organic orchards contained a satisfactory amount of adsorbed K in spite of the poor colloid content and high soil acidity. The Ca, Mg, Co and Zn contents of the integrated soils were significantly higher (P = 0.05) than in the organic orchard. For Mn, however, no substantial difference was found between the integrated and organic orchards. With the exception of Mn, the nutrient concentrations reflected the differences in the nutrient management of the integrated and organic apple orchards.


2021 ◽  
Vol 2 (6) ◽  
pp. 1-6
Author(s):  
Waghmare Kranti ◽  
Ghayal Nivedita ◽  
Mahesh Shindikar

The interaction between plant-aphid is phenomenal and complex. Aphids possess efficient mouthparts which feed on plant sap intensively. Adaptation to host plants and successful feeding is achieved through the strategic ability of aphids to reproduce sexually and asexually (parthenogenesis). Aphid infestation damages the plant in diverse ways and induces plant defense. Though plant elicit direct and indirect defense to resist aphid feeding, the effectiveness of plant resistance depends largely on the aphid infestation rate and quality of the host plant. To control aphid infestation and plant damage, dependency on insecticides is undesirable due to insecticidal resistance of aphids and environmental pollution. The approach towards the development of the genetically engineered crops which are aphid resistant can be the considerable potential to aphid control..


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