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41.
Resistance to chemicals and some biological control agents by Plutella xylostella has resulted in the search for alternatives, such as P. xylostella granulovirus (PlxyGV), for the management of P. xylostella. However, use of PlxyGV would be economical only if it is applied at the right crop stage and at economic threshold levels.
Hence, we evaluated the field level economic threshold for application of PlxyGV at the reproductive phase of cauliflower
taking into consideration both the economic threshold model and the economic optimization model. PlxyGV was found to be very
effective in management of the pest and was comparable to weekly applications of quinalphos 25EC. However, due to the higher
cost of PlxyGV application than quinalphos, the cost benefit ratio with quinalphos application was much higher than the virus
application. The net income from the virus application decreased both at lower thresholds—due to the higher cost of plant
protection, and at higher thresholds—due to the increased damage by the pest. Based on the economic threshold model, the economic
threshold for application of PlxyGV was estimated at 9–11 larvae per ten plants. Considering the net income per hectare and
the cost of plant protection, it was found that at a threshold of 12–14 larvae per ten plants net income was just equal to
the cost of plant protection. Based on the economic optimization model, the optimum threshold for application of PlxyGV was
15 larvae per ten plants when profits are maximum. 相似文献
42.
Ramasamy Srinivasan Subramanian Sevgan Sunday Ekesi Manuele Tam 《Pest management science》2019,75(9):2446-2454
Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest‐caused economic losses. However, over‐reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi‐based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry 相似文献
43.
Subramanian Rajesh C Kiruthiga Vittobai Rashika Revathi Priya Rangarajan Badra Narayanan 《Aquaculture Research》2010,41(4):545-551
The gene coding for translationally controlled tumour protein (TCTP) was polymerase chain reaction amplified from haemocyte cDNA of Indian shrimp, Penaeus indicus, and sequenced. The N‐terminal region, a conserved one among all the TCTPs, was shown to have one substitution at position 37, in the Indian isolate. Besides this, there were two substitutions in the C‐terminal region (135, 149), exclusive to the Indian isolate. Phylogenetic analysis suggested a close relatedness of TCTP from P. indicus to Fenneropenaeus chinensis compared with other isolates. Translationally controlled tumour protein gene expression was found to be elevated in the haemocytes of WSSV‐infected shrimps compared with the uninfected ones. However, tissues from the infected shrimps did not exhibit any detectable levels of TCTP expression. 相似文献
44.
Phenotypic and genetic parameters for body traits in the giant freshwater prawn (Macrobrachium rosenbergii) in India
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Bindu R Pillai Pa Luan Lalrinsanga Raul W Ponzoni Hooi Ling Khaw Kanta Das Mahapatra Swagatika Mohanty Gunamaya Patra Namita Naik Haramohan Pradhan Pallipuram Jayasankar 《Aquaculture Research》2017,48(12):5741-5750
Phenotypic and genetic parameters were estimated for three body traits (harvest weight, carapace length and standard length) and for adult male morphotypes of the giant freshwater prawn Macrobrachium rosenbergii in a fully pedigreed synthetic population in India. The data set included 9,173 progeny produced over four generations from 162 sires and 234 dams. Variance components and genetic parameters were estimated fitting an animal model using the residual maximum‐likelihood methodology. The heritabilities for harvest body weight (HW), carapace length (CL) and standard length (SL) were moderate (0.22 ± 0.056, 0.22 ± 0.055 and 0.25 ± 0.059 respectively). The common environmental effects for HW, CL and SL were 0.10 ± 0.020, 0.08 ± 0.018 and 0.10 ± 0.021 respectively. As M. rosenbergii is sexually dimorphic, we estimated heritabilities within each sex. Heritability of HW in females (0.27 ± 0.068) was greater than that in males (0.15 ± 0.057). CL and SL followed the same pattern. The occurrence of male morphotypes is a unique characteristic of adult populations of M. rosenbergii. Populations from culture ponds exhibit a wide range of sizes. To examine whether there was a heritable component in male morphotype frequencies, we treated male morphotypes as traits. The additive genetic variance (and hence the heritability) was zero for male morphotype, indicating that selective breeding to increase the proportion of desirable male morphotypes would not be effective. The genetic correlations among body traits were all positive, high and approaching unity. The results are discussed in relation to selection plans for the giant freshwater prawn. 相似文献
45.
The nature of cell-mediated immune (CMI) responses was studied in cross-bred bovine calves, immunised by attenuated and allogeneic macroschizonts of Theileria annulata. The CMI responses were also investigated in calves, destined to survive or die of tropical theileriosis (Theileria annulata) induced by a virulent dose of sporozoites or macroschizont-infected lymphoblasts. Calves suffering fatal theileriosis showed poor CMI response. Microcytotoxicity assay revealed an enhanced population of specific cytotoxic cells amongst the peripheral blood lymphocytes (PBL) of calves resolving the infection successfully. The E rosette assay showed proliferation of T cells and the assay for macrophage migration inhibition factor (MIF) demonstrated antigen sensitised cells in the PBL. Calves, immunised by allogeneic and attenuated macroschizont-infected lymphoblasts or those recovering from virulent macroschizont-induced infection, showed protective CMI responses with patterns similar to those appearing after non-fatal sporozoite infection. 相似文献
46.
Primary left ventricular hemangiosarcoma diagnosed by endomyocardial biopsy in a dog 总被引:1,自引:0,他引:1
B W Keene J E Rush A J Cooley R Subramanian 《Journal of the American Veterinary Medical Association》1990,197(11):1501-1503
An 8-year-old spayed Golden Retriever was examined because of recent onset of congestive heart failure complicated by ventricular arrhythmias. Echocardiography revealed a thickened, hypokinetic region of the left ventricular free wall. Fluoroscopically guided transarterial endomyocardial biopsy of the hypokinetic region of the left ventricle revealed infiltration of the endocradium by neoplastic cells consistent with hemangiosarcoma. The dog's clinical condition deteriorated 7 weeks later, and necropsy confirmed the diagnosis and primary site of origin of the tumor. This report describes the clinical use of an endomyocardial biopsy technique to diagnose an infiltrating myocardial tumor that was associated with signs mimicking canine dilated cardiomyopathy. 相似文献
47.
A close identity in virulence and cross-protection of four isolates of Theileria annulata was observed when infection was produced in naive, crossbred (Bos taurus male X B. indicus female) male calves. The evidence that strains of T. annulata in India differ in virulence and immunogenicity is equivocal at present. 相似文献
48.
K. S. Subramanian G. Selvakumari K. V. Selvaraj K. N. Chinnaswami 《Journal of Agronomy and Crop Science》1991,167(3):155-158
With a view to study the influence of irrigation regimes at critical stages of sugarcane an investigation was carried out at Agricultural Research Station, Tamil Nadu Agricultural University, Bhavanisagar, India during Mid-late season (March–April) using Co 6304 as test variety. Treatments consisted of eight irrigation regimes created by imposing two levels of irrigation 0.75 and 0.5 IW/CPE ratio at critical stages (tillering, grand growth and maturity). The results revealed that irrigating sugarcane at 0.75 IW/CPE ratio at tillering and growth and 0.5 IW/CPE at maturity phase recorded highest nutrient uptake, cane yield (139 t/ha) with 10.6 % CCS consuming 1791 mm of water the highest water use efficiency of 77.3 kg/ha mm. 相似文献
49.
Patnaik Siddhi Sahoo Lakshman Mohanty Mausumee Bit Amrita Meher Prem Kumar Das Sachidananda Jayasankar Pallipuram Saha Jatindra Nath Das Paramananda 《Fish physiology and biochemistry》2021,47(5):1353-1367
Fish Physiology and Biochemistry - Activin receptor type IIB (ActRIIB) is a transmembrane serine/threonine kinase receptor which plays a pivotal role in regulating the reproduction in vertebrates... 相似文献