NITROGEN FERTILIZATION OF THE HOST TREE AND POPULATION GROWTH OF THE BALSAM WOOLLY APHID, ADELGES PICEAE (HOMOPTERA: ADELGIDAE)

1968 ◽  
Vol 100 (5) ◽  
pp. 478-485 ◽  
Author(s):  
J. Roderick Carrow ◽  
K. Graham

AbstractThe relationship between nutrition of the host tree, Abies amabilis (Dougl.) Forbes, as influenced by nitrogen fertilizers, and the growth of populations of the balsam woolly aphid, Adelges piceae (Ratz.), was investigated. Sixty trees, growing in a greenhouse in two soil types, a nutrient-deficient mineral soil and an enriched humic soil, were infested with woolly aphid larvae. Subsequently, groups of 10 trees received foliar treatments of various concentrations of ammonium nitrate and urea. The following year, 32 young trees in Seymour Valley, B.C., were studied to determine the effect of fertilization of uninfested trees on establishment of aphid larvae.In the greenhouse, foliar sprays of 1% ammonium nitrate solution resulted in a 23% decrease in population in 10 weeks, as contrasted with a 31% increase in the control population. In the field, larval establishment was 31% to 37% lower on the ammonium nitrate-treated trees than on the control trees. Inasmuch as there was no evidence of increased mortality of aphids in situ, we infer that the fertilizer acts primarily by inhibiting initial settling of larvae on the host trees.

2021 ◽  
Vol 325 ◽  
pp. 131-136
Author(s):  
Iveta Plšková ◽  
Petr Hrubý ◽  
Libor Topolář ◽  
Michal Matysík

The paper summarizes partial results of a study of degradation of materials based on alkali-activated blast-furnace slag (AAS) and comparative on cement CEM III/A 32.5 R after exposure to aggressive environments. It further specifies the possibilities for utilising destructive and non-destructive techniques to determine the progress of degradation and characterizes the degree of their correlation. After 28 days of ageing in a water environment, the produced test specimens (40×40×160 mm beams) were placed in aggressive media (ammonium nitrate solutions; sodium sulfate, rotating water) and after subsequent 28, 56 and 84 days of degradation were subjected to testing. Testing comprised both a destructive form (determination of compressive strength and flexural strength) and a selected non-destructive technique (Impact-echo method). The partial outputs were supplemented by the results acquired from monitoring weight changes. In addition, the development of Ultrasonic Pulse Velocity in relation to the progress of the degradation processes was also monitored. While the exposure of both test specimens to water and sodium sulfate did not result in any significant changes, the exposure to the ammonium nitrate solution exhibited rapid signs of degradation associated with a significant reduction in functional characteristics.


2014 ◽  
pp. 431-438 ◽  
Author(s):  
Quoc Phung ◽  
Norbert Maes ◽  
Diederik Jacques ◽  
Geert De Schutter ◽  
Guang Ye

2001 ◽  
Vol 79 (8) ◽  
pp. 1207-1212 ◽  
Author(s):  
Abdul Wahab ◽  
Sekh Mahiuddin

Density, electrical conductivity, speeds of sound, and viscosity of aqueous ammonium nitrate solutions were measured as functions of concentration (m, mol kg–1) (0.1599 [Formula: see text] m [Formula: see text] 20.42) and temperature (T, K) (273.15 [Formula: see text] T [Formula: see text] 323.15). Experimental values are consistent with the reported data. Variation of isotherms of electrical conductivity, isentropic compressibility, and structural relaxation time with concentration evoke structural information on the ion solvation in aqueous ammonium nitrate solution at different concentration regions. The primary hydration numbers of ammonium nitrate were estimated at a particular concentration at which the isentropic compressibility isotherms converge. The existence of free hydrated ions, resulting from strong ion solvent interactions in dilute to 9.1 mol kg–1, the solvent-separated ion-pairs resulting from the relative competition between the ion–solvent and the ion–ion interactions in 9.1 to 12.0 mol kg–1, and the solvent-shared ion-pairs beyond 12.0 mol kg–1 resulting from a decrease in the number of solvent molecules, govern the transport process.Key words: electrical conductivity, speeds of sound, viscosity, ammonium nitrate, hydration number.


1973 ◽  
Vol 3 (1) ◽  
pp. 122-139 ◽  
Author(s):  
J. Roderick Carrow ◽  
Robert E. Betts

Balsam woolly aphids were reared on young grand fir trees maintained in controlled environment or outdoors. Solutions of various nitrogen fertilizers were applied repeatedly to the trees and the effects on aphids and bark amino acids were studied. On trees fertilized with ammonium nitrate or a sequence of compounds, aphid population growth was less than on trees fertilized with urea or potassium ammonium nitrate. On urea-fertilized trees, populations multiplied 16.5 times in five generations, compared with a 5.7-fold increase on unfertilized trees and a 1.4-fold increase on ammonium nitrate-fertilized trees. These differences resulted from effects of these nutrients on aphid life history. Urea promoted aphid establishment and reproduction, whereas ammonium nitrate affected these processes, as well as survival, adversely. The highest establishment and survival rates resulted from potassium ammonium nitrate.These differences may be related to fertilizer-induced changes in the amino acid diet of the aphid. Thin layer electrophoresis and chromatography revealed that urea, ammonium nitrate, and calcium nitrate each increased arginine concentrations in the bark, the highest levels resulting from ammonium nitrate. Traces of phenylalanine and asparagine, found in other treatments, were absent from trees fertilized with ammonium nitrate during June.


1983 ◽  
Vol 23 (7) ◽  
pp. 733-752 ◽  
Author(s):  
Pushpalatha C. Bhat ◽  
M.P. Sathyavathiamma ◽  
N.G. Puttaswamy ◽  
R.M. Mallya

Author(s):  
O. Kruchynenko ◽  
A. Antipov

The coproovoscopic methods involving count chambers are widely used in the veterinary practice for diagnostics. These methods are important in assessments of the prevalence rates of nematode infections in pigs and for FECR tests. However, more basic data is needed on the efficiency of the commercial methods of diagnostics, tested at the different specific gravity of the flotation solutions. In a thorough analysis of publications of Ukrainian scientists, we have found that the data is sparse on the efficiency comparison of the modified McMaster’s and MiniFLOTAC methods. The aim of our study was to compare the efficiency of the commercial coproovoscopic techniques: the modified McMaster’s method (with sensitivity of 25 EPG), and MiniFLOTAC combined with Fill-FLOTAC (with sensitivity of 5 EPG) in testing for A. suum infection in piglets. Results of approbation of the mentioned methods are presented for the following saturated solutions: NaCl (SG=1.2), MgCl2 •6H2 O (SG =1.27) and NH4 NO3 (SG=1.28). Fecal samples were taken at own private farm, in Mlynok village of Onufriivka district, Kirovohrad region from 20 4 month old pigs with spontaneous A. suum infection. The laboratory assessments were performed in the Scientific Laboratory of Parasitology and Veterinary and Sanitary Expertise of the Poltava State Agrarian Academy. It is established that at high rates of A. suum infection in young pigs, McMaster’s method with the ammonium nitrate solution is more efficient compared to the Mini-FLOTAC method. In average, 5331.2 eggs of A. suum were determined per 1 g of feces using the former method, compared to 4567.5 EGP according to the Mini-FLOTAC technique (P < 0.001). The highest diagnostic efficiency of the modified McMasters method and the combination of Mini-FLOTAC and Fill-FLOTAC is seen when ammonium nitrate (NH4 NO3 ) solution of 1.28 SG is used (P < 0.001). Our results add new data on the efficiency of the commercial methods of diagnostics with varying specific gravity of the flotation solutions, for pigs infected with nematodes. Key words: EPG, pigs, nematode, ascariasis, diagnostics, efficiency.


Author(s):  
Sergey I. Lazarev ◽  
Sergey V. Kovalev ◽  
Dmitry N. Konovalov ◽  
Olga A. Kovaleva

The paper presents a generalized analysis of literature data on the current-voltage, omics characteristics and electrical conductivity of membrane systems. Based on an analysis of the literature, it is noted that electrodialysis is a promising method for the separation of solutions for the production of ammonium nitrate. An analysis of literature revealed that the application of an external constant electric field to the membrane separation of solutions containing charge-transporting components (nitrate ions and ammonium ions) causes the directed transfer of cations and anions through the membranes. The studies revealed that with the baromembrane separation of the studied solutions with increasing transmembrane pressure, the specific output stream increases. This is due to an increase in the driving force of the process. For the OFAM-K anode membrane, with an increase in the current density, with the electrobaromembrane separation of the ammonium nitrate solution, the specific output stream decreases, which is associated with a change in the pH value of the acidified anode permeate. nd for the OPMN-P cathode membrane, the specific output stream increases with a change in the pH of the alkalized cathode permeate. A modified mathematical equation is proposed for theoretical calculation of the specific output stream and the retention coefficient of the OFAM-K and OPMN-P nanofiltration membranes. Experimental studies of membrane systems equipped with the anode OFAM-K and the near-cathode OPMN-P membranes from voltage and transmembrane pressure revealed that for the aqueous solution of ammonium nitrate there are two characteristic periods on the current-voltage, omics characteristics and electrical conductivity of the membrane system (the first period is beyond regime, dissociation of water (H+ and OH-) at the phase boundary with the advent of additional electric current carriers, the second is the degradation of the active layer of a semipermeable membrane). When studying the current-voltage characteristics of a membrane system equipped with an anode OFAM-K and a near-cathode OPMN-P membranes, when separating model and technological solutions, a decrease in the total omics resistance of the system is observed, which is associated with the solution throttling process.


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