CHEMICAL CONTROL OF WEEDS IN LINING-OUT STOCK

1964 ◽  
Vol 40 (3) ◽  
pp. 392-397
Author(s):  
M. G. Johnson

The following herbicides were used in attempts to control weeds in lining-out stock of 16 species of trees and shrubs: simazine, neburon, endothal, CIPC, DNBP and 2, 4-D. Only simazine and neburon produced a significant reduction in weed crops. In further studies on simazine applications of 3 and 4 pounds per acre of the wettable-powder formulation provided good control. The granular formulation of simazine did not produce a significant reduction in either the number of species or crops of weeds. Variation in survival of nursery stock was more closely related to the individual species of trees and shrubs than to the formulations or rates of application of simazine.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1076c-1076
Author(s):  
J. J. Knabke ◽  
H. G. Hancock

Talstar 10WP insecticide/Miticide (bifenthrin) is used for the control of a broad spectrum of economic pests on ornamentals. Over 100 species of greenhouse and field–grown plants, trees and shrubs have been shown to exhibit no phytotoxic response to the wettable powder formulation. Research efforts with alternative bifenthrin, formulations, which exhibit equivalent pest efficacy and lack of phytotoxicity, may also provide unique application opportunities.


2021 ◽  
Vol 9 (4) ◽  
pp. 797
Author(s):  
Davide Mugetti ◽  
Mattia Tomasoni ◽  
Paolo Pastorino ◽  
Giuseppe Esposito ◽  
Vasco Menconi ◽  
...  

The Mycobacterium fortuitum group (MFG) consists of about 15 species of fast-growing nontuberculous mycobacteria (NTM). These globally distributed microorganisms can cause diseases in humans and animals, especially fish. The increase in the number of species belonging to MFG and the diagnostic techniques panel do not allow to clarify their real clinical significance. In this study, biomolecular techniques were adopted for species determination of 130 isolates derived from fish initially identified through biochemical tests as NTM belonging to MFG. Specifically, gene sequencing and phylogenetic analysis were used based on a fragment of the gene encoding the 65 KDa heat shock protein (hsp65). The analyzes made it possible to confirm that all the isolates belong to MFG, allowing to identify the strains at species level. Phylogenetic analysis substantially confirmed what was obtained by gene sequencing, except for six strains; this is probably due to the sequences present in NCBI database. Although the methodology used cannot represent a univocal identification system, this study has allowed us to evaluate its effectiveness as regards the species of MFG. Future studies will be necessary to apply these methods with other gene fragments and to clarify the real pathogenic significance of the individual species of this group of microorganisms.


1967 ◽  
Vol 57 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Margaret E. Richardson ◽  
D. J. W. Rose

An account is given of the history of chemical control Phthorimaea operculella (Zell.) in potato fields in Rhodesia since the introduction of DDt prior to 1952. The failure of DDT and endrin, in routine spraying, to control field infestations is reproted, and some evidence that this is due to insecticide resistance is given. The results of critical field trials made in 1961, 1964 and 1965 to evaluate a range of insecticides for control of P. operculella and for their effects on populations of Macrosiphum euphorbiae (Thos.) are presented, together with the results of some laboratory tests. Good control of P. operculella in the field was obtained with sprays of azinphos-methyl at the rate of 0.5 lb active ingredient in 20 gal. water per acre, and two new compounds, methidathion and chlorfenvinphos, showed promise for the future.


Phytotaxa ◽  
2021 ◽  
Vol 502 (2) ◽  
pp. 191-207
Author(s):  
SHIVANI KASHYAP ◽  
CHANDAN KUMAR SAHU ◽  
ROHIT KUMAR VERMA ◽  
LAL BABU CHAUDHARY

Due to large size and enormous morphological plasticity, the taxonomy of the genus Astragalus is very complex and challenging. The identification and grouping of species chiefly based on macromorphological characters become sometimes difficult in the genus. In the present study, the micromorphology of the seeds of 30 species belonging to 14 sections of Astragalus from India has been examined applying scanning electron microscopy (SEM) along with light microscopy (LM) to evaluate their role in identification and classification. Attention was paid to colour, shape, size and surface of seeds. The overall size of the seeds ranges from 1.5–3.2 × 0.8–2.2 mm. The shape of the seeds is cordiform, deltoid, mitiform, orbicular, ovoid and reniform. The colour of seeds varies from brown to blackish-brown to black. Papillose, reticulate, ribbed, rugulate and stellate patterns were observed on the seed coat surface (spermoderm) among different species. The study reveals that the seed coat ornamentations have evolved differently among species and do not support the subgeneric and sectional divisions of the genus. However, they add an additional feature to the individual species, which may help in identification in combination with other macro-morphological features.


Author(s):  
Julie M. Fives ◽  
F. I. O'Brien

The Galway Bay area was sampled quantitatively for plankton during 1972–3. The larvae and/or post-larvae of 67 species of fish were identified from the plankton. The recorded occurrence per m3 and the percentage occurrence of the individual species is presented and discussed, and reference is made to the concurrent occurrence of various chaetognath species and copepod species. The results of previous investigations of the plankton of the Galway Bay area are mentioned.


2019 ◽  
Vol 30 (3) ◽  
pp. 15-22
Author(s):  
Katarzyna Szyszko-Podgórska

Abstract The purpose of the work was to identify the occurrence of butterflies depending on landform uses and human influence on the population domination structure. The research was conducted in the ‘Krzywda’ field-and-forest Site occupying 172 ha. The area consists of the land leaving in fallow, meadows and wasteland including about 68 ha of swamps that are strongly eutrophic due to human economic activity. The area is subjected to artificial succession inhibition processes in the form of mowing and cutting of trees and shrubs. 32 species of butterflies were recorded during the research, that is, 20% of all species within this group occurring in Poland. The research has approved the great spatial and quantitative diversification of the occurring area of butterflies depending on the form of the land uses. The greatest number of species and their greatest populations were found in the land laying in fallow without the removal of the biomass. The least number of species and their specimens were collected in the unmown laying fallow land. Lycaena virgaureae was the most numerous species collected. The correct domination structure characterized by a small number of numerous species and a large number of species consisting of a low number of specimens. Processes observed in the studied Site subjected to various types of land use influence the occurrence diversity of this group of insects.


Author(s):  
Lorena Lanthemann ◽  
Sofia van Moorsel

Duckweeds (Lemnaceae) are increasingly studied for their potential for phytoremediation of heavy-metal polluted water bodies. A prerequisite for metal removal, however, is the tolerance of the organism to the pollutant, e.g., the metal zinc (Zn). Duckweeds have been shown to differ in their tolerances to Zn, however, despite them most commonly co-occurring with other species, there is a lack of research concerning the effect of species interactions on Zn tolerance. Here we tested whether the presence of a second species influenced the growth rate of the three duckweed species Lemna minor, Lemna gibba, and Lemna turionifera. We used four different Zn concentrations in a replicated microcosm experiment under sterile conditions, either growing the species in isolation or in a 2-species mixture. The response to Zn differed between species, but all three species showed a high tolerance to Zn, with low levels of Zn even increasing the growth rates. The growth rates of the individual species were influenced by the identity of the competing species, but this was independent of the Zn concentration. Our results suggest that species interactions should be considered in future research with duckweeds and that several duckweed species have high tolerance to metal pollution, making them candidates for phytoremediation efforts.


2015 ◽  
Vol 24 (1) ◽  
pp. 34-40 ◽  
Author(s):  
B. P. Heyojoo ◽  
S. Nandy

This study aims to estimate above-ground phytomass and carbon of TROF ecosystem in part of Bijnor district in Uttar Pradesh state of India using IRS P6 LISS-IV satellite image by geo-spatial approach coupled with field sampling. Chacko’s formula was referred to compute number of samples in each TROF types and the sample plot size in each stratum was adopted from Vegetation Carbon Project (VCP) under National Carbon Project (NCP). With the help of field data consisting mainly the height and girth information, volume of each individual tree per plot was obtained using site and tree species-specific standard volumetric equations. The phytomass was calculated by multiplying volume with Biomass Expansion Factor (BEF) then with regional specific gravity of the individual species and summed up in each plot to get total phytomass per plot. The total phytomass per plot was reported to be maximum 544.00 t/ha for linear TROF followed by 121.89 t/ha for block TROF. The carbon from phytomass was obtained by multiplying the total phytomass by a conversion factor that represents the average carbon content in phytomass. Spectral modeling for phytomass with different bands and indices were established and the best fit curve (R2 = 0.552) with red band was applied to generate phytomass and carbon distribution map of the study area.Banko Janakari, Vol. 24, No. 1, pp. 34-40


2020 ◽  
Author(s):  
Alexander A. Zhgun

A filamentous fungus (also called molds or moldy fungus) is a taxonomically diverse organism from phylum Zygomycota and Ascomycota with filamentous hyphae and has the ability to produce airborne spores or conidia. Currently, more than 70,000 molds are known, and some of them contain unique and unusual biochemical pathways. A number of products from such pathways, especially, the secondary metabolite (SM) pathways are used as important pharmaceuticals, including antibiotics, statins, and immunodepresants. Under different conditions, the individual species can produce more than 100 SM. The strain improvement programs lead to high yielding in target SM and significant reduction of spin-off products. The main tool for the strain improvement of filamentous fungi is random mutagenesis and screening. The majority of industrial overproducing SM strains were developed with the help of such technique over the past 50–70 years; the yield of the target SM increased by 100- to 1000-fold or more. Moreover, most of the strains have reached their technological limit of improvement. A new round of mutagenesis has not increased overproduction. Recently, it was shown that that the addition of exogenous polyamines may increase the production of such improved strains of filamentous fungi. The possible molecular mechanism of this phenomenon and its biotechnological applications are discussed.


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