A small plot study ofChalarainfestation in a recently established natural stand of ash, UK

2016 ◽  
Vol 38 (3) ◽  
pp. 122-133 ◽  
Author(s):  
Peter R. Hobson ◽  
Pierre L. Ibisch ◽  
Richard Parmee
Keyword(s):  
2014 ◽  
Vol 1 (2) ◽  
pp. 20-23
Author(s):  
O. Ivashchenko ◽  
O. Ivashchenko

Aim. Studying of black nightshade young plants’ response to the induced mechanical stresses. Methods. Researches conducted in small plot fi eld experiments. Results. Change of sensitivity level of Solanum nigrum L. plants depending on phases of their development at the moment of damage of elevated parts has been proven. Owing to loss of the surface capable to photosynthesis, there is an essential decrease in volumes of photosynthesis at plants of weed survived and their possibilities of ontogeny passage. The deep induced dis- stresses reduce biological effi ciency of plants, their ability to accumulate weight and to form seeds and even lead them to death. Conclusions. The defi ned principles of response of weed plants to the induced mechanical dis-stresses are can be used for working out and ecological receptions of crops protection from weeds.


2000 ◽  
Vol 48 (2) ◽  
pp. 191-195
Author(s):  
C. Kondora ◽  
M. Szabó ◽  
A. Máté ◽  
G. Szabó

Owing to the significant differences in the adaptability of state-registered varieties, those which can adapt well to the local conditions should be given preference. There are several high-yielding varieties available in Hungary with excellent agronomic properties, good adaptability and satisfactory baking quality. This study was conducted to analyse the adaptability of 34 state-registered winter wheat varieties tested in the small plot trials of the National Institute for Agricultural Quality Control (NIAQC) at 5–9 locations between 1994 and 1997 based on their gluten quantity and farinographic index. For the comparison of the varieties the evaluation method of Eberhart and Russell (1966) was applied as modified by Bedő and Balla (1977). The qualitative stability and adaptability values of the varieties differ from the adaptability and stability values calculated from the grain yields. Some winter wheat varieties have good qualitative adaptability and stability, while others have special adaptability and poor qualitative stability, but the majority of the varieties do not belong to these groups.


Author(s):  
M.S. Kolychikhina ◽  

In the small-plot experiment of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy against potato viruses in 2014-2019 were tested some kinds of preparations with antiviral activity: Pharmayod, GS (100 g/l of iodine); Immunocytophyte, TAB (20 g/kg arachidonic acid ethyl ester); Ecogel, WS (30 g/l of chitosan lactate); Amulet, TAB (composition of linear polyaminosaccharides (chitosan) in succinic acid solution); Zerox, WS (3000 mg /l colloidal silver); Viron, WS (biostimulant based on urea and citric acid with the addition of essential oils). According to the results of the studies, it was found that, in addition to the effect on the causative agents of viral diseases of potatoes, all tested preparations had a stable tendency to maintain or increase the yield of tubers of infected plants. The increase in the yield of tubers ranged from 0.5 to 1.3 kg/m2. In 2016 under the production conditions of Astrakhan region on the potato variety Impala infected with the PVM + PVS and PVM + PVS + PVY virus complexes a comparative assessment of the effect of Pharmayod and Immunocytophyte revealed a significant increase in the gross and marketable yield of potato plants in the areas with the use of these preparations compared to with control.


1971 ◽  
Vol 63 (6) ◽  
pp. 951-952 ◽  
Author(s):  
R. F. McCormick ◽  
C. S. Hoveland
Keyword(s):  

Crop Science ◽  
1979 ◽  
Vol 19 (4) ◽  
pp. 559-560
Author(s):  
D. D. Wolf ◽  
H. L. Alls
Keyword(s):  

1999 ◽  
Vol 64 ◽  
Author(s):  
D. Van den Meersschaut ◽  
B. De Cuyper ◽  
K. Vandekerkhove ◽  
N. Lust

Natural  stand changes in the forest reserve of Liedekerke were analysed during the  period    1986-1996, using a permanent grid of circular plots. The monitoring  concentrated on natural    changes in species composition, using stem number and basal area as  indicators, and changes    in spatial distribution and colonization capacities of trees and shrubs,  with special interest in the    competition between exotic and indigenous species. After only a decade of  monitoring important    natural changes in the woody layer were detected. The pioneer forest is  gradually maturing    through self-thinning processes and shifts in species composition. The  overall stem number    decreased with 33.6%, while the basal area increased with 20.9%. Birch (Betula pendula/    pubescens) and indigenous oak (Quercus robur/petraea) remained  dominant. More tolerant    exotic species, like red oak (Quercus rubra) and sweet chestnut (Castanea  sativa), are slowly    increasing their share in the species composition and expanding their  range. Pioneer species on    the other hand, like aspen (Populus tremula), willow (Salix  capreaicinerealaurita), alder buckthorn    (Frangula alnus) and  common (Alnus glutinosa)  and grey alder (A. incana),  strongly declined.    Black cherry (Prunus serotina) seems to be slowly invading the forest due to its  massive    natural regeneration. Strong competition may be expected especially from  rowan ash (Sorbus    aucuparia), which showed similar regeneration  and colonization capacities. Elder (Sambucus    nigra) dramatically extented its range, though  its share remains marginal. Beech remained absent    most probably due to the lack of mature trees in the vacinity of the  forest. Finally this    change detection allowed that general predictions could be made on the  future natural development    and composition of this forest reserve, which could serve forest management  decisions.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 405
Author(s):  
Miroslav Jursík ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.


1991 ◽  
Vol 10 (2) ◽  
pp. 129-135 ◽  
Author(s):  
R.H. Elliott ◽  
L. Mann ◽  
D.T. Spurr ◽  
E.R. Sacher
Keyword(s):  

1984 ◽  
Vol 62 (9) ◽  
pp. 1968-1970 ◽  
Author(s):  
William G. Roland ◽  
L. Michael Coon

Recovery of intertidal Porphyra beds following hand harvest was studied near the northwest tip of the Queen Charlotte Islands, B.C. Twenty-six percent of the standing crop of Porphyra perforata J. Ag. was removed in a large plot in June 1981; no negative effect on standing crop was apparent in May 1982 as compared with the adjacent control area. There was no negative impact on percent cover of Porphyra (mostly P. perforata) within 1 year after hand harvest of seven, approximately 1-m2 plots, as compared with respective controls. Annual fluctuation in cover, biomass, and relative mix of Porphyra species was large. Porphyra cover in a small plot harvested in early June 1981 increased to 86% of the June value by mid-July 1981, indicating substantial growth of the remaining thallus fragments and small, whole plants within one season. It was concluded that sustained yield of Porphyra beds can be assured if harvest is restricted to gathering by hand.


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