scholarly journals INFLUENCE OF CERTAIN SOIL FUNGI ON ALFALFA

1970 ◽  
Vol 50 (2) ◽  
pp. 159-162 ◽  
Author(s):  
CLAUDE AUBE ◽  
CAMILIEN GAGNON

Under the conditions of the present work with fungi isolated from the rhizosphere of diseased alfalfa roots, Gliocladium roseum (Link) Bainier and Trichoderma viride Pers. ex Fries were pathogenic to alfalfa seedlings. They stimulated the pathogenicity of Pyrenochaeta terrestris (Hans.) Gorenz, J. C. Walker and Larson and Rhizoctonia solani Kühn as measured by the dry weight of roots. Both T. viride and G. roseum significantly lowered the nitrogen content in shoots when inoculated alone, but the reverse was observed in the roots.

1969 ◽  
Vol 49 (6) ◽  
pp. 737-742
Author(s):  
Claude Aubé

Under the conditions of the present work with four soil fungi and four substrates, the reaction of alfalfa to Trichoderma viride Pers. ex Fries, Pythium debaryanum Hesse, Fusarium oxysporum Schlecht. var. rodelens (Wr.) Gordon, and Rhizoctonia solani Kühn in greenhouse tests was affected by the nature of the growth substrate. The above-mentioned fungi were more pathogenic in artificial substrates, such as the vermiculite-perlite and vermiculite-white sand mixtures, than in natural soil. The increase of pathogenicity in artificial substrates varied with the fungus. In natural soil, the temperature was consistently higher than in artificial media which might account for the difference in pathogenicity of the fungi in the different substrates.


2021 ◽  
Vol 52 (2) ◽  
pp. 239-250
Author(s):  
X.J. He ◽  
W.W. Zhu ◽  
F.Z. Wu

We studied the effects of 7-crop rotations and continuous - monocropping systems on soil microorganism and its feedback. The results showed that absolute abundance of soil bacteria (Pseudomonas and Bacillus) in tomato - celery - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than control (CK). Absolute abundance of soil fungi in tomato - celery - cucumber - cabbage, kidney bean - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than CK. Dry weight of cucumber seedlings was significantly positively correlated with bacterial (Pseudomonas and Bacillus) abundance, and negatively correlated with fungal count. The results of inoculation with Fusarium oxysporum f.sp. cucumerinum showed that plant dry weight of cucumber seedlings in tomato - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage, cucumber - tomato - cucumber - cabbage rotation soil was significantly higher than other treatments, and their disease index was significantly lower than other treatments. There was no significant difference in dry weight of cucumber seedlings in rotation and CK in the soil sterilization test. The results of plant - soil feedback experiment showed that soil microbial changes caused by different rotation patterns had a positive feedback effect on growth of cucumber seedlings.


Author(s):  
Andréia de L. Moreno ◽  
Jorge F. Kusdra ◽  
Angelita A. C. Picazevicz

ABSTRACT Rhizobacteria have a wide range of plant growth-promoting mechanisms of action, making them an alternative and/or complementary biological input for chemical fertilizers. In this respect, the present study aimed to assess growth and nitrogen accumulation in maize plants as a function of Azospirillum brasilense, Bacillus subtilis, zinc and nitrogen application at sowing. The experiment with the ‘AL Bandeirante’ maize variety was conducted in a greenhouse, using a completely randomized design. The treatments were arranged in a 2 x 2 x 2 x 2 factorial scheme, with six repetitions, considering the presence and absence of Azospirillum brasilense (5 g kg-1), Bacillus subtilis (5 mL kg-1) and zinc (20 g kg-1) in the seeds and addition or not of nitrogen (30 kg ha-1) to the soil. The variables assessed were plant height, stem diameter, leaf, stem, shoot, root and total dry weight, and shoot nitrogen content. Nitrogen fertilization in the absence of zinc increased shoot and total dry weight as well as shoot nitrogen content. Zinc applied to the seeds improved the total and stem dry weight of maize plants in the absence of Bacillus subtilis. Inoculation with Azospirillum brasilense and Bacillus subtilis increased the stem diameter and shoot nitrogen content of maize plants when nitrogen fertilization was not performed at sowing. There was no isolated or interaction effect between factors for plant height and root dry weight.


2014 ◽  
Vol 13 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Zbigniew Weber

The forecrops applied in potato cultivation affected the occurrence of <i>Rhizoctonia solani</i> Kühn and other soil fungi. The most common species found appeared to be: <i>Penicillium nigricans</i> Thom, <i>P. jenseni</i> Zaleski, <i>P. vinaceum</i> Gilman et Abbott. and <i>P. raciborskii</i> Zaleski.


1974 ◽  
Vol 66 (5) ◽  
pp. 701-702 ◽  
Author(s):  
G. A. Rottman ◽  
J. A. Tweedy ◽  
George Kapusta
Keyword(s):  

1958 ◽  
Vol 36 (1) ◽  
pp. 45-49
Author(s):  
S. Fedoroff ◽  
R. Altschul

In an attempt to elucidate the increase of growth promotion of tissue cultures by extracts obtained from tissues chilled before extraction, determinations of nitrogen content were made on (a) fresh, and chilled chick embryos, (b) extracts prepared from fresh and chilled chick embryos, (c) fresh and chilled human placenta, (d) extracts prepared from fresh and chilled human placenta.There was no difference in dry weight, nitrogen content, phosphorus content, and nitrogen: phosphorus ratio between chilled and fresh chick embryos and chilled and fresh human placenta. There was, however, a significant difference in the nitrogen content of the extracts prepared from fresh and from chilled tissues, It is suggested that chilling of tissues for 7 days at + 4 °C. prior to extraction may render the cells more easily destructible during extraction, and thus supply a better yield of nutritive substances.


2011 ◽  
Vol 48 (No. 8) ◽  
pp. 356-360
Author(s):  
V. Milić ◽  
N. Mrkovački ◽  
M. Popović ◽  
Đ. Malenčić

The objective of the study was to investigate how the inoculation of soybean seed (variety Afrodita, and lines NS-L-2016 and NS-L-300168) with strains of Bradyrhizobium japonicum (1, 1a, 2b), Azotobacter chroococcum (3, 13, 14), and GA3&nbsp;(gibberellic acid) affected plant dry weight, nitrogen content of nodules and whole plant, the enzymes of nitrogen assimilation (NR, GS) and soluble protein content. The highest dry matter mass and nitrogen content were found in the variety Afrodita, followed by line NS-L-300168. The GS and NR activity was increased significantly by all three inoculation treatments relative to the control. In all three genotypes, the highest values for the enzymatic activity were achieved with treatment mixture of B. japonicum and A. chroococcum strains. Each measurement was performed with three replications. The results were processed using variance analysis and the values were tested with the LSD at 5%.


2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.


1969 ◽  
Vol 20 (6) ◽  
pp. 1073 ◽  
Author(s):  
DS Letham

The respiration rates and tissue contents of nitrogen, phosphorus, and titratable acidity were determined for apple fruit from trees receiving differential fertilizer treatments U, N, P, NP, and NPK (U, no fertilizer; N, 2 lb ammonium sulphate; P, 4 1b superphosphate; and K, 1 Ib potassium sulphate, per tree per year). The results obtained (expressed on a dry weight basis) are summarized as follows: Respiration rate: N > NP = NPK = U > P. Total nitrogen content: NPK > NP = N > U = P. Ethanol-insoluble nitrogen content: NPK = NP = N > U = P. Ethanol-soluble nitrogen content: NPK > NP = N > U = P. Phosphorus content : P > NP = NPK > U > N. Titratable acidity content: NPK > N > NP = U > P. The incidence of internal breakdown in stored fruit from these treatments has positively correlated with respiration rate per cell and negatively correlated with phosphorus content. Phosphorus content was negatively correlated with cell volume and respiration rate. Mechanisms by which phosphorus content might regulate the incidence of internal breakdown are discussed.


1963 ◽  
Vol 14 (6) ◽  
pp. 725 ◽  
Author(s):  
TF Neales ◽  
MJ Anderson ◽  
IF Wardlaw

When wheat plants were deprived of nitrogen in the rooting medium at anthesis there was a small, but significant, increase in the nitrogen content of the grain at maturity. It was shown that there was a greater migration of nitrogen from the leaves and stem to the ear in plants deprived of nitrogen than in those plants supplied with nitrogen throughout ear development. In an examination of the effects on grain nitrogen content of leaf removal at anthesis, it was shown that this treatment reduces the uptake of nitrogen into the culm and the nitrogen content of the grain at maturity. Ear shading treatments significantly reduced the total nitrogen content of the grain in one experiment. Ear shading also decreased the amino nitrogen, and increased the nitrate nitrogen, content of the ear. Variation of the grain dry weight per ear, induced by shading, by defoliation treatments, or by differences in variety, were positively correlated with grain nitrogen content. Either the movement of dry matter and nitrogen into the ear are interdependent, or they are both promoted by some external factor, such as rate of growth of the ear. The possible importance of the leaves of the wheat plant in promoting the uptake of nitrogen into the culm and in supplying nitrogen to the grain is discussed.


Sign in / Sign up

Export Citation Format

Share Document