Fungitoxicity of some higher plants againstRhizoctonia solani

Summary Leaves ofChenopodium ambrosioides exhibited strong fungitoxicity against the mycelial growth ofRhizoctonia solani causing damping off diseases of some seedlings. Minimum inhibitory concentration of the fungitoxic constituent isolated in form of essential oil, was found to be 1000 ppm at which it was fungicidal in nature. It exhibited broad range of antifungal activity and did not show any phytotoxicity on the germination and seedling growth ofPhaseolus aureus.     

Investigations on fungicides. XXI. The fungitoxicity and systemic antifungal activity of some aromatic quaternary ammonium salts

Root application of certain quaternary ammonium salts, most notably tri-n-butyl-and tri-n-pentyl-4-chlorobenzylammonium bromides, to wheat seedings grown in water culture enhanced their resistance to powdery mildew (Erysiphe graminis) but not to brown rust (Puccinia recondita). Anti-mildew activity was much less apparent if the compounds were applied to sand- or soil-grown seedlings. Systemic activity is considered in relation to the fungitoxicity, phytotoxicity and growth-retardant activity of these compounds.     

Chemical characterization of new oxylipins from Cestrum parqui, and their effects on seed germination and early seedling growth

Isolation, chemical characterization, and phytotoxicity of five new oxylipins, together with seven already known related compounds, from Cestrum parqui L' Hérl. is reported. All the structures were elucidated on the basis of their spectral data, especially 1D-(1H- and 13C-NMR, DEPT) and 2D-NMR (COSY, TOCSY, HSQC, HMBC, and NOESY). The configurations of the stereogenic C-atoms were determined by the Mosher's method. The compounds have been assayed for their phytotoxicity on Lactuca sativa at concentrations ranging between 10(-4) and 10(-8) M. The results of the phytotoxicity tests on the germination and growth of the test species, obtained by a cluster analysis, showed interesting relationship between the chemical structures of the compounds and their biological effects.     

Liming to remediate Ni contaminated soils with diverse properties and a wide range of Ni concentration

Historic emissions from a Ni refinery at Port Colborne, Ontario, caused Ni contamination of regional soils and raised concerns about potential Ni phytotoxicity. Previous tests revealed that if these soils were made alkaline and fertilized with Mn and other common nutrients as needed to maintain fertility of such alkaline soils, full remediation (prevention of Ni phytotoxicity) would be obtained. This experiment was conducted to test this method of remediation on diverse soils from Port Colborne, and to evaluate chemical extraction tests which would be predictive of plant uptake and potential for Ni phytotoxicity in Ni-contaminated soils. Ten soils with varied levels of Ni contamination and varied soil properties were amended with limestone or nitric acid to raise or lower pH so that a wide pH range could be examined for the soils. For lower Ni organic and mineral soils near the Ontario remediation limit (200 mg/kg), neither crop suffered Ni phytotoxicity at any pH tested. Only when more highly contaminated soils were strongly acidic did Ni phytotoxicity occur. Phytotoxic soils were fully remediated by making soils alkaline even for these Ni-sensitive crop species. Only the most contaminated organic soil remained slightly toxic – but this soil was remarkably contaminated (over 1.1% of Ni). The Sr nitrate extraction method was much more effective in predicting plant Ni concentrations than the DTPA method. This test provides an inexpensive soil extraction result highly predictive of potential for Ni phytotoxicity across soils.     

γ-Asarone – the fungitoxic principle of the essential oil of Caesulia axillaris

The essential oil of Caesulia axillaris has exhibited its fungitoxicity against Aspergillus flavus at its minimum inhibitory concentration of 1300 mg/l. It showed the potentiality of an ideal fungitoxicant because of its long shelf life, thermostable nature, broad fungitoxic spectrum and persistence of fungitoxicity even on introduction of high inoculum density of the test fungus. The fungitoxic principle of the oil was standardized as -asarone which showed fungitoxicity against the test fungus at 500 mg/l.     

抑制茄子黄萎菌的植物提取物的筛选

从蔬菜、花卉、树木、作物和杂草等植物中选取29科73种植物材料,通过室内生物测定和田间试验,筛选出的葡萄叶、大葱叶提取物对黄萎菌具有较强的抑制作用,菌丝生长抑制率达68.44%和61.31%,孢子萌发抑制率达到95%以上,田间防病效果与茄子"病菌净"药剂达到同一显著水平,防效分别达到了75.76%和71.72%。丁香枝叶、薄荷叶、辣椒叶、番茄叶、醉蝶根、南瓜叶、韭菜叶、核桃叶、银杏叶、大蓟叶、藿香叶、苣卖菜叶、万寿菊叶、柳枝叶、花椒果和橘皮等也具有较好的抑菌活性,可作为其它病原菌的天然抗菌剂筛选研究试材。     

Fungitoxicity of Some Higher Plants with Special Reference to the Synergistic Activity Amongst some Volatile Fungitoxicants

During screening of the leaves of 25 plant species for their volatile toxicity against the test pathogen Fusarium lateritium f.sp.cajani, Aegle marmelos (Ae), Citrus aurantifolia (Ci) and Mentha arvensis var. piperascens (Me) exhibited strong toxicity inhibiting the mycelial growth completely. The active volatile constituents from each plant were isolated in the form of essential oil and the fungitoxicity of each oil was tested separately. The Aegle oil was found fungistatic while Citrus and Mentha oils were fungicidal in nature. Three oil combination (1:1 v/v) viz., Ae-Ci, Ae-Me and Ci-Me were made and their fungitoxicity was tested. The oil combinations were found to be more fungitosic than the individual oils, which were fungistatic in nature. The Ci-Me combination exhibited a broad fungitoxic spectrum while the other two Ae-Ci and Ae-Me possessed a narrow range of toxicity. The oils were found to have no toxic effect on seed germination, seedling growth (root and shoot length), and general morphology of the host plant(Cajanus cajan).     

Differential phytotoxicity among species and cultivars of the genus Brassica to wheat

Field and controlled environment studies were conducted to examine the effects of plant stress during growth on the subsequent phytotoxicity of residues ofBrassica napus andBrassica campestris. High temperatures (30°C compared to 15°C day temperature) and short days (8 hours light compared to 16 hours light) increased the phytotoxicity of residues as measured by a wheat bioassay. Low levels of nutrient supply during growth also increased the toxicity of Brassica residues. The effect of water stress was less clear; severe moisture stress resulted in less phytotoxicity than mild water stress. The two species showed some differences in wheat phytotoxicity following applied plant stress and the field experiments suggested there was a potential for greater toxicity from summer grown residues.     

Studies on the Mode of Action of Organophosphorus Fungicide,Kitazin

Studies were conducted on the influence of Kitazin analogues on the incorporation of ¹⁴C-glucosamine into the mycelial cell wall fraction of Pyricularia oryzae. Compounds of thiolates and phosphates, both having in vitro inhibitory activities toward the mycelial growth, inhibited the incorporation, whereas those of thionates and dithioates, either having no fungitoxicity, did not inhibit the incorporation. Mycelia of P. oryzae treated with Kitazin-P (S-benzyl O,O′-diisopropyl phosphrothioate; IBP) accumulated about twice as much an amino sugar derivative as untreated ones. Mycelia treated with thiono or dithio analogues, which have no fungitoxicity, showed no accumulation. The accumulated substance gave a identical spot with authentic UDP-N-acetyl glucosamine on paper chromatograms developed with four solvent systems.     

Investigations on fungicides: X. The antifungal activity of 2-deoxy-D-glucose

The fungitoxicity of 2-deoxy-D-glucose was examined in spore germination tests using Botrytis cinerea, B. fabae, Alternaria brassicicola, Aspergillus niger, Cladosporium cucumerinum, C. fulvum, Sclerotinia fructigena, Verticillium albo-atrum and Glomerella cingulata. It proved to be toxic, at concentrations below 10 μg./ml., to all of these fungi except G. cingulata which was resistant to concentrations up to 2000 μg./ml. The effect of a-deoxy-D-glucose on the mycelial growth of these fungi was assessed and again G. cingulata proved to be resistant to high concentrations of the compound, as also did A. niger.
The results are discussed in relation to the known inhibitory nature of 2-deoxy-D-glucose in other systems.     

Performance of aqueous extract of Aegle marmelos based Amaext-a,an antifungal product against Pyricularia grisea causing blast disease of rice

In order to enhance the efficacy of aqueous extract of Aegle marmelos, a present study was undertaken. The aqueous extract was combined with a formulating agent (coded B+) and named Amaext-a, bioassayed under in vitro condition against Pyricularia grisea Sacc. causing blast disease of rice. The product was found to inhibit conidial germination completely at 0.1% concentration and mycelial growth at 1% concentration, whereas the extract alone could inhibit the germination only partially at the same concentration. The formulated product, Amaext-a, retained its fungitoxicity till 18 months storage period in all treatments. In a separate test, the efficacy of the product was also accessed in the greenhouse and under field condition, and compared with the standard fungicide carbendazim. This formulated product has therefore improved the efficacy of fungitoxicity compared to the unformulated botanical extract under in vitro and in vivo conditions and so found comparable with standard fungicide carbendazim (Bavistin 50% wp).     

Chlorpyrifos immersion to eliminate third instars of Japanese beetle (Coleoptera: Scarabaeidae) in balled and burlapped trees and subsequent treatment effects on red maple

This study examined chlorpyrifos immersion of balled and burlapped (B&B) nursery trees for elimination of third instars of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), and for phytotoxicity on red maple, Acer rubrum L. Trees were harvested as 45- and 60-cm-diameter B&B and immersed in chlorpyrifos at U.S. Domestic Japanese Beetle Harmonization Plan rate (0.24 kg active ingredient [AI/100 liters) or lower rates of 0.015, 0.03, 0.06, and 0.12 kg (AI)/100 liters. The 0.03, 0.06, and 0.24 kg (AI) rates provided 100% control of Japanese beetle grubs in both 45- and 60-cm B&B. The 0.015 and 0.12 kg (AI) chlorpyrifos rates were 100% effective in three tests. However, in another test, 0.015 and 0.12 kg (AI) chlorpyrifos treatments had four (93% control) and one (98% control) grubs recovered, respectively. Root ball soils consisted of loam, silt loam, or clay loam texture classifications. Trunk diameter and internode growth of red maple harvested as 45-cm B&B decreased linearly with increasing chlorpyrifos dip rate during the first year, but effects were unapparent in the second year. Chlorpyrifos rates had no measurable impact on growth of red maples harvested as 60-cm B&B. No visual phytotoxicity symptoms were detected for chlorpyrifos rate or root ball size treatments. In conclusion, results support lowering the U.S. Domestic Japanese Beetle Harmonization Plan chlorpyrifos dip rate for category 2 states to at least 0.03 kg (AI) for B&B diameters < or =60 cm. Chlorpyrifos rates < 0.24 kg (AI) will lower cost, reduce worker exposure, and lessen potential environmental contamination.     

Fungitoxic and Phytotoxic Studies with Essential Oil of Ocimum adscendens

On screening the leaf extracts of some higher plants for their volatile antifungal activity against the test organism Aspergillus flavus, the extract of Ocimum adscendens exhibited the strongest fungitoxicity. The leaves showed maximum, fungitoxicity as compared with other plant parts. The volatile fungitoxic fraction obtained as an essential oil was standardized by various physico-chemical properties. The oil showed its fungicidal nature and broad range of activity at its minimum inhibitory concentration. The oil was thermostable and the toxicity remained unchanged even on autoclaving and on storage for up to 360 days. Moreover, the oil proved more active than some prevalent synthetic fungicides and exhibited no phytotoxic effect onVigna radiata.     

化学品植物毒性的评价和鉴别

简述了进行化学品植物毒性评价和鉴别的种类、方法和意义,强调有毒化学品对维管束植物的毒性和严重后果,呼吁加强我国在这方面的研究并尽快建立相应的评价方法和标准,以完善我国化学品生物毒性鉴别和评价方法及标准体系,为保护环境质量,提高人们生活水平,维护我国的生态安全服务。虽然过去由于我国工业化程度较低而没有出现什么问题,但现在必须及时给予重视,防患未然,以免重走西方发达国家的弯路。     

Some observations on size and biological activity of spray deposits produced by various formulations of copper oxychloride

Chemical estimations and biological assays, using Botrytis fabae, of spray deposits on beans (Vicia faba) in the laboratory have shown that the amount of an initial spray deposit of copper oxychloride is dependent on the volume of application used per unit area and the concentration of copper in the spray liquid. The addition of 0.1 % of an anionic surfactant (dioctyl sodium sulpho-succinate) greatly reduced the amount of these initial deposits although another anionic surfactant did not. In the laboratory trials the fungitoxicity of the spray deposit was related to the actual copper levels initially present. In general, the addition of surfactants improved the fungitoxicity of the initial deposit. The addition of surface-active agents did not materially affect the rain-resistance of the spray deposits, while their presence in emulsions of PVA, PVC and PVB gave an improved biological performance. All three polymeric materials greatly improved the tenacity of copper oxychloride spray deposits without reducing their fungitoxicity in laboratory tests. When examined in field experiments against potato blight (Phytophthora infestans) these apparent biological advantages due to the tenacity and good distribution of the polymeric emulsion formulations did not materialize. An explanation for this apparent contradiction between laboratory and field data has been given based on certain features of the epidemiology of the pathogen.     

Response of sweet pepper to phenols accumulated in greenhouse substrate

Prolonged cucumber cultivation in the same substrates leads to accumulation of phytotoxic phenolic compounds. Introduction of sweet pepper as an aftercrop eliminates substrate phytotoxicity. The aim of the study was to examine whether in sweet pepper detoxication of substrate phenols occurs by means of the glucosylation process. The examined materials were substrates differing in phytotoxicity level, and sweet pepper plants grown on these substrates. Substrate phytotoxicity was obtained by means of either repeated cucumber cultivation or by phenolic acid addition. During the vegetative growth phase of sweet pepper, the phytotoxicity and phenolic compound levels in the substrate, and the glucosylated phenol contents in above-ground plant parts were determined. Results showed that sweet pepper responds to an increased presence of phenols in the substrate by an intensified glucosylation.     

A modified static respiration assay and its relationship with an enzymatic test to assess compost stability and maturity

Despite the numerous compost stability and maturity tests, no universally accepted compost stability or maturity index exists. The fluorescein di-acetate (FDA) enzymatic assay, originating from soil studies, is examined here as a potential new compost stability test, and is compared to microbial respiration and phytotoxicity indices. Thirteen composts were used in the study from different source materials. Static microbial respiration activity indices calculated were the cumulative O₂ consumptions, O₂ consumption rates, total C-CO₂ production, the respiratory quotient and the bio C/N ratio. Compost phytotoxicity was quantified via a 7-day tomato seed germination assay. Results showed that the net fluorescein release rates correlated with all stability indices. The germination index marginally correlated with the fluorescein release rates, but not with any of the other stability indices. New limits to classify composts regarding their stability were proposed.     

Toxic effects of digested, composted and thermally-dried sewage sludge on three plants

In order to evaluate potential toxic effects of stabilized sewage sludge that are currently applied to agricultural soils, three types of municipal sewage sludge and one pig slurry were subjected to phytotoxicity assays using three plants (Brassica rapa, Lolium perenne and Trifolium pratense). Equivalent batches of aerobically and anaerobically-digested sludge (F) from two municipal wastewater treatment plants, were composted (C) or thermally dried (T). In addition, one anaerobically-digested and thermally-dried pig slurry (P) was tested. A seedling growth test was performed in accordance with the OECD Guideline 208A, using seed emergence and shoot length as endpoints to identify the inhibition of plants growing in increasing doses of sludge. A correlation analysis between EC50 and physico-chemical parameters or the pollutant burden of the biosolids was also calculated. In all tests, lower germination rates were observed for T. pratense than for L. perenne and B. rapa. A moderate stimulatory effect on shoot length at low doses was observed for the three plants. In these wastes, a strong positive correlation was found between higher values of EC50 (less toxicity) and the stability degree of their organic matter, and a negative correlation between EC50 and total N, hydrolysable N or NH4-N content. No correlations were found with heavy metal or organic pollutant content in those wastes. Results indicate that digested sludge, thermally-dried sludge and thermally-dried pig slurry have non-negligible short term phytotoxic effects, and confirm that composting is an effective sludge treatment for the reduction of phytotoxicity.     

Fungitoxic effects of extracts from some West African plants

Extracts from five West African plants were evaluated in vitro for fungitoxicity against Ustilago maydis, Ustilaginoidea virens, Curvularia lunata and Rhizopus sp. Steam distillate from leaves of Cymbopogon citratus completely inhibited the growth of all four fungi, and hot water extracts from fresh leaves of Ocimum gratissimum and Chromoleana odorata, and dry fruits of Xylopia aethiopica, reduced radial growth by 10–60%. A hot water extract from dry fruits of Monodera myrstica was ineffective as a fungitoxicant.     

Anaerobically digested poultry slaughterhouse wastes as fertiliser in agriculture

Chemical and physical analysis, 27-d plant growth assays with carrot (Daucus carota) and Chinese cabbage (Brassica campestris var. chinensis), and 5-d phytotoxicity assays with Chinese cabbage and perennial ryegrass (Lolium perenne) were used to investigate the suitability of anaerobically digested poultry slaughterhouse waste for fertiliser in agriculture and the effect of aerobic post-treatment on the properties of the digested material. The digested material appeared to be rich in nitrogen. In 27-d assays with digested material as nitrogen source, carrots grew almost as well as those fertilised with a commercial mineral fertiliser used as reference, whereas, the growth of Chinese cabbage was inhibited. In further 5-d phytotoxicity assays, the digested material inhibited the germination and root growth of ryegrass and Chinese cabbage, apparently because of organic acids present in it. Aerobic post-treatment of the material reduced its phytotoxicity but, probably due to the volatilisation of ammonia, resulted in loss of nitrogen.