Title: Methods to evaluate allelopathic effects on nodulating bacteria and nodulation in legumes

Author(s): Mallik MAB

Source: ALLELOPATHY JOURNAL 7 (2): 197-213 JUL 2000

Abstract: Research of the last three decades has contributed greatly in understanding some ecological factors impacting symbiotic nitrogen fixation. However, allelopathic effects of weeds and crop plants on the microsymbiont the legume host and their interactions on nitrogen fixation are poorly understood. Methods described here are intended for those interested in studying allelopathic effect on symbiotic nitrogen fixation but have little or no experience in working with rhizobia. Methods for maintenance and preservation Of rhizobia and their purity check; and for studies of allelopathic effect on the microsymbiont in situ and in vitro and their interaction on nitrogen fixation are described. Methods are also given for growing leguminous plants under sterile conditions within test tube and in Leonard jar to study allelopathic effect of plant residue and associated crop on nitrogen fixation.

Author Keywords: allelopathy; antibiotic resistant strain; bacterial direct count; legumes; Leonard jar; nodulation; plant dilution method

KeyWords Plus: GROWTH

Addresses: Mallik MAB (reprint author), Langston Univ, Agr Res & Extens Programme, POB 730, Langston, OK 73050 USA
 

Title: Rice allelopathic potential and its modes of action on Barnyardgrass (Echinochloa crus-galli)

Author(s): Lin WX, Kim KU, Shin DH

Source: ALLELOPATHY JOURNAL 7 (2): 215-224 JUL 2000

Abstract: Six lines of rice (AC1423, Kouketsumuchi, Taichung Native 1, Woo Ca Chin Yu, YH-1 and CN-15) showing higher biological suppression of barnyardgrass in field trials and control (Nancheum), were screened against barnyardgrass in pot culture in green house. In petri-plate bioassays, the aqeous extracts of different rice accessions varied in their inhibitory allelopathic effects on barnyardgrass and the inhibition followed the order:Woo Co Chin Yu > Kouketsumuchi > AC1423 > CN-15 > Taichung Native I > YH-1. The inhibition in weed growth increased with increasing concentration of extract. The radical length was found more sensitive to aqueous extract than hypocotyl length. The phytotoxicity was density-dependent i.e. the growth inhibition was negatively and significantly correlated with barnyardgrass densities in pots. Such a result was contrary to the predicted effect of resource competition and provided an evidence for a hypothesis of chemical interference. Biochemical analysis demonstrated that aqueous extracts significantly blocked activity of superoxide dismutase and catalase, thereby increasing free radicals, consequently resulting in higher lipid peroxidation and altered membrane potential in barnyardgrass seedling. Activities of ATPase and amylase at different germination time courses of barnyardgrass were also significantly inhibited by aqueous extracts, but the reverse was true in peroxidase and IAA oxidase. This was attributed to combined action of allelopathic compounds, suggesting that phytotoxicity of allelopatliic extracts might result from generalized cellular disruption, rather than from Specific mechanisms.

Author Keywords: allelopathic rice; barnyardgrass; bioassay; modes of action

Addresses: Lin WX (reprint author), Fujian Agr Univ, Coll Crop Sci, Dept Agron, Fuzhou, 350002 Peoples R China
　

Title: Allelopathic potential of Eupatorium maximiliani Schrad. leaves

Author(s): Correa JF, Souza IF, Ladeira AM, Young MCM, Aragushi M

Source: ALLELOPATHY JOURNAL 7 (2): 225-233 JUL 2000

Abstract: Eupatorium maximiliani Schrad leaves were extracted with chloroform:methanol 2:I and the extract was applied to four crops [rice (Oryza saliva L. Cv. Caiapo, corn (Zea mqw L. Cv. AG302A), beans (Phaseolus vulgaris Cv. Carioquinha) and lettuce (Lachuca saliva Cu. Grand rapids)] and two weed species [pigweed (Amaranthus spp) and hairy baggarticks (Bidens pilosa L.)]. The extract significantly reduced seed germination of lettuce, pigweed and hairy beggarticks, radicle elongation and shoot growth in lettuce, beans and rice and had no effect on corn. Fractions from Eupatorium extract were obtained through fractionation in silica gel column. Two flavonoids were isolated and identified through (NMRH)-H-1, (NMRC)-C-13, ME and IR. Bioassays showed that 5,6,7,3',4',5'-hexametoxyflavone at 10 mg/l concentration stimulated the lettuce radicle elongation. The fraction 6 which showed strong biological activity and was found to contain 5,6,7,3 ,4',5'-hexametoxyflavone. This substance has been reported for the first time.

Author Keywords: allelochemicals; allelopathy; Amaranthus spp.; beans; Bidens pilosa; corn; flavonoids; germination; lettuce; phenolics; rice; seedling growth; weeds

Addresses: Souza IF (reprint author), Univ Fed Lavras, Dept Agr, Caixa Postal 37, Lavras, MG BR-37200000 Brazil
　

Title: Effect of cropping systems on chemical and thermal properties of humic acids in soil

Author(s): Szajdak L, Wegner K, Matuszewska T

Source: ALLELOPATHY JOURNAL 7 (2): 235-241 JUL 2000

Abstract: The chemical and thermal properties of humic acids from the soils under cropping systems [continuous cropping (monoculture) of rye and crop rotation] were studied. The soils were fertilized either with fertilizers (nitrogen, phosphorus and potassium) or with manure. The shape of differential thermal analysis, thermogravimerty and differential thermogravimetry curves indicated the presence of various structures in humic acids. The crop rotation decreased the temperature and head of combustion. Humic acids from soils under monocultures of rye, contained more aromatic compounds than from crop rotation. The application of fertilizers increased aliphatic structures in humic acids than manure application. Aromaticity of humic acids from soils under monoculture of rye fertilized with manure, was higher than from crop rotation fertilized with manure.

Author Keywords: crop rotation; cropping system; fertilizers; humic acids; manure; monoculture; thermal analysis; thermogravimetry

KeyWords Plus: THERMOGRAVIMETRY; RYE

Addresses: Szajdak L (reprint author), Polish Acad Sci, Res Ctr Agr & Forest Environ, St Bukowska 19, Poznan, PL-60809 Poland

Title: Effect of leaf litter of poplar on Phalaris minor weed

Author(s): Sharma NK, Samra JS, Singh HP

Source: ALLELOPATHY JOURNAL 7 (2): 243-253 JUL 2000

Abstract: The effect of aqueous extracts of popular (Populus deltoides) trees was studied on germination and growth of Phalaris minor, a major weed of wheat crop. The extracts from partially decomposed leaves of poplar significantly reduced the germination and growth of Phalaris minor as compared to control. The magnitude of reduction was greater during the initial stages of decomposition. Irrespective of decomposition stage, intensity of inhibitory effect increased with higher concentration of extract. The extract of soil up to a distance of 3 m from the tree base of three years old plantation, also significantly decreased the germination and seedling growth of P. minor, which further intensified and extended up to 6 m in the fourth year. Thus, it can be inferred that presence of allelochemicals in leaves and in soil underneath the poplar tree reduced the germination as well as suppressed the growth of P, minor and effect was more pronounced with advancement of tree age.

Author Keywords: allelopathy; germination; growth; leaves extract; Phalaris minor; Populus deltoides; soil extract

Addresses: Sharma NK (reprint author), Cent Soil & Water Conservat Res & Training Inst, 218 Kaulagarh Rd, Dehradun, 248195 India

Title: Effect of Dalbergia sissoo extracts, rhizobium and nitrogen on germination, growth and yield of Vigna radiata

Author(s): Tripathi S, Tripathi A, Kori DC, Paroha S

Source: ALLELOPATHY JOURNAL 7 (2): 255-263 JUL 2000

Abstract: In bioassays, allelopathic activity of leaf and root aqueous extracts of Dalbergia sissoo Roxb. was studied on germination, growth, yield, nodulation and biochemical changes in Vigna radiata. In second study, effect of rhizobium and nitrogen along with extracts was studied Chemical analysis of D. sissoo leaves and root revealed the presence of appreciable amount of phenolics and carbohydrates and traces of flavonoids and terpenoids. Leaf and root extracts stimulated the germination, shoot length, production of seeds, seed protein, leaf protein, soluble sugar of leaf, nodulation and adversely affected total chlorophyll of leaf and had no impact on nitrate reductase activity (NR). Nitrogen along with all extracts adversely affected the germination, production of seeds, seed protein, chlorophyll and nodulation. It also adversely affected the NR activity. Rhizobium treatments were better than extracts alone or nitrogen However, all treatments produced more number of seeds per plant with less weight. It is presumed that stimulatory activity may be due to the presence of phenols, carbohydrates, terpenoids and flavonoids in extracts.

Author Keywords: allelochemicals; Dalbergia sissoo; germination; growth; nitrate reductase; phenolic acids; rhizobia; Vigna radiata; yield

Addresses: Tripathi S (reprint author), Trop Forest Res Inst, Div Chem Forest Produce, PO RFRC,Mandla Rd, Jabalpur, 482021 India

Title: Allelopathic effects of Quercus spp. on crops of Garhwal Himalaya

Author(s): Bhatt BP, Chauhan DS

Source: ALLELOPATHY JOURNAL 7 (2): 265-272 JUL 2000

Abstract: The allelopathic influence of Quercus glauca Thunb, and Q. leucotrichophora A. Camus was tested on three crops viz; wheat (Triticum aestivum), mustard (Brassica campestris) and lentil (Lens culinaris). In bioassay studies, aqueous extracts of dried fresh leaves, leaf liner and flaked off bark suppressed the germination, plumule and radicle length of all test crops. In pot culture, soil amended with leaf litter and bark also suppressed the germination, shoot length and dry mater: of test crops. The rhizosphere soil of both tree spp. also significantly suppressed the pigment contents and dry matter of all test crops.

Author Keywords: allelopathy; dry mater; germination; growth; pigments

Addresses: Bhatt BP (reprint author), HNB Garhwal Univ, Dept Forestry, Post Box 59, Srinagar Garhwal, Uttar Pradesh 246174 India

Title: Effects of drought on allelopathic activity of Datura stramonium L.

Author(s): Dias AS, Dias LS

Source: ALLELOPATHY JOURNAL 7 (2): 273-277 JUL 2000

Author Keywords: allelopathy; Datura stramonium; drought; germination; growth analysis; leaf extracts; number of lateral roots; root extracts; root length

Addresses: Dias LS (reprint author), Univ Evora, Dept Biol, Ctr Ecol Aplicada, Evora, P-7002554 Portugal
　

Title: Effect of allelochemicals on germination and seedling growth of rice (Oryza sativa L.) cultivars

Author(s): Gogoi B, Das K, Baruah KK

Source: ALLELOPATHY JOURNAL 7 (2): 279-283 JUL 2000

Author Keywords: allelochemicals; benzoic acid; coumaric acid; inhibitory effect; phenolic compounds; rice; vanillic acid

Addresses: Baruah KK (reprint author), Assam Agr Unit, Dept Crop Physiol, Jorhat, Assam 785013 India
　

Title: Exogenous salicylic acid reduces Meloidogyne incognita infestation of tomato

Author(s): Nandi B, Sukul NC, Babu SPS

Source: ALLELOPATHY JOURNAL 7 (2): 285-288 JUL 2000

Author Keywords: allelochemical; Meloidogyne incognita; resistance; salicylic acid; tomato

KeyWords Plus: DISEASE RESISTANCE; ASPIRIN; TOBACCO; VIRUS

Addresses: Babu SPS (reprint author), Visva Bharati Univ, Dept Zool, Santiniketan, W Bengal 731235 India
　

Title: Juglans spp, juglone and allelopathy

Author(s): Willis RJ

Source: ALLELOPATHY JOURNAL 7 (1): 1-55 JAN 2000

Author Keywords: allelopathy; crops; history; Juglans spp.; juglone; phytoplankton; walnut; soil; trees

KeyWords Plus: NATURALLY-OCCURRING NAPHTHOQUINONES; BLACK-WALNUT; ANTIMICROBIAL ACTIVITY; HYDROJUGLONE GLUCOSIDE; NITROGENASE ACTIVITY; ALNUS-GLUTINOSA; SOIL BACTERIA; GROWTH; GERMINATION; 5-HYDROXY-1,4-NAPHTHOQUINONE

Addresses: Willis RJ (reprint author), Univ Melbourne, Sch Bot, Parkville, Vic 3052 Australia

Title: Effect of aqueous extracts of Populus deltoides M. on germination and seedling growth. 1. Wheat

Author(s): Sharma NK, Samra JS, Singh HP

Source: ALLELOPATHY JOURNAL 7 (1): 56-68 JAN 2000

Abstract: Laboratory study was carried out to investigate the allelopathic effects of 3 and 4 year old poplar (Populus deltoides) trees existing in irrigated agricultural land, on wheat crop. The experiment consisted of field data and two bioassay studies with aqueous extracts of partially decomposed leaves of poplar and that from surface soil. In the field, performance of wheat planted in poplar field with boundary plantation was determined. In the first bioassay, three concentrations (0.45, 0.90 and 1.40 g leaf l(-1)) of aqueous extract of partially decomposed leaves of poplar (0, 30, 90, 145 and 365 days after soil incorporation in litter bag) were studied on germination and seedling growth of wheat. The distilled water was served as control. In second bioassay, aqueous extract of surface soil (0-15 cm), collected from 0-3, 3-6, 6-9 and >15 m(control) distance from tree line of 3 and 4 year old poplar trees was used. The aqueous extract of soil collected from > 15 m from the tree line was used as control. The aqueous extracts of partially decomposed poplar leaves retarded the germination and growth of wheat. Relatively more retardation was noticed with extracts from partially decomposed leaves and the magnitude of reduction was greeter during the initial stages of decomposition. Irrespective of decomposition stage, adverse effect was intensified with increase in concentration of extracts. Germination and growth of wheat were suppressed by extract of soil sampled from a distance of 0-3 m with 3 year old plantation, which further intensified and extended up to 6m in fourth year. Thus, adverse effect of aqueous extracts of soil underneath poplar tree indicated the accumulation of allelochemicals in the soil and the effect was more pronounced with advancement of tree age. Results of the laboratory study confirmed the field observations.

Author Keywords: allelopathy; germination; growth; leaves and soil extract; Populus deltoides; wheat

KeyWords Plus: LITTER

Addresses: Sharma NK (reprint author), Cent Soil & Water Conservat Res & Training Inst, 218 Kaulagarh Rd, Dehra Dun, Uttar Pradesh 248195 India

Title: Allelopathic potential of Eucalyptus leaf litter leachates on germination and seedling growth of fingermillet

Author(s): Padhy B, Patnaik PK, Tripathy AK

Source: ALLELOPATHY JOURNAL 7 (1): 69-78 JAN 2000

Abstract: The influence of different concentrations of aqueous leachates of Eucalyptus globulus Labill litter on seed germination, seedling growth and some physiological and biochemical processes of fingermillet (Eleusine coracana Gaertn cv. AKP-2) was studied. Ail the concentrations (5, 10, 15 and 20%) of leachate considerably inhibited the seed germination. Longer the duration of pre-soaking of seeds in leachates, greater was inhibition in germination. Increase of pre-soaking time of seeds in leachate as well as increase of leachate concentration, decreased the respiration rate, catalase and alpha-amylase activities but increased the peroxidase activities. The chlorophyll synthesis in leaves as well as protein, carbohydrates and nucleic acids (DNA and RNA) contents in both shoot and root of the seedlings were also decreased with increase in leachate concentration.

Author Keywords: allelochmicals; alpha-amylase; catalase; chlorophyll; nucleic acid; eucalyptus litter leachates; fingermillet; peroxidase; respiration; seedling growth

KeyWords Plus: PEROXIDASE; SENESCENCE; CATALASE

Addresses: Padhy B (reprint author), Berhampur Univ, Dept Bot, Berhampur, Orissa 760007 India

Title: Organic management of concomitant Meloidogyne incognita and Rotylenchulus reniformis on chickpea

Author(s): Anver S, Alam MM

Source: ALLELOPATHY JOURNAL 7 (1): 79-84 JAN 2000

Abstract: In chickpea, Meloidogyne incognita caused greater reduction in plant growth, chlorophyll content, water absorption capacity of roots and root nodulation than Rotylenchulus reniformis. These nematodes inhibited each other in concomitant infections. Both the nematodes together caused more damage to the test plants than was caused by either of them singly, but it was less than the cumulative damage caused by them individually. Oil-seed cakes of neem/margosa, castor, mustard, rocket salad and nematicides (carbofuran, dimethoate, phorate) significantly reduced the multiplication of nematodes and thus improved the crop plants growth, the water absorption capacity of roots and root nodulation. The effect of oilseed cakes and nematicides on nematodes was similar in the absence or presence of Rhizobium, but the multiplication of M. incognita and R. reniformis was more in the absence of Rhizobium.

Author Keywords: chickpea; Cicer arietinum; Meloidogyne incognita; nematicide; nematode management; organic amendment; Rotylenchulus reniformis

Addresses: Anver S (reprint author), Aligarh Muslim Univ, Dept Bot, Aligarh, Uttar Pradesh 202002 India

Title: Inhibitory effects of phenolic compounds on fungal metabolism in host-pathogen interactions in Fusarium wilt of cumin

Author(s): Mandavia MK, Khan NA, Gajera HP, Andharia JH, Parameswaran M

Source: ALLELOPATHY JOURNAL 7 (1): 85-92 JAN 2000

Abstract: Cumin varieties, tolerant (EC-232684, EC 243375 and UC-198) and susceptible (GC-1, UC-209 and RZ-19) to fusarium wilt disease were grown in sick plot. Roof stem and leaf tissues collected at pre-infection and post-infection stages were analysed for phenolic compounds. Eight phenolics viz, hydroquinone, umbelliferone, catechol, p-coumaric acid, salicylic acid, chlorogenic acid, ferulic acid and vanillic acid were identified in these tissues, At pre-infection stage, the roof stem and leaf tissues of tolerant varieties exhibited higher content of salicylic acid and hydroquinone. The umbelliferone content was higher in root tissue of tolerant varieties at pre-infection and post infection stages. Spore germination and mycelial growth were significantly inhibited by phenols (salicylic acid and p-coumaric acid).

Author Keywords: cumin; Fusarium wilt; hydroquinone; mycelial growth; salicylic acid; spore germination; umbelliferone

Addresses: Mandavia MK (reprint author), Gujarat Agr Univ, Dept Biochem, Junagadh, Gujarat 362001 India
　

Title: Allelopathic effects of shoot extracts and residues of weeds on field crops

Author(s): Beres I, Kazinczi G

Source: ALLELOPATHY JOURNAL 7 (1): 93-98 JAN 2000

Author Keywords: Abutilon theophrasti; allelopathy; Amaranthus retroflexus; aqueous extracts; Asclepias syriaca; barley; Chelidonium majus; Chrysanthemum vulgare; corn; Datura stramonium; plant residues; Rumex obtusifolius; Solidago gigantea; sunflower; wheat

KeyWords Plus: THEOPHRASTI

Addresses: Kazinczi G (reprint author), Pannon Univ Agr Sci, Inst Plant Protect, POB 71, Keszthely, H-8361 Hungary

Title: The activity of deltoside saponin from Allium nutants L. in model system

Author(s): Akhov LS, Musienko MM, Oleszek W, Shakun M

Source: ALLELOPATHY JOURNAL 7 (1): 99-104 JAN 2000

Author Keywords: Allium nutans; Cucumis sativus; deltoside; phytotoxicity; plant density; Tagetes erecta; target-neighbour design

KeyWords Plus: EXPANSION; MIXTURES

Addresses: Oleszek W (reprint author), Inst Soil Sci & Plant Cutlivat, Dept Biochem, Czaroryskich Str 8, Pulawy, PL-24100 Poland; Kiev State Univ, Dept Plant Physiol, Kiev, UA-252033 Ukraine

Title: Allelopathic potential of root extracts of Parthenium hysterophorus L.

Author(s): Gupta A

Source: ALLELOPATHY JOURNAL 7 (1): 105-108 JAN 2000

Author Keywords: Amaranthus gangeticus; Cyamopsis psoralioides; dry weight; germination; Hibiscus esculentus; Parthenium hysterophorus; root extract

Addresses: Gupta A (reprint author), Manipur Univ, Dept Life Sci, Imphal, Manipur 795003 India
　

Title: Autotoxicity in Tagetes erecta L. on its own germination and seedling growth

Author(s): Kaul K

Source: ALLELOPATHY JOURNAL 7 (1): 109-113 JAN 2000

Author Keywords: African marigold; aqueous extracts; autotoxicity; germination; heterotoxicity; hypocotyl; organic extracts; radicle; seedling growth; Tagetes erecta

Addresses: Kaul K (reprint author), CSIR, Extens Ctr, Reg Res Lab, PO Bandia, Palampur, Himachal Prades 176061 India