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Allelopathic research on rice
seeds in Chhattisgarh (India) region : An Overview
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Research Note - Pankaj Oudhia
© 2001,2002,2003 Pankaj Oudhia - All Rights ReservedThe term Allelopathy is derived from two Greek words Allelon means each other and Pathos means to suffer i. e. the injurious effects of one upon another. However, Molisch (1937) coined this term which refers to all biochemical interactions (stimulatory and inhibitory) among plants, including micro organisms. It represents the plant-against plant aspect of the broader field of chemical ecology. Some authors have used the term in a more restricted sense to describe only the harmful effects of one higher plant upon another. Allelochemicals which inhibited the growth of some species at certain concentrations may stimulate the growth of same or different species at lower concentrations (Narwal, 1994). Allelopathy is relatively a new branch of science. Positive (inhibitory) allelopathic effects of any weed on other weeds can be exploited to develop ecofriendly, cheap and effective "Green herbicides’. Many experiments conducted around the world have clearly indicated that "Green herbicides" containing "Green Allelochemicals" are an integral part of eco or organic farming (Oudhia et al., 1999a). Use of natural compounds as herbicides or as the chemical basis for the development of new herbicides offers several advantages. (a) The wide array of phytotoxic compounds produced by plants provide many complex chemical structures that are unlikely to be discovered in the traditional synthetic strategies used by pesticide companies. (b) Degradation of natural compounds in the environment proceeds faster than that of synthetic compounds and thus reduces the environment pollution and ground water contamination etc.( c) The halogenated hydrocarbons which constitute about 60% of the registered herbicides are of environmental concern, while vast majority of natural compounds from plants pose little health hazards and therefore, are environmentaly safe (Narwal, 1994).
The negative (stimulatory) allelopathic effects of weeds on agricultural crops can be used to develop 'Green growth promoters'. Many studies conducted at Department of Agronomy, Indira Gandhi Agricultural University, Raipur (India) have clearly revealed that stimulatory allelopathic effects of weeds on crops can be utilized successfully for higher crop production (Oudhia, 1996, Lal and Oudhia, 1999). Weeds are always considered as unwanted plants (Oudhia, 1999a). They compete with agricultural crops for nutrient, light and moisture and harbour many diseases and insects (Oudhia, 1999b). In ancient Indian literatures, it is mentioned that every plant on this earth is useful for human beings, crops and animals (Oudhia, 1999c). The only need is to identify its uses. Hence, we can consider the weeds as useful plants. Chhattisgarh is rich in bio-diversity (Oudhia, 1998a and 1999b) and medicinal weeds (Oudhia and Dixit, 1994; Oudhia and Tripathi, 1998a; Oudhia et al., 1998a). Allelopathic (Oudhia, 1996 and 1999e; Oudhia et al., 1999b) and industrial uses of common weeds of Chhattisgarh have been reported. It has been also revealed that weeds having medicinal values are a boon for Chhattisgarh farmers (Oudhia and Tripathi 1999c). Chhattisgarh is also known as 'Rice bowl of India' and the area under high yielding Rice and hybrid Rice varieties are increasing very rapidly (Oudhia et al., 1999c, 1999d, 1999e .and 1999f). Many weeds including Echinocloa colonum, Cynodon dactylon, Cyperus rotundus, Parthenium hysterophorus, Blumea lacera, Ageratum conyzoides, lpomoea carnea, Calotropis gigantea etc. infest Rice fields and bunds in Chhattisgarh region (Pandey et al. 1999, Oudhia, 1999f and 1999g). Allelopathic effects of these weeds on germination and seedling vigour of Rice were not well studied. Due to non-availability of any information regarding allelopathic effects of different parts of common weeds including Parthenium hysterophorus, Blumea lacera, Lantana camara, Ageratum conyzoides, lpomoea carnea, Calotropis gigantea, Datura stramonium etc. on germination and seedling vigour of Rice varieties like Mahamaya, Proagro-6201, Proagro-6111 etc., a series of experiments were started at Department of Agronomy, IGAU, Raipur from 1995. The objectives of studies were (i) To evaluate the allelopathic potential of different parts of weed, (ii) To find out farmer's friendly method for preparation of weed extracts, (iii) To identify the promising and potential extract for increasing Rice production.
In all experiments different parts of weeds were collected from fields adjacent of Agriculture College Campus randomly before flowering, washed thoroughlv, cut into fine pieces and immersed in distilled water in different ratio (i.e.,1/10, 1/15, 1/ 20, 1/25 w/v respectively). In majority of experiments, 1:10 w/v concentration was used. The weeds or weed parts were decayed in water for different duration i. e., 24, 120, 168,216 and 264 hours. After decaying the extraction was done and extracts were passed/filtered through sieve (2 mm mesh). These extracts were applied on Rice seeds is kept in petridishes (10 cm dia) or seeds were soaked overnight in extracts and sown in earthen pots. In case of control, distilled water was used. Germination was noted at 3, 5, 7, 9 and 11 DAS (Days After Sowing) and abnormalities in seedlings produced by harmful extracts were also noted. The pH and electrical conductivity of extracts were also measured with the help of pH meter and conductivity bridge. The experiments were -lid out in Completely Randomised Design and Randomized Block Design. Each experiment was replicated for atleast 5 times and repeated for a tleast 3 times to avoid the errors. The method described above was a new method for allelopathic studies earlier and now it is recognised as most simple and farmer's friendly method. Many scientists around the world have opinion that this is an unique method and they have termed it as new Ollelopathic (O for Oudhia) method. The weeds used for study are given in Table 1. The allelopathic effects of weeds used for study and promising extracts identified are described separately.
(A) ALLELOPATHIC EFFECTS OF PARTHENIUM HYSTEROPHORUS
Parthenium hysterophorus is a common problematic weed in wastelands and crop fields in India. Parthenium is one of the most feared weed species and believed to have entered India in mid fifties (Oudhia, 1998b, Vyas and Oudhia , 1999). Adverse effects of Parthenium not only on human beings but also on animal health have been well documented. The chemical analysis has indicated that all the plant parts including trichomes and pollens contain toxin called sesquiterpene lactones. The major components of toxin being parthenin and other phenolic acids such as caffeic acid, vanillic acid, anisic acid, chlorogenic acid, parahydroxybenzoic acid and p-anisic acid are lethal to human beings, animals and crops. Parthenium has prolific seed bearing capacity producing a minimum of 330 crores of pollen per m2 land area, of which 1500 to 20000 seeds are produced per plant per year depending upon growth, habitat and longevity. Its high rate of fecundity, efficient seed dispersal, mechanisms due to the presence of two persistent disc florets which act as floats coupled with adverse allelopathic effects on many species enable its quick spread and establishment (Mahadevappa, 1997, Oudhia 1998c). Positive and negative allelopathic effects of Parthenium on many agricultural crops have been reported (Oudhia et al. 1997a 1997b, Oudhia and Tripathi, 1998b). In experiments conducted at IGAU, Raipur, Parthenium leaf extract (5%) of 24 hours was identified as promising extract whereas Parthenium leaf extract (6.7%) of 24 hours was identified as harmful extract.
(B) ALLELOPATHIC EFFECTS OF BLUMEA LACERA
Blumea lacera, is one of the common rabi season weeds of India. In Chhattisgarh earlier Blumea was bund weed but now it has became the weed of upland crop fields. Allelopathic effects of Blumea on agricultural crops have been reported (Oudhia and Thakur, 1996, Oudhia 1997, 1999 h and 1999I; Oudhia and Ganguli, 1999; Oudhia and Tripathi 1999d: Oudhia et al., 1997c and 1997d, Oudhia et a/„ 1998b and 1998c). The -experiments for evaluating the allelopathic potential of Blumea lacera on agricultural crops are first time conducted in the world at IGAU, Raipur. In experiments conducted at Blumea stem extract (1:10) of 168 hours and leaf extract of 216 hours were identified as promising extracts whereas harmful effects of stem extract of 216 hours have been noted.
( C) ALLELOPATHIC EFFECTS OF DATURA STRAMONIUM
Datura stramonium is important weed in USA, Australia, tropics and subtropics. It contains a number of alkaloides mainly Scopolamine and hyoscyamins which are produced in the roots and translocated to the leaves and seeds. In podzolic soil the toxicity of alkaloides to seed germination persisted upto 15 weeks in the field and up to 35 weeks under controlled conditions. That is why Australian farmers complain failures of Cotton, Soybean and Sorghum in the fields heavily infested with this weed because total alkaloid concentrations in the soil was 0.02% (Narwal, 1994), Datura is common weed of Chhattisgarh and its allelopathic effects on many agricultural crops have been reported (Oudhia et al. 1996a, 1998d and 1999g: Oudhia and Tripathi 1998b and 2000a). In experiments conducted on stem and leaf extract of 168 hours were identified as promising extracts whereas stem extract of 264 hours was identified as harmful extract.
(D) ALLELOPATHIC EFFECTS OF LANTANA CAMARA
Lantana camara is one of the 10 worst weeds of the world and is serious weed in 14 crops in 47 countries. However, its allelopathic effects on crops have been studied least (Narwal, 1994). Alletopathic effects of Lantana camara on germination and seedling vigour of many agricultural crops have been reported (Oudhia, 2000a Oudhia and Tripathi, 1999e, 2000b, 2000c, 2000d; Oudhia et a1., 1998e). In experiments conducted, on stem + leaf extract of 168 hours and 216 hours were identified as promising extracts. Root extract of 168 hours was identified as harmful extract.
(E)ALLELOPATHIC EFFECTS OF AGERATUM CONYZOIDES
Allelopathic effects of this roadside, wasteland and field weed on agricultural crops have been reported (Oudhia, 2000b; Oudhia et a1., 1995, 1996b and 1998f). In experiments conducted, Ageratum stem+leaf extract of 216 hours and leaf extract of 216 hours were identified as promising extract whereas Ageratum root extract of 264 hours was identified as harmful extracts.
(F) ALLELOPATHIC EFFECTS OF IPOMOEA CARNEA
lpomoea carnea, is an exotic weed and introduced in India as green manure crop. Allelopathic effects of lpomoea on many agricultural crops have been reported (Oudhia, 2000b ; Oudhia and Tripathi, 1997 a and 1998c). In experiment conducted on lpomoea leaf extract of 264 hours was identified as promising extract. Maximum harmful effects of stem + leaf extract of 168 hours was observed and this extract was identified as harmful extract.
(G) ALLELOPATHIC EFFECTS OF CALOTROPIS GIGANTEA
Calotropis gigantea, is common wasteland and bund weed in Chhattisgarh. Like Blumea, allelopathic studies related to Calotropis were conducted for the first time in the world. Allelopath'ic effects of Calotropis on germination and seedling vigour of many agricultural crops have been reported (Oudhia et al., 1997d and 1998g and 1998h, Oudhia and Tripathi, 1997b). In experiments conducted, Calotropis stem + leaf extract of 216 hours was identified as promising extract whereas leaf extract of 120 hours was identified as harmful extract.
The experiments are still in progress at IGAU, Raipur. In these studies, the isolation of the allelochemicals from extracts was not done because of lack of laboratory facilities and high cost of the chemical analysis weeds have different allelopathic potential. However, from these studies many basic informations have been gathered. The studies revealed that (i) Different parts of weed have different allelopathic potential, (ii) The method adopted for preparing extract can alter the allelopathic potential of weed parts. The study indicated that there is a tremendous scope of utilizing the extracts of different weeds for pre sowing soaking of Rice seeds in order to stimulate the early germination seedling vigour.
REFERENCES
Lal, B.and P.Oudhia (1999). Beneficial effects of Allelopathy : I Crop Production. Indian J. Weed Sci. 31 (1 &2): 103-105.
Mahadevappa, M. 1997. Ecology, distribution, menace and management of Parthenium. :Proc. First International Confr. On Parthenium Management (Vol. 1) UAS, Dharwad, 6-8 Oct. 1997:1-12.
Molisch, H. 1937. Der Enfusslinear Pflanze aufdie andere- Allelopathic Fischer, Jena, GDR.
Narwal, S.S. 1994. Allelopathy in Crop Production. Scientific Publishers, Jodhpur. pp. 288.
Oudhia. Pankaj 1996. Allelopathic effects of selected weeds on crops. M.Sc. (Ag.) Thesis, Indira Gandhi Agricultural Unversity, Raipur (India).pp. 250.
Oudhia, P. 1997. Evaluation of host specificity of Blumea leaf beetle (Chrysolina sp.nr. madrasae Jackoby). Insect Environment. 3 (3) : 80.
Oudhia, P. 1998a Harmonywith nature. Abstract All India Conf. on Sci. and Engin. for holistic Dev. and meditation Retreat at Brahma Kumaris, Shantivan, Talheti, Abu Road. 23-26 Oct.: 2.
Oudhia, P. 1998b. Parthenium hysterophorus : A curse for the bio-diversity of Chhattisgarh Plains. Abstract. National Res. Seminar on Biochemical Changes. An Impact on Environ, R.D. Govt. P.G. College, Mandla, 30-31 July: 26.
Oudhia, P. 1998c. Gajarghas: Ek Ghatak Shatru (Hindi) Pbl. Agrocrat's Society For Rural Development, Raipur (India), pp. 50.
Oudhia. P. 1999a. Medicinal Weeds in Groundnut Fields of Chhattisgarh (India). International Chickpea and Pigeonpea Newsletter (ICRISAT). 19:62-64.
Oudhia, P. 1999b. Studies on allelopathy and medicinal weeds in chickpea fields. International Chickpea and Pigeonpea Newsletter (ICRISAT). 6: 29-33.
Oudhia, P. 1999c. Medicinal weeds in wheat fields of Chhattisgarh (India). Rachis (ICARDA). 18 (1) : 40-41.
Oudhia, P. 1999d. The possibilities of utilizing beneficial effects of Indian classical music for crop production with special reference to Chhattisgarh : A Review. Abstract. National Seminar on Music, Kamla Devi Sangeet Mahavidyalaya, Raipur, 12-14 March: 5.
Oudhia, P. 1999e. Allelopathic effects of some obnoxious weeds on germination of Melilotus alba. Legume Res. 22 (2): 133- 134.
Oudhia, P. 1999f. Phyto-sociological studies of rainy season wasteland weeds with special reference to Parthenium hysterophorus L. in Raipur (India) district. Asian J.Microbiol. Biotech and Environ. Sci. (In press).
Oudhia, P. 1999g. Medicinal weeds in rice fields of Chhattisgarh (India). International Rice Res. Notes (IRRI) . 24 (1): 40.
Oudhia, P. 1999h. Blumea leaf beetle in Chhattisgarh plain. Insect. Environ. 5 (1) : 22.
Oudhia, P. 1999i. Effect of some botanicals on hatchability of Blumea leaf beetle. Insect Environ. 4(4): 154.
Oudhia, P. 2000a. Allelopathic effect of Lantana camara L. on germination of Soybean. Legume Res. (In press)
Oudhia, P. 2000b. Allelopathic effects of Ageratum and Ipomoea carnea on mustard. Eco Environ. And Consv. (In press).
Oudhia, P. andA.Dixit. 1994. Weeds in Ambikapur region (Madhya Pradesh) and their medicinal use. Weed News. 1 (2) : 19-21.
Oudhia, P. and R.N.Ganguli, 1999. Chrysolina madrasea : A potential bio-control agent for Blumea lacera. Abstract VIII Biennial Conf. of Indian Society of Weed Sci., BHU, Varanasi, 5-7 Feb..-134.
Oudhia, P. and B.S. Thakur 1996. New record of the leaf beetle on a weed. Current Res. 25:218.
Oudhia, P. and R.S. Tripathi, 1997a. Germination and seedling vigour of soybean as affected by allelopathy of lpomoea carnea Jacq. Legume Res. 20 (3/4): 227- 229.
Oudhia, P. and R.S. Tripathi, 1997b. Allelopathic potential of Calotropis gigantea. R.Br. World Weeds. 4:109-119.
Oudhia, P. and R.S. Tripathi, 1998a. The possibilities of utilization of medicinal weeds to increase the income of the farmers. Abstract. National Seminar on Medicinal Hant Resources development. Organised by Gujarat Government and AADAR, Gandhi Labour Institute. Ahmedabad. 4-5 Oct.: 3.
Oudhiua P. and R.S. Tripathi, 1998b. Allelopathic effects of Parthenium hysterophours L. on kodo, mustard and problematic weeds. Proc. First International Conf. On Parthenium Management (Vol. II), UAS, Dharwad, 6-8 Oct. 1997 136-139.
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Oudhia, P. and R. S. Tripathi, 1999a. Scope of cultivation of important medicinal plants in Chhattisgarh plains. Proc. National Conf. On Health Care and Development of Herbal Medicines. IGAU, Raipur (India)29-30Aug. 1997:215-222.
Oudhia, P. and R.S.Tripathi 1999b. Medicinal Weeds of Raipur and Durg (M.P.) region. Proc. Nat. Conf. on Health Care and Dev. of Herbal Medicine. IGAU, Raipur 29.30. August.
Oudhia, P. and R.S. Tripathi, 1999c. Medicinal weeds: A boon for the farmers of Chhattisgarh.: Abstract. VIII Biennial Conference of Indian Society of Weed Science, BHU, Varanasi, 5-7 Feb.: 152.
Oudhia, P. and R.S. Tripathi, 1999d. A useful weed Blumea lacera L.: A review. Indian J.WeedSci. 31 (1 & 2): 108-109.
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Ouhdia P., and R.S. Tripathi, 2000a. Germination of mustard as affected by allelopathy of Datura stramonium L. Weed News (In press)
Oudhia, P., and R.S. Tripathi, 2000b. Allelopathic effect of Lantana camara L. on germination of Kodo (Paspalum scrobiculatum L.) Weed News (In press).
Oudhia, P., and R.S. Tripathi, 2000c. Allelopathic effect of Lantana camara L. on germination and seedling vigour of mustard. Bhartiya Krishi Anusandhan Patrika (In press).
Oudhia, P., and R.S.Tripathi, 2000d. Allelopathic effects of Lantana . camara on Wheat. Crop Res. (In press).
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1995. Allelopathic effect of Ageratum conyzoides on germination of linseed var. Kiran. Weed News: 2 (1 &2) 15-18.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1996a. Allelopathic effect of Datura stramonium L. on Linseed. Agrl. Biol. Res. 12 (1 & 2): 12-17.
Oudhia, P., S.S.Kolhe and R.S. Tripathi 1996b. Allelopathic effect of Ageratum conzoides L. on paddy. Abstract. International Symposium on rainfed Rice for Sustainable Food Security, CRRI, Cuttack, 23-25 Sept. : 95.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997a. Allelopathic effect of White top (Parthenium hysterophorus L.) on Chickpea. Legume Res. 20 (2): 117-120.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997b. Allelopathic effect of Parthenium hysterophorus L. on germination of Linseed. Indian J. Plant Physiol. 2 (4) : 327-329.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997c. Allelopathic effect of Blumea lacera L. on wheat. Indian J. Weed Sci. 29 (1 & 2): 4-7.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997d. Allelopathic effect of Blumea lacera L. on chickpea and rabi weeds. Agril. Sci. Digest. 17 (14) : 275-278.
Oudhia, P., B.S. Joshi and V.K.Kosta. 1998a. The possibilities of preparing Homoeopathic drugs from the obnoxious weeds of Chhattisgarh. Bharitya Krishi Anusandhan Patrika. 13 (1 & 2) : 53-57.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998b. Allelopathic effect of Blumea lacera L. on Rice and common kharif weeds. Oryza. 35(2): 175-177.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998c. Germination and seedling vigour of mustard as affected by allelopathy of Blumea lacera L. Agril. Sci. Digest. 18 (3) : 183-16.
Oudhia, P.,S.S. Kolhe and R.S. Tripathi. 1998d. Germination and seedling vigour of chickpea as affected by allelopathy of Datura stramonium . L. Int. Chickpea and Pigeonpea News letter (ICRIST). 522-24.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998e. Negative (stimulatory) allelopathy of Lantana camara L on linseed var. Kiran. : Abstract. International Symp. on Microbial Biotech for Sustainable Dev. and Productivity, R.D.U., Jabalpur 14-16 November: 64,
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998f. Germination and seedling vigour of chickpea as affected by allelopathy of Ageratum conyzoides L. Abstract. National Symposium on Management of Biotic and Abiotic Stresses in Pulse Crops, IIPR, Kanpur, 26-28 June : 40.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998g. Allelopathic effect of Calotropis gigantea R.Br. on Wheat: Abstract. Ill International Cong. on Allelopathy in Eco. Agr. and Forestry, UAS, Dharwad 18-21 Aug.: 151.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998h. Stimulatory allelopathy of Calotropis gigantea R.Br. on germination and seedling vigour of Linseed. Abstract. First Inter. Agronomy Cong. on Agronomy, Environ, and Food Security for 21st Century, Vigyan Bhawan, N. Delhi 23-27 Nov. 227.
Oudhia, P., R.S.Tripathi and P.Katiyar. 1999a. Weed management through Green Allelo- chemicals :an eco-friendly approach towards sustainable agriculture. Abstract. National Seminar on Chemistry of Environmental Pollution with Special Emphasis on Pesticides, Dept. of Chemistry, Govt. D.B Girls PG College, Raipur (India). 28-29 Jan:22.
Oudhia, P., N.Pandey and R.S. Tripathi. 1999b. Allelopathic effects of obnoxious weeds on germination and seedling vigour of hybrid Rice. International Rice Research Notes (IRRI). 24(2): 36.
Oudhia, P., N.Pandey and R.S. Tripathi and R.N.Ganguli. 1999c. Reaction of hybrid Rice varieties to gall midge (Orsolia oryzae). Insect Environ. 4(4) : 134.
Oudhia, P., N. Pandey and R.S. Tripathi and R.N.Ganguli. 1999d. Effect of nitrogen and water management practices on gall midge (Orseolia oryzae) infestation in hybrid Rice. Insect Environment. 4 (4): 199-120.
Oudhia, P., N. Pandey and R.S. Tripathi and R.N.Ganguli. 1999e. Gall midge (Orseolia oryzae) infestation in hybrid Rice as affected by Agronomical practices. Insect. Environ. 4 (4) : 123-124.
Oudhia, P., N.Pandey and R.S. Tripathi and R.N.Ganguli, 1998f. Response of different hybrid rice varieties to Brown Plant Hopper {Nilparvata lugens (Stal.)} Insect Environ. 5(1):10-11.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1999g. Germination and seedling vigour of Rice var. Mahamaya as affected by allelopathy of Datura stramonium. Crop. Res. 18 (1) : 46-49.
Pandey, N., P., Oudhia, S.S. Kolhe and R.S.Tripathi. 1999. Identification of weed flora of paddy fields and bunds in Raipur (Chhattisgarh) region of India. VIII Biennial Conference of Indian Society of Weed Science, BHU, Varanasi, 5-7 Feb. p. 142.
Vyas, S.and P, Oudhia, 1999., Parthenium hysterophorus L. : A potential threat to public health, crop productiviy and bio-diversity . of Chhattisgarh. Abstract National Seminar on Geography ' with special Emphasis on Environment, Durga College, Raipur (India), 6-7 March : 3.(Source : Advances in Agricultural Research in India; Special Volume - II on Rice Research and management in India, Vol XIV, December, 2000 : 69-80)
Table - 1 Parthenium hysterophorus Gajar Gas Obnoxious weed, harmful for human beings, animals and crops Lantana camara Goti phool Obnoxious weed found as wasteland weed in Chhattisgarh Blumea lacera Kukurmutta Upland rabi weed Ageratum conyzoides Gandhila Crop and wasteland weed Ipomoea carnea Beshram Wasteland weed, shelter place of harmful insects and pathogens Calotropis gigantea Fudhar Wasteland weed Datura stramonium Dhatura Wasteland weed Obnoxious weed in Australia. Cyperus rotundus Motha Obnoxious weed in all most all crops of Chhattisgarh Aeschynomene americana Soli Comon problematic weed in Rice fields and bunds Abutilon indicum Raksi Kharif weed Echinocloa colonum Sawan Obnoxious kharif weed REFERENCES
Lal, B.and P.Oudhia (1999). Beneficial effects of Allelopathy : I Crop Production. Indian J. Weed Sci. 31 (1 &2): 103-105.
Mahadevappa, M. 1997. Ecology, distribution, menace and management of Parthenium. :Proc. First International Confr. On Parthenium Management (Vol. 1)
UAS, Dharwad, 6-8 Oct. 1997:1-12.
Molisch, H. 1937. Der Enfusslinear Pflanze aufdie andere- Allelopathic Fischer, Jena, GDR.
Narwal, S.S. 1994. Allelopathy in Crop Production. Scientific Publishers, Jodhpur. pp. 288.
Oudhia. Pankaj 1996. Allelopathic effects of selected weeds on crops. M.Sc. (Ag.) Thesis, Indira Gandhi Agricultural Unversity, Raipur (India).pp. 250.
Oudhia, P. 1997. Evaluation of host specificity of Blumea leaf beetle (Chrysolina sp.nr. madrasae Jackoby). Insect Environment. 3 (3) : 80.
Oudhia, P. 1998a Harmonywith nature. Abstract All India Conf. on Sci. and Engin. for holistic Dev. and meditation Retreat at Brahma Kumaris, Shantivan, Talheti, Abu Road. 23-26 Oct.: 2.
Oudhia, P. 1998b. Parthenium hysterophorus : A curse for the bio-diversity of Chhattisgarh Plains. Abstract. National Res. Seminar on Biochemical Changes. An Impact on Environ, R.D. Govt. P.G. College, Mandla, 30-31 July: 26.
Oudhia, P. 1998c. Gajarghas: Ek Ghatak Shatru (Hindi) Pbl. Agrocrat's Society For Rural Development, Raipur (India), pp. 50.
Oudhia. P. 1999a. Medicinal Weeds in Groundnut Fields of Chhattisgarh (India). International Chickpea and Pigeonpea Newsletter (ICRISAT). 19:62-64.
Oudhia, P. 1999b. Studies on allelopathy and medicinal weeds in chickpea fields. International Chickpea and Pigeonpea Newsletter (ICRISAT). 6: 29-33.
Oudhia, P. 1999c. Medicinal weeds in wheat fields of Chhattisgarh (India). Rachis (ICARDA). 18 (1) : 40-41.
Oudhia, P. 1999d. The possibilities of utilizing beneficial effects of Indian classical music for crop production with special reference to Chhattisgarh : A Review. Abstract. National Seminar on Music, Kamla Devi Sangeet Mahavidyalaya, Raipur, 12-14 March: 5.
Oudhia, P. 1999e. Allelopathic effects of some obnoxious weeds on germination of Melilotus alba. Legume Res. 22 (2): 133- 134.
Oudhia, P. 1999f. Phyto-sociological studies of rainy season wasteland weeds with special reference to Parthenium hysterophorus L. in Raipur (India) district. Asian J.Microbiol. Biotech and Environ. Sci. (In press).
Oudhia, P. 1999g. Medicinal weeds in rice fields of Chhattisgarh (India). International Rice Res. Notes (IRRI) . 24 (1): 40.
Oudhia, P. 1999h. Blumea leaf beetle in Chhattisgarh plain. Insect. Environ. 5 (1) : 22.
Oudhia, P. 1999i. Effect of some botanicals on hatchability of Blumea leaf beetle. Insect
Environ. 4(4): 154.
Oudhia, P. 2000a. Allelopathic effect of Lantana camara L. on germination of Soybean. Legume Res. (In press)
Oudhia, P. 2000b. Allelopathic effects of Ageratum and Ipomoea carnea on mustard. Eco Environ. And Consv. (In press).
Oudhia, P. andA.Dixit. 1994. Weeds in Ambikapur region (Madhya Pradesh) and their medicinal use. Weed News. 1 (2) : 19-21.
Oudhia, P. and R.N.Ganguli, 1999. Chrysolina madrasea : A potential bio-control agent for Blumea lacera. Abstract VIII Biennial Conf. of Indian Society of Weed Sci., BHU, Varanasi, 5-7 Feb..-134.
Oudhia, P. and B.S. Thakur 1996. New record of the leaf beetle on a weed. Current Res. 25:218.
Oudhia, P. and R.S. Tripathi, 1997a. Germination and seedling vigour of soybean as affected by allelopathy of lpomoea carnea Jacq. Legume Res. 20 (3/4): 227- 229.
Oudhia, P. and R.S. Tripathi, 1997b. Allelopathic potential of Calotropis gigantea. R.Br. World Weeds. 4:109-119.
Oudhia, P. and R.S. Tripathi, 1998a. The possibilities of utilization of medicinal weeds to increase the income of the farmers. Abstract. National Seminar on Medicinal Hant Resources development. Organised by Gujarat Government and AADAR, Gandhi Labour Institute. Ahmedabad. 4-5 Oct.: 3.
Oudhia P. and R.S. Tripathi, 1998b. Allelopathic effects of Parthenium hysterophours L. on kodo, mustard and problematic weeds. Proc. First International Conf. On Parthenium Management (Vol. II), UAS, Dharwad, 6-8 Oct. 1997 136-139.
Oudhia, P. and R.S. Tripathi, 1998c. Allelopathic potential of Ipomoea carnea Jacq. Agril. Biol Res. 14 (3&4) : 1-8.
Oudhia, P. and R. S. Tripathi, 1999a. Scope of cultivation of important medicinal plants in Chhattisgarh plains. Proc. National Conf. On Health Care and Development of Herbal Medicines. IGAU, Raipur (India)29-30Aug. 1997:215-222.
Oudhia, P. and R.S.Tripathi 1999b. Medicinal Weeds of Raipur and Durg (M.P.) region. Proc. Nat. Conf. on Health Care and Dev. of Herbal Medicine. IGAU, Raipur 29.30. August.
Oudhia, P. and R.S. Tripathi, 1999c. Medicinal weeds: A boon for the farmers of Chhattisgarh.: Abstract. VIII Biennial Conference of Indian Society of Weed Science, BHU, Varanasi, 5-7 Feb.: 152.
Oudhia, P. and R.S. Tripathi, 1999d. A useful weed Blumea lacera L.: A review. Indian J.WeedSci. 31 (1 & 2): 108-109.
Oudhia, P., and R.S. Tripathi 1999e. Allelopathic effect of Lantana camara L. on Rice Agril. Sci. Digest 19(1) : 43-45.
Ouhdia P., and R.S. Tripathi, 2000a. Germination of mustard as affected by allelopathy of Datura stramonium L. Weed News (In press)
Oudhia, P., and R.S. Tripathi, 2000b. Allelopathic effect of Lantana camara L. on germination of Kodo (Paspalum scrobiculatum L.) Weed News (In press).
Oudhia, P., and R.S. Tripathi, 2000c. Allelopathic effect of Lantana camara L. on germination and seedling vigour of mustard. Bhartiya Krishi Anusandhan Patrika (In press).
Oudhia, P., and R.S.Tripathi, 2000d. Allelopathic effects of Lantana . camara on Wheat. Crop Res. (In press).
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1995. Allelopathic effect of Ageratum conyzoides on germination of linseed var. Kiran. Weed News: 2 (1 &2) 15-18.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1996a. Allelopathic effect of Datura stramonium L. on Linseed. Agrl. Biol. Res. 12 (1 & 2): 12-17.
Oudhia, P., S.S.Kolhe and R.S. Tripathi 1996b. Allelopathic effect of Ageratum conzoides L. on paddy. Abstract. International Symposium on rainfed Rice for Sustainable Food Security, CRRI, Cuttack, 23-25 Sept. : 95.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997a. Allelopathic effect of White top (Parthenium hysterophorus L.) on Chickpea. Legume Res. 20 (2): 117-120.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997b. Allelopathic effect of Parthenium hysterophorus L. on germination of Linseed. Indian J. Plant Physiol. 2 (4) : 327-329.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997c. Allelopathic effect of Blumea lacera L. on wheat. Indian J. Weed Sci. 29 (1 & 2): 4-7.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1997d. Allelopathic effect of Blumea lacera L. on chickpea and rabi weeds. Agril. Sci. Digest. 17 (14) : 275-278.
Oudhia, P., B.S. Joshi and V.K.Kosta. 1998a. The possibilities of preparing Homoeopathic drugs from the obnoxious weeds of Chhattisgarh. Bharitya Krishi Anusandhan Patrika. 13 (1 & 2) : 53-57.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998b. Allelopathic effect of Blumea lacera L. on Rice and common kharif weeds. Oryza. 35(2): 175-177.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998c. Germination and seedling vigour of mustard as affected by allelopathy of Blumea lacera L. Agril. Sci. Digest. 18 (3) : 183-16.
Oudhia, P.,S.S. Kolhe and R.S. Tripathi. 1998d. Germination and seedling vigour of chickpea as affected by allelopathy of Datura stramonium . L. Int. Chickpea and Pigeonpea News letter (ICRIST). 522-24.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998e. Negative (stimulatory) allelopathy of Lantana camara L on linseed var. Kiran. : Abstract. International Symp. on Microbial Biotech for Sustainable Dev. and Productivity, R.D.U., Jabalpur 14-16 November: 64,
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998f. Germination and seedling vigour of chickpea as affected by allelopathy of Ageratum conyzoides L. Abstract. National Symposium on Management of Biotic and Abiotic Stresses in Pulse Crops, IIPR, Kanpur, 26-28 June : 40.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998g. Allelopathic effect of Calotropis gigantea R.Br. on Wheat: Abstract. Ill International Cong. on Allelopathy in Eco. Agr. and Forestry, UAS, Dharwad 18-21 Aug.: 151.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1998h. Stimulatory allelopathy of Calotropis gigantea R.Br. on germination and seedling vigour of Linseed. Abstract. First Inter. Agronomy Cong. on Agronomy, Environ, and Food Security for 21st Century, Vigyan Bhawan, N. Delhi 23-27 Nov. 227.
Oudhia, P., R.S.Tripathi and P.Katiyar. 1999a. Weed management through Green Allelo- chemicals :an eco-friendly approach towards sustainable agriculture. Abstract. National Seminar on Chemistry of Environmental Pollution with Special Emphasis on Pesticides, Dept. of Chemistry, Govt. D.B Girls PG College, Raipur (India). 28-29 Jan.
:22.
Oudhia, P., N.Pandey and R.S. Tripathi. 1999b. Allelopathic effects of obnoxious weeds on germination and seedling vigour of hybrid Rice. International Rice Research Notes (IRRI). 24(2): 36.
Oudhia, P., N.Pandey and R.S. Tripathi and R.N.Ganguli. 1999c. Reaction of hybrid Rice varieties to gall midge (Orsolia oryzae). Insect Environ. 4(4) : 134.
Oudhia, P., N. Pandey and R.S. Tripathi and R.N.Ganguli. 1999d. Effect of nitrogen and water management practices on gall midge (Orseolia oryzae) infestation in hybrid Rice.
Insect Environment. 4 (4): 199-120.
Oudhia, P., N. Pandey and R.S. Tripathi and R.N.Ganguli. 1999e. Gall midge (Orseolia oryzae) infestation in hybrid Rice as affected by Agronomical practices. Insect. Environ. 4 (4) : 123-124.
Oudhia, P., N.Pandey and R.S. Tripathi and R.N.Ganguli, 1998f. Response of different hybrid rice varieties to Brown Plant Hopper {Nilparvata lugens (Stal.)} Insect Environ. 5(1):10-11.
Oudhia, P., S.S.Kolhe and R.S. Tripathi. 1999g. Germination and seedling vigour of Rice var. Mahamaya as affected by allelopathy of Datura stramonium. Crop. Res. 18 (1) : 46-49.
Pandey, N., P., Oudhia, S.S. Kolhe and R.S.Tripathi. 1999. Identification of weed flora of paddy fields and bunds in Raipur (Chhattisgarh) region of India. VIII Biennial Conference of Indian Society of Weed Science, BHU, Varanasi, 5-7 Feb. p. 142.
Vyas, S.and P, Oudhia, 1999., Parthenium hysterophorus L. : A potential threat to public health, crop productiviy and bio-diversity . of Chhattisgarh. Abstract National Seminar on Geography ' with special Emphasis on Environment, Durga College, Raipur (India), 6-7 March : 3.(Source : Advances in Agricultural Research in India; Special Volume - II on Rice Research and management in India, Vol XIV, December, 2000 : 69-80)