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Articles 421 - 443 of 443

Full-Text Articles in Agricultural Science

Reproductive Performance And Population Dynamics Of Cowpea Aphid (Homoptera: Aphididae) On Leaf Extracts Of Resistant And Susceptible Cowpeas, I. Billy Annan, Ward M. Tingey, George A. Schaefers, Kailash N. Saxena Jan 1996

Reproductive Performance And Population Dynamics Of Cowpea Aphid (Homoptera: Aphididae) On Leaf Extracts Of Resistant And Susceptible Cowpeas, I. Billy Annan, Ward M. Tingey, George A. Schaefers, Kailash N. Saxena

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Membrane feeding studies were conducted to determine the effects of raw juices and chemical extracts of leaves of aphid-resistant (ICV-12) and aphid- susceptible (ICV-1) cultivars of cowpea [Vigna unguiculata L. (Walp.)], on the survival, growth, and reproduction of cowpea aphid Aphis craccivora Koch. Life table and demographic statistics of the cohort population and subsequent generations were estimated. Compared to ICV-1, the leaf juices and chemical extracts of ICV-12 exhibited significant (P ≤ 0.05) adverse effects on aphid survival, growth, and reproduction. Raw leaf juice and ethyl acetate extract of ICV-12 in both water and sucrose significantly (P ≤ 0.05) limited …

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Suitability Of Graminaceous Weed Species As Host Plants For Rice Leaffolders, Cnaphalocrocis Medinalis And Marasmia Patnalis, Z. R. Khan, M. L.P. Abenes, N. J. Fernandez Jan 1996

Suitability Of Graminaceous Weed Species As Host Plants For Rice Leaffolders, Cnaphalocrocis Medinalis And Marasmia Patnalis, Z. R. Khan, M. L.P. Abenes, N. J. Fernandez

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The suitability of 12 graminaceous weeds of ricefields as host plants for two rice leaffolders, Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae) was compared to a susceptible (IR36) and a moderately resistant (TKM6) rice variety in laboratory and greenhouse tests. Although rice was the most preferred host of the two leaffolder species, their responses to the test weeds varied significantly. Cnaphalocrocis medinalis responded better to most of the test weeds than did M. patnalis, suggesting a wider host range for C. medinalis. Third instar larval orientation and settling, and food consumption and assimilation of C. medinalis on Leersia …

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1,8-Cineole: An Attractant For The Banana Weevil, Cosmopolites Sordidus, Isaiah O. Ndiege, Willam J. Budenberg, Dalmas O. Otieno, Ahmed Hassanali Jan 1996

1,8-Cineole: An Attractant For The Banana Weevil, Cosmopolites Sordidus, Isaiah O. Ndiege, Willam J. Budenberg, Dalmas O. Otieno, Ahmed Hassanali

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1,8-Cineole was identified as one of the electrophysiologically active components of the volatiles from banana cultivars susceptible to the banana weevil. It was also shown to be an attractant for the banana weevil Comopolites sordidus in laboratory behavioural bioassays. The resistant cultivar did not contain 1,8-cineole. β-Phellandrene, which exhibited electrophysiological activity, but did not show any attraction to the banana weevil, was found only in the resistant banana cultivar.

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Linkage Relationships Among Loci Controlling Morphological Traits In Cowpea (Vigna Unguiculata (L.) Walp.), S. M. Githiri, P. M. Kimani, R. S. Pathak Jan 1995

Linkage Relationships Among Loci Controlling Morphological Traits In Cowpea (Vigna Unguiculata (L.) Walp.), S. M. Githiri, P. M. Kimani, R. S. Pathak

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Linkage among loci controlling various morphological traits in cowpea were determined using F2 progenies. Data were collected on individual plants of four crosses segregating for several loci. Recombination estimates between the following pairs of loci were as follows: Sw (swollen vs normal stem base)-Fbc (cream vs green flower buds) (41±4.8%), Pus(purple vs green stems)-Cbr (cocoa-brown vs straw-yellow dry pods) (31±5.7%), Pup(purple vs green immature pods)-Cbr (30±5.7%), Pus-Pup (4±1.5%), Ndt (non-determinate vs determinate)-Pd (peduncle colour) (26±2.8%), Ndt-Hg (semi-erect vs erect plant type) (26±2.8%), Pt(purple vs green pod tips)-Bk (greyish-black vs straw-yellow dry pods) (19±2.4%) and Hg-Bpd (normal vs branching peduncle (24±9.5%). …

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Limonoids From Turraea Floribunda, Baldwyn Torto, Michael D. Bentley, Barbara J.W. Cole, Ahmed Hassanali, Fu Yung Huang, Leslie Gelbaum, Donald G. Vanderveer Jan 1995

Limonoids From Turraea Floribunda, Baldwyn Torto, Michael D. Bentley, Barbara J.W. Cole, Ahmed Hassanali, Fu Yung Huang, Leslie Gelbaum, Donald G. Vanderveer

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Extracts of the root bark of Turraea floribunda have yielded four new limonoids of the havanensin class: 28-nor-4α-carbomethoxy-11β-acetoxy-12α-(2-methylbutanoyloxy)-14,15-deoxyhavanensin-1,7-diacetate; 28-nor-4α-carbomethoxy-11β-hydroxy-12α-(2-methylbutanoyloxy)-14,15-deoxyhavanensin-1,7-diacetate; 18-nor-4α-carbomethoxy-11β-acetoxy-12α-(2-methylbutanoyloxy)-14,15-deoxyhavanensin-1-acetate; and 28-nor-4α-carbomethoxy-7-deoxy-7-oxo-11β-acetoxy-12α-(2-methylbutanoyloxy)-14,15-deoxyhavanensin-1-acetate. The structures were determined by spectroscopic methods. The structure for the first of these compounds was also confirmed by X-ray diffraction methods. © 1995.

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Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe Jan 1995

Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe

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Pubescence (trichomes) in wild and cultivated cowpeas, Vigna vexillata and V. unguiculata, adversely affected oviposition, mobility, and food consumption and utilisation by the legume pod borer, Maruca testulalis (Geyer), in tests conducted with TVnu 72 (wild, highly resistant and highly pubescent), TVu 946 (semi-wild, moderately resistant and pubescent) and IT82D-716 (cultivated, highly susceptible and pubescent). In free-choice and no-choice tests, significantly (P < 0.05) fewer eggs were laid on 3-week-old potted plants of TVnu 72, the highly pubescent and wild species; this species also received fewer eggs on abaxial and adaxial leaf surfaces. Ovipositional activity on stipules, stem, branches, terminal shoots, adaxial and abaxial leaf surfaces of the susceptible cultivar, IT82D-716 was higher (P < 0.05) than on TVu 946 and TVnu 72. More eggs were laid on the abaxial surfaces than on the adaxial surfaces of leaves for all tests conducted, except for the TVnu 72 no-choice test. Significant negative correlations (r = -0.99** and r = -0.99**) were found between mean number of eggs laid and length and density of non-glandular trichomes. There was a significant negative correlation (r = -0.99**) between larval velocity and length of non-glandular trichomes on pod surface. Similarly, significant negative correlations (r = -0.85* and -0.89*) were found between larval velocity and density and length of non-glandular trichomes on leaf surface. Pods of IT82D-716 and TVnu 72 were the most - and least - preferred for settling by larvae of M. testulalis, respectively. There was a significant positive correlation (r = 0.99**) between larval penetration time on pods and length of non-glandular trichomes. Weight loss, number of feeding punctures and number of larvae on whole pods of TVnu 72 were lower and significantly different (P < 0.05) from IT82D-716 and TVu 946. This study showed that it would be advantageous to use TVnu 72 in a breeding programme to incorporate pubescence into high-yielding commercial cultivars for resistance against M. testulalis and possibly other major pests. © 1995.

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Effects Of Neem Seed Derivatives On Brown Planthopper Symbiotes, S. Raguraman, R. C. Saxena Jan 1994

Effects Of Neem Seed Derivatives On Brown Planthopper Symbiotes, S. Raguraman, R. C. Saxena

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Populations of intracellular symbiotes declined significantly in brachypterous females of the brown planthopper, Nilaparvata lugens (Stål), which were stressed during nymphal development by caging them on IR20 rice plants treated with 3% neem oil, 5% neem seed kernel aqueous extract, or 10% neem cake aqueous extract. In addition, nymphs grew poorly and symbiote populations in prospective females declined, when reared on rice plants grown in soil treated with neem cake; this indicates systemic action of bioac-tive neem constituents. Addition of custard-apple oil to neem oil did not enhance the inhibitory effects. The effects of neem derivatives on the symbiotes may …

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Distribution And Sampling Of Chilo Partellus (Lepidoptera: Pyralidae) In Maize And Sorghum On The Kenya Coast, W. A. Overholt, K. Ogedah, P. M. Lammers Jan 1994

Distribution And Sampling Of Chilo Partellus (Lepidoptera: Pyralidae) In Maize And Sorghum On The Kenya Coast, W. A. Overholt, K. Ogedah, P. M. Lammers

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The seasonal occurrence and spatial distribution of the crambine stem borer, Chilo partellus (Swinhoe) were investigated in maize, Zea mays, and sorghum, Sorghum bicolor, fields at the Kenya coast. During the vegetative growth stage, small-sized larvae were typically found behind leaf sheaths and in whorls in maize and sorghum. In reproductive and senescent maize, small-sized larvae were also found feeding in ears. Later immature life stages were located predominantly in stems in sorghum, and in the stems and ears in maize. Density and variance estimates of small, medium-, and large-sized larvae and pupae in maize and sorghum were fitted to …

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Grain Yield Losses In Maize (Zea Mays L.) Genotypes In Relation To Their Resistance Against Chilo Partellus (Swinhoe) Infestation At Anthesis, Harish Kumar, Gershon O. Asino Jan 1994

Grain Yield Losses In Maize (Zea Mays L.) Genotypes In Relation To Their Resistance Against Chilo Partellus (Swinhoe) Infestation At Anthesis, Harish Kumar, Gershon O. Asino

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Resistance/susceptibility of 12 maize genotypes to stem borer Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) was measured under artificial infestation at the time of anthesis during the short rainy seasons of 1989/90 and 1990/91. The maize genotypes tested were Inbred A (Kenya), Pwani hybrid (Kenya), Hybrid 511 (Kenya), ICZ2-CM (CIMMYT), MBR-8637 (CIMMYT), MBR-8650 (CIMMYT), MBR-8668 (CIMMYT), Poza Rica 7832 (CIMMYT), Mp704 (USDA), Katumani Composite B (Kenya), Bulk CG 4141 (Zambia), and MMV 400 (Zambia). Under low infestation (50-60 eggs per plant), the differences between susceptible and resistant genotypes in terms of stalk damage or grain damage were not apparent, whereas under high …

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Interrelationship Among Chilo Partellus (Swinhoe) Damage Parameters And Their Contribution To Grain Yield Reduction In Maize (Zea Mays L.), S. O. Ajala, K. N. Saxena Jan 1994

Interrelationship Among Chilo Partellus (Swinhoe) Damage Parameters And Their Contribution To Grain Yield Reduction In Maize (Zea Mays L.), S. O. Ajala, K. N. Saxena

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Understanding the relationship among the spotted stem borer (Chilo partellus) damage parameters and grain yield reduction on maize (Zea mays L.) will aid in elucidation of the most important damage parameters that reduce yield, and may consequently lead to development of functional criteria to quantify tolerance and resistance. Correlations, stepwise multiple regressions and path coefficient analyses were used to study the interrelationship among the three damage parameters (foliar lesions, dead heart and stem tunnelling) and their contribution to grain yield reduction using three separate groups of genotypes in trials conducted between 1990 and 1991. Foliar lesions and stem tunnelling were …

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Evidence For Volatile Male-Produced Pheromone In Banana Weevil Cosmopolites Sordidus, William J. Budenberg, Isaiah O. Ndiege, Florence W. Karago Sep 1993

Evidence For Volatile Male-Produced Pheromone In Banana Weevil Cosmopolites Sordidus, William J. Budenberg, Isaiah O. Ndiege, Florence W. Karago

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Females of the banana weevil, Cosmopolites sordidus, were attracted to and made longer visits to live conspecific males, trapped volatiles from males, and dissected male hindguts in a still-air olfactometer. Male weevils were attracted to volatiles trapped from males and made longer visits to live males and volatiles from males. Live females, collected volatiles from females and female hindguts, elicited small or no behavioral responses from either sex. Electroantennogram (EAG) responses from both male and female antennae were elicited by collected volatiles from males and by dichloromethane extracts of male hindguts and bodies but not by surface washes of males. …

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Striga Hermonthica Resistance In Upland Rice, Z. Harahap, K. Ampong-Nyarko, J. C. Olela Jan 1993

Striga Hermonthica Resistance In Upland Rice, Z. Harahap, K. Ampong-Nyarko, J. C. Olela

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Upland rice breeding lines were evaluated in field trials for resistance to the obligate hemi-root parasite Striga hermonthica at two sites in Kenya in 1990 and 1991. The lines differed in their reaction to S. hermonthica ranging from highly resistant to extremely susceptible. IR 49255-B-B-5-2, IR 38547-B-B-B-7-2-2, IR 47255-B-B-5-4 and Ble Chai were confirmed resistant to S. hermonthica. The indication is that the gene for resistance to S. hermonthica is widespread in rice. © 1993.

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Effectiveness Of The Entomopathogenic Fungus Beauveria Bassiana (Bals.) Vuill. For Control Of The Stem Borer Chilo Partellus (Swinhoe) In Maize In Kenya, Nguya K. Maniania Jan 1993

Effectiveness Of The Entomopathogenic Fungus Beauveria Bassiana (Bals.) Vuill. For Control Of The Stem Borer Chilo Partellus (Swinhoe) In Maize In Kenya, Nguya K. Maniania

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The fungus Beauveria bassiana (Bals.) Vuill. and insecticide trichlorfon were compared for the control of stem borer, Chilo partellus (Swinhoe) in field experiments at different times of infestation. Egg masses of C. partellus at the blackhead stage were pinned to the undersurface of the maize leaves. Two fungal formulations, conidial aqueous suspensions and a granular formulation, were applied. Compared with the untreated checks, the numbers of surviving C. partellus larvae were significantly reduced in treatments where B. bassiana was applied at a concentration of 1013 conidia ha-1 as granules and as two aqueous spray formulations. No significant difference in numbers …

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Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). Ii. Reduction In Bean Yields, M. W. Ogenga-Latigo, C. W. Baliddawa, J. K.O. Ampofo Jan 1992

Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). Ii. Reduction In Bean Yields, M. W. Ogenga-Latigo, C. W. Baliddawa, J. K.O. Ampofo

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Field studies were conducted to assess the effects of intercropping common beans (Phaseolus vulgaris L.) with maize (Zea mays L.), at two growth stages and four row spacings (0.5, 1.0, 1.5 and 2.0 m), on Aphis fabae infestation of beans and on the magnitudes of bean yield losses due to aphid attack and to competition by maize. The first maize planting (Old maize) was carried out 3 weeks earlier than beans, while the second planting (Young maize) was done simultaneously with beans. Significantly (P < 0.05) fewer plants were infested by A. fabae when beans were intercropped with older or densely planted maize. Aphid colonies on beans were also smaller, and there was reduced aphid damage to beans in the intercrops. However, whereas bean yield loss from aphid attack was less than 3.5% in all intercrop situations, yield loss from competition by maize was very high, being up to 98% when beans were intercropped with early-planted maize at 0.5-m row spacing. Yields of intercropped maize planted at row spacings of 0.5, 1.5 and 2.0 m were also depressed. The results show that both maize growth and row spacing could be exploited for the control of A. fabae on intercropped beans. However, adequate consideration must be given to the negative effects of maize planting density and growth on yields of both crops. © 1992.

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Larval Development Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) On Artificial Diet Incorporating Leaf Tissues Of Sorghum Lines In Relation To Their Resistance Or Susceptibility, Kailash Narain Saxena Jan 1992

Larval Development Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) On Artificial Diet Incorporating Leaf Tissues Of Sorghum Lines In Relation To Their Resistance Or Susceptibility, Kailash Narain Saxena

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This study was taken up to examine the relationship between the susceptibility or resistance of six sorghum lines to Chilo partellus and dietary quality of their leaf tissues, incorporated in an artificial diet, to support larval development. The diets tested were agar based basic medium with or without cellulose powder, dry leaf powder or fresh leaf-paste of the sorghum lines. The basic medium alone or with cellulose powder showed the poorest dietary quality in-as-much as it did not support more than 26–32% larval development. The tolerant sorghum IS 18520 leaf tissues, incorporated in the artificial diet as dry powder or …

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Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). I. Incidence Of Aphids, M. W. Ogenga-Latigo, J. K.O. Ampofo, C. W. Baliddawa Jan 1992

Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). I. Incidence Of Aphids, M. W. Ogenga-Latigo, J. K.O. Ampofo, C. W. Baliddawa

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Investigations were carried out in the field and in the glasshouse to asses the influence of row spacing of intercrop maize on the incidence of the bean aphid, Aphis fabae Scop. (Homoptera: Aphididae), on common beans, Phaseolus vulgaris L., and on aphid dispersal within the intercrops. Maize was planted in the field twice at a 3-week interval, at row spacings of 0.5, 1.0, 1.5 and 2.0 m, while sole and intercropped beans were planted simultaneously with the second maize, at a row spacing of 0.5 m. Aphis fabae incidence was lower on beans intercropped with densely planted maize, with strong …

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Oviposition, Larval Arrest And Establishment Of Chilo Partellus (Lepidoptera: Pyralidae) On Maize Genotypes During Anthesis, Harish Kumar Jan 1992

Oviposition, Larval Arrest And Establishment Of Chilo Partellus (Lepidoptera: Pyralidae) On Maize Genotypes During Anthesis, Harish Kumar

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The oviposition, larval arrest and establishment by the stem borer Chilo partellus (Swinhoe) were measured on different maize genotypes during anthesis. The maize genotypes tested were: Inbred A (Susceptible), Mp 704, MBR-8637, MBR-8650, MBR-8668, Poza Rica 7832, ER-29 SVR, Katumani Composite B, MMV 400, Bulk CG 4141, and ICZ2-CM. The moths oviposited on the middle leaves of the plant and the neonate larvae moved to leaf sheaths and ear husks to feed (arrest). As they grew older, the larvae invaded the stem, ear shanks and tassel to complete feeding (establishment) and to pupate. The response of the stem borer differed …

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Mechanisms Of Resistance In Wild Rice Oryza Brachyantha To Rice Leaffolder Cnaphalocrocis Medinalis (Guenée) (Lepidoptera: Pyralidae), R. Ramachandran, Z. R. Khan Jan 1991

Mechanisms Of Resistance In Wild Rice Oryza Brachyantha To Rice Leaffolder Cnaphalocrocis Medinalis (Guenée) (Lepidoptera: Pyralidae), R. Ramachandran, Z. R. Khan

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A wild rice, Oryza brachyantha, was rated as highly resistant to rice leaffolder, Cnaphalocrocis medinalis (Guenée), while its F1 hybrid from a cross with a high-yielding, leaffolder-susceptible rice, IR31917-45-3-2, was rated resistant in a standard screening test. In comparison with IR31917-45-3-2, O. brachyantha and the F1 hybrid were unsuitable for oviposition, survival, and growth of C. medinalis. However, growth and survival of larvae in artificial diets containing lyophilized leaf powder of IR31917-45-3-2 and O. brachyantha were comparable. Studies on the feeding and settling preference of the larval stages suggested that the mechanism of resistance of O. brachyantha is that of …

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Feeding Responses Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) Larvae To Sorghum Plant Phenolics And Their Analogs, Baldwyn Torto, Ahmed Hassanali, Kailash N. Saxena, Sagary Nokoe Jan 1991

Feeding Responses Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) Larvae To Sorghum Plant Phenolics And Their Analogs, Baldwyn Torto, Ahmed Hassanali, Kailash N. Saxena, Sagary Nokoe

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Phagostimulatory responses of third-instar larvae of Chilo Partellus to phenolic components identified in an ethyl acetate extract of the leaf whorls of 3-week-old plants of Sorghum bicolor cultivar IS 18363 were studied in no-choice bioassays. The major components in the extract were identified as 4-hydroxybenzaldehyde and 4-hydroxybenzoic acid, with 4-hydroxy-3-methoxycinnamic acid, 3,4-dihydroxycinnamic acid, and 4-hydroxycinnamic acid present in minor amounts. All but 4-hydroxycinnamic acid were stimulatory at the doses tested. 4-Hydroxybenzaldehyde was more stimulatory than other potential biogenetic analogs. Hydroxybenzoic acids generally elicited greater feeding response than cinnamic acids, and the pattern of oxygen substitution in the benzene ring was …

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Volatile Components Of Banana Pseudostem Of A Cultivar Susceptible To The Banana Weevil, Isaiah O. Ndiege, William J. Budenberg, Wilber Lwande, Ahmed Hassanali Jan 1991

Volatile Components Of Banana Pseudostem Of A Cultivar Susceptible To The Banana Weevil, Isaiah O. Ndiege, William J. Budenberg, Wilber Lwande, Ahmed Hassanali

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Volatiles from banana ('githumo''cultivar) pseudostem were trapped using porapak S. The trapped volatiles were desorbed from porapak columns by elution with dichloromethane and analysed using GC and GC-MS. The volatile compounds identified included α-pinene, β-pinene, β-myrcene, limonene, α-cubebene, α-copaene, α-cedrene, β-caryophyllene and α-humulene. © 1992.

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Enhancement Of Diapause Development In A Stem Borer, Busseola Fusca (Lep.: Noctuidae) By Dry Conditions, Takashi Okuda Jan 1991

Enhancement Of Diapause Development In A Stem Borer, Busseola Fusca (Lep.: Noctuidae) By Dry Conditions, Takashi Okuda

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Water was an important factor for diapause termination only during the late stage of the diapause in Busseola fusca. Exposure to dry conditions for 2 months accelerated diapause development more. Diapause development proceeded at warm temperatures only. © 1991, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.

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Policy Structures And Crop Productivity In Third World Countries, Zerubabel M. Nyiira Jan 1987

Policy Structures And Crop Productivity In Third World Countries, Zerubabel M. Nyiira

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Deciding what should be done in the crop-production sector is a policy issue and a public and management responsibility. Entrusted with that responsibility, governments formulate policies which should ensure maximum crop productivity. The impact of policies and policy structures on crop productivity, and the role of policy makers, administrators and scientists in research and development systems are the subjects of this paper. Observations are made on the role played by government policies in the generation, diffusion and application of crop-production technology and a brief discussion is presented of issues of public and international policies and crop productivity. © 1987.

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Influence Of The Termite Macrotermes Michaelseni (Sjöst) On Soil Fertility And Vegetation In A Semi-Arid Savannah Ecosystem, M. A. Arshad Jan 1982

Influence Of The Termite Macrotermes Michaelseni (Sjöst) On Soil Fertility And Vegetation In A Semi-Arid Savannah Ecosystem, M. A. Arshad

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The growth and species structure of vegetation in relation to the proximity of termite (M. michaelseni) mounds was studied in a semi-arid savannah ecosystem during 1978-1980. The dry matter yield in the termite-modified area at 1-10 m distance from mounds was significantly greater (P < 0.01) than that in the area beyond 22 m which is relatively unaffected by the termites. Themeda triandra and Digitaria scalarum, dominant grass species of the area, were totally absent in the 1-10 m zone around the mound. The major species in the immediate vicinity of the mound were Pennisetum stramineum and Cynodon dactylon, the latter was a dominant species (over 90%) within the 0-10 m zone and entirely absent beyond 15 m from the mound. The number of grass species increased from 2-3 species around the mound to 6-7 species in the area apparently beyond the influence of the mound. High concentration of nutrients and favourable water availability, together with good drainage, appeared to be the major causes of increased biomass and different species composition of vegetation around the mound. © 1982.

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