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Population changes of Macrophomina phaseolina and Fusarium oxysporum f. sp. cumini in oil-cake and crop residue-amended sandy soils
Applied Soil Ecology ELSEVIER
Applied Soil Ecology 2 (1995) 281-284
Short communication
Population changes of Macrophomina phaseolina and Fusarium oxysporum f. sp. cumini in oil-cake and crop residue-amended sandy soils SK. Sharma, RX
Aggarwal, Satish Lodha”
PlantPathologyLaboratory,CentralArid Zone ResearchInstitute,Jodhpur, 342003, India Accepted 23 May 1995
Abstract Population changes of Macrophomina phaseolina and Fusarium oxysporum f. sp. cumini were followed in a sandy soil amended with mustard and castor cakes or nitrogen-enriched pearl millet residue, singly or in combined form. Populations of both the pathogens were reduced by 100% in the mustard-cake-amendedsoil within a period of 30 days after addition. Amendment with nitrogen-enriched pearl millet residue significantly reduced the population of M. phaseolina within 45 days, but not that of F. oxysporum. However, incorporation of pearl millet residue in both types of cakes delayed the rate of reduction. The induced suppressiveness in the cake-amended soil was associated with a substantial increase in the population of antagonistic actinomycetes. These results suggest that amendment of soil with mustard cake in fields infested with M. phaseolina and F. oxysponrm f. sp.cumini may reduce yield loss caused by dry root rot of guar (Cyamopsis tetragonoloba (L.) Taub.) and wilt of cumin (Cuminum cyminum L.) . Keywords:Amendments; Antagonistic actinomycetes; Biological control; Cumin; Guar; Fusariumoxysporumf. sp. cumini; Macrophomina phaseolina
1. Introduction Macrophomina
phaseolina
(Tassi) Goid. and Schl. f. sp. cumini Prasad and Patel, cause dry root rot in guar (Cyamopsis tetragonoloba (L.) Taub. and wilt in cumin (Cuminurn cyminum L.) crops, respectively, in arid regions of India (Lodha et al., 1986). Low organic matter content associated with a small microbial population and moisture stress are responsible for severe losses caused by M. phaseolina (Dhingra and Sinclair, 1978). Heavy yield losses owing to wilt often compel growers to
Fusarium
oxysporum
* Corresponding author. 0929.1393/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved .SSDIO929-1393(95)00070-4
abandon the cultivation of cumin, though a cash crop, after three successive years of cropping. Crop rotation with non-host crops was not found effective in reducing wilt incidence. As guar and cumin are cultivated in the same field in rainy and winter seasons, respectively, it is important to reduce the inoculum density of both of the pathogens by an integrated approach. Use of organic amendments such as oil cakes and crop residues is one approach to decrease the population of soil-borne pathogens. However, these pathogens often differ in their response to organic amendments. Amendment of soil with alfalfa meal is followed by an increase of the chlamydospore population of F. oxysporum (Zakaria et al., 1980)) but decreased the number of M. phaseo-
282
SK. Sharmaet al. /Applied Soil Ecology 2 (1995) 281-284
lina propagules (Hakeem and Ghaffar, 1977). The objective of the present investigation was to study the influences of cakes and pearl millet (Pennisetum glaucum (L) R.Br.) residue separately and in combination on the inoculum density of hf. phaseolina and F. oxysporum f. sp. cumini in a coarse-textured soil.
2. Materials and methods The loamy sand soil (85.1% sand, 8.9% clay, 5.5% silt) of the experiment had 0.031% nitrogen, 0.25% organic carbon and 7 pg g- ’ available phosphorus (Olsen-P). The pH and EC (soil/water ratio 1:2.5) were 8.1 and 0.088 dS m-‘, respectively. Sclerotia of M. phaseolina and spores of F. oaysporum f. sp. cumini were produced separately on 5% maize meal:sand medium and then mixed uniformly with 5 kg of the field soil to establish populations of M. phaseolina and F. oxysporum f. sp. cumini of 2753 g - ’propagules and 330 g - ’spores (conidia and chlamydospores) , respectively. The population of M. phaseolina was determined by sprinkling 50 mg of soil on chloroneb mercury-rose bengal agar (CMRA) medium (Meyer et al., 1973) in Petri dishes of 9 cm diameter, and that of F. oxysporum f. sp. cumini on modified peptonepentachloronitrobenzene (PCNB) medium (Papavizas, 1967) following the procedure suggested by Chaube and Singh (1969). Total microbial populations in soil were enumerated by serial dilution on Martin’s Rose Bengal agar (fungi) and Thornton’s agar (bacteria and actinomycetes). Six Petri dishes of each medium were used for enumeration of each category. The infested soil was sub-divided into many lots for mixing with pearl millet residue (PMR at 0.9%equivalent to 60 kg N ha- ‘) enriched with urea (40 kg N ha- ’) , mustard cake (MC at l%-containing 5.1% N, 1.7% P20, and 0.9% K20) and castor cake (CC at l%-containing 5.6% N, 1.9% P20s and 1% K20) separately and a combination of the above. The six treatments were: ( 1) N + PMR; (2) N + PMR + MC; (3) N+PMR+CC; (4) MC; (5) CC; (6) infested non-amended soil only. The moisture level in all treatments was maintained at 50% of the water-holding capacity (WHC) throughout the experiment. Amended and non-amended soils were incubated at 28 k 2°C in punctured polythene bags (three replicates per treatment). After thoroughly shaking for 20 s, a soil sample
of about 10 g was withdrawn from each bag at 15 day intervals and air-dried for 24 h. The population densities of M. phaseolina, F. oxysporum f. sp. cumini, bacteria, actinomycetes and fungi, were estimated in triplicate following the procedures described above. Samples were taken until a significant reduction was achieved for both the soil-borne pathogens. Populations of actinomycetes and bacteria antagonistic to pathogenic fungi were detected on Czapeck Dox agar (pH 7.2) against M. phaseolina and F. oxysporum f. sp. cumini separately following the method of Ghaffar et al. (1969). Antagonistic actinomycetes and bacterial strains were transferred on liquid Ken-Knight medium (Allen, 1959). Individual actinomycete and bacterial strains were spotted at three equidistant points 1 cm from the edge of Petri dishes of 9 cm diameter containing Czapeck Dox agar. After growth in the dark for 48 h at 28 ? 2”C, mycelium discs of the test fungi were placed in the centre of each dish and incubated for three more days. Strains that induced a fungal inhibition zone were recorded to confirm their antagonistic activity. The data were subjected to analysis of variance (ANOVA) and the treatment means were compared with LSD (P < 0.05).
3. Results and discussion A significant reduction in the population of M. phasin the cake- and pearl-millet-residueamended soil (Table 1). In the MC alone and N + PMR + MC-amended soil, 100% reduction was achieved within a period of 30 and 45 days, respectively. In N+PMR-amended soil, numbers of viable propagules of M. phaseolina were reduced by 94% in 45 days. Moist addition of urea (40 kg N ha- ‘) decreased the C:N ratio and hastened the decomposition of crop residues. Low C:N ratio amendments have been found effective in reducing the population of M. phaseolina (Dhingra and Sinclair, 1974). A decline of 59% of propagules in the non-amended soil maintained at 50% of WHC confirmed the significance of soil moisture alone in reducing the M. phaseolina population (Dhingra and Sinclair, 1975). The population of F. oxysporum f. sp. cumini showed a dramatic rise ( (13-92) X lo- 3, after 15 days in all the cake-amended treatments. However, in MC-amended soil a 100% reduction was achieved within 30 days. eolina occurred
SK. Sharma et al. /Applied Soil Ecology 2 (1995) 281-284
Table 1 Effect of soil amendments on population population” g-’ soil after 45 days
283
of Macrophomina phaseolinn, total numbers of bacteria and fungi and the antagonistic
actinomycete
Amendments”
M. phaseolina
Bacteria and actinomycetes ( x 106)
Fungi ( x 104)
Antagonistic actinomycetes (X 106)
N+PMR N+PMR+MC N+PMR+CC MC cc None LSD (0.0s) Initial population
152 0 366 0’ 200 1132 116 2153
109 145 164 162 143 9-l 9 87
14 23 16 8 2 2 2 1
4.3 23.3 38.3 21.3 24.0 2.3 4.4 0.9
aAverage of six replications. ‘N-Nitrogen (40 kg ha-‘) as urea; PMR-pearl ‘Same as after incubation for 30 days.
millet residue (0.9%);
After 60 days, the population had declined in all treatments. Stimulatory and inhibitory effects of soil amendments with oil cakes on Fusarium populations have also been reported by Singh and Singh (1970). Contrary to the effect on M. phaseolina, the propagule population of Fusarium in the infested soil without amendments showed a gradual increase. This increase might be due to the availability of nutrients and soil moisture conditions affecting the two fungi in different ways. Significantly higher populations of M. phaseolina in the CC as compared with MC-amended soil might suggest that CC does not contain toxic substances to the Table 2 Effect of soil amendments on population of Fusarrum actinomycete population” g- ’soil after 60 days
oqsporum
MC-mustard
cake (1%); CC-castor
cake ( 1%).
level of MC. Crucifer plant residue incorporation in the soil was shown to reduce the population of soil-borne pathogens effectively (Ramirez-Villapudua and Munnecke, 1987). The effect was mainly attributed to the release of toxic volatiles such as mercaptan, dimethyl sulphide, and isothiocyanate (Gamliel and Stapleton, 1993). Incorporation of N + PMR in MC and CC maintained higher populations of M. phaseolina and F. oxysporum f. sp. cumini than when the cakes were added separately. This observation indicates that incorporation of nitrogen-enriched crop residues might have affected the release of toxic volatiles from cakes. The total population of fungi was also significantly higher
f. sp. cumini, total numbers
of bacteria
and fungi and the antagonistic
Amendment?
Fusarium oxysporum f. sp. cumini (X 10’)
Bacteria and actinomycetes (X106)
Fungi (X 104)
Antagonistic actinomycetes ( x 10”)
N+PMR N+PMR+MC N+PMR+CC MC cc None LSD (0.05) lnitial population
1.3 8.3 2.0 0’ 1.3 1.7 I .9 0.3
136 209 634 240 486 94 84 87
16 20 19 4 3 4 3 1
4.3 10.6 14.5 11.0 6.6 0.3 2.4 0.3
“Average of six replications. “N-Nitrogen (40 kg ha-‘) as urea; PMR-pearl ‘Same as after incubation for 30 days.
millet residue (0.9%);
MC-mustard
cake (1%); CC-castor
cake ( 1%)
284
S. K. Sharma et al. /Applied Soil Ecology 2 (1995) 281-284
in all treatments having N+PMR (Tables 1 and 2). The population of bacteria and actinomycetes increased considerably in amended soils. Over 90% of the total number of actinomycetes were antagonistic to M. phuseolina, with the highest numbers in the N + PMR + CCamended soil. However, populations of actinomycetes antagonistic to Fusurium propagules were less as compared with M. phaseolina. The number of bacterial antagonists did not differ significantly in amended soils. Thus, apart from the toxic effect of cakes, increased populations of actinomycetes and bacteria might have also contributed in reducing the population of M. phaseolina and F. oxysporum f. sp. cumini. These results demonstrate the efficacy of mustard cake in controlling M. phaseolina and F. oxysporum f. sp. cumini within a period of 30 days. However, nitrogen-enriched pearl millet residue reduced only the population of M. phaseolina. Increased populations of antagonistic actinomycetes, which were found to suppress F. oqsporum f. sp. cumini and M. phaseolina propagules (Mathur and Mathur, 1964; Lodha et al., 1990)) further augmented the effect of amendments by inducing suppressiveness in sandy soils. In a separate field experiment, 0.18% mustard cake combined with one irrigation in summer at a soil temperature above 50°C drastically reduced the population of M. phaseolina and F. oxysporum f. sp. cumini within 30 cm depth (S. Lodha, S.K. Sharma and R.K. Aggarwal, unpublished data, 1995). Mustard (Brassica juncea (L.) Czern. and Coss) is extensively cultivated in this region and cake is readily available as a by-product of the oilseed extraction industry.
Dhingra, O.D. and Sinclair, J.B., 1974. Effect of soil moisture and carbon:nitrogen ratios on survival of Macrophomina phaseolina in soybean stems in soil. Plant Dis. Rep., 58: 1034-1035. Dhingra, O.D. and Sinclair, J.B., 1975. Survival of Macrophomina phaseolina sclerotia in soil: effect of soil moisture, carbon:nitrogen ratios, carbon sources and nitrogen concentrations. Phytopathology, 65: 236240. Dhingra,
O.D. and Sinclair, J.B., 1978. Biology and pathology
of
Macrophominaphaseolina. Universidad Federal de Vicosa, Brazil, 166 pp. Gamliel, A. and Stapleton, J.J., 1993. Characterization compounds
residue. Phytopathology, Ghaffar,
A., Zentmeyer,
83: 899-905. G.A. and Erwin,
D.C., 1969. Effect of
on severity of Macrophomina phaseolina
organic amendments
root rot of cotton. Phytopathology, Hakeem,
of antifungal
evolved from solarized soil amended with cabbage
A. and Ghaffar,
59: 1267-1269.
A., 1977. Reduction
of the number
of
sclerotia of Macrophomina phaseolina in soil by organic amendments. Phytopathol. Z., 88: 272-275. Lodha, S., Gupta, G.K. and Singh, S., 1986. Crop disease situation and new records in Indian arid zone. Ann. Arid Zone, 25: 31 l320. Lodha, S., Mathur, B.K. and Solanki, K.R., 1990. Factor influencing population dynamics of Macrophomina phaseolina in arid soil. Plant Soil, 125: 75-80. Mathur, B.L. and Mathur, R.L., 1964. Studies on antibiosis between soil actinomycetes
and fungi in vitro. Proc. Nat. Acad. Sci. B,
India, 34: 350-352. Meyer, W.A., Sinclair,
J.B. and Khare, M.N., 1973. Biology
of
Macrophomina phaseolina in soil studied with selective media. Phytopathology, Papavizas,
63: 613-620.
G.C., 1967. Evaluation
of various media and antimicro-
bial agents for isolation of Fusarium from soil. Phytopathology, 57: 848-852. Ramirez-Villapudua,
J. and Munnecke, D.E., 1987. Control of cab-
bage yellow (Fusarium oxysporum f. sp. conglutinans) by solar heating of field soil amended with dry cabbage residues. Plant Dis., 71: 217-221.
References Allen, O.N., 1959. Experiments in Soil Bacteriology, 3rd edn. Burgess, MN, 117 pp. Chaube, H.S. and Singh, R.S., 1969. Relative abundance of hyphal and conidial propagules of Fusarium in rhizosphere and nonrhizosphere soil Indian Phytopathol., 22: 273-275.
Singh, R.S. and Singh, N., 1970. Effect of oil-cake amendments soil on populations Phytopathol.
of
of some wilt causing species of Fusarium.
Z., 69: 160-167.
Zakaria, M.A., Lockwood, J.L. and Filonow, A.B., 1980. Reduction in Fusarium population
density in soil by volatile degradation
products of oilseed meal amendments. 499.
Phytopathology,
70: 495-
Applied Soil Ecology 2 (1995) 281-284
Short communication
Population changes of Macrophomina phaseolina and Fusarium oxysporum f. sp. cumini in oil-cake and crop residue-amended sandy soils SK. Sharma, RX
Aggarwal, Satish Lodha”
PlantPathologyLaboratory,CentralArid Zone ResearchInstitute,Jodhpur, 342003, India Accepted 23 May 1995
Abstract Population changes of Macrophomina phaseolina and Fusarium oxysporum f. sp. cumini were followed in a sandy soil amended with mustard and castor cakes or nitrogen-enriched pearl millet residue, singly or in combined form. Populations of both the pathogens were reduced by 100% in the mustard-cake-amendedsoil within a period of 30 days after addition. Amendment with nitrogen-enriched pearl millet residue significantly reduced the population of M. phaseolina within 45 days, but not that of F. oxysporum. However, incorporation of pearl millet residue in both types of cakes delayed the rate of reduction. The induced suppressiveness in the cake-amended soil was associated with a substantial increase in the population of antagonistic actinomycetes. These results suggest that amendment of soil with mustard cake in fields infested with M. phaseolina and F. oxysponrm f. sp.cumini may reduce yield loss caused by dry root rot of guar (Cyamopsis tetragonoloba (L.) Taub.) and wilt of cumin (Cuminum cyminum L.) . Keywords:Amendments; Antagonistic actinomycetes; Biological control; Cumin; Guar; Fusariumoxysporumf. sp. cumini; Macrophomina phaseolina
1. Introduction Macrophomina
phaseolina
(Tassi) Goid. and Schl. f. sp. cumini Prasad and Patel, cause dry root rot in guar (Cyamopsis tetragonoloba (L.) Taub. and wilt in cumin (Cuminurn cyminum L.) crops, respectively, in arid regions of India (Lodha et al., 1986). Low organic matter content associated with a small microbial population and moisture stress are responsible for severe losses caused by M. phaseolina (Dhingra and Sinclair, 1978). Heavy yield losses owing to wilt often compel growers to
Fusarium
oxysporum
* Corresponding author. 0929.1393/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved .SSDIO929-1393(95)00070-4
abandon the cultivation of cumin, though a cash crop, after three successive years of cropping. Crop rotation with non-host crops was not found effective in reducing wilt incidence. As guar and cumin are cultivated in the same field in rainy and winter seasons, respectively, it is important to reduce the inoculum density of both of the pathogens by an integrated approach. Use of organic amendments such as oil cakes and crop residues is one approach to decrease the population of soil-borne pathogens. However, these pathogens often differ in their response to organic amendments. Amendment of soil with alfalfa meal is followed by an increase of the chlamydospore population of F. oxysporum (Zakaria et al., 1980)) but decreased the number of M. phaseo-
282
SK. Sharmaet al. /Applied Soil Ecology 2 (1995) 281-284
lina propagules (Hakeem and Ghaffar, 1977). The objective of the present investigation was to study the influences of cakes and pearl millet (Pennisetum glaucum (L) R.Br.) residue separately and in combination on the inoculum density of hf. phaseolina and F. oxysporum f. sp. cumini in a coarse-textured soil.
2. Materials and methods The loamy sand soil (85.1% sand, 8.9% clay, 5.5% silt) of the experiment had 0.031% nitrogen, 0.25% organic carbon and 7 pg g- ’ available phosphorus (Olsen-P). The pH and EC (soil/water ratio 1:2.5) were 8.1 and 0.088 dS m-‘, respectively. Sclerotia of M. phaseolina and spores of F. oaysporum f. sp. cumini were produced separately on 5% maize meal:sand medium and then mixed uniformly with 5 kg of the field soil to establish populations of M. phaseolina and F. oxysporum f. sp. cumini of 2753 g - ’propagules and 330 g - ’spores (conidia and chlamydospores) , respectively. The population of M. phaseolina was determined by sprinkling 50 mg of soil on chloroneb mercury-rose bengal agar (CMRA) medium (Meyer et al., 1973) in Petri dishes of 9 cm diameter, and that of F. oxysporum f. sp. cumini on modified peptonepentachloronitrobenzene (PCNB) medium (Papavizas, 1967) following the procedure suggested by Chaube and Singh (1969). Total microbial populations in soil were enumerated by serial dilution on Martin’s Rose Bengal agar (fungi) and Thornton’s agar (bacteria and actinomycetes). Six Petri dishes of each medium were used for enumeration of each category. The infested soil was sub-divided into many lots for mixing with pearl millet residue (PMR at 0.9%equivalent to 60 kg N ha- ‘) enriched with urea (40 kg N ha- ’) , mustard cake (MC at l%-containing 5.1% N, 1.7% P20, and 0.9% K20) and castor cake (CC at l%-containing 5.6% N, 1.9% P20s and 1% K20) separately and a combination of the above. The six treatments were: ( 1) N + PMR; (2) N + PMR + MC; (3) N+PMR+CC; (4) MC; (5) CC; (6) infested non-amended soil only. The moisture level in all treatments was maintained at 50% of the water-holding capacity (WHC) throughout the experiment. Amended and non-amended soils were incubated at 28 k 2°C in punctured polythene bags (three replicates per treatment). After thoroughly shaking for 20 s, a soil sample
of about 10 g was withdrawn from each bag at 15 day intervals and air-dried for 24 h. The population densities of M. phaseolina, F. oxysporum f. sp. cumini, bacteria, actinomycetes and fungi, were estimated in triplicate following the procedures described above. Samples were taken until a significant reduction was achieved for both the soil-borne pathogens. Populations of actinomycetes and bacteria antagonistic to pathogenic fungi were detected on Czapeck Dox agar (pH 7.2) against M. phaseolina and F. oxysporum f. sp. cumini separately following the method of Ghaffar et al. (1969). Antagonistic actinomycetes and bacterial strains were transferred on liquid Ken-Knight medium (Allen, 1959). Individual actinomycete and bacterial strains were spotted at three equidistant points 1 cm from the edge of Petri dishes of 9 cm diameter containing Czapeck Dox agar. After growth in the dark for 48 h at 28 ? 2”C, mycelium discs of the test fungi were placed in the centre of each dish and incubated for three more days. Strains that induced a fungal inhibition zone were recorded to confirm their antagonistic activity. The data were subjected to analysis of variance (ANOVA) and the treatment means were compared with LSD (P < 0.05).
3. Results and discussion A significant reduction in the population of M. phasin the cake- and pearl-millet-residueamended soil (Table 1). In the MC alone and N + PMR + MC-amended soil, 100% reduction was achieved within a period of 30 and 45 days, respectively. In N+PMR-amended soil, numbers of viable propagules of M. phaseolina were reduced by 94% in 45 days. Moist addition of urea (40 kg N ha- ‘) decreased the C:N ratio and hastened the decomposition of crop residues. Low C:N ratio amendments have been found effective in reducing the population of M. phaseolina (Dhingra and Sinclair, 1974). A decline of 59% of propagules in the non-amended soil maintained at 50% of WHC confirmed the significance of soil moisture alone in reducing the M. phaseolina population (Dhingra and Sinclair, 1975). The population of F. oxysporum f. sp. cumini showed a dramatic rise ( (13-92) X lo- 3, after 15 days in all the cake-amended treatments. However, in MC-amended soil a 100% reduction was achieved within 30 days. eolina occurred
SK. Sharma et al. /Applied Soil Ecology 2 (1995) 281-284
Table 1 Effect of soil amendments on population population” g-’ soil after 45 days
283
of Macrophomina phaseolinn, total numbers of bacteria and fungi and the antagonistic
actinomycete
Amendments”
M. phaseolina
Bacteria and actinomycetes ( x 106)
Fungi ( x 104)
Antagonistic actinomycetes (X 106)
N+PMR N+PMR+MC N+PMR+CC MC cc None LSD (0.0s) Initial population
152 0 366 0’ 200 1132 116 2153
109 145 164 162 143 9-l 9 87
14 23 16 8 2 2 2 1
4.3 23.3 38.3 21.3 24.0 2.3 4.4 0.9
aAverage of six replications. ‘N-Nitrogen (40 kg ha-‘) as urea; PMR-pearl ‘Same as after incubation for 30 days.
millet residue (0.9%);
After 60 days, the population had declined in all treatments. Stimulatory and inhibitory effects of soil amendments with oil cakes on Fusarium populations have also been reported by Singh and Singh (1970). Contrary to the effect on M. phaseolina, the propagule population of Fusarium in the infested soil without amendments showed a gradual increase. This increase might be due to the availability of nutrients and soil moisture conditions affecting the two fungi in different ways. Significantly higher populations of M. phaseolina in the CC as compared with MC-amended soil might suggest that CC does not contain toxic substances to the Table 2 Effect of soil amendments on population of Fusarrum actinomycete population” g- ’soil after 60 days
oqsporum
MC-mustard
cake (1%); CC-castor
cake ( 1%).
level of MC. Crucifer plant residue incorporation in the soil was shown to reduce the population of soil-borne pathogens effectively (Ramirez-Villapudua and Munnecke, 1987). The effect was mainly attributed to the release of toxic volatiles such as mercaptan, dimethyl sulphide, and isothiocyanate (Gamliel and Stapleton, 1993). Incorporation of N + PMR in MC and CC maintained higher populations of M. phaseolina and F. oxysporum f. sp. cumini than when the cakes were added separately. This observation indicates that incorporation of nitrogen-enriched crop residues might have affected the release of toxic volatiles from cakes. The total population of fungi was also significantly higher
f. sp. cumini, total numbers
of bacteria
and fungi and the antagonistic
Amendment?
Fusarium oxysporum f. sp. cumini (X 10’)
Bacteria and actinomycetes (X106)
Fungi (X 104)
Antagonistic actinomycetes ( x 10”)
N+PMR N+PMR+MC N+PMR+CC MC cc None LSD (0.05) lnitial population
1.3 8.3 2.0 0’ 1.3 1.7 I .9 0.3
136 209 634 240 486 94 84 87
16 20 19 4 3 4 3 1
4.3 10.6 14.5 11.0 6.6 0.3 2.4 0.3
“Average of six replications. “N-Nitrogen (40 kg ha-‘) as urea; PMR-pearl ‘Same as after incubation for 30 days.
millet residue (0.9%);
MC-mustard
cake (1%); CC-castor
cake ( 1%)
284
S. K. Sharma et al. /Applied Soil Ecology 2 (1995) 281-284
in all treatments having N+PMR (Tables 1 and 2). The population of bacteria and actinomycetes increased considerably in amended soils. Over 90% of the total number of actinomycetes were antagonistic to M. phuseolina, with the highest numbers in the N + PMR + CCamended soil. However, populations of actinomycetes antagonistic to Fusurium propagules were less as compared with M. phaseolina. The number of bacterial antagonists did not differ significantly in amended soils. Thus, apart from the toxic effect of cakes, increased populations of actinomycetes and bacteria might have also contributed in reducing the population of M. phaseolina and F. oxysporum f. sp. cumini. These results demonstrate the efficacy of mustard cake in controlling M. phaseolina and F. oxysporum f. sp. cumini within a period of 30 days. However, nitrogen-enriched pearl millet residue reduced only the population of M. phaseolina. Increased populations of antagonistic actinomycetes, which were found to suppress F. oqsporum f. sp. cumini and M. phaseolina propagules (Mathur and Mathur, 1964; Lodha et al., 1990)) further augmented the effect of amendments by inducing suppressiveness in sandy soils. In a separate field experiment, 0.18% mustard cake combined with one irrigation in summer at a soil temperature above 50°C drastically reduced the population of M. phaseolina and F. oxysporum f. sp. cumini within 30 cm depth (S. Lodha, S.K. Sharma and R.K. Aggarwal, unpublished data, 1995). Mustard (Brassica juncea (L.) Czern. and Coss) is extensively cultivated in this region and cake is readily available as a by-product of the oilseed extraction industry.
Dhingra, O.D. and Sinclair, J.B., 1974. Effect of soil moisture and carbon:nitrogen ratios on survival of Macrophomina phaseolina in soybean stems in soil. Plant Dis. Rep., 58: 1034-1035. Dhingra, O.D. and Sinclair, J.B., 1975. Survival of Macrophomina phaseolina sclerotia in soil: effect of soil moisture, carbon:nitrogen ratios, carbon sources and nitrogen concentrations. Phytopathology, 65: 236240. Dhingra,
O.D. and Sinclair, J.B., 1978. Biology and pathology
of
Macrophominaphaseolina. Universidad Federal de Vicosa, Brazil, 166 pp. Gamliel, A. and Stapleton, J.J., 1993. Characterization compounds
residue. Phytopathology, Ghaffar,
A., Zentmeyer,
83: 899-905. G.A. and Erwin,
D.C., 1969. Effect of
on severity of Macrophomina phaseolina
organic amendments
root rot of cotton. Phytopathology, Hakeem,
of antifungal
evolved from solarized soil amended with cabbage
A. and Ghaffar,
59: 1267-1269.
A., 1977. Reduction
of the number
of
sclerotia of Macrophomina phaseolina in soil by organic amendments. Phytopathol. Z., 88: 272-275. Lodha, S., Gupta, G.K. and Singh, S., 1986. Crop disease situation and new records in Indian arid zone. Ann. Arid Zone, 25: 31 l320. Lodha, S., Mathur, B.K. and Solanki, K.R., 1990. Factor influencing population dynamics of Macrophomina phaseolina in arid soil. Plant Soil, 125: 75-80. Mathur, B.L. and Mathur, R.L., 1964. Studies on antibiosis between soil actinomycetes
and fungi in vitro. Proc. Nat. Acad. Sci. B,
India, 34: 350-352. Meyer, W.A., Sinclair,
J.B. and Khare, M.N., 1973. Biology
of
Macrophomina phaseolina in soil studied with selective media. Phytopathology, Papavizas,
63: 613-620.
G.C., 1967. Evaluation
of various media and antimicro-
bial agents for isolation of Fusarium from soil. Phytopathology, 57: 848-852. Ramirez-Villapudua,
J. and Munnecke, D.E., 1987. Control of cab-
bage yellow (Fusarium oxysporum f. sp. conglutinans) by solar heating of field soil amended with dry cabbage residues. Plant Dis., 71: 217-221.
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