sapstain fungi of some commercially important timbers and their ...

More documents

Recommendations

Info

-Table 12 Inhibitory zone (in mm) produced by antagonisticagainst various fungi.Bacillus subtilisNo. Fungi tested Clear zone1 Aspergillus flavus 62 A. niger 73 Trichoderma viride 94 Meninoniella echinata135 Botryodiplodia theobromae186 Acremoniuni recefei97 Scytalidium lignicola118 Cera tocys tis fim bria ta59 Fusarium solani1410 Corticium salnionicolor1411 Sclerotium rolfsii912 Pestalotiopsis sp.1713 Rhizoctonia solani1414 Collectotrichum gloeosporioides1015 Pythium sp.00(c) Field testing of the bacteriumThe maximum control of fungal growth was recorded on rubber woodplanks sprayed with bacterial suspension and piled one above the other withoutleaving any space in between. The analysis of variance showed significant differencebetween treatments at p = 0.01 (Table 13). Treatment 3 was found to besignificant when compared to all other treatments.Table 13 Analysis of variance of data on inhibition of fungal growth onrubber wood planks treated with Bacillus sub tilis suspension.--- -_I--Sources ss DF MSS FTreatments 639443.180 7 91349.026 8.4221**Replication 28163.804 3 9387.935 0.8655( ns)Residual 227772.598 21 10846.314Total 895379.582 31______---__-----_I_________________II___---------------------------------------------------------** Significant at p = 0.01 ns = non-significant-
Biological control of plant pathogens, free from hazards, is a difficult butimportant necessity. The antagonistic potential of certain bacteria can be quiteeffective and if well regulated, provide an industrially useful method for woodprotection. Among the various bacterial antagonists tested Bacillus subtilis hasbeen reported to control several plant pathogens (Dunleavy; 1955; Aldrich andBaker, 1970; Broadbent et al., 1971; Swinburne and Brown, 1976; Singh and Deverall,1984). Results of this study are in agreement with earlier reports on the efficacyof Bacillus subtilis in controlling sapstain and mould on various timber species.Laboratory studies were successfully carried out to evaluate the efficacy ofbacteria as a biological control agent against 5 brown rot and 3 white rot fungi(Benko and Highley, 1990). Tests were also carried out in Australia to screenbacteria effective against fungi causing blue stain (Benko, 1988). Bacillus subtilisstrain 186 inhibited the growth of three sapwood inhabiting fungi on agar andprevented colonisation of spruce blocks placed on agar plates (Bernier et al.,1986). More detailed studies with the same strain of bacterium revealed that itcan be used as a potential biological control agent for sapstain and mould growthon unseasoned timber (Seifert et al., 1987). All these reports indicate that B.subtilis can be used in the biological control of sapstain. However, large scale pilottrials are necessary to work out the economic feasibility of this method.
Page 4 and 5: INTRODUCTIONFungi cause different k
Page 6 and 7: MATERIALS AND METHODSSurveyA prelim
Page 8 and 9: Table 1 Relative humidities over sa
Page 10 and 11: Optimum moisture content of wood fo
Page 13 and 14: Treatment 1 : Dipping and stacking
Page 15: Ceratocystis fimbriata was prominen
Page 18 and 19: Table 5Percentage of weight loss du
Page 20 and 21: Table 7Growth rating of B.theobroma
Page 22 and 23: y the boron diffusion process and f
Page 24 and 25: Table 11 Percent control of fungal
Page 28 and 29: CONCLUSIONS1. Botryodiplodia theobr
Page 30 and 31: Colley, R. H. and Rumbold, C. T. 19
Page 32: Verrall, A. F. 1941. Fungi associat

sapstain fungi of some commercially important timbers and their ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?