Abstract
Experiments in the laboratory and on farms with potato tubers in storage are described in which sclerotia ofRhizoctonia solani were inactivated after inoculation of infected tubers with a suspension of conidia and hyphal fragments ofVerticillium biguttatum.
Sclerotia on freshly harvested tubers can be killed in a period of six to eight weeks, provided that (1) a direct contact between sclerotia and conidia ofV. biguttatum is obtained, (2) the temperature during the storage period is at least 15 °C, but preferably closer to 20 °C during the first weeks, and (3) the relative humidity of the air between the tubers is at least 99%.
Seed tubers are only certified as export quality if the infection withR. solani, visible as sclerotia on the tubers, is assessed as below a specified incidence. To restore the economical value of tubers with many sclerotia, living sclerotia can be inactivated byV. biguttatum. However, also dead sclerotia have to be removed, as dead and living sclerotia cannot be distinguished visually by inspectors. A satisfactory way to remove dead sclerotia from tubers has not yet been found.
Samenvatting
In proeven in het laboratorium en in de praktijk werden sclerotiën vanRhizoctonia solani (lakschurft) gedood door met lakschurft bezette knollen te beënten met sporen vanVerticillium biguttatum. Sclerotiën op kort tevoren gerooide knollen worden bijna volledig gedood in 6–8 weken, als aan de volgende voorwaarden wordt voldaan.
-
(1)
Er moet een direct contact zijn tussen de sclerotiën en de sporen vanV. biguttatum. De sclerotiën op de knollen moeten dus vrij zijn van aanhangende grond.
-
(2)
De temperatuur moet gedurende de bewaring tenminste 15 °C zijn en gedurende de eerste weken liever 20 °C of dicht hierbij. Dit is in augustus, als de poters in de bewaarplaats worden gebracht, meestal wel het geval.
-
(3)
De relatieve vochtigheid van de lucht tussen de knollen moet 100% zijn. Dit is meestal het geval in een hoop pas gerooide, jonge knollen. Om de bovenste laag van 40–50 cm niet te droog te laten worden kan het oppervlak afgedekt worden met een laag grove jute zakken.
Door borstelen kunnen dode sclerotiën soms grotendeels worden verwijderd; dit is nodig voor de keuring omdat dode en levende sclerotiën op het oog niet te onderscheiden zijn. Voor de verwijdering van dode sclerotiën wordt naar een betere methode gezocht.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Aluko, M.O., 1968. Microbial antagonism in the control ofRhizoctonia solani Kühn on potatoes. Thesis University of Nottingham.
Aluko, M.O. & Hering, T.F., 1970. The mechanisms associated with the antagonistic relationship betweenCorticium solani andGliocladium virens. Transactions of the British Mycological Society 55: 173–179.
Barnett, H.L., 1964. Mycoparasitism. Mycologia 56: 1–19.
Barnett, H.L. & Binder, F.L., 1973. The fungal host-parasite relationship. Annual Review of Phytopathology 11: 273–292.
Butler, E.E. & Bracker, C.E., 1970. Morphology and cytology ofRhizoctonia solani. In: J.R. Parmeter Jr (Ed.),Rhizoctonia solani, biology and pathology. University of California Press, Berkeley, Los Angeles and London. p. 32–52.
Chand, T. & Logan, C., 1984. Post-harvest development ofRhizoctonia solani and its penetration of potato tubers in Northern Ireland. Transactions of the British Mycological Society 82: 615–619.
Harris, R.F., Gardner, W.R., Adebayo, A.A. & Sommers, L.E., 1970. Agar disk isopiestic equilibration method for controlling the water potential of solid substrates. Applied Microbiology 19: 536–537.
Jager, G. & Velvis, H., 1983. Suppression ofRhizoctonia solani in potato fields. 1. Occurence. Netherlands Journal of Plant Pathology 89: 21–29.
Jager, G. & Velvis, H., 1985. Biological control ofRhizoctonia solani on potatoes by antagonists. 4. Inoculation of seed tubers withVerticillium biguttatum and other antagonists in field experiments. Netherlands Journal of Plant Pathology 91: 49–63.
Jager, G. & Velvis, H., 1986. Biological control ofRhizoctonia solani on potatoes by antagonists. 5. The effectiveness of three isolates ofVerticillium biguttatum as inoculum for seed tubers and of soil treatment with a low dosage of pencycuron. Netherlands Journal of Plant Pathology 92: 231–238.
Jager, G., Hoopen, A. ten & Velvis, H., 1979. Hyperparasites ofRhizoctonia solani in Dutch potato fields. Netherlands Journal of Plant Pathology 85: 253–268.
Velvis, H. & Jager, G., 1983. Biological control ofRhizoctonia solani on potatoes by antagonists. 1. Preliminary experiments withVerticillium biguttatum, a sclerotium-inhabiting fungus. Netherlands Journal of Plant Pathology 89: 113–123.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Jager, G., Velvis, H. Inactivation of sclerotia of Rhizoctonia solani on potato tubers by Verticillium biguttatum, a soil-borne mycoparasite. Netherlands Journal of Plant Pathology 94, 225–231 (1988). https://doi.org/10.1007/BF01977311
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01977311