Volume 10 Part 2 Article 27
Title: Verticillium Control in Mushroom Growing Using Different Fungicides
Authors: S. Gaal, J. Stanek and I. Szili
In Hungary only the “DUNA” farmer’s co-operative deals with mushroom growing on a large scale at the present time. The farmer’s co-operative produces about 2,5-3 million kg mushrooms every year in old stone-mines transformed into “mushroom cellars”, and this amounts to about 80% of the national quantity. This quantity is the result of a large scale modernization and further developments taking into consideration, the farmer’s co-operative will presumably produce about 4-5 million kg mushrooms a year.
Composting and spawning take place in a modern mechanized plant at the surface, far away the growing places (cellars). The spawned compost was packed into polyethylene bags and was placed in the cellars where spawn running took place at about 18-20°C air temperature. One week after placing of bags the compost was cased with a mixture (3:1) of ground limestone and peat. Fruitbodies appeared about 3 weeks after casing and harvesting started in 1-2 weeks from this time. Picking lasted 30-40 days. The cellar temperature was during that time 15-16 0C and relative humidity of the air was about 90%. The main works were : picking, treatment, watering, aeration.
The cellars – with cultures being in different growing phases – are comparatively near to each other and for this reason the possibility of complete separation and perfect hygiene is limited.
In other countries production takes place in built and controlled mushroom houses or in rooms suitable for steaming. Steaming serves for compost heat treatment and for disinfection of the spent (and contaminated) compost at the end of growing period. Hygienic requirements are here more insurable particularly if aeration happens with filtered air. At such circumstances chemical control is of less importance. The modernest plants especially where harvesting is also mechanized can be regarded as “mushroom factories” where programmed production goes on.
Under our special economic and natural endowments respectively growing methods we have to reckon with the different harmful organisms, first of all with Verticillium malthousei WARE.
Conditions of development of an epidemic are given in almost every cellar and culture and we can only strive to detain the development of an epidemic. In this task the expert fulfilment of the most technological processes is of great importance and we can wait for a yield increasing effect of the preventive chemical intervention only in accord with these. In the area of hygiene formalin is of great importance among disinfectants, moreover it is possible to use it for the treatment of casing soil – with a solution of 0,1-0,3% (2 L/m2 ) after casing – to avoid primer infection.
Under the existing technology included chemical control a yield of 140-170 kg mushrooms per compost ton is quite acceptable. In case of lack of chemical control yield would decrease to 100-130 kg in the plant as a whole.
The chemical control on Verticillium malthousei WARE means watering the casing material with a fungicide solution. Because of public health directions the casing material can be treated only before appearance of mushrooms. (In other countries treatment performed with Zineb is possible during the growing period and permission is in progress in Hungary too.) Treatments are combined with the necessary waterings above all immediately after casing. In two weeks a second treatment is also given in the case of Zineb 80.
At the “DUNA” farmer’s co-operative we have systematically started to use the benomyl containing fungicides such as NS 02 50 WP and Fundazol 50 WP in the summer of 1972. One year later that is in 1973 a considerably decrease in the effect was observed. We hoped that this was not the sign of development of resistance. We examined the fungicide. Increased the dose of application, altered the time of treatment (we used the fungicide not immediately after casing but after 10 days), changed the quantity of water, the method of dissolution (it was dissolved in warm water). The manufacturer (CHINOIN) placed other benzimidazol products at ours disposal but in our experiments they did not prove better than Fundazol 50 WP.
The zineb and mancozeb containing fungicides were not applied ut to that time because we used ground limestone as casing material and these fungicides checked the growth of the mushrooms (in the case of bag-production). However experiments performed in 1974 proved that there was no inhibition if peat was added to the ground limestone and their effect on Verticillium disease was more favorable as in the case of benomyl containing fungicides. Residue examinations were done with Dithane M-45 in 1972 and with Zineb 80 in 1975. Meanwhile residue examinations and experiments were extended and by this means we obtained encouraging results on the folpet, kaptafol and chlortalonil containing fungicides (Ortho-Phaltan, Buvicid F, Mycodifol, Daconil). In this paper we should like to report on these results.Please login to download the PDF for this proceeding.