Fungicides and the control ofPithomyces chartarum

Abstract

Thiabendazole and eight other fungicides were applied to pasture by a number of different methods and the effect on numbers of Pithornyces chartarum spores examined. Thiabendazole and benornyl sprayed at rates of 2-32 ozjacre reduced spore numbers during periods of accelerated production by 40-90% for 6 weeks. Application rate within this range had little effect on the length of time for which the fungicides were effective. Cercobin (NF44) at 4 oz gave control equal to that of thiabendazole at 4 oz, but 32 oz of Phenzidol and 16 oz of EL273 were needed to give the same measure of control. Fuberidazol, DUI3710, and Busan 72 at rates up to 16 oz and Euparen at 160 oz did not control spore numbers. The use of different formulations of thiabendazole did not affect results. Ultra-law-volume formulation of Fuberidazol and the addition of wetting agent to Euparen did not improve the performance of either of these materials. Thiabendazole applied aerially gave the same control as the hand-sprayed fungicide. Simulated rain, applied at rates of 1-2 in. within 3 days of spraying of 4 oz thiabendazole, removed all fungicidal effect, but control remained when only t in. of rain was applied. Early spraying of thiabendazole in November, December, or January affected spore numbers only for the 6-week period of effectiveness of the fungicide; subsequent spore counts on sprayed plots were equal to those on unsprayed controls.

A history of facial eczema (pithomycotoxicosis) research

“…Trap counts on pasture were low whilst pasture was wet with dew, increased as the dew dried and fell again in the evening (Smith & Crawley 1964). The trap was used in the irrigation trial of Brook & Mutch ( 1964) and the fungicide trials of Parle & di Menna (1972a) and Wallace (1976). it was generally agreed that rapidly rising numbers indicated dangerous conditions but not what was a dangerous count, although Wallace (1976) used 353 000 spores/m 3 as a dangerous count.…”

“…To prevent any build up in P. chartarum populations during early danger periods, the fungicide thiabendazole was applied to pasture plots at 16 oz ai/acre (1.12 kg/ha) on 24 November and on 19 december and spore counts made for 80 days after spraying (Parle & di Menna 1972a). When weather conditions were favourable, there were almost equal rises in spore numbers on the sprayed and on the unsprayed control plots 74 days after spraying.…”

Biomass Reducing Potential and Prospective Fungicide Control of a New Leaf Blight of Miscanthus × giganteus Caused by Leptosphaerulina chartarum

“…However, investigations conducted to identify effective chemical fungicide treatments for the control of L. chartarum on pasture grasses have been performed [25,26,28,30,37] due to the veterinary importance of this fungus [1,8,12,15,19,21,29,33]. In our experiments, cyproconazole, flutriafol, prothioconazole, and tebuconazole treatments resulted in consistent and significantly lower disease severity and belonged to the DMI group (Table 3).…”

“…Early research on the chemical control of the fungus L. chartarum, the causative agent of facial eczema, determined that a number of compounds in the MBC group, which includes thiabendazole, benomyl, carbendazim, and thiophanate-methyl, reduced spore production in pastures [26-28, 30, 35]. Thiabendazole and benomyl reduced spore numbers during periods of accelerated production by 40 % to 90 % for 6 weeks [26]. Wallace [35] evaluated the effectiveness of three fungicides carbendazim, benomyl, and thiophanate methyl in the field and found that a carbendazim pre-danger spore level application (at 0.15 kg a.i./ha) was effective in significantly reducing L. chartarum spore counts in pasture to a below danger level on treated pasture (700×10 3 spores per m 3 air).…”

“…The need for an effective control of L. chartarum has long been recognized, particularly in grass pastures due to its economic importance as a mycotoxigenic fungus. Some efforts directed at biological control using non-toxigenic Leptosphaerulina strains based on the competitive exclusion principle [7,11] and use of chemical fungicides [25,26,28,30,37] have been made in the past but without any significant success. The objectives of our current study were to: (1) evaluate the potential effect of Pithomyces blight on M.×giganteus biomass and (2) determine the efficacy of selected fungicides for control of Pithomyces blight on M.×giganteus.…”