Herbicide Fungicide Research Articles

Agroecological justification of winter wheat fertilization systems in the south-west of the Central Black-soil region

Under the conditions of the south-western part of the Central Black-soil region in the grain-and-plant crop rotation on the black-soil the typical maximum yield of winter wheat was 5.52 t/ha when using the organic-mineral fertilizer system as part of mineral fertilizers in the dose of N60P60K60 and manure in the dose of 40 t/ha according to the third level of plant protection (seed etching of herbicide fungicide insecticide growth substances) with maximum payback of 1 kg of mineral fertilizers with grain harvest increase – 15.5 kg. Yield increase at the 1st level of plant protection (seed etching) was 1.86 t/ha (68.1%), at the 2nd level of protection (seed etching of herbicide fungicide) – 2.55 t/ha (93.4%) and at the 3rd level of protection – 2.79 t/ha (102.2%). The highest increase from pesticides was 0.69 and 0.93 t/ha (15.0 and 20.3%), respectively. The use of such a fertilizer system is justified, in which the energy coefficient was 1.03 and 1.05. The design of an organic fertilizer system using manure does not meet the requirements of bioenergy efficiency at all levels of plant protection (Кee = 0.79-0.87).

Response of winter wheat to herbicide plus fungicide plus ammonium thiosulphate tank-mixes

A study was conducted at six field sites near Exeter and Ridgetown, ON, over a 3 yr period (2014, 2015, and 2016) to determine the effect of ammonium thiosulphate (ATS), various fungicides (azoxystrobin/propiconazole, trifloxystrobin/prothioconazole, or pyraclostrobin/metconazole), and various herbicides (bromoxynil/MCPA, thifensulfuron/tribenuron + MCPA, pyrasulfotole/bromoxynil, or 2,4-D/dichlorprop) applied alone and in tank-mix combinations on winter wheat crop injury and grain yield. The treatments were applied using Hypro ULD120-02 flat-fan nozzles around Zadoks growth stage 30. The herbicides and fungicides caused <0.6% leaf injury when ATS was not added to the tank-mix. When averaged across fungicides in ATS tank-mixes, leaf injury 1 wk after treatment application was 3.5% to 3.7% with thifensulfuron/tribenuron and dichlorprop-P/2,4-D herbicides and 5.1% to 5.8% injury with bromoxynil/MCPA and thifensulfuron/tribenuron herbicides. On the three field sites with the highest leaf injury, a fungicide–ATS tank-mix increased injury to 4.5% averaged across fungicides and to 4.3% with a herbicide–ATS tank-mix averaged across herbicides. Three-way tank-mixes of herbicide–fungicide–ATS caused the highest injury (7.1%). Despite significant crop injury 1 WAA with some tank-mixes, there was no evidence that grain yields were adversely affected. This study shows that the co-application of a three-way tank-mix of ATS with fungicides (azoxystrobin/propiconazole, trifloxystrobin/prothioconazole, or pyraclostrobin/metconazole) and herbicides (bromoxynil/MCPA, thifensulfuron/tribenuron + MCPA, pyrasulfotole/bromoxynil, or dichlorprop-P/2,4-D) has the potential to cause considerable injury in winter wheat under some environmental conditions in Ontario, but the effect seems transient, with no grain yield reductions detected.

Winter wheat (Triticum aestivum L.) tolerance to mixtures of herbicides and fungicides applied at different timings

Robinson, M. A., Cowbrough, M. J., Sikkema, P. H. and Tardif, F. J. 2013. Winter wheat (Triticum aestivum L.) tolerance to mixtures of herbicides and fungicides applied at different timings. Can. J. Plant Sci. 93: 491–501. Farmers commonly tank-mix herbicides and fungicides to reduce application costs. In the spring of 2008, there were reports of winter wheat injury with the application of herbicide–fungicide tank-mixes early in the growing season. This study was established to determine the tolerance of winter wheat to herbicide–fungicide mixtures as influenced by time of application. Field studies were conducted at four Ontario locations in 2009 and 2010 with three herbicides and four fungicides. Herbicide–fungicide tank-mixes were applied early, under cold conditions, and late at growth stage Zadoks 37–39. Dichlorprop/2,4-D mixed with tebuconazole caused up to 15% injury when applied early and up to 29% injury when applied late. Bromoxynil/MPCA mixed with tebuconazole injured wheat up to 15% when applied early but only 10% when applied late. Other herbicide and fungicide mixes caused a lower level of injury. Visible injury was transient and did not reduce winter wheat yields. The likelihood of tank-mixes causing injury was greater when they were applied late. The fungicide tebuconazole caused the highest level of injury when mixed with herbicides and injury was particularly high with dichlorprop/2,4-D.