Applied Crop Protection 2017

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APPLIED CROP PROTECTION 2O17

LISE NISTRUP JØRGENSEN, BENT J. NIELSEN, SOLVEJG K. MATHIASSEN, PETER KRYGER JENSEN, HELENE SALTOFT KRISTJANSEN, THIES MARTEN HEICK, NANA VAGNDORF, PETER HARTVIG &

STEEN SØRENSEN

DCA REPORT NO. 117 · APRIL 2018

AARHUS UNIVERSITY

AU

DCA - DANISH CENTRE FOR FOOD AND AGRICULTURE

APPLIED CROP PROTECTION 2017DCA REPORT NO. 117 • APRIL 2018

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Applied Crop Protection 2017

Supplementary information and clarifications (October 2019)

In an effort to ensure that this report complies with Aarhus University's guidelines for transparency and open declaration of external cooperation, the following supplementary information and clarifications have been prepared in collaboration between the researcher (s) and the faculty management at Science and Technology:

The Publication Applied Crop Protection is a yearly report providing output to farmers, advisors, industry and researchers in the area of crop protection. The publication typically summarizes data, which is regarded to be of relevance for practical farming and advice. It covers information on the efficacy profiles of new pesticides, effects of implementation of IPM principles (integrated pest management) aiming at reducing the use of pesticides and illustrates the use of Decision Support Systems (DSS) in combination with resistant cultivars. It also includes an update on pesticides resistance to ensure that only effective strategies are used by the farmers to minimize build-up of resistance.

The report was initiated in 1991, when Danish Research Service for Plant and Soil Science (Statens Planteavlsforsøg) as part of the Ministry of Agriculture was responsible for Biological testing of pesticides and provided a certificate for biological efficacy based on the level of efficacy in field trials.

Later this system was replaced by EU’s rules for efficacy data. Efficacy testing of pesticides was opened up to all trial units, which had obtained a GEP approval (Good Efficacy Practice) and fulfilled the requirements based on annual inspections.

Since 2007 the report has been published by Aarhus University (AU) and since 2015 it has been published in English to ensure a bigger out-reach. The choice of topics, the writing and publishing of the report is entirely done by staff from Aarhus University and the report content is not shared with the industry before publication. All authors and co-authors are from AU. The data on which the writing is based is coming from many sources depending on the individual chapter. Below is a list with information on funding sources for each chapter in this report.

Chemical companies have supplied pesticides and advice on their use for the trials and plant breeders have provided the cultivars included in specific trials. Trials have been located either on AU’s research stations or in fields owned by private trial hosts. AU has collaborated with local advisory centres and SEGES on several of the projects e.g. when assistance is needed regarding sampling for resistance or when looking for specific localities with specific targets. Several of the results have also been published in shared newsletters with SEGES to ensure a fast and direct communication with farmers.

Chapter 1: Climate data for the growing season 2016/2017 and specific information on disease attack 2017Information collected by AU.

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Chapter 4: Disease control in grain maize

Trials in this chapter have been financed by inputs from BASF. Certain elements have been based on AU’s own funding as part of a PhD project (Rose Kristoffersen).

Chapter 5: Fungicide resistance-related investigations in cereals

Testing for fungicide resistance is carried out based on a shared cost covered by projects and the industry. In 2017 ADAMA, Dupont, Bayer, BASF and Syngenta were involved from the industry. The Swedish part is financed by Swedish Board of Agriculture (Jordbruksverket) and also money AU-agro have been included.

Chapter 6: Spore trapping of sugar beet rusts (Uromyces beticola)

The results presented in this chapter are financed by a GUDP project “IPM in sugar beet”. Specific elements have been financed by Sukkerroeafgiftfonden and other parts by AU – with elements coming from a Master’s thesis by Rose Kristoffersen.

Chapter 7: Testing different Septoria models in field trials

Results have been generated during a project from The Danish Environmental Protection Agency's research funding (Miljøstyrelsens forskningsmidler).

Chapter 8. Resistance stability of Septoria tritici blotch

The presented data represent elements from Nana Vagndorfs industrial PhD, which was financed by Innovation Fund Denmark and Pajbjergfoundation.

Chapter 9: Control of late blight (Phytophthora infestans) and early blight (Alternaria solani) in potatoes

Trials in this chapter have been financed by income from Nordisk Alkali, Bayer, BASF, Syngenta.

Certain elements have been based on AU’s own funding as part of a PhD project (Isaac Abuley). Several of the trial plans have been carried out in collaboration with SEGES, which include the testing of DSS.

Testing of DSS have also partly been financed by a project from The Danish Environmental Protection Agency's research funding (Miljøstyrelsens forskningsmidler).

Chapter 10: Herbicide resistance in Lolium multiflorum and Lolium perenne The project was financed by the Danish Environmental Protection Agency.

Chapter 11: Herbicide susceptibility of different populations of Canada thistle.

The project was financed by agricultural tax funds (promilleafgiftsmidler) via SEGES.

Chapter 12: Longevity of seed of blackgrass following different stubble cultivation treatments The project was financed by agricultural tax funds (promilleafgiftsmidler) via SEGES.

Chapter 13: Results from crop protection trials in minor crops in 2017

The project was financed by various agricultural tax funds, GUDP, chemical companies, Swedish minor use funding.

Chapter 14: Results from testing of herbicides, growth regulators and desiccants in agricultural crops in 2017

No data has been presented.

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AARHUS UNIVERSITY

Lise Nistrup Jørgensen Bent J. Nielsen Solvejg K. Mathiassen Peter Kryger Jensen Helene Saltoft Kristjansen Thies Marten Heick Nana Vagndorf Peter Hartvig Steen Sørensen

Aarhus University

Department of Agroecology Forsøgsvej 1

DK-4200 Slagelse

APPLIED CROP PROTECTION 2O17

DCA REPORT NO. 117 · APRIL 2018

AARHUS UNIVERSITY

AU

DCA - DANISH CENTRE FOR FOOD AND AGRICULTURE

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Series: DCA report

No.: 117

Authors: Lise Nistrup Jørgensen, Bent J. Nielsen, Solvejg K. Mathiassen, Peter Kryger Jensen, Helene Saltoft Kristjansen, Thies Marten Heick, Nana Vagndorf, Peter Hartvig & Steen Sørensen

Publisher: DCA - Danish Centre for Food and Agriculture, Blichers Allé 20, PO box 50, DK-8830 Tjele. Tel. 8715 1248, e-mail: dca@au.dk, web: www.dca.au.dk

Photo: Front page: Lise Nistrup Jørgensen Print: www.digisource.dk

Year of issue: 2018

Copying permitted with proper citing of source

ISBN: Printed version 978-87-93643-32-1. Electronic version 978-87-93643-33-8

ISSN: 2245-1684

Reports can be freely downloaded from www.dca.au.dk

Scientific report

The reports contain mainly the final reportings of research projects, scientific reviews, knowledge syntheses, commissioned work for authorities, technical assessments, guidelines, etc.

APPLIED CROP PROTECTION 2O17

AARHUS UNIVERSITY

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Preface

This report contains results from crop protection trials in agricultural crops and focuses to a major extent on results with different pesticides. To a great extent the results are presented through graphics and in the form of tables. Trial results from specific IPM-related activities which are not specifically related to pesticides are also included.

The report also gives a description of the climate as well as the pest incidence in the crops. The report is a summary of the publicly available results generated every year by the Department of Agroecology.

The results concerning new products and marketed pesticides will moreover be included in the annual updating of the advisory programme “Crop Protection Online”. Many of the results in this year’s report are results from single trials or trial series. Trials from several years are also summarised in several cases.

The report was compiled and edited by Lise Nistrup Jørgensen, Department of Agroecology, Aarhus University, Flakkebjerg, Denmark in collaboration with other scientists in the team at Flakkebjerg.

Thanks are due to all who have contributed to generating the results described in this report. Special acknowledgement is given to both the chemical companies selling pesticides, private trial hosts, staff at local advisory centres, SEGES and staff at the Department of Agroecology.

Crop Health, Department of Agroecology Aarhus University, Flakkebjerg

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Applied Crop Protection 2017

I Climate data for the growing season 2016/2017

Helene Saltoft Kristjansen

The growing season (Sept. 2016–Aug. 2017) started out dry and warm; especially September had high temperatures; on average 16.2°C, which was 3.5°C above normal and the highest recorded September temperature since the autumn 1874. October and November were slightly below normal. The average precipitation in September-November for the country in general was 184 mm, which was 19% below normal and the lowest precipitation recorded since 2011. In autumn, the rainfall was very uneven, and while some parts of the country were flooded other areas got less than normal precipitation. The first frosty days were recorded in late October, and the number of frosty days was 11 days and occurred mainly in November. The average temperature was 9.7^oC, which is 0.9^oC above normal.

The dry and warm weather continued during the winter; the average temperature was 2.3°C, which was 1.1°C above normal. Consecutive hours (24) with frost occurred 37 times during the winter 2016-17, which was below normal (53 times). The precipitation was 20% below normal; especially December and January had low precipitation. The spring (2017) was quite normal with a temperature average of 7.7°C, which was 1.5°C above normal. The number of frosty days was 11 days and occurred mainly in March and April. In May, precipitation was quite low, an average of only 17 mm, which was 35% below normal. The precipitation was unevenly distributed across the country; hence, the growing conditions differed from area to area. Sunny intervals in spring 2017 were a bit above normal and mostly because May had 240 hours of sun, which was 15% above normal. The summer (2017) had an average temperature of 15.4^oC with sunny intervals below normal. Besides the lack of sun in primarily June and August, especially June had a high surplus of precipitation, 94 mm, which was 71% above normal. With a total precipitation of 268 mm, the summer of 2017 was wet and precipitation in general above normal.

At Flakkebjerg, the autumn and winter (September–February) were generally warm with low precipitation (51/25 mm in November/December – the normal average is 52/54 mm). The first night with frost and snow did not occur until mid-November, and there were no frosty nights or snow in December.

Apart from a few frosty days in January and an average temperature in January lower than normal, the warm and dry conditions characterised the winter 2017. February and March had much higher temperatures than normal and only few frosty nights. The spring had a surplus of precipitation in March and April, which prolonged the time before the soil was cultivable for sowing. Temperatures in May

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Figure 1. Daily values of precipitation and temperatures from the growing season 2016 at Flakkebjerg.

The automatic weather station at Flakkebjerg is located 12 km from the West Zealand coast. The climate at Flakkebjerg is representative of the area in which most of our trials are located. The normal climate is given as an average of thirty years (1973-2003).

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Figure 2. Climate data from AU Flakkebjerg for the growing season September 2016–August 2017. The temperature is in°C, the global radiation is measured in MJ/m², the precipitation in mm and the water balance is the difference between precipitation and potential evaporation.

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In this chapter, information about the diseases occurring in the trials carried out in 2017 is given. This makes it possible to evaluate if the target diseases were present at a significant level and whether or not the trials gave representative results. Yield levels in cereal trials were also ranked and compared with the previous year’s responses.

Wheat

Powdery mildew (Blumeria graminis). Severe attacks of mildew developed in the mildew specific trials at Jyndevad. The sandy soil in Southern Denmark are well known for its severe attack of powdery mildew and in 2017 very severe attacks developed as expected. For the country in general, mildew attacks were delayed in early spring due to the cold weather. Moderate attacks were recorded during May, especially in the cultivar Torp. Recordings carried out by the advisors in the national monitoring system organised by SEGES also showed moderate attacks this year.

Septoria leaf blotch (Zymoseptoria tritici). The level of Septoria attack varied and depended on location, but in general the attacks were moderate to high. The mild winter gave good conditions for inoculum to survive the winter. Particularly early sown fields and susceptible cultivars were seen to give increased levels of attack in April. Moderate to high levels of attack were recorded in trials early in the season, but the development of attack was delayed due to lack of precipitation in May, especially in Cen- tral Jutland (LMO). Higher precipitation at the beginning of June gave rise to an increased attack, which developed especially on the flag leaves. As result of increased precipitation in June, trials at Flakkebjerg developed severe attacks at the upper leaves with especially susceptible cultivars such as Hereford and Cleveland developing severe attacks.

Yellow rust (Puccinia striiformis). Cold and windy weather around field inoculation with yellow rust in susceptible cultivars delayed the development of yellow rust. Dry and warmer weather in May increased attack particularly in the cultivar Substance. The cultivar Ambition developed only a slight to moderate attack of yellow rust. Ambition is in general less susceptible to yellow rust than Substance, which is well known for its high susceptibility.

Brown rust (Puccinia triticina). The mild winter 2016/2017 gave good conditions for inoculum to survive the winter. In a susceptible cultivar, Hereford, natural infections were recorded at a low level during June and July. In Hereford trials inoculated with brown rust, severe attacks developed during the summer. The level of attack in these trials increased to 15% on the flag leaf at GS 75.

1. Disease attacks in 2017

Lise Nistrup Jørgensen, Bent J. Nielsen, Helene Saltoft Kristjansen & Isaac Kwesi Abuley

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Tan spot (Drechslera tritici repentis). The attack developed from early April in fields which had winter wheat as previous crop and minimal tillage. Due to dry and cold weather in the spring, the attack of tan spot never developed to a significant extent in these fields. Trials carried out at trial sites previously infected with infected straw gave rise to a significant attack, which gave good options for efficacy evaluations. In trials with infected straw, the level of attack increased to 65% at GS 77. Generally, DTR developed on the flag leaf in most trials at GS 75 giving mixed infections with Septoria tritici.

Fusarium head blight (Fusarium spp.). Trials with fusarium head blight as target were inocu- lated to ensure attack. As the result of optimal weather conditions and irrigation, moderate to severe attacks of fusarium head blight were seen in field trials this year. This level of attack gave good opportunities for distinguishing differences between fungicide and cultivar susceptibility.

A significant attack of brown rust was seen late in the season in several cultivars. The photos illustrate the severe attack with uredospores to the left and both uredospores and teleutospores to the right.

A significant attack of fusarium head blight was seen in many fields. Particularly Torp had a clear attack.

However, an analysis for mycotoxins showed that the content of mycotoxins was relatively low in grain samples. The exceptions were trials where we inoculated with mixtures of Fusarium culmorum and F.

graminearum.

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Triticale and rye

Yellow rust (Puccinia striiformis). Moderate attacks of yellow rust developed in the triticale trials in 2017.

The triticale trials were naturally infected and levels increased to 18% at GS 75 on the upper leaves. The disease level gave good opportunities for distinguishing the performance of the products.

Glume blotch (Phaeosphaeria nodorum). In this year’s triticale trials the attack of glume blotch was recorded to be at a low level.

Brown rust (Puccinia recondita) developed late in the season resulting in very severe attacks. Brown rust is known to reduce yields, and most products were seen to provide good control even with only one treatment in the trial plan. The attack of brown rust in triticale increased to a level between 35 and 60%

on the upper leaves.

Mildew (Blumeria graminis secalis). A significant attack of mildew developed in the trials giving the opportunity for distinguishing the performance of the products. The disease attack increased to 14%

at GS 65-73.

Winter barley

Powdery mildew (Blumeria graminis). The attack in 2017 developed from slight to moderate;

especially the cultivar Matros developed a moderate attack, which gave good opportunities for distinguishing the performance of the products. The attack of mildew in winter barley increased to a level between 2 and 19% at GS 51-75.

Brown rust (Puccinia hordei) occurred with a significant and severe attack in 2017 supported by a mild and early spring. In particular the cultivars Wootan and Celtic developed severe attacks, which gave good options for separating the efficacy of the different fungicides in 2017. The average attack of brown rust in this year’s trial at AU reached a level of 20.8 % by GS 71-75.

Rhynchosporium (Rhynchosporium commune). In general, only a minor attack of Rhynchospori- um was recorded in winter barley trials 2017. The cultivar Frigg developed a moderate attack and gave opportunities for distinguish the performance of the products. The average attack of Rhynchosporium reached a level of 5% by GS 69-73.

Net blotch (Drechslera teres) occurred with only a minor attack in winter barley fields in general.

The attack of net blotch in trials was in general low, apart from Celtic, which developed a moderate attack and gave opportunities for separating fungicide performance. The. In trials with net blotch the average attack in the susceptible cultivars reached a level of 11% at GS 75.

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Ramularia leaf spot (Ramularia collo-cygni). The disease appeared with a highly significant attack in winter barley fields and in most trial cultivars as well. The trials developed a relatively late but significant attack of this disease in 2017. In the specific trials the average attack of ramularia leaf spot reached a level of 53.6% by GS 71-75.

Spring barley

Powdery mildew (Blumeria graminis). The attack in 2017 was minimal and limited to the cultivars Sissy and Milford, which both do not carry mlo resistance. In the trials both cultivars provided limited possibilities for ranking the performance of the products. The attack of powdery mildew reached a level between 2 and 5% at GS 71-75 (average of 5 trials: 4.1%).

Net blotch (Drechslera teres) appeared with a significant attack in some new cultivars. Particularly the cultivar Chapeau developed a severe attack in specific trials for ranking fungicide effect on this disease. In addition, the cultivar Laurikka developed a moderate attack also with the possibility of ranking the performance of the products. The attack of net blotch in specifically Chapeau and Laurikka reached an average level of 10% on the upper leaves at GS 75-77.

Rhynchosporium (Rhynchosporium secalis). No attack of Rhynchosporium appeared in spring barley trials in 2017.

Brown rust (Puccinia hordei). All trials developed a very severe attack in 2017. Especially high le- vels of attack were seen in the cultivars Chapeau, Laurikka and Sarbi. The attack at Flakkebjerg reached 11-70%, which also caused significant yield reductions if not controlled.

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Yield increases in fungicide trials in cereals

The harvest 2017 was difficult due to increased precipitation in August and September. The yield average in winter wheat 2017 set a new record of 83 hkg/ha. The winter wheat trials generally yielded well and typically in the range of 80-110 dt/ha and in winter barley around 60-80 dt/ha. In spring barley the level was moderate, around 50-75 dt/ha.

Yield increases following fungicide treatments in wheat were above the levels from previous seasons following severe attack of Septoria. The yield response in both winter and spring barley was also very high. Standard treatments in spring barley in AU trials resulted in 11.4 hkg/ha. The high response for fungicide treatments in the AU trials is most likely due to the very severe attack of especially brown rust.

The general yield response was high for winter barley. Severe attacks of rust and in particular Ramula- ria are the reason for very high yield responses. Standard treatments in AU winter barley trials yielded an average of 13.6 hkg/ha (Table 1).

Maize

Eye spot (Kabatielle zeae). Only a moderate attack of eye spot developed in trials during the 2017 season. The trials were irrigated one time in May, and the first attack on leaves around cob was assessed in late August. The attack increased on a moderate level during the summer, and assessments in mid- September gave the first opportunity to distinguish between the performance of the products. The attack in September reached a moderate level of attack between 15 and 60% on the upper leaves. The attack did not have a significant effect on yield parameters.

Northern leaf blight (Setospharia turcica) developed to a limited level and never caused more than a minor attack early in the season.

Grass seed – ryegrass

Table 1. Yield increases (dt/ha) for control of diseases using fungicides in trials. The responses are picked from standard treatments typically using 2 treatments per season. Numbers in brackets give the number of trials behind the figures. Data originate from SEGES and AU Flakkebjerg trials.

Year Winter wheat Spring barley Winter barley

2005 6.4 (126) 5.4 (43) 4.6 (60)

2006 8.0 (106) 3.3 (63) 5.1 (58)

2007 8.5 (78) 7.2 (26) 8.9 (13)

2008 2.5 (172) 3.1 (29) 3.2 (36)

2009 6.3 (125) 5.1 (54) 6.3 (44)

2010 6.6 (149) 5.6 (32) 5.9 (34)

2011 7.8 (204) 3.9 (43) 4.3 (37)

2012 10.5 (182) 6.7 (38) 5.1 (32)

2013 10.3 (79) 5.2 (35) 5.5 (27)

2014 12.0 (82) 3.0 (19) 4.1 (18)

2015 10.9 (73 SEGES + 29 AU) 9.1 (20) 7.3 (19)

2016 10.9 (59 SEGES + 34 AU) 8.0 (16 SEGES + 13 AU) 4.0 (11 SEGES + 10 AU) 2017 15.0 (94 SEGES + 55 AU) 10.4 (11 SEGES + 16 AU) 11.9 (11 SEGES + 14 AU)

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Potato

Potato early blight (Alternari solani). Most of the early blight trials at Flakkebjerg were artificially inoculated on 5 July with autoclaved barley seeds inoculated with A. solani. The first attacks on the lower leaves were detected on 13 July in most of the trials. The 2017 season was characterised by several days with leaf wetness, high humidity and temperatures favourable for early blight attack. However, the disease development was slow in most of the trials until late August. In the last part of September, there was a severe disease development, and at the end of September 80-100% of the leaves were attacked in untreated plots.

Potato late blight (Phytophthora infestans)

Untreated spreader rows in the field were inoculated on 5 July with a suspension of P. infestans sporan- gia. The first attacks were seen in the spreader rows on 10 July and in the untreated plots of the trials on 15 to 19 July (varieties Kuras and Signum). The weather 2017 was favourable for late blight, and there was a severe development in the trials in late July and August. In the first week of September 100% of the leaves were attacked by late blight in most of the untreated field plots. With all the rain in the season it was expected that the tubers had been infected, but only very few tuber infections were seen in the variety Kuras.

Potato plot with attack of early blight (Alternaria solani) at Flakkebjerg, September 2017. (Photo: Bent J. Nielsen).

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Applied Crop Protection 2017

II Disease control in cereals

Lise Nistrup Jørgensen, Thies Marten Heick, Niels Matzen, Hans-Peter Madsen, Helene Saltoft Kristjansen, Sidsel Kirkegaard & Anders Almskou-Dahlgaard

Introduction

In this chapter, field trials in cereals carried out with fungicides in 2017 are described in brief and results are summarised. In graphs or tables are also included results from several years if the trial plan concerns several years. Included are main results on major diseases from both protocols with new fungicides and protocols in which products applied at different dose rates and timings are compared. Part of the trial results are used as part of the Biological Assessment Dossier, which the companies have to prepare for new products or for re-evaluations of old products. Other parts of the results aim at solving questions related to optimised use of fungicides in common control situations for specific diseases.

Apart from the tables and figures providing main data, a few comments are given along with some con- cluding remarks.

Methods

All field trials with fungicides are carried out as GEP trials. Most of the trials are carried out as field trials at AU Flakkebjerg. But some trials are also sited in farmers’ fields, at Jyndevad Experimental Station or near Hadsten in collaboration with a GEP trial unit at the advisory group LMO. Trials are carried out as block trials with randomised plots and 4 replicates. Plot size varies from 14 to 35 m², depending on the individual unit’s equipment. The trials are sited in fields with different, moderately to highly susceptible cultivars, specifically chosen to increase the chances of disease development. Spraying is carried out using a self-propelled sprayer using atmospheric air pressure. Spraying is carried out using 150 or 200 l water per ha and a nozzle pressure of 1.7-2.2 bar.

Attacks of diseases in the trials are assessed at approximately 10-day intervals during the season. Per cent leaf area attacked by the individual diseases are assessed on specific leaf layers in accordance with EPPO guideline 1/26 (4) for foliar and ear diseases in cereals. At the individual assessments, the leaf layer that provides the best differentiation of the performances of the fungicides is chosen. In most cases this is the 2 upper leaves. In this publication only some assessments are included – mainly the ones giving the best differentiation of the efficacy of the products.

Nearly all trials are carried through to harvest, and yield is adjusted to 15% moisture content. Quality parameters like specific weight, % protein, % starch and % gluten content are measured using NIT in- struments (Foss), and thousand grain weight is calculated based on 250 grains counted. In spring barley, which can potentially be used for malting grain, size fractions are also measured. For each trial, LSD⁹⁵ values or specific letters are included. Treatments with different letters are significantly different, using the Student-Newman-Keuls model.

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Control of powdery mildew (Blumeria graminis)

Several trials were carried out at Jyndevad Experimental Station, which is located on sandy soil close to the German border in Jutland and known for being a good site for investigation of mildew efficacy. The cultivar Torp was used in the trials.

Flexity (metrafenon) is available for specific mildew control, but the efficacy is low due to an erosion in the sensitive isolates. Azoles like tebuconazole and prothioconazole have also over the years been seen to provide good control, if used at an early timing, but if attack is very severe, azoles have proved insufficient.

Talius (proquinazid) got a dispensation for use in the season 2017, and also Input EC 460 (spiroxamine + prothioconazole) got an authorisation for control of powdery mildew. However, this happened very late – and after the peak time for control of powdery mildew. Due to frosty nights in late April, it was difficult to apply the fungicide under optimal condtions. Even so and despite some attack already visible in the trials, most treatments still provided good control. Four dose rates of Talius were tested in mixture with quarter rate of Prosaro EC 250. Talius showed a clear dose response when going from 0.1 to 0.25 l/

ha (Table 1, Figure 1). A major improvement in yields (>1 t/ha) was gained from treatments with Talius, which verifies that powdery mildew can be very yield reducing if attacks are significant. Overall, two treatments with Talius provided the best increase (tr. 7), and from single treatments 0.25 l/ha gave the best net return. The situation at Jyndevad is regarded as a worst-case scenario for control of mildew, and it is expected that lower rates will be sufficient in fields with more moderate attacks. The crop at Jyndevad clearly suffered from severe attacks of powdery mildew, and as can be seen in the photo below

1. Control of diseases in winter wheat

Denmark has only few specific fungicides for control of powdery mildew. In 2017 Talius got a dispensation for use once in the season, which was a major step forward as this product is very effective.

Flexity only performs moderately in line with or poorer than azole solutions. Input EC 460 also got an authorisation, but only very late in the season. Input EC 460 performed in line with azole solutions (Prosaro EC 250), while Talius showed a very good and long-lasting control. Several of the cultivars grown (Benchmark, Sheriff, Pistoria) provided good resistance to mildew, while for instance Torp showed high susceptibility.

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Photo from a drone above the mildew trial at Jyndevad. Yellow areas suffer from severe mildew attack.

Table 1. Control of powdery mildew using different mildewicides in 1 trial from 2017 (17344).

Treatments, l/ha % powdery mildew Yield and

increase hkg/ha

increaseNet hkg/ha GS 31

(A) GS 37-39

(B) GS 51

L 2 GS 65 L 2 GS 71

L 2 GS 71 L 1

1. Untreated Untreated 15.0 31.3 46.3 16.3 - -

2. Untreated Viverda 0.6 + Ultimate S 0.6 9.0 18.8 33.8 4.5 13.0 9.5

3. Talius 0.25 + Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 4.5 5.0 10.0 0.9 29.0 22.3 4. Talius 0.20 + Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 6.0 7.0 12.5 1.3 26.8 20.4 5. Talius 0.15 + Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 4.3 8.8 16.3 2.0 26.5 20.5 6. Talius 0.10 + Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 5.8 11.5 18.8 2.0 23.2 17.5 7. Talius 0.15 + Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 + Talius 0.1 5.5 8.8 15.5 0.9 31.3 24.6

8. Prosaro EC 250 0.25 Viverda 0.6 + Ultimate S 0.6 8.3 20.0 32.5 4.0 15.9 10.9

No. of trials 1 1 1 1 1 1 1

LSD₉₅ 3.6 5.5 8.7 2.0 4.0 -

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In a second trial (17339) different azole solutions (Prosaro EC 250 and Proline Xpert) were compared with Input EC 460 – all tested at low rates (Table 2, Figure 2). The same solutions were tested as a single solution or as a solution in mixtures with a low rate of Talius (0.1 l/ha). The control from the azole solutions and Input EC 460 was short-lived and rather limited, but adding Talius increased the duration of control and also the yield significantly.

Figure 2. Per cent control of powdery mildew using different products with mildew effects. 1 trial from Jyndevad 2017 (17339) assessed at GS 37 and 51 (70% and 12.5% attack in untreated, respectively).

Table 2. Control of powdery mildew using different mildewicides in 1 trial from 2017 (17339).

increaseNet hkg/ha

GS 31 GS 37-39 GS 37

L 2 GS 51 L 2 GS 65

L 2 GS 75 L 1

1. Untreated Untreated 12.5 10.8 35.0 32.5 40.5 -

2. - Bell 0.3 + Prosaro EC 250 0.25 11.3 7.8 26.3 23.8 4.6 1.8

3. Prosaro EC 250 0.5 Bell 0.3 + Prosaro EC 250 0.25 11.3 8.8 23.8 21.3 8.7 3.6

4. Proline Xpert 0.45 Bell 0.3 + Prosaro EC 250 0.25 10.0 8.0 23,8 25.0 9.4 4.3

5. Prosaro EC 250 0.35 + Talius 0.1 Bell 0.3 + Prosaro EC 250 0.25 6.0 3.0 13.8 17.5 21.6 16.3 6. Proline Xpert 0.3 + Talius 0.10 Bell 0.3 + Prosaro EC 250 0.25 7.3 5.3 21.3 20.0 16.9 11.7

7. Input EC 460 0.5 Bell 0.3 + Prosaro EC 250 0.25 10.0 7.5 21.3 25.0 8.3 2.8

8. Input EC 460 0.3 + Talius 0.1 Bell 0.3 + Prosaro EC 250 0.25 6.8 6.5 20.0 21.3 15.0 9.6

No. of trials 1 1 1 1 1 1 1

LSD 3.5 2.8 7.5 7.8 3.9 -

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Table 3. Control of powdery mildew using different mildewicides in 1 trial from 2017 (17308). The whole trial was also cover treated at heading with 0.75 l/ha Bell (also untreated).

Net increase hkg/ha

GS 31 GS 37

L 2-3 GS 37

L 3-4 GS 65

L 2 GS 75

L 1

1. Untreated 5.0 32.5 27.5 12.5 46.3 -

2. Flexity 0.133 4.0 28.8 27.5 10.0 0.6 -0.8

3. Flexity 0.2 2.8 27.5 27.5 10.3 0.5 -1.3

4. Flexity 0.33 3.8 28.8 25.0 11.3 1.2 -1.3

5. Flexity 0.5 6.5 27.5 23.8 12.3 0.4 -3.1

6. Talius 0.25 1.5 9.3 13.8 8.8 12.7 10.4

7. Kumulus S 6 kg/ha 7.0 30.0 26.3 14.3 0.1 -10.0

8. Flexity 0.2 + Talius 0.125 2.5 16.3 18.8 9.0 8.0 5.4

No. of trials 1 1 1 1 1 1

LSD₉₅ 2.9 4.5 6.2 3.0 3.6 -

Untreated plots at Jyndevad with a severe attack of powdery mildew.

Plot treated with 0.25 l/ha Talius + 0.25 l/ha Prosaro EC 250 at GS 31.

Talius provided long-lasting effect of powdery mildew.

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Control of tan spot (Drechslera tritici repentis)

Four trials were carried out in 2017 testing the efficacy of different fungicides for control of tan spot.

Straw infected with tan spot was spread in the autumn of 2016 at the trial site, which is a method known to provide good attack of this disease. In early April the first clear symptoms of tan spot were recognised at the site. The trial developed minor attacks of Septoria and severe attacks of tan spot. When first established, tan spot is found to be the faster of the two diseases, particularly when developing on newly developed upper leaves.

Different timings and combinations of treatments were tested (Table 4). As tan spot has a very short latent period (less than a week), it is important to keep on controlling this disease also during flowering.

This is in contrast to Septoria, which due to its long latent period will stop creating a yield reducing attack at an earlier stage. As in previous seasons, all treatments only provided very moderate control.

However, as also seen in previous seasons, it was clear that the late timing improved the control at the last assessments.

Both Bumper 25 EC and Proline EC 250 provided moderate to good control of tan spot. Bumper 25 EC is Only few fungicides provide high levels of tan spot control. Bumper 25 EC and Proline EC 250 are the best products and provide very similar control. The efficacy does not last when severe outbreaks occur. Cultivar resistance is only moderate. Only Creator showed again in 2017 a clear reduction in the level of attack.

Untreated. Bumper 25 EC/Proline EC 250/Bumper 25 EC/

Proline EC 250.

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GF-3307, which includes a mixture of Inatreq + prothioconazole, showed moderate control of tan spot using 1.5-2.0 l/ha GF-3307 (Table 6). The efficacy provided control in line with or better than Propulse SE 250 but slightly superior to 2.5 l/ha Ascra Xpro. Two treatments were clearly superior in both control and yields compared to solo treatments applied at GS 59.

Table 4. Effects of different fungicides on tan spot and yield responses following 2-4 applications in wheat. 1 trial (17326).

Treatments, l/ha % tan spot Yield and

2017

Net in- crease hkg/ha

GS 32 GS 37 GS 51-55 GS 61-65 GS 71

L 1 GS 71 L 2 GS 77

L 1

1. Bumper 0.25 Proline Xpert 0.5 Bumper 0.5 Proline EC 0.4 2.0 13.8 16.8 13.2 5.4

2. Bumper 0.25 Proline Xpert 0.5 Propulse 0.5 Bumper 0.5 4.3 20.0 23.0 14.5 6.5

3. Bumper 0.25 Proline Xpert 0.5 Bumper 0.5 Propulse 0.5 1.5 10.0 12.0 18.9 10.9

4. Bumper 0.25 Proline Xpert 0.5 Propulse 0.5 - 4.8 17.5 35.0 14.2 7.9

5. Bumper 0.25 Bumper 0.5 Bumper 0.5 - 2.3 12.0 21.3 14.9 10.5

6. Bumper 0.25 Propulse 0.5 Proline Xpert 0.5 - 7.0 17.5 35.0 13.9 7.6

7. Bumper 0.25 Viverda 0.5 + Proline EC 0.2 Viverda 0.5 + Proline EC 0.2 - 6.5 26.3 33.8 13.3 4.6

8. Bumper 0.25 Proline EC 250 0.4 Armure 0.4 - 4.3 17.5 30.8 15.9 9.9

9. Untreated - - - 15.0 42.5 55.0 71.6 -

LSD₉₅ - - - 2.7 7.8 10.2 5.2 -

Table 5. Results of 2 trials from 2016 (16326-1) and 2017 (17326-1) with tan spot.

*Tr. 1-4 were at GS 37 treated with 0.4 l/ha Proline EC 250 in 2016 and 0.5 l/ha Proline Xpert in 2017.

Treatments, l/ha 2016

2017+ 2016 2017+

Yield and increase, hkg/ha

2017

increase Net hkg/ha

GS 32 GS 37 GS 71

L 2 GS 61-65 GS 71

L 2 GS 75

L1 2016 +

2017 2016 + 2017

1. Bumper 0.25 Proline Xpert 0.5* Bumper 0.5 Proline EC 0.4 8.9 25.3 10.3 2.5

2. Bumper 0.25 Proline Xpert 0.5* Propulse 0.5 Bumper 0.5 12.8 29.0 12.1 4.1

3. Bumper 0.25 Proline Xpert 0.5* Bumper 0.5 Propulse 0.5 3.6 23.5 14.4 6.4

4. Bumper 0.25 Proline Xpert 0.5* Propulse 0.5 - 6.8 38.2 12.3 6.0

5. Bumper 0.25 Bumper 0.5 Bumper 0.5 - 11.0 31.3 9.6 5.2

6. Bumper 0.25 Propulse 0.5 Proline Xpert 0.5 - 11.3 40.0 11.2 4.9

7. Bumper 0.25 Viverda 0.5 + Proline EC 0.2 Viverda 0.5 + Proline EC 0.2 - 16.9 38.2 10.5 1.8

8. Bumper 0.25 Proline EC 250 0.4 Armure 0.4 - 15.0 38.6 11.4 5.4

9. Untreated - - - 34.0 66.9 71.7 -

LSD₉₅ - - - - - 4.8 -

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Table 6. Effects of different fungicides on tan spot and yield responses following 1 or 2 applications in wheat. 1 trial (17316-1).

Treatments, l/ha % DTR Yield and increase

hkg/ha, 2017

GS 37-39 GS 59 GS 71

L 1 GS 71

L 2 GS 77

L 1

1. Untreated 10.0 31.3 43.8 64.0

2. GF-3307 1.5 4.8 17.5 21.3 4.0

3. Viverda + Ultimate S 0.6 + 0.6 GF-3307 0.5 2.4 13.8 16.8 12.0

4. GF-3307 1.5 GF-3307 1.5 1.6 7.8 17.5 12.0

5. Propulse SE 250 1.0 2.8 16.0 25.0 5.0

6. Ascra Xpro 1.5 2.0 17.5 17.3 9.0

7. Proline EC 250 0.8 6.6 24.5 26.3 4.0

8. GF-3307 2.0 3.6 16.8 18.8 6.0

LSD₉₅ 7.3 19.0 20.1 0.9

Tan spot: More resistant cultivar such as Creator.

Tan spot: Susceptible cultivar such as Ritmo.

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Tan spot (DTR) in winter wheat

Approximately 20 cultivars were tested for sensitivity to tan spot. The cultivars were placed in a field with debris of infected straw spread in the field in the autumn 2016. This is known to stimulate the attack of this disease. The trial layout was similar to the Fusarium trial using small plots with 2 x 1 metre row and 4 replicates. The trial was assessed several times. The ranking for DTR susceptibility among the cultivars was not very consistent, but Creator has in several seasons proved to be one of the most resistant cultivars – this year also Informer looked like having moderate to good resistance (Figure 3).

Figure 3. Ranking of cultivars resistance to tan spot. Based on data from a small plot trial with straw infected with tan spot spread in the autumn to ensure good attack.

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Control of Septoria (Zymoseptoria tritici)

Comparison of azoles (17329)

Two trials testing different azoles were carried out in the cultivars KWS Cleveland at Flakkebjerg and Hereford at Horsens. The trials included two treatments using 2 half rates applied at GS 33 and 45-51. In line with previous seasons, a moderate control was achieved from the old azoles and mixtures of azoles (Table 7). The ranking in efficacy is shown in Figures 4 and 5. A new triazole, Revyzol, was included in the testing in 2017 under the name Code 1. This product showed an outstanding control (approx. 90%) compared with the old single azoles as well as the azole mixtures. Single azoles gave between 25 and 50% control. The better of the azole mixtures provided as an average 60% control. In the 2017 season prothioconazole and epoxiconazole performed very differently at the two sites; epoxiconazole performed best at Flakkebjerg, while prothioconazole performed best at the site near Horsens. This variation in control is in line with experiences also seen in other seasons where the better of the two has varied between years and sites.

Including data from all azoles across several years has shown a clear drop in efficacy from all azoles.

Compared with previous years the last four seasons have especially shown a reduced control from epoxiconazole and prothioconazole. Summarised across years, the trials represent results from two sites – Flakkebjerg and LMO (Horsens/Hadsten) (Figure 5, Table 8).

Looking at the performance of azoles during a longer time spell, the drop in performance began in 2014, was less pronounced in 2015 but continued in 2016 and 2017 (Figure 5). Some of the yearly variation can be linked to the levels of attack, but as discussed in chapter xx the Septoria populations have changed and do now include many more mutations than previously. The mutations are known to influence the sensitivity to azoles in general but are also seen to influence specific azoles differently. The drop in efficacy from tebuconazole has been known since about 2000 and has been quite stable. The drop in performance from tebuconazole used alone was not pronounced in 2017 where tebuconazole was seen as the only azole not dropping further; in fact, this product gained slightly better efficacy, which is seen as linked to higher proportions of D134G and V136A. Again in 2017 it was seen that the mixtures prothioconazole + tebuconazole and difenoconazole + propiconazole performed best as the two actives are seen to support each other, when it comes to controlling the different strains with different mutations.

In Table 9, trials with azoles are summarised acros many sites and indicate that the epoxiconazole and Septoria attack in 2017 was moderate to high. In line with data from the two previous seasons, triazo- les again showed a reduced control from epoxiconazole and prothioconazole. Mixtures with triazoles showed better efficacy than single azoles. Mixtures of SDHIs generally showed better control than azoles used as solo products.

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Table 7. Effects of triazoles on Septoria and yield responses following 2 applications in wheat. 2 trials (17329).

Treatments, l/ha % Septoria Yield and

Net yield hkg/ha

GS 33 GS 51-55 GS 75-77

Leaf 1 GS 72-73 Leaf 2

1. Rubric 0.5 Rubric 0.5 53.8 26.0 10.8 5.9

2. Proline EC 250 0.4 Proline EC 250 0.4 57.5 32.5 9.2 4.2

3. Juventus 90 0.5 Juventus 90 0.5 55.6 30.6 7.5 4.2

4. Bumper 25 EC 0.25 Bumper 25 EC 0.25 67.5 35.3 3.5 1.2

5. Folicur EW 250 0.5 Folicur EW 250 0.5 46.9 28.9 11.9 8.2

6. Proline EC 250 0.4 Armure 0.4 27.5 18.5 15.3 10.5

7. Prosaro EC 250 0.5 Prosaro EC 250 0.5 37.5 22.3 15.0 10.4

8. Proline Xpert 0.25 + Juventus 90 0.25 Proline Xpert 0.25 + Juventus 90 0.25 45.0 27.9 12.6 8.5

9. Code 1 Code 1 10.6 7.5 24.6 -

10. Untreated Untreated 86.9 48.4 77.9 -

No. of trials 2 2 2 2

LSD⁹⁵ 15.2 11.8 4.2

Table 8. Effect of triazoles on Septoria and yield responses following 2 applications in wheat. 8 trials from 4 seasons (14329, 15329, 16329, 17329).

Treatments, l/ha % Septoria

GS 33 GS 51-55 GS 73-75

Leaf 1 2014

GS 73-77 Leaf 1

2015

GS 73-77 Leaf 1

2016

GS 73-77 Leaf 1

2017

1. Rubric 0.5 Rubric 0.5 9.5 13.3 26.3 10.0

2. Proline EC 250 0.4 Proline EC 250 0.4 12.3 4.1 32.5 12.5

3. Juventus 90 0.5 Juventus 90 0.5 10.8 13.1 34.4 12.0

4. Bumper 25 EC 0.25 Bumper 25 EC 0.25 12.3 22.8 40.7 16.6

5. Folicur EW 250 0.5 Folicur EW 250 0.5 14.3 24.3 42.1 9.7

6. Proline EC 250 0.4 Armure 0.4 10.0 6.3 33.2 8.2

7. Prosaro EC 250 0.5 Prosaro EC 250 0.5 9.5 8.5 26.9 8.2

8. Untreated Untreated 25.0 41.2 54.4 21.2

No. of trials 2 2 2 2

(30)

Figure 4. Control of Septoria and yield increases from treatments with azoles. Average of 2 trials from 2017 (17329). Untreated with 87% Septoria attack on 1^st leaf and 48% on 2^nd leaf. Yield in untreated = 77.9

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Table 9. Average effect of epoxiconazole and prothioconazole for control of Septoria using full and half rates applied between GS 37 and 51. Data were extracted from different trial plans in which the two products were included – in most cases as reference products. Data are summarised for 2015-17. The lower table com- pares efficacy of Proline EC 250 with SDHI solutions, which shows that a major difference exists between solo azoles and SDHI solutions.

Opus/Rubric Proline EC 250

Flag leaf 2nd leaf Flag leaf 2nd leaf

Full rate (9 trials) 2015 65 63 73 68

Half rate (8 trials) 2015 59 48 68 55

Full rate (9 trials) 2016 64 50 72 48

Half rate (8 trials) 2016 48 37 33 32

Full rate (4 trials) 2017 73 77 68 66

2017 Flag leaf 2nd leaf

Proline EC 250 0.8 58.3 36.8

Viverda 1.25 + Ultimate S 1.0 83.7 71.2

Aviator Xpro 1.0 85.1 72.4

No. of trials 4 5

Figure 5. Per cent control of Septoria using 2 half rates of different triazoles. Average of 2 applications at GS 33-37 and 51-55.

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EuroWheat project

The EuroWheat project, which was initiated in 2015, has included a total of 40 field trials in wheat, following one protocol with 4 azoles used alone or in mixture. Results were published in 2017 (Jørgensen et al., 2017).

The project continued in 2017 with a new protocol, which also included azoles tested in 6 countries.

The project aims at testing the current European situation regarding control efficacies of different single triazole products against wheat diseases with focus on Septoria.

The compositions of CYP51 mutations of Septoria populations were investigated, and isolates were ana- lysed for EC₅₀ values for main triazoles. The data are being presented on the platform www.EUROwheat.

au.dk. The test sites are shown in Figure 6.

The Danish trial was carried out in the cultivar Hereford, and a clear difference was seen between the tested products. Revysol was included in the trial and outperformed the other tested azoles (Table 10).

Also pyraclostrobin was included, which gave results in line with the weaker of the azoles. It was seen as a slight surprise that Folicur EW 250 performed so well in this trial, which most likely is the result of Figure 6. Locations of 11 trials carried out in 2017.

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Table 10. % control of Septoria using different azoles in the EuroWheat project. Yield and yield incre- ase. (17309).

Treatments, l/ha % Septoria %

GLA Yield and

GS 37-39 GS 73

Leaf 1 GS 73

Leaf 2

1. Untreated 31.3 82.5 7.7 78.6 -

2. Code 1 (Revysol) 1.5 4.5 10.5 55.7 15.7 -

3. Opus Max 1.5 6.5 16.3 30.9 10.4 -

4. Proline EC 250 0.8 10.5 32.5 32.2 12.1 7.8

5. Folicur EW 250 1.0 5.5 13.0 58.6 13.6 10.6

6. Caramba 60 1.5 12.5 31.3 19.2 8.8 -

7. Score 250 EC 0.5 11.8 30.0 23.4 8.4 -

8. Tilt 250 EC 0.5 22.5 70.0 8.6 5.2 3.6

9. Code 2 (Comet 200) 1.25 25.0 76.3 12.3 4.6 -0.6

No. of trials 1 1 1 1 1

LSD₉₅ 7.2 13.5 6.8 4.6

Figure 7. Control of SEPTTR. a) % control of SEPTTR on flag leaf – average of 5 trials. Treatments are reflecting preventive treatments. Assessments were carried out at GS 69-85, 30-44 DAA. b) % control of SEPTTR on 2^nd leaf – average of 8 trials. Treatments are reflecting curative treatments. Assessments were carried out at GS 69-73, 30-43 DAA.

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Comparison of available solutions for ear treatments (17325)

In line with trials from previous years, treatments with different fungicides were tested when applied during heading (GS 51-55) (Table 11). A cover spray was applied at GS 32 using a low dose of Prosaro EC 250 (0.35 l/ha). The control of Septoria on the flag leaf varied between 30 and 85% control. Elatus Era and GF-3307 provided the best control, and 0.4 l/ha Proline EC 250 and 0.5 l/ha Rubric gave least control (Figure 8). The benefit from adding SDHI was clear when compared to using triazoles alone. This is illustrated in Figure 9, which indicated that the per cent point between Viverda and Rubric is increasing.

This is not because SDHIs perform better but is a result of the reduced efficacy of triazoles.

Yield increases in all 3 single trials were significant. As an average of the 3 trials the best yield increases were approximately 17 hkg/ha and were measured from applying 1.0 l/ha GF-3307. This was followed by 0.5 l/ha Elatus Era, which also provided both excellent control and high yield responses.

Solutions with boscalid and fluopyram (Bell, Viverda and Propulse SE 250) also performed better than the single azole solutions. Prosaro EC 250 (0.35 l/ha) used at the early timing as a single treatment provided insufficient control and did only add very little to the final net yield.

Table 11. Effect of ear applications for control of Septoria in wheat. 3 trials (17325).

Treatments, l/ha % Septoria %

GLA Yield and increase

hkg/ha

GS 31-32 GS 51-55 GS 73-77

Leaf 1 GS 71-75 Leaf 2

1. Prosaro EC 250 0.35 Rubric 0.5 20.5 26.3 17.8 7.9 3.7

2. Prosaro EC 250 0.35 Proline EC 250 0.4 26.1 29.8 16.9 6.9 2.6

3. Prosaro EC 250 0.35 Bell 0.75 13.3 18.0 35.9 13.9 8.2

4. Prosaro EC 250 0.35 Armure 0.4 22.1 22.1 23.4 9.9 5.8

5. Prosaro EC 250 0.35 Viverda + Ultimate S 0.75 + 0.75 13.4 18.2 35.0 12.5 6.4

6. Prosaro EC 250 0.35 Viverda + Ultimate S 1.25 + 1.0 6.8 12.9 44.4 15.3 6.9

7. Prosaro EC 250 0.35 Bell + Prosaro EC 250 0.375 + 0.25 13.8 17.9 34.8 12.9 8.0

8. Prosaro EC 250 0.35 Proline Xpert 0.5 25.2 32.7 21.6 7.9 3.6

9. Prosaro EC 250 0.35 Propulse SE 250 1.0 10.3 15.1 33.8 13.7 7.2

10. Prosaro EC 250 0.35 Propulse SE 250 0.5 20.1 27.9 21.8 9.6 5.1

11. Prosaro EC 250 0.35 Proline Xpert + Viverda 0.25 + 0.375 16.5 22.5 25.9 10.5 5.5

12. Prosaro EC 250 0.35 GF-3307 1.0 9.1 12.8 47.8 17.0 -

13. Prosaro EC 250 0.35 Elatus Era 0.5 6.1 14.9 50.9 15.4 -

14. Prosaro EC 250 0.35 - 32.1 42.5 8.4 2.0 0.2

15. Untreated - 48.3 58.8 2.2 80.9 -

No. of trials 3 3 3 3 3

LSD₉₅ 5.2 7.5 15.8 3.4 -

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A summary of data from 5 seasons is given in Table 12, and the yield response from 2 seasons is shown in Figure 10. The net yield as an average of the 15 trials is varying from 4.9 to 6.9 hkg/ha for the most effective solutions. The data from two seasons given in Figure 10 show a similar pattern, but here also Propulse SE 250 is included – giving control that is slightly inferior to solutions with Bell and Viverda.

Figure 8. Per cent control of Septoria and yield responses using half rates of several solutions (17325).

Average following a T1 treatment and 1 application at GS 45-51.

Applied Crop Protection 2017

APPLIED CROP PROTECTION 2O17

AU

Applied Crop Protection 2017

APPLIED CROP PROTECTION 2O17

AU

APPLIED CROP PROTECTION 2O17

Contents

Preface

Applied Crop Protection 2017

I Climate data for the growing season 2016/2017

1. Disease attacks in 2017

Applied Crop Protection 2017

II Disease control in cereals

1. Control of diseases in winter wheat