Integreeritud taimekaitse kasutamine odral ja kaeral

Haiguskindlad sordid ja fungitsiidid omavad sarnaseid mõjusid haigustekitajate populatsioonide piiramisel ja taimehaiguste tõrjel. Taimede haiguskindluse ja fungitsiidide oskuslik kasutamine võimaldab tagada taimehaiguste efektiivse ja keskkonnasäästliku tõrje. Haigustekitajad võivad geneetiliselt muutuda, mistõttu väheneb taimede haiguskindlus või fungitsiidi toime efektiivsus. Väitekirjas esitatakse taimekaitse soovituste teaduslikult põhjendatud praktilised täpsustused odral võrklaiksuse (Pyrenophora teres) ja kõrreliste pruunlaiksuse (Cochliobolus sativus), kaeral kroonrooste (Puccinia coronata) ja pruunlaiksuse (Pyrenophora avenae) kohta. Patogeeni virulentsuse monitooringu katses (1996-2002) selgitati uued virulentsed kaera kroonrooste rassid. Selgus, et rassispetsiifiline resistentsus on võrreldes 1996.a. vähenenud kõige enam diferentsiaatorliinidel Pirol, Pc 58, Pc 61 ja sortidel Alo, Jaak, Edith. Odra ja kaera haiguste katsetes (2003-2005) selgitati sordi resistentsuse ja fungitsiidi kooskasutamise võimalusi efektiivse haigustõrje tagamiseks, sordi resistentsuse täiendamist fungitsiidide vähendatud dooside kasutamisega epidemioloogiliselt olulisel ajal. Odral oli efektiivsem triasooltüüpi tebukonasool fungitsiidi täisdoosi jagatud pritsimine. Ka programmi I-Taimekaitse soovitatud kulunormid on piisavad õigeaegse tõrje korral, kuna arvestavad sordi resistentsuse ja ilmastiku näitajatega. Haiguskindlamal sordil on erinevate normide kasutamisel tõrjeefektiivsused sarnased, seega täisnormi kasutamine on õigustatud ainult vastuvõtliku sordi puhul haiguse levikule soodsal aastal. Kaera pruunlaiksuse infektsioon vähenes oluliselt täisnormi kasutamisel lipulehe kuni viljatupe avanemise kasvufaasides haigusele vastuvõtlikumatel sortidel. Kroonrooste virulentsuse spekter ja sellele soodsad levimise tingimused mõjutasid pritsimisaja efektiivsust. Oluline on pritsimise ajastamine, mis põhineb taimehaiguste survele. Keemilise tõrje mõju jääb nõrgaks, kui haigustekitaja juba kahjustab taime, kuid väldib efektiivselt uute eoste põlvkonda. Taimekaitse ja tootmise strateegiad on kõrgel tasemel, kui nad on kohandatud konkreetse sordi vajadustele konkreetsetes tingimustes. Enamsaagi väärtuse ja majandusliku tasuvuse analüüs näitab, et fungitsiidi kasutamine odral on majanduslikult kasulik väiksema haiguskindlusega sortidel mõlemas töödeldud variandis. Kuigi täisnormiga pritsimisel saadakse suure tõenäosusega suurim saak, on keskmise haiguse levikuga aastatel kulutused tõrjele suuremad, võrreldes saagilisast saadud kasumiga. Odra katses (2004-2006) selgitati kasvuaegse haigustõrje mõju seemnega edasikanduvate seente nakkuse vähendamisele. Selgus, et sortide ja fungitsiidide valikuga saab lisaks kasvuaegsete taimehaiguste tõrjeefektiivsuse tõstmisele mõjutada järgmistesse aastatesse edasikanduvate fütopatogeensete ja saprotroofsete seente esinemist. Kaera katses (2006-2008) selgitati väetisfooni ja fungitsiidide kasutamise mõju kaerahaigustele. Selgus, et ainult külvieelse väetamise korral korreleerub kroonrooste intensiivsus tugevasti aasta ilmastiku, sordi resistentsuse ja mulda viidud väetise kogusega. Pruunlaiksuse esinemist mõjutab aasta, väetamine, sordi haiguskindluse ja aasta koosmõju, aasta ja väetamise koosmõju. Intensiivsel foonil väetamise ja taimekaitsega oli suurim seos aasta ja kroonrooste esinemise vahel.Publication of this thesis is supported by the Estonian University of Life Sciences and by the Doctoral School of Earth Sciences and Ecology created under the auspices of European Social Fund

The advantage of Decision Support System for managing spring barley disease in Estonia

ArticleA Decision Support System (DSS) I - Taimekaitse focusing on use of timely applied and reduced fungicide rates in control of cereal diseases has been tested in field trials since 2003 . We compared the conventional treatment and the DSS - based spray practices in 18 field trials in five agricultural locations over 7 - year period. Efficacy of the control of net blotch caused by Pyrenophora teres (Drechsler, am Drechlera teres Sacc. Shoem), the main fungal disease in spring barley has been tested to determine the economic advantage of DSS use. Compared with the conventional spray practices, the advantage I - Taimekaitse resulted in reduction of application doses by 30 to 60% of the registered rate. According to I - Taimekaitse , the fungicides were applied mainly between heading and flowering growth stages (GS 55 – 65), whereas traditional routine spraying is commonly made at booting (GS 37 – 49) . The experiment clarifies the cost - benefit of using DSS - based approach in barley disease management with average yield increase above the control in 12.8% and above the conventional treatment in 14.1%. I - Taimekaitse gave competitive disease control and average yield output reduction compared with conventional practice by 9%. In general the Treatment Frequency Index applied in conventional treatment was 0.65 and in DSS 0.41. Although the cost of treatment expense in DSS was 20% less compared with conv entional practice, the performance of conventional used spray practices was outstanding in economic return

Effect of seed treatment with biostimulants and fungicide on development and yield potential of spring wheat

ArticleSaabunud / Received 18.04.18 ; Aktsepteeritud / Accepted 18.06.18 ; Avaldatud veebis / Published online 20.06.18 Vastutav autor / Corresponding author: Pille Sooväli e-mail: [email protected] the years 2013–2014, the Estonian Crop Research Institute conducted a field trial in order to investigate the effect of seed treatment with seaweed based biostimulants and fungicide on spring wheat (Triticum aestivum L.). Seed treatments of the varieties 'Specifik' and 'Uffo' were used with (fludioxonil + cyproconazole) and without fungicide (biostimulants Raykat Start, Fertigrain Start) and mixture (fludioxonil + cyproconazole + Fertigrain Start), and untreated seed as the control were evaluated. The objective of this study was to assess the development, growth and yield potential of spring wheat under the action of biostimu-lants, with the presence and absence of treatment of seed with fungicide. In the laboratory, we measured: 1) the length of roots and shoots of germinated seed, 2) total number and total weight of grains per ear, 3) one kernel weight per ear. In the field, we evaluated: 4) plant height, 5) the number of generative tillers that were counted in one linear meter at physiological maturity. Results showed that the application of biostimu-lants and fungicide for seed treatment influence the wheat early development and growth of radicle. They can increase the root length however the biostimulants and fungicide can have an opposite effect on germination of wheat seed. They can decrease the length of the first true leaf emerged from coleoptile. We noticed that seed treatment with Raykat Start increased significantly (p ≤ 0.05) the plant height of variety 'Specifik' compared to untreated. There was tendency that by using both biostimu-lants for seed treatment of variety 'Specifik' more generative tillers emer-ged, but this was not significant compared with untreated. The results suggested that solely the seed treatment with biostimulants and fungicides, there was no effect on total grain number and total grain weight per ear of wheat varieties

Resistance developments in Estonia’s population of pollen beetles (Brassicogethes aeneus)

A total of 111 local pollen beetle populations were collected from both winter and spring oilseed rape fields, in the main oilseed growing regions of Estonia between 2015−2019. The objective was to analyse the insecticide-susceptibility of the pollen beetle population (in the form of Brassicogethes aeneus). The pollen beetle samples were tested for sensitivity to lambda-cyhalothrin, thiacloprid, and chlorpyrifos. The efficacy of the tested insecticides varied considerably by region. We observed a clear decrease in susceptibility to lambda-cyhalothrin and thiacloprid, but sensitivity to chlorpyrifos remained stable throughout the period between 2015 and 2019. Amongst the tested samples in that period, a total of 3% were classified as susceptible to lambda-cyhalothrin, 18% as moderately resistant, 70% as resistant, and 7% as highly resistant. In the case of thiacloprid, 21% of the samples were highly susceptible to the insecticide, 39% were susceptible, and 41% had reduced levels of susceptibility to the insecticide. The information which was presented tended to confirm the ongoing evolution of insecticide resistance in the B. aeneus population in Estonia, while also highlighting the importance of data-based decisions when optimising insecticide resistance management in the field

Hea põllumajandustava

Põllumajandussektoris ei ole võimalik keskenduda üksnes klassikalises mõttes efektiivsele tootmisele. Loodus- ja elukeskkonda hoides peab järjest suuremal määral panustama keskkonnahüvedesse. On vaja tagada kliimamuutuste mõjudega arvestamine, põhja- ja pinnavee hea seisund, tasakaalustatud maa- ja mullakasutuse jätkusuutlikkus, looduse elurikkuse ja elupaikade säilimine ning inimeste ja loomade tervise ohtude ärahoidmine. Hea põllumajandustava on põllumajanduse üldtunnustatud reeglistik, mis koosneb õigusaktidega määratud keskkonnanõuetest ja soovituslikest juhistest. Keskkonnanõuete ja soovituslike juhiste järgimine vähendab keskkonna reostumise või keskkonnaseisundi halvenemise ohtu. Kõigile põllumajandustootjatele mõeldud hea põllumajandustava soovituslike juhiste järgimine on vabatahtlik. Käesolev juhendmaterjal on kolmas sellelaadne väljaanne Eestis. Esimene Hea põllumajandustava anti Keskkonnaministeeriumi ja Põllumajandusministeeriumi koostöös välja 2001. aastal. Materjale uuendati 2006. aastal lähtudes sel ajal kehtivatest õigusaktidest ja Euroopa Liidu liikmesriikide analoogilistest dokumentidest. Riigikogu võttis 2019. aastal vastu uued veeseaduse ja jäätmeseaduse eelnõud. Uute seaduste ja nendega seotud rakendusmääruste vastuvõtmisega jõudis lõpule üle 10 aasta kestnud keskkonnaõiguse korrastamise protsess, mille käigus töötati välja süstematiseeritud ja ühtlustatud keskkonnaõiguse kontseptsioon. Käesolevas väljaandes on lähtutud 2020. aasta alguses kehtivatest õigusaktidest. Selguse huvides peab märkima, et kuna tegemist ei ole ametlikult kinnitatud dokumendiga, ei ole käesolev väljaanne hea põllumajandustava eeskiri Euroopa Ühenduste Nõukogu nitraadidirektiivi (91/676/EMÜ) tähenduses. Nimetust „Hea põllumajandustava“ kasutame näitamaks seost kahe varasema põllumajanduse keskkonnanõudeid ja soovituslikke juhiseid koondava samanimelise trükisega. Materjali jälgitavuse huvides on kohustuslikud nõuded välja toodud punase tekstiga ja soovituslikud nõuded rohelise tekstiga.Autoriõigus kuulub Eesti Taimekasvatuse Instituudile, varalised õigused kuuluvad materjali tellijale. Materjal valmis Maaeluministeeriumi ning Põllumajanduse Registrite ja Informatsiooni Ameti (PRIA) tellimusel 2020. a. Kõik autoriõigused on kaitstud

A Survey Using High-Throughput Sequencing Suggests That the Diversity of Cereal and Barley Yellow Dwarf Viruses Is Underestimated

Worldwide, barley/cereal yellow dwarf viruses (YDVs) are the most widespread and damaging group of cereal viruses. In this study, we applied high-throughput sequencing technologies (HTS) to perform a virus survey on symptomatic plants from 47 cereal fields in Estonia. HTS allowed the assembly of complete genome sequences for 22 isolates of cereal yellow dwarf virus RPS, barley yellow dwarf virus GAV, barley yellow dwarf virus PAS (BYDV-PAS), barley yellow dwarf virus PAV (BYDV-PAV), and barley yellow dwarf virus OYV (BYDV-OYV). We also assembled a near-complete genome of the putative novel species BYDV-OYV from Swedish samples of meadow fescue. Previously, partial sequencing of the central part of the coat protein gene indicated that BYDV-OYV represented a putative new species closely related to BYDV-PAV-CN, which currently is recognized as a subtype of BYDV-PAV. The present study found that whereas the 3′gene block of BYDV-OYV shares the closest relationship with BYDV-PAV-CN, the 5′gene block of BYDV-OYV shows the closest relationships to that of BYDV-PAS. Recombination detection analysis revealed that BYDV-OYV is a parental virus for both. Analysis of complete genome sequence data indicates that both BYDV-OYV and BYDV-PAV-CN meet the species criteria of genus Luteovirus. The study discusses BYDV phylogeny, and through a systematic in silico analysis of published primers for YDV detection, the existing gaps in current diagnostic practices for detection of YDVs, proposing primer pairs based on the most recent genomic information for the detection of different BYDV species. Thanks to the rising number of sequences available in databases, continuous updating of diagnostic primers can improve test specificity, e.g., inclusivity and exclusivity at species levels. This is needed to properly survey the geographical and host distribution of the different species of the YDV complex and their prevalence in cereal/barley yellow dwarf disease epidemics

The severity of diseases of faba bean depending on sowing rate and variety

Little research has been published about the occurrence of diseases in faba bean such as chocolate spot, ascochyta blight, or rust in Northern Europe. There is also little data about the impact of sowing rate or variety on disease development. Therefore, the purpose of this study was to assess the impact of variety and seeding rate on disease severity at Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie (BBCH) 75 (which is when 50% of pods have reached full length). Five varieties were tested from multiple Northern European countries: Bauska (Latvia), Jõgeva (Estonia), Gloria (Sweden), Julia (Sweden) and Lielplatones (Latvia). Two sowing rates were used: 30 seeds m-2 (100%) and 36 seeds m-2 (120%). The sowing rate did not influence disease severity. The varieties which were most damaged by chocolate spot were Gloria and Jõgeva and the varieties least damaged were Julia and Lielplatones. Variety did not influence the severity of ascochyta blight. The variety most damaged by rust was Gloria and the variety least damaged was Julia. The varieties most susceptible to disease Gloria and Jõgeva while Julia was least susceptible. Thus, Julia can be recommended for faba bean production in Northern Europe

The severity of field pea diseases depending on sowing rate and variety

Six varieties of field pea (Pisum sativum L.) were sown at two sowing rates over two years to assess the impact on disease occurrence in a Baltic climate. The varieties used were Bruno (Latvia), Capella (Sweden), Clara (Sweden), Kirke (Estonia), Onward (Greece), and Vitra (Latvia). The two sowing rates were 120 seeds per m2 and 144 seeds per m2. The increase in sowing rate by 20% did not influence field pea diseases. Variety influenced the incidence of disease in field pea. The varieties most damaged by pod spot (Ascochyta blight caused by Ascochyta spp.) were Vitra and Onward and least damaged were Bruno and Clara. The variety most damaged by downy mildew (caused by Peronospora viciae) was Vitra and least damaged was Bruno. The variety most damaged by white mould (or Sclerotinia rot caused by Sclerotinia sclerotiorum (Lib.) de Bary) was Onward. The varieties that had the most disease damage were Vitra and Onward, while least susceptible were Clara and Bruno. Therefore, Clara and Bruno are recommended for field pea production in a Baltic climate

Ramularia collo-cygni: a new pathogen spreading in barley fields in Estonia

Ramularia leaf spot (RLS) caused by the fungus Ramularia collo-cygni (Rcc) is affecting barley fields throughout temperate regions worldwide. The first finding of RLS in Estonia was reported on spring barley in 2012 and since then the area of RLS infection has been widening in Estonia. This work has been carried out to monitor the natural infection of Rcc in two winter barley cultivars and to follow artificial fungal infection by a PCR-based assay. Using our approach, we could detect presence of the fungal pathogen in barley leaves before the appearance of disease symptoms at early growth stages. Response of two tested cultivars to Rcc infection in the field conditions was different, showing genotype-environment interaction in the development and spreading of Rcc. In harvested grain samples at the end of growing season no Rcc infection was detected. The role of external inoculum, Rcc conidia transmitted from various grasses (Poaceae) growing next to crop fields, is discussed. These results provide further insight into the epidemiology of Rcc