ryegrass. 3. Speckled leaf 4. Fungicides in crops trials. (See FAR target? In cereal the same. disease,

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1 Fridy 6 December Keywords: Yield potentil, Speckled lef blotch, Lef rust, Blind seed disese in ryegrss, Stem rust in ryegrss. This edition includes:. Hrnessing the yield potentil. Lef rust on the move. Speckled lef blotch (Septori tritici blotch) in whet. Fungicides in perennil ryegrss seed crops. Hrnessing the yield potentil With recent rinfll events t key growth stges this spring, crops hve good yield potentil. At the FAR Arble Site in Mid Cnterbury, there is little difference between the drylnd nd equivlent irrigted trils. Where crops hve excellent yield potentil, mke sure tht input strtegies hve been djusted to hrness tht potentil. Is your nitrogen optiml? Cerel crops cn give yield responses up to er emergence (GS 9) (See FAR Cropping Strtegies Issue Spring ). Will higher yield potentil reducee your grin protein below trget? Cerel crops cn give protein increses from folir nitrogen up until erly grin. Is my cultivr susceptible to disese? Check your disese rtings nd mke sure tht fungicide cover is sufficiently robust to protect the crop for potentilly longer grin fill period.. Lef rust on the move In cerel crops with no fungicide or poor fungicide cover lef rust is the most prominent disese t present. Whilst theree re seprte specie forms tht infect whet nd brley, the conditions tht drive the disese in the two cerels re the sme. Wrmer conditions in the second hlf of the growing seson fvour the spred of this irborne disese, providedd there is periodic rinfll to boost crop cnopy humidity. Where crops re yet to receive their finl fungicide ppliction mke sure you hve sufficient cover both in terms of rte nd product to protect your crop from this disese. The product mixtures of Opus nd Amistr nd Opus nd Comet hve been prticulrly strong on lte seson lef rust.

2 In sesons with n extended grin fill period control of this disese hs been ssocited with yield increses from fungicides pplied t much lter timings thn previously consideredd effective. In irrigted winter whet these so clled T (Timing ) fungicides hve been pplied in mid lte In seson such s this, lter sown utumn whet nd spring whet my benefit from incresing the December, however plese note the withholding periods when considering fungicides. rtes of the er wsh fungicide pplied t er emergence GS 9. In lter sown spring sown brleys the rtes of the second fungicide pplied t GS 9 9 ( st wns er emergence) my lso need to be incresed if cultivrs re susceptible to disese. Conquest susceptibility Plese remember tht the populr milling whet cultivr Conquest is now susceptible to lef rust, following the discovery of new pthotype (strin) lte lst seson. Lef rust in utumn sown whet smpled from the FAR Arble Site this week (note the generl yellow chlorosiss ssocited with high levels of infection) Close up of lef rust pustultion. Speckled lef blotch (Septori tritici blotch) in whet This wet wether hs lso been more problemtic this seson, llowing reserchers gret opportunity to look t cultivr resistnce. The following dt hs been kindly provided by Mtthew Cromey from Plnt nd Food Reserch, Lincoln, who hs been ssessing utumn sown feed nd biscuit whets in FAR s Cultivr Performnce Trils (CPT).

3 Tble. % Speckled lef blotch infection in whet cultivr trils in CPT Feed & Biscuit whet trils % Speckled lef blotch infection in whet cultivr trils Tril Site Chertsey St St Chertsey Chertsey* St Dte ssessed Clire Einsteinn Excede Phoenix Richmond Svnnh Wknui CRWT CRWT68 KWW KWW KWW KWW6 KWW8 / / 8 / / 6 6 / / * Untreted with fungicide. All other sites ssessed hd fungicides pplied Following comments courtesy of Mtthew Cromey, Plnt & Food Reserch St / Temuk / Svnnh: the stnd oulso looking firly susceptible (not s bd s Svnnh). Richmond: modertely susceptible consistently some disese in the trils. most susceptible; the one to wtch out for. Excede: Einstein: very vrible between the trils, nd we hve noted this before. Perhps there is rce effect? Wknui: modertely resistnt generlly low disese levels. Phoenix: modertely resistnt generlly low disese levels. Clire: we hve clled Clire MS in the pst, but this yer it looks similr to Wknui nd Phoenix, so more like n MR.. Fungicides in perennil ryegrss seed crops Stem rust is currently being observed in turf type perennil ryegrss crops throughout mid Cnterbury. Mny of these cultivrs re close to mid flowering, nd given current wether ptterns will require trizole fungicide for the prevention of blind seed disesee nd the control of stem rust.

4 Blind seed disese Blind seed disese is fungus which infects grsses nd cuses loss of germintion. The germintion issues re ssocited with both primry infection nd secondry infection. Primry infection occurs t flowering when the florets re open for pollintion. During this time spores re relesed from ner the soil surfce nd infect the open flowers. Trizole fungicides re the primry form of control during the primry infection phse. Appliction timing should occur when mximum numbers of florets re open for pollintion. Secondry infection occurs during wet wether when the initil infection develops n ooze which under prolonged dmp conditions cn move from one spikelet to nother on the seed hed. Crbendzim pplied t frequent intervls helps to protect the crop from secondry infection. This my men treting fter ech rinfll event. For further informtion refer to FAR Herbge Arble Updte, No Stem rust Turf ryegrss cultivrs, especilly those with inherent US germplsm re more susceptible to stem rust infectionn in New Zelnd. In six previous FAR turf ryegrsss trils n verge seed yield incresee of % ( kg/ h) ws reported from fungicides; rnging from to 9%. In 9/ there ws severe stem rust infection nd lrge seed yield responsee (see Appendix Tble ). This yer new clsss of fungicides hve become commercilly vilble; in the form of Seguris Flexi (Syngenti) with isopyrzm s the ctive ingredient. A tril in / included some previous comprisons of one versus multiple pplictions nd the use of trizole strobilurin mixes. Results The seed yield verged kg/ /h cross ll tretments in the tril. There ws low level of disese pressuree nd the seed yield of the nil fungicide control ws kg/h. The highest seed yield ws kg/h from Proline + Comet pplied times (Tble ). This is the third yer in row tht this hs been the highest yielding tretment; lthough it ws not significntly different from mny others. The seed yield of single fungicide ppliction ws in the rnge of 99 to kg/ /h with n verge reltive seed yield (RSY) of 6 compred to the control (= ); while the three ppliction tretments n verged 8 kg/h with RSY of 8 (Tble ). The seed yield gin from the best fungicide tretment ws kg/h; the second lowest from seven trils in turf ryegrss. Over the seven yers of trils in turf ryegrss there hve been three yers with severe infections where fungicides hve incresed seed yields by between nd kg/h. In the other four yers seed yield increses from fungicide ws between 8 nd 8 kg/ /h.

5 Tble. Tretments, fungicides nd rte (l/h), ppliction dtes, mchine dressed seed yield, difference (LSD %) nd reltive seed yield (RSY). Tmt Dec hed emergence Dec + Jn mid flower + lte flower Yield kg/h Difference RSY c. Opus. Proline.6 S.F* 99 c b b 99. Fndngo 6. Opus +. Comet. Proline +. Comet. Fndngo. Opus +. Comet. Proline +. Comet S.F. 9.6 S.F. +. Comet.6 S.F. +. Proline. Accuro +. Tsr *S.F.=Seguris Flexi.6 S.F..6 S.F. +. Comet.6 S.F. +. Proline. Accuro +.Tsr 8 Men sig *** CV%.9 LSD % Higher seed yields were correlted with lower stem rust incidence nd with higher flg green lef re nd higher stem sheth green lef re. Contct us Rob Crigie Richrd Chynoweth 86 6 crigier@fr.org.nz chynowethr@fr..org.nz NOTE This FAR Crop Action Report ws prepred with current informtion t the time of publiction. Neither FAR or its stff my be held lible for ny crop dmge or loss from interprettion of the informtion contined within this or ny edition of Crop Action. Informtion contined in this Crop Action is intendedd s guide only. Plese edit your profile informtion if you do not wish to receivee this emil Plese dvise if you chnge your emil ddress.

6 Appendix Tble A. Seed yield nd tretments from 9/ tri Tmts MD Yield Hed emergence Flowering + dys + 8 dys (kg/h) 8 e 6. Acnto d. Amistr 88 d. Proline 9 c.8 Comet c.8 Proline cb. Fndngo c 9. Proline +. Acnto c 8. Proline +. Amistr cb. Proline+. Comet b. Proline. Proline. Proline. Proline 6. Fndngo. Fndngo. Fndngo. Fndngo 9. Proline+. Amistr. Proline+. Amistr. Proline+. Amistr. Proline+. Amistr 8. Proline+. Acnto. Proline+. Acnto. Proline+. Acnto. Proline+. Acnto 8. Proline+. Comet. Proline+. Comet. Proline+. Comet. Proline+. Comet 9 CV% 6. LSD % 98 Men sig ***

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