BACTERIAL PLANT SYMBIOTIC NITROGEN FIXATION • Atmospheric nitrogen is reduced to ammonia using energy from plant photosynthesis. • Occurs within cells of nodules formed on legumes by rhizobia and on shrubs and trees by frankia. • Occurs within stem gland cells of angiosperms (Gunneraceae) invaded intracellularly by nostoc cyanobacteria. • Requires the formation of membrane-bounded vesicles containing nitrogen-fixing bacteria within the cytoplasm of plant cells. 2/7/2019 Event Name and Venue 31
2/7/2019 Event Name and Venue 33
BORLAUG’S DREAM “In my dream I see green, vigorous, high-yielding fields of wheat, rice, maize, sorghum and millet which are obtaining, free of expense, 100 kilogram of nitrogen per hectare from nodule-forming, nitrogen-fixing bacteria … This scientific discovery has revolutionized agricultural production for the hundreds of millions of humble farmers throughout the world, for they now receive much of the needed fertilizer for their crops directly from these little wondrous microbes that are taking nitrogen from the air and fixing it without cost in the roots of cereals, from which it is transformed into grain … “ The Green Revolution: Peace and Humanity Norman E Borlaug 1970 Nobel Peace Prize 2/7/2019 Event Name and Venue 34
Ability to colonise any crop plant – has a simple natural route of entry Ability to colonise each cell of the plant forming a symbiotic relationship with the plant- Ability to move throughout the plant - not restricted to just the roots Ability to fix-nitrogen under a range of conditions – including different fertiliser regimes Have additional plant growth benefits Harmless to mankind, animals and environment 35
If nitrogen-fixing bacteria (blue dots) penetrate through the cell wall (shaded) they can become internalized in vesicles by endocytosis.
THE NITROGEN BOUNDARY Creating new strains of rice, wheat and corn that fix their own nitrogen could achieve in the twenty-first century what the Haber-Bosch breakthrough managed for the twentieth, and without the serious environmental drawbacks of industrial ammonia production. Environmentalists should not be scared of this prospect; they should welcome it. There can be no more important task than feeding people whilst protecting the planet. We must use the best of science and technology to help us to achieve this vital aim. The God Species Mark Lynas (2011) How the Planet can Survive the Age of Humans Thursday, February 7, 2019 Event Name and Venue 37
Professor Johanna Döbereiner discoverer of Gluconacetobacter diazotrophicus .
Gluconacetobacter diazotrophicus • An “extraordinary”, nitrogen-fixing, acid tolerant, IAA producing bacterium isolated from sugar cane juice (Döbereìner, 1988). It is non-nodulating. • Possesses no nitrate reductase and nitrogen fixation is not inhibited by nitrate. Ammonium shows only partial inhibition. Excretes half of the nitrogen fixed in a form potentially available to plants. • Plant cell wall penetration facilitated by bacterial genes encoding a ß-expansin and an endo-1, 4-ß-glucanase. • Fixes nitrogen aerobically. Its production, from sucrose, of a mucoid levan fructan is an effective resistance to oxygen diffusion. 2/7/2019 Event Name and Venue 39
MICROSCOPIC INVESTIGATIONS OF THE INTERACTION OF G. diazotrophicus (Gd) WITH CEREALS AND OTHER NON-LECUME CROPS • Using seedlings grown aseptically in sucrose containing media. • Inoculation with very low numbers of ß-Glucuronidase (gus) labelled Gd enabled histochemical localisation of blue- staining Gd. • Microscopic examination of the sections of resin embedded inoculated roots, stems and leaves showed blue-staining intracellular Gd in the cytoplasm, and systemic colonization. • Electron microscopy confirmed that blue-staining Gd in the cytoplasm were within membrane-bounded vesicles. • Similar results were obtained for maize, rice, wheat, oilseed rape and tomato. • Field evaluation of reductions possible in the use of synthetic nitrogen fertilizers are in progress. 2/7/2019 Event Name and Venue 40
• Section of maize root showing intracellular blue- stained G. diazotrophicus (Bar 10 µm).
Section of maize leaf showing blue-stained G. diazotrophicus associated with chloroplasts.
THE FORMATION OF DIAZOCHLOROPLASTS Very close association of chloroplasts with nitrogen-fixing bacteria in leaf cells could result in their fusion to form a “diazochloroplast”. This close association could increase photosynthetic efficiency, by decreasing photorespiration, with resulting increase in crop yields. 2/7/2019 Event Name and Venue 43
Direct evidence of Gd fixing nitrogen • University of Nottingham, Azotic Technologies and University of Manchester collaboration on the use of labelled 15 N 2 to demonstrate nitrogen fixation in Gd with the the NanoSIMS microscope. • Gd in vitro culture (red and yellow/green) with a non nitrogen fixng bacteria (blue) Enterococcus faecalis . 2/7/2019 Event Name and Venue 44
Gd-Nitrogen fixation in maize leaves using NanoSIMS microscopy University of Manchester University of Nottingham AzoticTechnologies Ltd 15 N 2 is present at elevated levels in maize leaves. red = high levels of labelled 15 N 2, yellow = medium levels and green = lowest levels. 45
Rice Section of rice root showing intracellular colonies of blue-stained G. diazotrophicus associated (Bar 10 µm).
Tomato Section of tomato root showing blue-stained G. diazotrophicus (Bar 10 µm).
Efficacy of Intracellular Colonisation - Validation Staple food crops: Wheat, maize and rice Commodity crops: Oilseeds: Every crop species Tea, cotton and coffee evaluated with Oil seed rape N-Fix Successfully (Oil Palm, 2015) colonised by Gd! Forage crops: Horticultural crops: Pasture grass Tomato and potato and white clover Ornamental and amenity: Turf grass
Example: Independent Field Trials Results Research undertaken by Contract Research Organisations
Example: Independent Field Trials Results Research undertaken by Contract Research Organisations
Initial Rice Field Trials – Vietnam 2017 In the first trial yields at all levels of Nitrogen fertiliser were 30% higher, than untreated controls. In Trial 2 the yield increase was 9-15% 52 52
Grain protein improvements Summarizing across all the 2016 UK (10), US (3) and Canada (2) field trials, N-Fix increase grain protein at all N fertiliser levels tested by 4%. 53 53
Implications of Yield and Fertiliser Benefits? Moving from a nitrogen pollution reduction and maintenance of yields to improved food security and nitrogen pollution reduction with enhanced yield performance! Ability to provide a sustainable N alternative for nitrogen vulnerable zones across the world Ability to enhance yields and reduce N fertiliser use, costs and pollution in commercial agriculture Ability to enhance yields in countries where conventional N fertilisers are unavailable or inaccessible
2/7/2019 Event Name and Venue 55
HABER LOOKS TO THE FUTURE “It may be that this solution (the chemical synthesis of ammonia) is not the final one. Nitrogen bacteria teach us that nature, with her sophisticated forms of the chemistry of living matter, still understands and utilises methods which we do not as yet know how to imitate.” Synthesis of Ammonia Fritz Haber 1920 Nobel Prize for Chemistry 2/7/2019 Event Name and Venue 56
Symbiotic Nitrogen fixation with N-Fix 57 57
Thank you. Any questions?
Indicators of high cereal yields … evidence from Yield Enhancement Network, 2013-2018 Analysis by: Funded by: Roger Sylvester-Bradley
Re Regi gion on Cou Count nty y Par arish ish Fa Farm rm Field eld Zone Normal field trial 0.1-0.5 ha
Metrics & benchmarks that explain yield … Biomass t/ha = 11 t/ha Grain Yield 20 9.5 t/ha @15% moisture Solar Grain Biomass energy 10 Straw & Chaff Biomass 9.5 t/ha April - July Rainfall e.g. 200mm 0 3,000 47% Energy Capture Biomass growth 2,000 1 150mm Soil Water Capture plus summer rain = 350mm total 1,000 water capture 2 metres Root growth Soil texture and depth dictate Soil Water Holding Capacity (e.g. 150mm / m for a medium soil type)
YEN N Repo ports rts
YEN entries: 2013 , 2014 , 2015 , 2016, 2017, & 2018 ■ ~570 yields ■ From >250 farms ■ Almost all Winter Wheat ■ Each farms’ best crop(s) ─ or Field Zone(s): all 2+ hectares ─ Usually selected after emergence ■ Average yield = 10.8 t/ha ─ Range 5.0 to 16.5 t/ha ■ Multi-variate data analysis ─ gives Associations, NOT Effects ─ NB Associations are not Causes.
■ 15 t/ha is possible ... almost anywhere ■ It’s less about what you spend, more about … ‘Attention to Detail’ ■ Large yields come from large crops ─ With more ears than average … and tending to be taller, with greater straw N% ─ So important associations include good nutrition, and control of disease & lodging risks ─ Husbandry factors associated with high yields included: … following a break crop … narrow row widths … applying slurry … adequate N use … but liquid N (straight) was questionable … and several PGR applications.
Location, Site & Season: ■ Large yield gaps are everywhere ! Long Term < 18 Average ■ and High yields are widespread Potential < 19 Grain Yields Deep, medium soil ■ ‘Year’ caused only ~25% of variation < 20 ─ Cool summers best and … ─ Dry, bright autumns-winters, & bright springs ─ Summer rain only important in 2018 < 21 < 20 ■ 75% variation associated with farm, < 22 husbandry , etc. < 23
Soil factors: ■ Water-retentive soils yielded more Sands < Medium < Shallow (not over chalk) < Clay < Silty < Shallow over chalk ■ Yields larger with slurry applied (+0.9 t/ha , ±0.53 ) … but no positive association with compost or biosolids ■ Lower yields after cover crops? … (52 cover crops declared) ■ Soil nutrients and organic matter not significant ─ Positive yield association with soil pH (+0.3 t/ha/unit, ±0.14 )
Species & Variety: ■ Wheat yielded more than other cereal species ■ Variety (& nabim Group) explained grain protein variation ─ but not grain yield ■ Site, weather and husbandry factors had more influence on yield than variety choice.
Previous cropping, and sowing: ■ Yields best after break crops ─ & with straw incorporation (+0.3 t/ha, ±0.18 ) ─ No association with cultivations or grass history ■ Higher yields with closer drill rows ─ (-0.03 t/ha/cm row width ±0.015 ) ■ Possible associations with seed treatment ─ Needs further investigation ■ No yield association with ─ Historic use of manures or previous grassland ─ Date of sowing, seed rate or Cultivation strategy ─ Herbicide use.
Crop nutrition ■ N fertiliser rate positive (~6kg grain/kg N, ±2.0 ) ■ Liquid N associated with lower yields ─ Less so if S included … needs further investigation ■ Yields may be higher with 5 or 6 N splits ■ Some association with P Fertiliser ─ Was stronger before 2018 data included ■ Yield not related to K, S, or micronutrients ■ Some association with biostimulant use.
Crop protection ■ PGR use showed strong positive association with yield level ─ Needs further investigation ■ Fungicide use related to yield ■ No association between yield and insecticide or herbicide use.
Crop characteristics ■ Large yields tended to come from large crops ─ With high ear populations ─ With high biomass, and … ■ Large shoots with high straw N% also important Maybe … a) As stores of redistributable reserves (e.g. sugars) b) In maintaining photosynthesis … especially towards the end of grain filling NB: Large crops require careful management of ─ disease risks and ─ lodging risks.
YEN 2013-18 results: Conclusions ■ Database analysis can only show ‘associations’ ─ not ‘cause & effect’ … it just highlights good questions ■ N evertheless … Yield Enhancement is possible! Yield was more about the farm than about weather! ■ P ray for: dry, bright winters, bright springs & cool summers (& no extreme drought) ■ But a ‘Farm Factor’ affected yields significantly ─ Soil type played a part, but also … Attention to Detail ■ Yield appears vital for both Profit & Sustainability ─ Because yields did NOT relate well to inputs.
… to develop the confidence to do better than ‘best practice’ Networking Measuring Testing Competition & Benchmarking Ideas & Understanding Learning, Confidence & Progress
YENs would not exist without their sponsors Cereal YEN sponsors Oilseed YEN sponsors For further information contact: Daniel Kindred, Roger Sylvester-Bradley or Mark Ramsden at ADAS Boxworth Tel: 01954 268200; Email: yen@adas.co.uk
= better than ‘best practice’
Thank you. Any questions?
Fungicide Performance and Disease Management 2019 Stuart Knight, NIAB
Fungicide Performance and Disease Management 2019 Stuart Knight, NIAB
Outline • Season overview • Wheat disease management ─ Septoria ─ Rusts ─ Head blight ─ Conclusions for 2019 • Barley disease management • Oilseed rape disease management
Weather: 2018 vs 1981-2010 (East Anglia) 120 100 Rainfall (mm) or % anomaly 80 60 40 20 0 -20 -40 -60 -80 -100 Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Source: 2017 2018 Rainfall (mm) % anomaly Met Office 2018 Anomaly Jan Feb Mar Apr May Jun July Aug Sept Oct Nov Dec Max temp ( O C) +1.4 -1.6 -1.9 +1.2 +2.4 +2.0 +3.9 +0.9 +0.6 +1.2 +1.2 +2.2 Min temp ( O C) +1.1 -1.4 -0.9 +2.5 +0.8 +0.9 +1.5 +0.8 -0.4 +0.1 +1.3 +2.2 Frosts (days) -4.2 +4.6 +2.6 -3.1 -0.5 0 0 0 0 -0.2 -3.1 -6.7
Wheat
Septoria Disease development in 2018 limited to an extent by dry May / June So far this season, mild autumn and winter have been favourable for septoria On the 2019/20 Recommended List: • 57% of varieties have RL disease rating of less than 6.0 for septoria • 34% of varieties have RL disease rating of between 6.0 and 6.9 • Three varieties have RL rating of 7.0 or above: KWS Extase (group 2, 8.1), KWS Firefly (group 3, 7.0) and LG Sundance (group 4S, 7.9) Oakley 27 April 2015 Nr Kings Lynn
Fungicide Performance Product Active(s) Bravo chlorothalonil Products were not in all trials / years Proline prothioconazole Bassoon epoxiconazole Caramba metconazole Folicur tebuconazole Soleil bromuconazole + tebuconazole Comet pyraclostrobin Unizeb Gold mancozeb Imtrex fluxapyroxad Vertisan penthiopyrad Ascra Xpro bixafen + fluopyram + prothioconazole Elatus Era solatenol + prothioconazole Librax fluxapyroxad + metconazole Keystone epoxiconazole + isopyrazam Priaxor fluxapyroxad + pyraclostrobin
Septoria protectant over-year 2016-18 (n=17)
Septoria curative over-year 2016-18 (n=9)
Septoria yield over-year 2016-18 (n=17)
Septoria: azole performance over time (protectant, full label dose) 100 90 80 % Control Septoria 70 60 50 40 30 prothioconazole 20 epoxiconazole 10 0 2000 2003 2006 2009 2012 2015 2018
Septoria: SDHI performance over time 2013 2014 2015 2016 2017 2018 Imtrex (top curve = best control achieved, middle = average, bottom = worst control) Vertisan (top curve = best control achieved, middle = average, bottom = worst control)
Septoria: early-season sensitivity monitoring Rothamsted (updated 2018): azoles epoxiconazole prothio-desthio
Septoria: early-season sensitivity monitoring Rothamsted (updated 2018): SDHI bixafen Sdh mutations detected for the first time in 2017
Septoria: effects of sow date, variety & fungicide 10 Mean of 10 sites, 2016 and 2017 9 8 % Leaf area with S. tritici Untreated Low Medium High 7 6 5 4 3 2 1 0 Santiago* JB Diego Revelation* Santiago* JB Diego Revelation* Mid Sept sown Mid Oct sown Mean septoria Treatment T1 – GS32 T2 – GS39 levels on leaf 2 Low CTL 1.0 CTL 1.0 (T2 +3-4 weeks) Medium Brutus 1.5 + CTL 1.0 Brutus 2.25 + CTL 1.5 High Brutus 1.5 + CTL 1.0 + Imtrex 1.0 Brutus 2.25 + CTL 1.5 + Imtrex 1.5 All except untreated also received T0: CTL 1.0 and T3: Folicur
Septoria: effects of sow date, variety & fungicide 20 Mean of 4 sites, 2018 18 16 % septoria on leaf 2 or 3 Untreated Low Medium High 14 12 10 8 6 4 2 0 Santiago JB Diego Revelation Santiago JB Diego Revelation Mid Sept sown Mid Oct sown Early Late Mean septoria levels on leaf 2/3 Sowing date P = 0.003 Sowing date x Variety P = 0.051 (T2 +3-4 weeks) Variety P = 0.003 Sowing date x Fungicide P = 0.004 Fungicide P < 0.001 Variety x Fungicide P < 0.001
Yellow Rust and Brown Rust Cold Feb/March and hot summer compressed yellow rust development in 2018 Mild autumn 2018 and few frosts had been favourable for rusts (until last 2 weeks of Jan) 2019/20 RL disease ratings: • 63% of varieties rated 6 or less for brown rust. Most susceptible: Crusoe, KWS Siskin, KWS Lili, LG Detroit, KWS Barrel, KWS Basset, KWS Jackal, LG Skyscraper, Shabras, KWS Crispin, Costello • Only 17% of varieties have a rating of 6 or less for yellow rust. Most susceptible are: Skyfall, Zulu, Bennington, Leeds, Myriad, JB Diego Oakley 27 April 2015 Nr Kings Lynn https://cereals.ahdb.org.uk/ukcpvs
Yellow rust over-year 2016-18 (n=3)
Brown rust
Head blight symptoms
Head blight DNA results 2018 Fusarium 3.0 a Caution: DNA (pg/ng total DNA) 2.5 a Data is from ab 2.0 1 trial/year 1.5 only bc 1.0 c c 0.5 0.0 Untreated1Untreated2 Folicur Proline Soleil Unizeb Gold T3 treatment Microdochium 1.0 a DNA (pg/ng total DNA) 0.8 ab abc 0.6 bc bc 0.4 c 0.2 0.0 Untreated1Untreated2 Folicur Proline Soleil Unizeb Gold T3 treatment
Wheat: conclusions for 2019 Septoria tritici • SDHIs more effective than azoles, but efficacy beginning to decline • SDHI+azole mixtures achieved highest levels of control • Further sensitivity shifts (azoles and SDHIs) reinforce importance of multi-site protectants (especially CTL) in programmes • Varietal resistance, sowing date and (under some circumstances) seed rate offer opportunities to reduce risk Rusts • Azoles and pyraclostrobin retain good activity against yellow rust • SDHI + azole more effective against brown rust than azole alone Head Blight • Soleil performed similarly to Proline or Folicur against fusarium. Unizeb Gold was most effective on microdochium
Barley
Disease risk In 2018: • Rhyncho / net blotch limited by dry May/June • Very little ramularia due to dry summer 2019-20 RL disease ratings: • All but one 6-row winter barley rated rated 7 for rhynchosporium (Belmont 6). Most 2-rows rated 5 or 6 (KWS Glacier 4, Surge 7) • Spring barley varieties all have rhynchosporium rating of 5 or 6 except Concerto (4) • Only one w barley rated 7 for net blotch (Surge). KWS Creswell and KWS Tower have ratings of 4 • KWS Orwell / Infinity /Glacier / Cassia / Creswell, Oakley 27 April 2015 Nr Kings Lynn LG Flynn, Bazooka, Libra all rated 3 - 4 for mildew
Rhynchosporium over-year 2016-18 (n=9)
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