Effects of seed-applied fungicides on root growth of wheat under controlled conditions and in open fields

Transcription

1 Effects of seed-applied fungicides on root growth of wheat under controlled conditions and in open fields Prof. Teofilo Vamerali University of Padova - Italy

2 Wheat in Europe KEY POINTS: 225 Mt of wheat grains; Important actor in world production (~30%); Fast per-hectare yield increase (~4 t ha -1 ); Amelioration of agricultural practices; Further improvements are possible. Weaknesses: fungal diseases and mycotoxin control, weed management, nitrogen fertilisation with restrictive environmental regulations (Nitrate Directive). 50k 2013 Countries delivering the 5 highest yields Average Hg/Ha 40k 30k Hg/Ha 100k 20k Ok

3 Fungal diseases in small-grain cereals Seed-borne pathogens: Fusarium spp. Michrodochium nivale (seedling blight); Ustilago tritici (loose smut); Tilletia caries (common bunt / stinking smut). Soil pathogens: Septoria tritici (septoria leaf blotch); Stagonospora/Septoria nodorum; Rhizoctonia cerealis (sharp eyespot); Fusarium spp. Etc. Fusarium foot rots Many of these can seriously compromise plant establishment (particularly roots), crop success and yield. Mandatory strategies: 1. Prevention against fungal pathogens 2. Promotion of early plant growth Rhizoctonia

4 Research aims Framework: a new SDHI fungicide sedaxane available for seed treatments To study its growth (roots) enhancement power vs. older fungicides and untreated controls; GOLD (commercial formulation) Pathogen Efficacy Pathogen Efficacy Fusarium spp. Septoria nodorum To identify targeted root parameters; To verify whether any implication on yield performance or quality exists; To ascertain whether effects are stable across years and soil types. Macrodochium nivale Pyrenophora graminea Ustilago nuda Cochliobolus sativus Tilletia caries Excellent Good Puccinia recondita Erysiphe graminis * Rhizoctonia spp. * Typhula incarnata Gaeumannomyces graminis CONTEXT: Italian environment (controlled conditions and open fields). Common and durum winter wheat.

5 Methods 2-year field trial: 2012/13 & 2013/14 Legnaro - Experimental farm of the Univ. of Padova Foggia - Syngenta experimental farm 1 st year - common wheat: cv. ILLICO 2 nd year - durum wheat: - cv. SARAGOLLA (Foggia) - cv. ISILDUR (Legnaro) Legnaro - Padova lysimeters ROOT ENHANCEMENT Foggia open field plots

6 Treatments under study Seed-applied fungicides: GOLD (fludioxonil + difenoconazole + sedaxane ): 200 ml dt -1 5 g 5 g 10 g EXTRA (fludioxinil + difenoconazole): 200 ml dt -1 5 g 5 g Untreated controls 20 m 100-m 2 plots Rhizoboxes Lysimeters Open field 5 m

7 Rhizoboxes with various soils Effects of : Faster root deepening; Greater root length and area; Increased number of root tips and forks. SANDY SOIL: 43 days of cultivation Sandy Silty-loam Organic Clay Analysis with WINRHIZO TM 45 cm

8 Rooting power % increase vs. controls for significant root parameters PARAMETERS TYPES OF SOIL SANDY ORGANIC SILTY-LOAM CLAY LENGTH 54% 42% 54% 47% AREA (Horiz. Proj.) 51% 39% 52% 52% 48% 40% CONTACT SURFACE 51% 39% 52% 43% 48% 40% DIAMETER VOLUME 49% 45% 56% 54% No. TIPS 59% 80% 46% 54% No. FORKS 59% 65% Positive effects, as a trend (P>0.05) Root surface area is the most affected parameter; Generally: = (P = 0.05); No. root tips/forks: > ; Similar response in sterilised soil (protection and rooting power are separate mechanisms). +29% Sandy soil +26%

9 Lysimeters with various soils December 5, 2012 (40 DAS) Starter effect of, with faster soil cover; Improved seed emergence rates: 88% vs. 62% of controls. Sowing density: 385/m 2 Clay Sandy +42% Silty-loam Organic 45 cm

10 Root responses in various soils June 5, 2013 (harvest) April 5, 2013 (162 DAS) Sandy Silty-loam SANDY +95% SILTY-LOAM +15% 45 cm Improved Root Length Density in more crucial conditions; Clay and organic soils:

11 COMMON WHEAT at Legnaro (2012/13) December 18, 2012 (54 DAS) April 11, 2013 (168 DAS) Auger sampling and image analysis +13% +9% Silty-loam soil Harvest: mean RLD cm Improved Root Length Density by (early stages: above ploughing depth; later: below) Attenuated differences at harvest

12 DURUM WHEAT at Legnaro (2013/14) April 30, 2014 (spiking) January 15, % +5% +14% in RLD +8% Silty-loam soil Root length enhancement by and at both tillering and spiking stages; : better increases in root area (Surface area = projected area 3.14 ).

13 DURUM WHEAT at Foggia (2013/14) April 15, 2014 (spiking) January 10, 2014 Length +4% Area +3.4% Sandy-clay soil Contrasting results across soil profile, with a root enhancement effect of in top and deep soil; Root shifting in deeper layers; Unexpected great decrease of (-19%) due to anomalous calcareous subsoil.

14 Effects on grain: YIELD COMMON WHEAT (2013) July 2, ,2% +0,2% Substantial stable yields among treatments; Yield increases induced by better observable in conditions of lower fertility (e.g., Foggia). (d.w.) DURUM WHEAT (2014) +0,8% +0,8% +15% +25%

15 Effects on grain: QUALITY and N uptake LEGNARO N Grain + N straw +15 kg N Grain + N straw +24 kg Small variations among treatments, with more proteins in treated plants of durum wheat; Interesting greater N uptake in whole plants.

16 Phenolic acids at harvest Abundant antioxidant compounds in wheat STRAW GRAINS HPLC mg/kg d.w Untreated +5.9% +6.5% +3.4% Vibrance Untreated Vibrance Untreated Vibrance SANDY CLAY SILTY- LOAM Untreated +7.0% Vibrance ORGANIC T-Ferulic P-Coumaric Syringic Caffeic Vanillic mg/kg d.w % Vibrance +10.5% Vibrance Vibrance SANDY CLAY SILTY- LOAM +4.5% Vibrance ORGANIC T-Ferulic P-Coumaric Syringic Caffeic Vanillic Constantly greater concentration in -treated plants; some of these acids are active against fungal pathogens; Similar trend in the grains (concentration 75% lower): nutraceutical effect.

17 Conclusive remarks vs. Plants Both tested seed-applied fungicides have marked power rooting, but shows more stable effects; All improved root parameters (SURFACE, LENGTH, No. TIPS) can be related to efficient nutrient and water uptake, particularly in conditions of stress. vs. Farmers/Environment Starter effect of can be efficiently exploited for safe and quick plant establishment during the most delicate early phases; Quantitative/qualitative yield advantages cannot always be expected with this larger root apparatus, but a poor root system is always responsible for yield losses; With, reduced N leaching, improved NUE and reduction of N fertilisers can help the environment and save resources. A new concept of plant wellbeing Greater abundance of phenolic acids in green parts and in grains from seeds receiving.

18 Thank you for your attention The Root Lab team at the University of Padova Prof. Teofilo Vamerali Prof. Giuliano Mosca Dr. Valentina Zanella Dr. Giuseppe Barion Dr. Davide Piragnolo Dr. Marianna Bandiera Dr. Cristian dal Cortivo Mr. Adriano Massignan