Prac%cal applica%on of crop modelling in potato produc%on David Firman NIAB – CUF 1 Growers/agronomists Maximise value of their potato crops -‐ i.e. £/acre not lbs/acre Op%mise alloca%on of resources -‐ e.g. seed, water, nutrients, diesel, labour, storage, transport, management 8me Achieve contracted tonnages Ensure compliance with customer protocols Ensure long-‐term environmental and economic sustainability of business Packers/processors Ensure suﬃcient product available with viable quality/cost Intelligence of supply-‐chains -‐ No surprises Minimise wastage Ensure product complies with end-‐ user requirements Meet aspira%ons of stake/share holders 2 Plan Execute Measure 3 Simple models with rela%vely few inputs can be used to forecast yield forma%on 4 Tuber FW yield (t/ha) 60 50 40 Modelled total yield Grower harvested yield Sampled yield (+1 S.E.) 30 20 10 0 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct Our yield model is consistently as accurate as end of season yield samples in forecas%ng grower harvested yield 5 Average date Average forecasts were forecast of yield Number issued at defolia=on Season of crops (t/ha) (t/ha) Retrospec=ve modelled yield at defolia=on (t/ha) Average observed yield at defolia=on (t/ha) 2011 86 12 July 58.8 59.3 59.2 2012 118 18 July 46.9 46.1 41.9 2013 97 22 July 49.8 50.6 52.1 Mean 301 19 July 51.2 51.1 50.1 300 Free market price (£/t) By mid-‐July the yield model provides reliable es%mates of whether growers will be able to aYain their contracted tonnages 250 2012 2013 200 150 100 50 0 1 Aug 1 Sep 1 Oct 6 Principles of Irriga%on Management Evapotranspira%on •  •  •  •  •  Canopy size Wind-‐run Temperature Rela%ve Humidity Incident solar radia%on Irriga%on Rain Drainage Plant-‐unavailable water 7 171 mm irriga%on applied 5 mm drainage 197 mm (96 %) of poten%al water use met to 11 July (excellent) Well-‐scheduled (typically 15 mm SMD) Could have started each irriga%on 2 days later to run c. 20 mm SMD 8 Depending on the customer, contracts will value some sizes of potato more than others. For example: Ware size (mm) Value (£/t) < 20 0 20-‐28 260 28-‐35 220 35-‐41 100 > 41 60 How do we help growers maximise the value of their crops? Lady RoseYa Russet Burbank 9 Simple models that relate mean tuber diameter (i.e. riddle size) to mean tuber weight allows the mean tuber size that maximises crop value to be calculated. This helps with devising defolia%on strategies that minimise crop wastage. 50 3000 Mean tuber size Crop value 2900 40 2800 30 2700 20 2600 10 0 15 25 35 Total yield (t/ha) Gross crop value (£/ha) Mean tuber size (mm) 60 2500 45 10 Exploita%on of new technologies to capture key crop informa%on enables more eﬃcient work-‐ ﬂow. For example, a joint project with Landmark Informa%on Group. 11 12