Seedlot Handling and Tuber Yield Loretta Mikitzel, PhD, PAg NB Department of Agriculture, Aquaculture and Fisheries New Brunswick Potato Conference and Trade Show February 5, 2015

2014 Seed Handling demonstrations Seedlot comparison Seed warming and precutting New Brunswick Canadian Potato Industry Transformation Initiative – Seed Group

Seedlot Comparison 9 different 2013 seedlots Russet Burbank E3 and E4 Richmond to Drummond parishes Received in Wicklow on March 28, 2014 To evaluate physiological age, tubers held at 18°C in the dark

April 25,

5 4 6

7 8 9

Warm vs cold Divided each seedlot in half May 5, 2014 – cut half of each seed lot, treated with Maxim, stored at 10°C until planting (warm) Half of each lot stored at 4°C until May 27, 2014 then cut, treated and stored at 10°C until planting (cold) June 2, 2014 planted at Bloomfield in a processing field

At planting June 2, 2014

July 8, 2014 Seedlot # 1 WarmCold

July 8, 2014 Seedlot #2 WarmCold

July 8, 2014 Seedlot # 3 WarmCold

July 8, 2014 Seedlot # 4 Warm Cold

July 8, 2014 Seedlot # 5 WarmCold

July 8, 2014 Seedlot # 6 WarmCold

July 8, 2014 Seedlot # 7 WarmCold

July 8, 2014 Seedlot # 8 WarmCold

July 8, 2014 Seedlot # 9 Warm Cold Lot # 9

July 21, 2014 Seedlot # 3 Warm Cold Seedlot # 6

August 15, 2014

Stems per plant Seedlot #WarmCold

Total Yield (cwt/A) Warm = 350 cwt/A Cold = 312 cwt/A Top killed September 16, 2014 harvested September 24, 2014

Marketable Yield (cwt/A) Warm = 281 cwt/A Cold = 260 cwt/A

Tubers per plant Seedlot #WarmCold

Crop Value ($/acre) + $952+ $742 + $576 + $1,011+ $808

Crop Value ($/acre) - $299- $71 - $532 - $624

Seedlot Comparison Most seedlots benefit from warming seed before planting –More rapid emergence –More uniform emergence –Higher yield –Greater value Some seedlots warming for 4 weeks at 10°C before planting not beneficial Know the condition of your seedlot

Seed Warming Demonstration Russet Burbank Innovator Determined crop value after warming and precutting seed Planted June 3, 2014 Planted at McCain Research Farm, Greenfield

Seed Warming Treatments Cold whole seed4°C, 10°C 6 days before planting Warm whole seed10 °C for 26 days before planting Precut 40 daysCut, held 10°C for 40 days before planting Precut 33 daysCut, held 10°C for 33 days before planting Precut 26 daysCut, held 10°C for 26 days before planting Precut 19 daysCut, held 10°C for 19 days before planting Cold cut 6 days4°C, then cut and 10°C 6 days before planting Warmed 2 weeks + cut 6 daysHeld at 10°C for 2 weeks, cut 6 days before planting

Emergence (%) – Russet Burbank

Emergence (%) - Innovator

Russet Burbank July 3, 2014 Cold Whole Warmed whole Cold cut 6d warmed 2 wks + cut 6 d

Innovator July 3, 2014 Cold Whole Warmed whole Cold cut 6d warmed 2 wks + cut 6 d

Innovator July 16, 2014 CW WW 40 d 33 d 26 d 19 d Ccut 6d

Innovator July 18, 2014 CW WW 40 d 33 d 26 d 19 d Ccut 6d

Innovator July 23, 2014 CW WW 40 d 33 d 26 d 19 d Ccut 6d

Innovator August 13, 2014 CW WW 40 d 33 d 26 d 19 d Ccut 6d

Days after planting to flowering Russet BurbankInnovator Cold whole seed5450 Warm whole seed4443 Precut 40 days4443 Precut 33 days4443 Precut 26 days4850 Precut 19 days4852 Cold cut 6 days5250 Warmed 2 weeks + cut 6 days 5250

Marketable yield – Russet Burbank

Value ($/A) – Russet Burbank

Marketable yield - Innovator

Value ($/A) – Innovator

Seed Warming Demonstration Russet Burbank and Innovator benefit from precutting and warming seed –Precut and store at 10°C 26 to 33 days before planting Highest yield and crop value with precut seed Lowest yield and crop value when seed held at 4°C until planting warmed for 6 days before planting

2015 seed trials Repeat seedlot comparison Repeat seed warming trial –Reduce the holding temperature to 7°- 8°C instead of 10°C

Acknowledgements Seed growers who donated samples McCain Research Farm crew