Sprouting in Storage: Impact and Control Nora Olsen University of Idaho Kimberly, Idaho, USA Sprouting in Storage Seed age and behavior Sprouting and field performance Impact of variety/storage Dormancy Sprout control Product and temperature combinations 1
Photos courtesy of PVMI Clearwater Russet Alpine Russet Classic Russet Premier Russet Photos courtesy of PVMI 2
Variety Dormancy Processing Quality Attributes Dry Rot Weight Suggested Use Glucose Mottling Potential Loss Fresh Process Russet Burbank long mod mod mod low X X Alturas short mod low low - X Alpine Russet long low low high-mod mod-low X Bannock Russet mod mod low mod-low - X X Blazer Russet mod mod mod-low mod - X Classic Russet mod mod mod high-mod mod X Clearwater Russet short low low high mod-low X X Highland Russet short mod high mod-low mod X Owyhee Russet mod low low mod mod X X Premier Russet short low low high high X Ranger Russet short mod high mod low X Umatilla Russet mod mod-low high high-mod - X Western Russet short mod low low low X X mod = moderate Dormancy: (days after harvest) long >150 days, mod 101-149 days, short <100 days until sprout elongation begins when stored at 7.2 C Glucose: high 0.1, mod 0.051-0.1, low 0.05 at ~160 days after harvest when stored at 7.2 C Mottling: is the dark colored flecking that can occur in french fried potatoes, Weight Loss: is classified relative to Russet Burbank (RB), where high 2x that of RB, mod is 1.1-1.9x RB, and low = RB Weight loss: - denotes data not available Described Dormancy Length Long 150 days Moderate 101-149 days Short 100 days Russet B Bannock R Alturas Alpine R Blazer R Clearwater R Classic R Owyhee R Umatilla R Highland R Premier R Ranger R Western R R Norkotah Dormancy Length (days) = # of days until 80% tubers have one sprout < 5mm (elongation is beginning to occur); Data at 7.2 C 3
Knowledge of Dormancy Length Seed Temperature response Sprouting upon removal Physiological age desired size profile Selecting for short, mid- or long term storage Marketing of potatoes Proper timing of sprout inhibitors Change in quality Temperature and Dormancy Higher the storage temperature, shorter the dormancy period When warmer temperatures occurred and for how long In fall after harvest In spring, warming up seed prior to planting 4
Dormancy Length (days) Variety 5.6 C 7.2 C 8.9 C R Burbank 175 155 130 Alpine 185 165 140 Classic 155 130 100 Umatilla 145 130 100 Owyhee 140 120 100 Premier 120 100 85 Clearwater 110 90 85 Highland 110 85 80 Ranger 100 85 80 Ranger Russet Russet Burbank Seed storage treatments: 38 F 38 F & 45 F Prior to planting in spring 38 F & 60 F a) 3.3 C until planting (no aging) b) 3.3 C and 1 month at 7.2 C prior to planting c) 3.3 C and 2 weeks at 15.6 C 5
Ranger Russet 3.3 C 3.3 C & 7.2 C 3.3 C & 15.6 C Emergence, stem and yield Russet Burbank Ranger Russet 1. Control At 39 F 2. 48 days at 55 F 3. 102 days at 55 F 4. 20 days at 72 F 5. 45 days at 72 F 6. 13 days at 90 F Seed storage treatments: Occurred after harvest in fall After 2 weeks of curing at 12.8 C 7. 29 days at 90 F Russet Burbank 6
Ranger Russet 1. Control At 3.9 C 2. 48 days at 12.8 C 3. 102 days at 12.8 C 4. 20 days at 22 C 5. 45 days at 22 C 6. 13 days at 32 C 7. 29 days at 32 C Russet Burbank 2008 Percent Emergence in Seven Seed Age Treatments of 'Russet Burbank' Potatoes Russet Burbank Percent Emergence 2008 Percent Emergence in Seven Seed Age Treatments of 'Ranger Russet' Potatoes Ranger Russet % Emergence 100 80 60 40 20 RB-1 RB-2 RB-3 RB-4 RB-5 RB-6 RB-7 % Emergence 100 80 60 40 20 Rang-1 Rang-2 Rang-3 Rang-4 Rang-5 Rang-6 Rang-7 0 20 25 30 35 40 Days After Planting 0 20 25 30 35 40 Days After Planting 7
Warmer Temperature Exposure Other Impacts on Dormancy Variety Inherent dormancy Temperature Pre-harvest conditions Growing season, stress, temperature, maturity Post-harvest conditions Temperature- level, duration, fluctuation Light affects morphology of emerging sprouts Exogenous products 8
Shepody Sprouting at 3.3 C storage Percent Sprouting 100 80 60 40 20 99-00 00-01 0 60 80 100 120 140 160 180 200 220 Days after Harvest 100 90 Ranger Russet Sprouting at 3.3 C storage Percent Sprouting 80 70 60 50 40 99-00 00-01 30 40 60 80 100 120 140 160 Days after Harvest 9
Performance Seed Age and Performance Young T Ideal Shepody @ 3.3 C T R.Burbank @ 3.3 C Old Age Physiological age Cultivar Performance 10
Importance of Sprout Control Minimize weight loss Minimize physical and processing quality changes Maintain quality Fresh market- no visible sprout Seed potatoes Storage Management - temperature, air flow 11
Dormancy Length (days) Variety 5.6 C 7.2 C 8.9 C R Burbank 175 155 130 Alpine 185 165 140 Classic 155 130 100 Umatilla 145 130 100 Owyhee 140 120 100 Premier 120 100 85 Clearwater 110 90 85 Highland 110 85 80 Ranger 100 85 80 Mean Dormancy Length (days) for Russet Burbank Year 5.6 C 7.2 C 8.9 C 99-00 175 145 135 00-01 175 155 135 01-02 175 155 135 02-03 175 150 130 03-04 175 165 150 04-05 180 170 135 05-06 180 170 135 06-07 170 155 140 07-08 180 155 130 08-09 185 155 130 +/- 15 +/- 20 +/- 20 12
Sprout Control Options Variety selection Low storage temperatures Product application In-field In-storage Spray application at packing shed for fresh market Major Sprout Control Products in the US Chlorpropham (CIPC) Maleic hydrazide (MH) field applied Diisopropylnaphthalene (DIPN; Amplify) Dimethylnaphthalene (DMN; 1,4-sight) 3-decen-2-one (SmartBlock) Clove oil (Biox C; Sprout Torch)- organic *Mint oil or other essential oils- organic 13
Sprout Control Programs CIPC based Thermal (forced air storage; recirculation) and/or spray application May have other products in mix or sequence; reduced rates No CIPC Sole or multiple product programs Organic or non-cipc markets Seed potato options Product for sprout control and to blacken eyes for retail fresh market Thermal or spray CIPC In-storage (1 sprout inhibitor used) apply as thermal fog temperature, method of application and equipment are applicator dependent initial application early, before pile settles, after wound healing depending upon cultivar, temperature and duration in storage, typically apply 15 to 25 ppm; retreat only if necessary (~10-15 ppm) Packing sheds Spray (EC) formulation applied to washed potatoes 14
Maleic Hydrazide applied in field Russet Burbank July Non-registered compound Early MH + CIPC Late MH + CIPC 15
Maleic hydrazide Effective for severely retarding sprout growth Extend dormancy break by approximately 30 days Timing important Good for aggressive sprouting varieties Effective sprout control programs Alone MH-30 followed by CIPC or other sprout inhibitor in storage 16
Naphthalene based products Diisopropylnaphthalene (DIPN) Typically, thermally applied in combination with CIPC Dimethylnaphthalene (DMN) Thermally applied alone or with CIPC program Aerosol canisters for shipping containers Thermal application to seed (30 days before planting) 3-decen-2-one (SmartBlock) Long carbon chain ketone- (3-decen-2-one) Identified and patented by Dr. Rick Knowles of Washington State University Registered in US and Canada in 2013 by AMVAC Chemical Corp Chemically synthesized food additive but identical to naturally occurring substances found in food Generally Regarded As Safe (FEMA) 17
3-decen-2-one Apply thermally Apply at visual initiation of sprouting most effective Can apply earlier prior to visual and control sprouting Advanced sprouting- damage sprouts. Long-term sprout control with 1 to 3 applications depending upon storage temperatures and variety Higher storage temperatures; aggressive sprouting varieties may need additional applications Blackens eyes; damage immediately observed; odor Integrate into effective sprout control programs that may include CIPC, MH, others 18
Clove Oil Distilled from Syzygium aromaticum plant Active ingredient is eugenol Organic approved in US Apply thermally; EC Spray Mode of action: physically damages sprout Untreated CIPC Clove oil 90 ppm Essential Oils: Clove Oil; Mint Oil Effective for sprout control Reapplication is necessary for long-term control 50 to 100 ppm each treatment Dependent upon variety and storage temperature ~2 to 6 week intervals Blackens eyes; Odor Effective sprout control programs 4 Alone (organic approved) 2 MH plus clove oil (no CIPC) 0 CIPC plus clove oil= true mix or sequence Days after harvest Sprout length (cm/tuber) 12 10 8 6 Peppermint Spearmint Untreated CIPC 206 235 266 297 19
Taste difference Spearmint Peppermint Untreated CIPC Russet Burbank after 9 months in 7.2 C storage (8 applications of mint oil) 3-decen-2-one (SmartBlock) and clove oil on sprout control Variety: Chipeta; Temperature: 8.9 C 3 applications of either clove oil or 3-decen-2-one at ~ same time 20
Current Major Sprout Control Options Variety selection and cooler temperatures Maleic Hydrazide field application; 30 day longer dormancy; slow sprout growth CIPC highly effective DMN and DIPN mild sprout suppressants; use in combination with CIPC Clove oil- organic; mix with CIPC; blackens sprouts 3-decen-2-one alone or in combination with others. Blackens sprouts Development of integrated programs New chemistries CIPC Stewardship ~ Global Priority 21
6/12/0 9 5 ppm 10 ppm 2.5 ppm Untreated Seed Exposure to CIPC 22
Swabbing for CIPC residues (ppm) Treated Bins Preapplication September After application December After cleaning August Bin 1 Both years prior 18 240 3 Bin 2 Both years prior 35 1,100 3 Bin 3 Both years prior 19 320 2 Bin4 Only 1 year prior 10 210 4 23
Variety Dormancy Processing Quality Attributes Dry Rot Weight Suggested Use Glucose Mottling Potential Loss Fresh Process Russet Burbank long mod mod mod low X X Alturas short mod low low - X Alpine Russet long low low high-mod mod-low X Bannock Russet mod mod low mod-low - X X Blazer Russet mod mod mod-low mod - X Classic Russet mod mod mod high-mod mod X Clearwater Russet short low low high mod-low X X Highland Russet short mod high mod-low mod X Owyhee Russet mod low low mod mod X X Premier Russet short low low high high X Ranger Russet short mod high mod low X Umatilla Russet mod mod-low high high-mod - X Western Russet short mod low low low X X mod = moderate Dormancy: (days after harvest) long >150 days, mod 101-149 days, short <100 days until sprout elongation begins when stored at 7.2 C Glucose: high 0.1, mod 0.051-0.1, low 0.05 at ~160 days after harvest when stored at 7.2 C Mottling: is the dark colored flecking that can occur in french fried potatoes, Weight Loss: is classified relative to Russet Burbank (RB), where high 2x that of RB, mod is 1.1-1.9x RB, and low = RB Weight loss: - denotes data not available Sprouting in Storage: Impact and Control Variety Market sector Field and Storage Conditions Control Options Quality Maintenance 24