minimizing bitter pit in ‘honeycrisp’ apples...washington state university, pullman, wa, usa;...
TRANSCRIPT
Printed by BCU. Bcu.vetmed.wsu.edu
Calcium deficiencies contribute to thedevelopment of certain fruit disorders in apples,such as bitter pit. Bitter pit has long beenassociated with low levels of fruit calcium(Ferguson and Watkins, 1989)
Bitter pit (BP) is a physiological disorder ofapple fruit that has caused serious losses inHoneycrisp apples for many years
The susceptibility of ‘Honeycrisp’ to bitter pitreduces the amount of fruit pack-out and limitsthe profitability for growers
BP symptoms: necrotic spots on the superficialskin of the fruit. Pits may be few in number tonumerous, they are more prevalent on the calyxend of the fruit. This disorder can be evident atharvest but can develop in storage, resulting inextensive fruit loss (Fig.1)
Background
PRE-HARVEST SPRAY TREATMENTS
Goals and expected results
Washington State University, Pullman, WA, USA; [email protected]
Corina Serban and Lee Kalcsits
Minimizing Bitter Pit in ‘Honeycrisp’ Apples
Implications
The main advantages to grow ‘Honeycrisp’ applesare:
‘Honeycrisp’ is sold-out from every nursery
Brings good returns on investment
Is being used as a parent in every apple breedingprogram
Market performance/popularity in the market(Fig.9)
This research will benefit the tree fruit industryto minimize bitter pit in ‘Honeycrisp’ apples, aphysiological disorder that leads to significant fruitlosses and is related to calcium uptake anddistribution within the tree
Objectives
References
1. Evaluate how plant growth regulators (PGRs) sprays like gibberellic acid (GA) and Prohexadione-Ca (Apogee®) can enhance or reduce the incidence of BP in ‘Honeycrisp’
GA promotes shoot growth
BP has long been associated with low levels offruit calcium (Ferguson and Watkins, 1989).However, it has been clear that low Ca by itselfis not the only factor in the development of thedisorder. Work by de Freitas et. al (2008) andSaure (2001) suggested that the plant hormonegibberellic acid (GA) might play a role in boththe development of bitter pit and in thetransport of Ca to the fruit
Apogee is a PGR for vigor control in appleswhich will reduce the length of shoot growth
2. Evaluate Control Atmosphere (CA) durationimpacts on BP development, with or without theapplication of 1-MCP to slow fruit ripening
Compare how 1-MCP and rapid CAestablishment during temperature conditioningimpact BP and fruit quality
BP vs. Blotch pit – determine if blotch pit isrelated to 1-MCP treatment or is just a severform of BP (Fig.2)
3. Evaluate how the computer tomography (CT)-imaging helps to quantify bitter pit developmentinternally
Ferguson. I.B. and C.B. Watkins (1989) Bitter pitin apple fruit. Horticultural Reviews. 11:289-355
De Freitas, S. T., C.V.T. do amarante, J.M.Labavitch, and E.J. Mitcham (2010) Cellularapproach to understanding bitter pit developmentin apple fruit. Postharvest Biol. Technol. 57:6-13
Saure M.C. (2001) Blossom-end rot of tomato(Lycopersicon esculentum Mill.)—a calcium- or astress-related disorder? Scientia Hort. 90:193–208
Hewitt, E.W. (1984) Bitter pit reduction in‘Cox’s Orange Pippin’ apples by controlled andmodified atmosphere storage. Scientia Hort.23:59-66
Acknowledgements
Committee members:
Ines Hanrahan, WTFRC
James Mattheis, USDA-ARS
Sara Serra, WSU-TFREC
Kalcsits Lab., TFREC, Wenatchee
WTFRC Funding
Oneonta Starr Ranch
Material and Methods
Fig. 1. BP symptoms in ‘Honeycrisp’ apples two weeks beforeharvest (A) and at harvest (B), Photo credit: Ines Hanrahan
A B
Fig. 2. Severe form of BP (Blotch pit) after 1-MCP treatment. Photo credit:
Ines Hanrahan
Fig.3. CT imaging of mild BP apple (A) and severe
bitter pit apple (B). Photo credit: Dr. Sankaran
Fig. 9. Good quality ‘Honeycrisp’ apples in the supermarket,Yakima, WA, 2015. Photo credit: Corina Serban (WTFRC)
GA and Apogee will be applied in two concentrations(low vs. high)Two times during the growing season: (1) around thetime of petal fall in May (Fig. 4.) and at thinning time (June15)
Fig.4.’Honeycrisp’ floweraround the time of petalfall
Data collectionPre-harvest:Initial flower cluster countHand thinning (mid June)Shoot length (measured every week after the spraytreatments)Return bloom count (subsequent spring count initialflower cluster count)Nutrient analyses for leaves and fruitlets, in June(traditional vs. X-Ray Fluorescence (XRF)), (Fig.5)
Fig.5. X-Ray Fluorescence (XRF),non-destructive way to measure Ca,K and Mg. Kalcsits lab., Wenatchee
POST-HARVEST TREATMENTS
Fruit analysesAt harvest:Maturity analyses (starch index, firmness, soluble solidscontent, titratable acidity, weight, color, internal ethylenecontent, dry matter)CT scans (Fig.6.)Nutrient analyses for fruit (traditional vs. X-RayFluorescence (XRF)), (Fig.5.)Storage:Evaluate treatments after 2 months (November) and 4months (January)
Research will focus on understanding the physiologicalmechanisms of calcium uptake and distribution in apple
Develop pre- and post-harvest management practices toreduce possible financial losses due to bitter pit in‘Honeycrisp’ apples
Apogee spray will inhibit the shoot growth and thereforewill be expected a reduction in BP compared with GAtreatment, used as a negative control (will increase the BPincidence)
Produce bitter-pit free apples at harvest, in order toenhance storability (Fig.8)
months after harvest
1 2 3 4
bitte
r pit %
0
20
40
60
80
100
CA
RCA
Air
CA
RCA
Air
Control
1-MCP
A B
GA APOGEE
LOW HIGH LOW HIGH
UNSPRAYED (CONTROL)
CA Rapid CA RA
1-MCP CONTROL 1-MCP CONTROL 1-MCP CONTROL
After harvest, fruit will be treated or not with 1-MCP at 50ºFCA (2 % O2, 0.5 % CO2) will be establish the day after receipt, and fruit will remain in CA for 1, 2, 4 or 8 weeks followed by storage in air up to 4 monthsFinal storage temperature will be 37ºF
Fig. 6. CT imaging of ‘Honeycrisp’ apples (A) at harvest and (B)
at 15-63 days in storage Photo credit:
Dr. Sankaran
A B
Fig.7. ‘Honeycrisp’ BP incidence following up to 4 month cold storage. BP development was assessed using the same fruit throughout the 4 month storage period. The final assesment was 7 days after fruit were removed from cold storage (Mattheis, 2013 unpublished)
Fig. 8. Bitter pit free apples at harvest, Gleed WA, 2014 Photo credit:Corina Serban (WTFRC)
Controlled atmosphere (CA) storage has long beenknown to reduce bitter pit development (Hewett, E.W.,1984). Previous studies indicated 1-MCP + CA storage for1 week or more reduces BP development compared tountreated fruit stored in air (regular atmosphere) (Fig.7)
The combination of temperature management to reduceBP while use of CA and/or 1-MCP to slow fruit ripeningwill result in reduced disorder development while slowingripening to maintain market quality over long term storageperiods
The goal of the post-harvest component is toidentify CA storage conditions and optimize therapid CA protocol for ‘Honeycrisp’ and determinethe BP development in different storage conditions
A B
Corina Serban