effect of pre-harvest practice on storag

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Advances on effect of pre-harvest practices on storage and shelf-life of stone fruits Raja Hadin Shafi MSc. Pomology

STONE FRUITS : 

STONE FRUITS Fruits in which an outer fleshy part (exocarp and mesocarp) surrounds a shell (pit or stone) of hardened endocarp with a seed. Synonymous with peach, plum, apricot, cherry and nectarine.

The quality of horticultural productscannot be improvedduring post-harvest management : 

The quality of horticultural productscannot be improvedduring post-harvest management Achieving optimal post-harvest quality in; visual sensory nutritive attributes are determined or greatly influenced by pre-harvest events and management

Need for improvement : 

Need for improvement Stone fruits have a relatively short post-harvest life. Can quickly pass from ideal ripeness to over maturity, depending on temperature and handling exposures. Readily lose water and shrivel, depending upon surface characteristics of the fruit. Quickly destroyed by fruit rotting organisms. Become unmarketable as a result of internal breakdown

Pre-harvest Factors : 

Pre-harvest Factors Light/canopy position Irrigation Mineral nutrition Thinning Foliar sprays Harvest maturity Infection or infestation

Light/Canopy Position : 

Light/Canopy Position Importance Improves quality parameters Decrease susceptibility to physiological disorders Delays maturity

Influence of canopy position on the market life of peach and nectarines : 

Influence of canopy position on the market life of peach and nectarines (Crisosto et al 1997)

Irrigation and Fertilization : 

Irrigation and Fertilization Nitrogen Fertilization High N associated with excess vegetative growth High N associated with high leaf protein and pigment concentrations (chlorophyll, carotenoids) High N associated with reduced post-harvest life due to increased susceptibility to decay, mechanical damage and physiological disorders

Wall-thickness is important for shipping quality Prevents high rates of water loss/softening : 

Wall-thickness is important for shipping quality Prevents high rates of water loss/softening Good wall thickness is inhibited by Irregular irrigation Excessive N and high temperatures Heavy fruit set

Effect on cell wall thickenings by different irrigation regimes : 

Effect on cell wall thickenings by different irrigation regimes A B (deficit) C D(Optimum) E F (Excess) (Crisosto et al 1995)

Cross sections of fruit cuticle show the fruit showing the effect of different concentrations of nitrogen : 

Cross sections of fruit cuticle show the fruit showing the effect of different concentrations of nitrogen Low High (Danne et al 1995)

Physiological Role of CalciumCalcium is an important mineral determining quality and decay resistance : 

Physiological Role of CalciumCalcium is an important mineral determining quality and decay resistance Examples of impacts of low Ca concentration Internal breakdown Accelerated senescence Increased rate of softening of fruit Increased decay potential, especially at wounds More susceptible to physiological disorders

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Calcium Maintain membrane permeability Decrease in viscosity of membranes increase cell wall rigidity Improve cell wall structures Enhance storage life

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Effect of pre-harvest application of calcium chloride on the storage life of peach Plw (%) Days

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Contd… TSS (%) Total sugars (%) Days Days Mishra S 2002

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Fruits sprayed with calcium chloride at 2%, chelated calcium at 2% and boric acid at 0.50% and stored at 0ºC exhibited better yield and quality after 40 days storage in comparison with the other treatments. (Elham et al 2007) Calcium application has increased the calcium content of peach fruits and has also significantly reduced the number of brown rot infected fruit per tree at harvest and the incidence of postharvest rots. (Elmer et al 2006) Calcium chloride (0.5%) sprays significantly improved the storage life of peach by reducing the weight loss spoilage percentage and respiration rate and also by maintaining fruit firmness. (Singh et al, 2006) Calcium chloride have been found to improve the quality of cherry cv. Makhmali by increasing TSS, total sugars, anthocyanin content and ascorbic acid content of the fruits. (Bhat et al 1997)

THINNING : 

THINNING It refers to removal of some portion of fruit from the tree before its maturity in order to improve the general size and quality of remaining crop. Types of thinning Hand thinning: In this type of thinning the branches are first shaked to dislodge fruits which are likely to drop off naturally and then the surplus fruit is removed starting from to the bottom of the branches. b) Chemical thinning: this type of thinning is done with certain type of chemicals like ethephone, NAA etc.

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Physiology of thinning THINNING REDUCE CROP LOAD INCREASE PHOTOSYNTHETIC ASSIMILATES IMPROVES QUALITY ENHANCE STORAGE LIFE

Foliar sprays : 

Foliar sprays Growth regulators These are the organic compounds other then nutrients which in small quantity modify the plant physiological process. Growth regulators used to improve the storage life by pre harvest applications: Gibbrellic acid. Re Tain. Putriscine.

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POLY AMINES retarded colour changes, Increased fruit firmness, Delayed ethylene and respiration rate emissions, Induced mechanical resistance GIBBRELLIC ACID Cell enlargement Increase firmness Prevent Disorders AVG Delays ethylene rate emission Enhance storage life

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Role of AVG and Poly amines in inhibiting the ethylene synthesis

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Effects of different concentrations of PUT applied as pre-harvest spray and postharvest dip applications on the ethylene production in ‘Angelino’ plum Ahmad et al 2007 Pre-harvest sprays Post-harvest sprays Mean

Maturity and maturity indices : 

Maturity and maturity indices Maturity: derived from the Latin word “Maturus” which means ripen Stage of development which ensure attainment of maximum edible quality at the completion of ripening process Types of Maturity Physiological maturity Horticultural maturity

Maturity indices : 

Maturity indices The maturity index for a commodity is a measurement or measurements that can be used to determine whether a particular commodity is mature Importance of maturity indices Ensure sensory qualities. Ensure adequate post-harvest shelf-life. Facilitate scheduling at harvest and packaging operation. Facilitate marketing over the phone or through internet.

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Plum Surface color and flesh firmness (depending on cultivar) Nectarine & Peach Surface ground color change from green to yellow, shape (fullness of shoulder and suture) Cherry Entire surface solid light-red and 14 to 16% SS (depending on cultivar Apricot Color of the external surface area: >3/4 yellowish green or >1/2 yellow California minimum maturity indices for stone fruits

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1 2 3 4 5 Maturity and ripeness stage of some stone fruits Cherry 1 2 3 4 Nectarines Apricots

Post-harvest decay : 

Post-harvest decay It can cause severe losses Monetary losses Losses that a packer can suffer General loss of reputation

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Diseases Brown rot Monilinia ssp Rhizopus rot Rhizopus stolinifera Grey mould rot Botrytis cinerea Sour rot Geotrichum candidum Disorders Soft nose Internal breakdown Surface pitting and brusing Skin discolouration Important post harvest disease and disorder problems of stone fruits:

Brown rot : 

Brown rot Symptoms Small, circular, necrotic lesions may develop on fruit Soft, dry rot of fruit Rapid rotting (entire fruit rot may occur within 48 h) Pre-harvest and post-harvest rot Heavy sporulation on fruit No sporulation on infected fruit in transit and storage Brown rot

Control : 

Control Cultural practices Removing mummies Pruning infected twigs Reducing stresses of trees Pink growth stage - harvest Control of the insects that injure fruit and disseminate the pathogen

Rhizopus rot : 

Rhizopus rot The pathogen enters the peach only through an injury. Symptoms The skin of infected fruit readily slips. The flesh becomes brown, very soft, and soon collapses. The surface becomes covered with coarse black fungal growth Rhizopus rot in peach Rhizopus rot in Apricot

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Control Careful fruit handling to avoid cuts and bruises is an important factor in Rhizopus rot control. Pristine is registered for its control. It should be applied a day before harvesting.

Sour Rot : 

Sour Rot Symptoms Fruits affected by this has characteristic sour odour watery, soft decay with a thin layer of white mycelial growth on the fruit surface. Control Proper sanitation Proper control of insect pest Avoid injuries to the fruit

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Grey Mould Rot Symptoms Skin over the diseased flesh slip away. Decay surface become covered with gray-brown fungal growth. Control Proper sanitation of the field.

Chemical control of some stone fruit diseases : 

Chemical control of some stone fruit diseases

Control of decay of sweet cherry with combinations of pre-harvest iprodione and post harvest Cryptococcus infirmo-miniatus applications in 1996 : 

Control of decay of sweet cherry with combinations of pre-harvest iprodione and post harvest Cryptococcus infirmo-miniatus applications in 1996 Percent fruit decayed Treatments blue mould brown rot (Spotts et al 1998)

Disorders : 

Disorders Soft nose Cause Excessive use of nitrogen or deficiency of calcium. Symptoms Breakdown of flesh towards the apex of fruit before ripening through marked cell separation and cell wall disintegration in mesocarp cell. Management This can be reduced by maintaining leaf calcium at 2.5% either by supplying nitrogen as calcium nitrate or by adding lime stone or gypsum

Internal breakdown : 

Internal breakdown Synms : Chilling Injury, Dry Fruit, Mealiness, Woolliness Symptoms Flesh browning, flesh lack of juiciness due to leatheriness or mealiness, black pit cavity, flesh translucency, red pigment accumulation (bleeding), and loss of flavour. Control Avoid cultivars that are susceptible to IB whenever possible. Market susceptible cultivars according to their potential post-harvest life. Pick fruit "well matured." (Crisosto 2002)

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Symptoms Pits are small sunken areas on the fruit surface, larger flattened areas are called bruises Control Fruit factors such as high soluble solids concentration, warm temperature, pre-harvest use of Gibbrellic acid, and high fruit weight have been shown to reduce fruit susceptibility to damage Surface Pitting and Bruising (Thompson 2002)

Skin Discoloration(Inking, Black-Staining) : 

Skin Discoloration(Inking, Black-Staining) Symptoms Skin discoloration (SD) symptoms appear as brown and black spots or stripes that are restricted to the skin. Control Treat fruit gently. Check your water quality for contamination with metals (Fe, Cu & Al). Do not spray foliar nutrients containing Fe, Cu, or Al during fruit maturation. Stop pre-harvest applications of the following fungicides and foliar nutrients at the indicated days before harvest: (Crisosto 2002)