HRT 210: Deciduous Fruit Practices

• HRT 210 Introduction

Course Outline

• Practices within the Deciduous Fruit Industry will be covered
• Harvest and post-harvest handling of deciduous fruit will be covered

Post Harvest

• Ripening
• Maturity Indexing
• Harvesting and Handling
• Cold Storage of Fruit
• Post-Harvest Problems

Pre Harvest

• Soil Prep
• Fertilization
• Irrigation
• Weed Control and Cover Crops
• Pruning and Training
• Grafting, budding and topworking
• Rootstocks

HRT 210 Course

• Practicals are compulsory and worth 20%
• Presentations are worth 20%
• Predicate mark is 40%

Parts of The Flower

• Female parts: Carpel / Vrugblaar
• Stigma / stempel
• Style
• Ovary contains ovule/s (egg cells) / vrugbeginsel (eierselle)
• Male parts: Stamen / Meeldraad
• Anther (pollen) / helmknop (stuifmeel)
• Filament / helmdraad
• Other: Petals / kroonblare
• Sepals / kelkblaar
• Receptacle (modified)

Formation of Stone Fruit

• Stone fruit grows from the ovary

Stone fruit

• Contains exocarp, mesocarp, and endocarp
• Exocarp is the skin
• Endocarp is the pit
• Mesocarp is the flesh between the skin and the pit

Peach Pits

• Peaches contain amygdalin, which breaks down into hydrogen cyanide, however hydrogen cyanide is not heat-stable and does not survive cooking
• 68 kg: the amount a human can safely consume, up to 703 milligrams of hydrogen cyanide before suffering ill effects.
• Raw apricot seeds: eating 98 seeds
• Raw peach seeds :eating 120 seeds
• Raw cherry seeds: eating 1,400 seeds

Pome Fruit

• Pome flower fruit grows from the hypanthium, which is a cup or tubular-shaped expansion of the receptacle of a flower that forms from the fusion of the basal parts of sepals, petals, and stamen
• Becomes the fruit

Pome Fruit - Apple

• Ovary is surrounded by fleshy hypanthium
• Apple (Malus domestica cv. 'gala') is an example

Pome Fruit

• Includes cortex of receptacle
• Includes endocarp

Development

• Days After Anthesis
• 0-35 Cell division / seldeling
• 20-146 Cell expansion / selvergroting
• 30-60 Peak rate of cell expansion
• 90-146 Ripening / rypwording
• 35-87 Starch accumulation / stysel ophoping
• 87-135 Starch decline / stysel afname

Shapes

• Shapes and colors help identify cultivars with apples

Fruit Growth Curves

• Apple has a sigmoid curve
• Peach has a double sigmoid curve
• Cell division
• Pit hardening
• Cell enlargement

Fruit Growth

• Final swell: Trees must have a high demand for water and carbohydrates
• Tip change(stone starts hardening): Time to thin fruit; shoot growth is strong; trees must have good carbohydrate reserves and not suffer any kind of stress
• Period of cell expansion: Cells of flesh fill with water and sugar; the stone is completely lignified and the seed coat darkens.

Ripening

• Stage between growth and ripening
• Immature fruits are green, bitter and hard and prevents premature dispersal
• When physiologically mature, the seed is mature and ripening can begin, though it is not yet ready to eat
• Ripening leads to senescence

Apricot fruit

• Diagram showing development and initiation

Maturation

• Maturity indicates the optimum harvest date
• Depends on fruit uses include:
• Long-term storage
• Short-term storage
• Fresh
• Canning
• Juicing and drying

Ripening

• Certain fruits can be allowed to ripen after picking, e.g. pears, apples, banana and avocado

• Ripening can be postponed under controlled conditions

• Others such as cherries, berries and grapefruits must ripen on plants

• The maturity stage is the stage of the fruit when picked, without the tree's support

• Stage has a great impact on storage time without losing quality

• Picking immature results in poor color and favor, and the fruit will not ripen properly with poor eating quality

• Late picking gives better eating quality, versus easily damaged, prone to diseases and poor storage potential

Ripening

• Eating quality is "made" in the orchard
• The potential eating quality can never increase after harvest, excluding certain types of pears and apples that may increase flavor and sweetness in storage
• Quality usually decreases during storage

Ripening Changes

• Changes during maturation and ripening
• Respiration (Respirasie)
• Ethylene (etileen)
• Fruit softening or texture
• Starch to sugar
• Total soluble solids
• Background color of skin
• Acidity
• Aroma and Flavor

Ripening and Respiration

• Ripening is the transition from physiological maturity to senescence
• Seed-bearing organ (fruit) prepares for detachment from plant
• Ripening changes: -- Skin color -- Internal flesh texture -- Aroma -- Sweetness
• Ripening begins one fruit has reached its maximum size and is physiologically mature

Ripening and Respiration

• Climacteric fruits: have a visible increase in respiratory rates
• Non-climacteric fruits: Pattern is steadily decreasing rate of respiration.
• Some that do not fall into to any one group

Respiration

• Climacteric rise in respiration takes place during ripening process
• Regarded as the time when fruit reaches optimum eating quality
• After climacteric, ageing starts.
• Not all fruit has climacteric rise in respiration

Climacteric Fruit

• Climacteric can continue to ripen after harvest
• The fruit is harvested at the mature, unripe stage and then put into storage
• Is ripened shortly before marketing
• A small dose of ethylene is given to start ripening under temperature and humidity controlled storage

Non-Climacteric

• Fruits show no rise during respiration
• Respiration is low, sometimes with no change

Non-climacteric Fruit

• Do not ripen further removal from the tree
• Don't respond to ethylene treatment
• Show no increase in respiration or production of it

Climacteric advantage

• They get picked before fruit ripens
• Stored before being ripened later

Respiration Rate

• How quickly determined as the faster they'll ripen
• Slow and steady for long-term storage

List of Climateric fruits

• Apple
• Apricot
• Avocado
• Banana
• Mango
• Peach
• Persimmon
• Tomato

List of Non-climateric Fruits

• Sweet and Sour Cherries
• Orange
• Grapefruit
• Grapes
• Pineapple
• Strawberry
• Watermelon
• Litchi

Post harvest factors

• Affecting respiration include temperature, atmospheric composition, physical stress, and stage of development

Respiration & Temperature

• Most important postfactor
• Temperature affects respiration and metabolization
• Increase in respirations come from increase in temperature
• 2 to 3 fold increase for every 10c

Temperatures

• Fruit continues to develop
• Continue to carry out processes such as respiration (water cannot grow because it is away from the plant
• Temperatures need maintained and monitored carefully depending on type and need

Atmospheric Composition Control

• Decreased oxygen only under control over temperature
• Increased dioxide
• Lowering fungus
• Longer life

Ethylene

• What is ethylene
• Colorless gas
• Naturally active compound
• Reaction catalyst
• Needs good O2 and low CO2

Ethylene - Post Harvest

• Laagte ripening
• Color development
• Anthoncyanins -
• Breaks down Chlorophyll
• Degreening, and
• Increasses Respiration
• Separation

Affects of ethylene synthesis

• Genotype/ Cultivar
• Physiological / ripeness/ needs to be controlled
• Physical damage
• Low O -Activity
• CO -limits activity

Fruit Texture

• is the properties and perception of the items
• Softening process is activities that take place

Plants

• Structure and what occurs
• What the walls do and have
• How small the fruits are

Cell walls

• Has 1st layer that is formed
• Is connected to the plant itself

Changes in Fruite Texture

• Change the hardness and chewiness
• Effects cultural and practice aspects with harvest

Styself Stach

• Starches to sugars
• Begins Inside
• Broken at the top of test
• Use lodine test

Total Soluable Solids (TSS)

• Are measure using refractory.
• Starch and organic acids in solids
• Meet sucrose, use instrument

Fruit Color

• Is indicator of maturity
• Color helps in flavor and genetic control
• Growth us green, others show when ethylene are breaking down

Backgrounds

• Is the background og the skill
• Includes cholorpryli
• Effects of season

ABackground Skin

• Is by cartenoids and photosynsisis
• Absorb the light by plant activity

ABackground

• Changes form yellow to red
• Photosynis and water
• Hanges to be seen

Anthocyanins

• Soluble and is blou
• The start is from the process
• Is affected by light