Commercial Uses of plant hormones

Role of ethene (commercially)

Ripening of climacteric fruits

• Continue to ripen after harvested

• E.g. bananas, tomatoes, mangoes

What does ethene stimulate?

Rapid ripening of other fruits

• 1 ripe fruit, put in bunch, stimulates ripening of other fruits in bunch

Why is ethene used commercially?

Fruits are harvested when fully formed but not ripe

• Unripe fruit hard, much less easily damaged during transport around world than ripe versions

  • Prevents a lot of wastage of fruit during transport

• Increases time available for fruit to be sold

How is ethene used once fruit is needed for sale?

Fruit exposed to ethene under controlled conditions

• Each batch of fruit ripens at same rate

• All at same stage to put on shelves for sale

What needs to be considered before applying ethene

• concentration of ethene / stage of fruit development , needs to be known

• Use of ethene to ripen fruit (normally) needs controlled conditions

• Ethene is a gas won’t be effective outside

• ethene promotes fruit dropping (therefore apples may fall to the ground and be damaged)

How is auxin used as rooting powders

At low doses, auxin stimulates cuttings to grow new roots

Benefits of auxin being used as rooting powders

• Increases chances of roots forming & successful propagation occurring

• Makes it easier for horticulturists to develop cuttings to sell

• Horticulture & agriculture, many plans propagated on a large scale by micropropagation

• Quick & cheap

What is used as a hormonal weedkiller?

High doses of synthetic auxins

How do auxins act as weedkillers

Affects their metabolism, growth rate increases, becomes unsustainable, weed dies

• Absorbed by broad leafed plants (usually weeds synthetic dicot auxins used)

Benefits of synthetic auxin being used as weedkillers?

• Simple to use

• Cheap to produce

• Low toxicity to mammals

• Selective

How else can auxin be used in fruit?

Can be used to produce seedless fruit

How can other hormones be used commercially?

Ethene

• Promote fruit dropping in plants e.g. cotton, walnuts, cherries

Cytokines

• Prevent ageing of ripened things, used to control tissue development

Gibberellins

• Delay ripening & ageing; improve size & shape of fruits; speeds up malting process in beer brewing