Growing Conditions Factors that a gardener needs to consider to maximise plant growth: Water Light...
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Transcript of Growing Conditions Factors that a gardener needs to consider to maximise plant growth: Water Light...
Growing ConditionsFactors that a gardener needs to consider to
maximise plant growth:• Water• Light – motorised screens, shading• Suitable temperature – greenhouses,
polytunnels, cloches, ventilators, fans, fleece
• Growing medium (soil, compost etc)• Humidity
Photosynthesis
Carbon Dioxide + water Oxygen + glucose
Unhealthy Plant
• Wilting – under watering• Pest Damage – aphids, slugs• Poor Growth• Fungal Disease – damping off, potato
blight
Biological Pest Control
• Predator of the pest used to eat the pest• Example: Ladybird is a predator to an
aphid• Advantage – No pesticides• Disadvantage – Can change predator-prey
relationships, changing the ecosystems
Mineral Nutrients
N Nitrogen
K Potassium
P Phosphorus
Too much Nitrogen
Stem grows too tall and thin and crop falls over
Burns the roots
N,P,K,Mg
• Too much Nitrogen – excess growth, lot of green leaves, not many flowers
• Not enough Phosphorous – stunts growth (particularly roots), grow slowly, less resistant to disease or drought
• Not enough potassium – edge of leaves yellow/brown, fewer flowers/fruit
• Not enough Magnesium – yellow leaves, less healthy, yield lower
Fertilisers – absorbed by the roots
Organic Inorganic
• adds humus and so improves crumb structure
• decays slowly so releases nitrogen over a long time
• cheap and easy to obtain
• contains other nutrients needed by plants such as magnesium
• contains large quantities of known amounts of nutrients
• releases nutrients quickly
• easy to spread
Sepal
Protects the flower in bud
Anther
Produces pollen
(male gamete)
Stigma
Where the pollen lands
Style
Pollen travels down this Ovule
Egg
(female gamete)
Ovary
Develops into the fruit
Cross Pollination
The transfer of pollen from the anther of one flower to the stigma of another flower of the same species
This increases genetic variation so plants are able to adapt to their surroundings
Self Pollination
The transfer of pollen from the anther of one flower to the stigma of the same flower.
Does not require another plant of the same species near byAdvantage
Disadvantage Little genetic variation in offspring
Wind Pollinated Plants
Feathery Stigma hanging outside the flower to increase surface area to catch pollen
Anthers hanging outside the flower so wind will blow pollen away
Lots of small, light pollen produced so it can be carried by the wind
Flower small and green and not scented since it does not need to attract insects
Insect Pollinated Plants
Brightly coloured, scented flowers to attract insects
Anthers and stigma inside flower in the best position for the insect
Nectar is produced
Small quantities of large, sticky pollen is produced
A word of caution
Make sure that there are insects or wind in glass houses and polytunnels
Vegetative Reproduction
• This is asexual• All offspring are genetically identical to the
parents• Growers know what they will produce• If one plant gets a disease they will all get
the disease
Runners eg. Strawberry plants
An above ground stem
Rhizomes eg. Ginger
An underground stem
Bulbs eg. Onion
Leaves become swollen with food stores.
Seed Germination
Testa (Seed Coat)
Tough, so water is needed to swell the seed and break the testa before the seed can germinate
Cotyledons (Food Store)
Glucose + Oxygen Energy
Plumule
Young shoot
Radicle
Young root
Enzymes are needed for respiration therefore seeds only germinate in the warmth
Light is not usually needed for germination except in certain seeds such as lettuce
Raising Plants from Seed
Growing from seed
• Thinning out: weak seedlings removed to give others more room
• Pricking out: Lift the seedlings out carefully holding their cotyledons (seed leaves) and re-plant in a new tray to allow seedlings to grow well.
• Potting on – give seedlings more room to grow
• light sensors
• temperature probes
• carbon dioxide sensors
• pH meters
• humidity sensors
White Rose
Phenotype: white
Genotype: rr
Red Rose
Phenotype:Red
Genotype: Rr
The allele for red flowers is dominant over the allele for white flowers
All the F1 generation are Red
rr
rr
b
b
R r
Inheritance of Flower Colour Using A Punnet Square
Rr
Rr
A red flowered plant was crossed with a white flowered plant. What is the ratio of phenotypes and genotypes in their offspring?
R r
r
r
Percentage Genotypes: 1:1 Rr:rr
Percentage Phenotypes: 1:1 Red : white
Single Digging
• aerates the soil
• removes weeds
• improves drainage
• FYM can be added to improve crumb structure
• raked to produce a good tilth
Sand
Silt
Clay
Humus
Water
Storing Crops
Ripening
Bruising
Pests Diseases