Growing Conditions Factors 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

K Potassium Mineral Nutrients N Nitrogen 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 contains large quantities of known amounts of nutrients decays slowly so releases nitrogen over a long time cheap and easy to obtain releases nutrients quickly contains other nutrients needed by plants such as magnesium easy to spread

Anther Stigma Where the pollen lands Produces pollen (male gamete) Style Pollen travels down this Ovule Egg (female gamete) Sepal Protects the flower in bud 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. Advantage Does not require another plant of the same species near by 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 Small quantities of large, sticky pollen is produced Nectar is produced Anthers and stigma inside flower in the best position for the insect

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.

Cotyledons (Food Store) Seed Germination Testa (Seed Coat) Plumule Tough, so water is needed to swell the seed and break the testa before the seed can germinate Young shoot Radicle Cotyledons (Food Store) Young root Glucose + Oxygen Energy 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

All the F1 generation are Red Red Rose Phenotype:Red Genotype: Rr White Rose Phenotype: white Genotype: rr The allele for red flowers is dominant over the allele for white flowers All the F1 generation are Red

Inheritance of Flower Colour Using A Punnet Square A red flowered plant was crossed with a white flowered plant. What is the ratio of phenotypes and genotypes in their offspring? R r rr R r r Rr b Rr r b 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

Clay Water Humus Sand Silt

Storing Crops Ripening Bruising Diseases Pests