Here is a time lapse of a Broad bean showing hypogeal germination and root growth.
Hypogeal
‘Hypogeal’ means ‘underground’.
This is when the cotyledons of the germinating seed / bean remain below ground.
salts in the soil.
Roots and root hairs
The main functions of root are:
Absorption of water and nutrients,
Fixation of the plant to the soil,
Root bears unicellular root hairs.
Conduction of water and nutrients to aerial parts of plants
Root cap.
It is a cap-like structure at the tip of root. It cover and protects the growing point from injury as it pushes through the soil.
Tomato blight is weather-dependent and can be devastating during wet summers. Watch out for signs on outdoor tomatoes, which are most at risk; glasshouse tomatoes are less likely to become infected though the spores are carried in the wind and will enter through open windows and doors.
Tomato blight on leaf
Early Blight can affect the foliage, stems and fruit of tomatoes.
Symptoms: Dark spots with concentric rings develop on older leaves first. The surrounding leaf area may turn yellow. Affected leaves may die prematurely, exposing the fruits to sun scorching.
Management: Early Blight fungus overwinters in plant residue and is soil-borne. It can also come in on transplants. Remove affected plants and thoroughly clean fall garden debris. Wet weather and weak stressed plants increase the likelihood of attack. Copper and/or sulfur sprays can prevent further development of the fungus
Late Blight is caused by a fungus, Phytophthora infestans. It’s the same disease that led to the Irish potato famine almost 150 years ago.
The disease is not directly harmful to people as it only infects potatoes, tomatoes, and some related weeds, but it is not advised to eat the infected fruit or tubers.
It is important to catch any tomato disease early, before it spreads to all of your tomato plants and possibly other plants in the same family, such as potatoes, eggplants and peppers.
Look for brown, rapidly spreading patches on leaves and stems. The fruit, too, may show firm, quickly spreading brown patches followed by rotting. Infected parts die rapidly.
Destroy infected plants; but do not compost them as the plant residue is soil-borne and will spread the disease to your next years crop.
Late blight needs living plant tissue to survive, so infected tomato plants should be destroyed as soon as the disease is identified. In small gardens, this means removing plants in trash bags and sending them to the landfill;
Here is a time-lapse of a runner bean germinating underground. This is an example of Epigeal germination where the cotyledons expand, throw off the seed shell and become photosynthetic above the ground.
Beans like other seeds need temperature and moisture to stimulate germination.
Stage 1:
Radicle expands and pushes against the testa at the micropyle
Testa spilts open and radicle emerges
Lateral roots develop
Root hairs form behind tip of radicle which helps absorb water and mineral salts in the soil
Stage 2
Stem below cotyledons elongates
Pulling cotyledon through soil and above the ground
Sometimes the is testa remains underground or discarded above ground
Cotyledons are closed together to protect the delicate pumule within
Stage 3
Cotyledons open up above ground
Cotyledons turn green
First foliage leaves start to develop
Foliage expands and turns green carrying out photosynthesis
Runner bean seedling is now a self-supporting plant
Here is a time lapse of a Broad bean showing hypogeal germination and root growth. Hypogeal ‘Hypogeal’ means ‘underground’. This is when the cotyledons of the germinating seed / bean remain below ground. salts in the soil. Roots and root hairs The main functions of root are: Absorption of water and nutrients, Fixation of the plant to […]
Posted by Neil Bromhall 
Posted by Neil Bromhall 
Posted by Neil Bromhall 
