Sexual Propagation Ms. Avinelis

Why Use Seeds for Propagation? Reliable Uniform Crops Reliable Uniform Crops Low Cost Low Cost Easy to Handle Easy to Handle Mechanical Plantings Mechanical Plantings Shipping (Seed vs. Plants) Shipping (Seed vs. Plants) Storage (Cool, Low Humidity) Storage (Cool, Low Humidity)

Plantings Most of our food and fiber crops are planted directly in the field. Most of our food and fiber crops are planted directly in the field. The soil of the seedbed should be moist. The soil of the seedbed should be moist. Should be of smooth, fine, crumbly soil, and free of clods. Should be of smooth, fine, crumbly soil, and free of clods.

What conditions are necessary for seed germination? Seeds are designed to wait for favorable conditions to begin growth. Seeds are designed to wait for favorable conditions to begin growth. They may lay dormant for many years before conditions allow them to begin to grow. They may lay dormant for many years before conditions allow them to begin to grow.

Stratification When the seed must go through a period of cold temperatures before it will germinate. When the seed must go through a period of cold temperatures before it will germinate.

Scarification Breaking down of the seed coat. Breaking down of the seed coat. Some seeds have such a hard, thick seed coat that they prevent the absorption of water to enable germination to occur. Some seeds have such a hard, thick seed coat that they prevent the absorption of water to enable germination to occur. You can use sand paper or files to damage the seed coat. You can use sand paper or files to damage the seed coat.

Planting Depth Rule of Thumb – Plant seed twice as deep as the seed is. Rule of Thumb – Plant seed twice as deep as the seed is. Really small seed should be planted in greenhouses and then transplanted to field. Really small seed should be planted in greenhouses and then transplanted to field.

Irrigation in Field Flood Field and allow plants to be watered by capillary action. Flood Field and allow plants to be watered by capillary action. Sprinklers Sprinklers What would be a problem? What would be a problem? Be careful to avoid crusting of the soil. Be careful to avoid crusting of the soil. Why? Why?

Planting in Flats Usually done in greenhouses. Usually done in greenhouses. Controlled conditions – Quick Controlled conditions – Quick Medium that holds moisture and drains easy. Medium that holds moisture and drains easy. Sand, perlite and peat moss Sand, perlite and peat moss Plant in rows or sporadic. Plant in rows or sporadic. Too many seeds Too many seeds in flat = Spindly in flat = Spindly

Planting in Flats Continued Once you put seeds in tamp them down. Once you put seeds in tamp them down. Cover with a thin layer of soil on top Cover with a thin layer of soil on top Helps with moisture Helps with moisture Fungus Fungus Work with clean sterile tools and environment Work with clean sterile tools and environment Water Occasionally Water Occasionally Careful not to wash out Careful not to wash out Best Temperature 70-80°F Best Temperature 70-80°F

Germination process The germination process begins with the absorption of water. The germination process begins with the absorption of water. The seed swells and the embryo changes from a dormant state to an actively growing plant. The seed swells and the embryo changes from a dormant state to an actively growing plant. The embryo draws energy from starches stored in the endosperm or cotyledons. The embryo draws energy from starches stored in the endosperm or cotyledons. The embryo’s root emerges from the seed and develops into the primary root. Then, the stem of the embryo sprouts upward. The embryo’s root emerges from the seed and develops into the primary root. Then, the stem of the embryo sprouts upward.

Problems that Can Occur Old seed looses viability, percent reduced. Old seed looses viability, percent reduced. Even Moisture at all times Even Moisture at all times Temperature to Low or High (Field) Temperature to Low or High (Field) To shallow planted (Dry) To shallow planted (Dry) To deep planted (Energy) To deep planted (Energy)

Post Germination Care Constant Supply of Water Constant Supply of Water Low Fertilization Low Fertilization Bright Light reduces spindly Bright Light reduces spindly Maintain temperature Maintain temperature

Transplanting Seedlings can generally be transplanted after their first true leaves develop fully. Seedlings can generally be transplanted after their first true leaves develop fully. If going direct to field, more time to mature. If going direct to field, more time to mature. Hardening Hardening Reduce water, day/night temperatures. Reduce water, day/night temperatures. Handle only by leaves (not roots or stem) Handle only by leaves (not roots or stem) Depth Depth Dispose of damaged or diseased plants Dispose of damaged or diseased plants

Transplanting Double water plants right after transplanting. Double water plants right after transplanting. Water immediately Water immediately Make hole larger than Make hole larger than the root ball the root ball

Precautions for Young Plants Sunburn Sunburn Over watering Over watering Extreme Temperatures Extreme Temperatures Pests / Diseases Pests / Diseases

Fruit/Vegetable Dissection Break up into groups of 3 Break up into groups of 3 Cut open your Vegetable or Fruit Cut open your Vegetable or Fruit Count total seeds that you have in 1 fruit/vegetable. Count total seeds that you have in 1 fruit/vegetable. Plant pony packs of seeds. Plant pony packs of seeds. Bring one seed to the front to look at under microscope. Bring one seed to the front to look at under microscope.