1. New lecture notes
3. Pruners etc
4. Find seeds to test for germination
5. Find seeds to plant
6. Discuss different sizes of seeds for planting
7. The quiz (START)
8. Germ tests
"To 'keep the seeds alive'—both literally and metaphorically—they must be planted, harvested, and replanted, just as human culture must become truly engaging and meaningful to the soul, as necessary as food is to the body. The viable seeds of spirituality and culture that lie dormant within us need to “sprout” into broad daylight to create real sets of cultures welcome on Earth." From a book review for The Unlikely Peace at Cuchumaquic: The Parallel Lives of People as Plants: Keeping the Seeds Alive by Martin Prechtel
Our choices as a society have never been so starkly clear nor so hotly contested as they are now. In a case before the Supreme Court regarding the patenting of seeds, Supreme Court Chief Justice Roberts asked “Why in the world would anybody spend any money to try to improve the seed if as soon as they sold the first one anybody could grow more and have as many of those seeds as they want?” neglecting, I suppose out of absent-mindedness and not out of ignorance, that this is precisely the model that humankind has followed since we first began to save seeds, and therefore, most of the food we eat today was developed along that model.
What does comidification equal? Enslavement?
Single celled plants
Multi-cellular plants that were very little more than an aggregate of cells, no circulation system, liver worts, lichens, preparing the atmosphere for animals over thousands of years – Native American cosmologies
Advent of ferns and others: spores – central systems
Finally the gymnosperms
Then the angiosperms (Magnolia)
The plants we save seeds from are all angiosperms
Seeds only come from female flowers
Individual plant sexuality
- Many plants have complete flowers that have both male and female parts in each flower – botanists have called these “Perfect” flowers
- Others only have male or female parts: Monoecious, an individual that has both male and female reproductive units that are separate (flowers, conifer cones, or functionally equivalent structures) on the same plant; from Greek for "one household".
Hermaphrodite, a plant that has only bisexual reproductive units i.e. flowers, In angiosperm terminology a synonym is monoclinous from the Greek "one bed". Dioecious refers to a plant population having separate male and female plants.
Many plants have complete flowers that have both male and female parts others only have male or female parts still other plants have flowers on the same plant that are a mix of male and female flowers.
Some plants even have mixes that include all three types of flowers, where some flowers are only male, some are only female and some are both male and female.
Hermaphrodite, plants whose flowers have both male and female parts, usually called 'perfect flowers.'
Monoecious plants have separate male and female flowers on the same plant. A plant population where the male and female organs are found in different flowers on the same plant. Examples of monoecious plants include squash, cucumbers, corn,
Dioecious, all plants are either female or male. Spinach,
About 11% of all angiosperms are strictly dioecious or monoecious. Intermediate forms of sexual dimorphism, including gynodioecy and androdioecy, represent 7% of the species examined of a survey of 120,000 plant species. In the same survey, 10% of the species contain both unisexual and bisexual flowers.
The Asteraceae or sunflower family with close to 22,000 species, have highly modified inflorescences that are flowers collected together in heads composed of a composite of individual flowers called florets. Heads with florets of one sex, when the flowers are pistillate or functionally staminate, or made up of all bisexual florets, are called homogamous and can include discoid and liguliflorous type heads. Some radiate heads may be homogamous too. Plants with heads that have florets of two or more sexual forms are called heterogamous and include radiate and disciform head forms, though some radiate heads may be heterogamous too.
Seeds only happen in female flowers.
Pollination (Sex with flowers) (Birds and the Bees)
Ways plants are pollinated:
Self – perfect flowers (hermaphrodite)
Animals zoophily including bats, birds,
Insects Entomophily bees, wasps and occasionally ants ,beetles, moths and butterflies
Air Anemophily or wind pollination dominate in grasses (i.e. grain) Abiotic
Water Hydrophily Abiotic
Pollination of food crops has become an environmental issue, due to two trends. The trend tomonoculture means that greater concentrations of pollinators are needed at bloom time than ever before, yet the area is forage poor or even deadly to bees for the rest of the season. The other trend is the decline of pollinator populations, due to pesticide misuse and overuse, new diseases and parasites of bees, clearcut logging, decline of beekeeping, suburban development, removal of hedges and other habitat from farms, and public concern about bees. Widespread aerial spraying for mosquitoes due to West Nile fears is causing an acceleration of the loss of pollinators.
The US solution to the pollinator shortage, so far, has been for commercial beekeepers to become pollination contractors and to migrate. Just as the combine harvesters follow the wheat harvest from Texas to Manitoba, beekeepers follow the bloom from south to north, to provide pollination for many different crops.
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant. The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.
Metabolism in seeds
Seeds are metabolizing all the time – they breathe because they are alive. This respiration is very slow and slight. Still, a large quantity of beans in a sealed container can exhaust the available oxygen in the jar can render all the seeds nonviable.
Germination is the growth of a plant contained within a seed; it results in the formation of the seedling, it is also the process of reactivation of metabolic machinery of the seed resulting into the emergence of radicle and plumule. The seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All fully developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat. Some plants produce varying numbers of seeds that lack embryos; these are called empty seeds and never germinate. Dormant seeds are ripe seeds that do not germinate because they are subject to external environmental conditions that prevent the initiation of metabolic processes and cell growth. Under proper conditions, the seed begins to germinate and the embryonic tissues resume growth, developing towards a seedling.
Seed germination depends on both internal and external conditions. The most important external factors include right temperature,
oxygen or air
and sometimes light or darkness.
Conversely, saving seeds requires almost the opposite – seeds must be stored in dry, cool, and dark conditions. Like the Svalbard Global Seed Vault - The seeds are stored in four-ply sealed envelopes, then placed into plastic tote containers on metal shelving racks. The storage rooms are kept at −18 °C (−0.4 °F). The low temperature and limited access to oxygen will ensure low metabolic activity and delay seed aging. The permafrost surrounding the facility will help maintain the low temperature of the seeds should the electricity supply fail.
Various plants require different variables for successful seed germination. Often this depends on the individual seed variety and is closely linked to the ecological conditions of a plant's natural habitat. For some seeds, their future germination response is affected by environmental conditions during seed formation; most often these
In agriculture and gardening, the germination rate describes how many seeds of a particular plant species, variety or seedlot are likely to germinate over a given period. It is a measure of germination time course and is usually expressed as a percentage, e.g., an 85% germination rate indicates that about 85 out of 100 seeds will probably germinate under proper conditions over the germination period given. The germination rate is useful for calculating the seed requirements for a given area or desired number of plants. In seed physiologists and seed scientists "germination rate" is the reciprocal of time taken for the process of germination to complete starting from time of sowing. On the other hand, the number of seed able to complete germination in a population (i.e. seed lot) is referred as germination capacity.
The part of the plant that first emerges from the seed is the embryonic root, termed the radicle or primary root. It allows the seedling to become anchored in the ground and start absorbing water. After the root absorbs water, an embryonic shoot emerges from the seed. This shoot comprises three main parts: the cotyledons (seed leaves), the section of shoot below the cotyledons (hypocotyl), and the section of shoot above the cotyledons (epicotyl). The way the shoot emerges differs among plant groups.