Plant Propagation. Seed Starting for the Vegetable Garden. Propagation by Seed. Pollination. Pollination. Asexual Propagation

Transcription

1 Plant Propagation Seed for the Vegetable Garden Advanced MGV Training Mike Maddox Rock County UW-Extension Sexual Propagation Recombination of genetic materials to form uniquely genetic individual Asexual Propagation Use of vegetative organs to create plantlets genetically identical to parent plant Propagation by Seed Pollination Biology Pollination Anatomy Applied Purchasing Transplanting Storing Pollination: transfer of pollen from anther (male part) to stigma (female part) in a flower. Exchange of genetic material Pollination Self pollination: Transfer on same flower From different flowers on the same plant o From flowers on different plants of the same cultivar Beans, peas, lettuce, eggplant, peppers, and tomatoes 1

2 Pollination Cross pollination: Transfer of pollen on plants of different cultivars of the same species Onions, cucumbers, corn, pumpkins, squash, broccoli, beets, carrots, cabbage, cauliflower, melons, radishes, spinach, Swiss chard and turnips Pollination Fertilization the union of a male reproductive cell and a female reproductive cell that is capable of developing into an new individual Anatomy Anatomy Embryo: miniature plant in arrested development Endosperm (Cotyledons): built-in food storage Seed Coat: hard out covering for protection, prevents water from entering and initiating germination before proper time. Seed Coat Endosperm The process of seed growth and development Embryo 2

3 Dormancy Viable seed that will not germinate when in proper environment Due to internal or external cause Quiescent Ripened seed, ready to germinate, waiting for the proper environmental conditions for germinations Allows seed to survive over periods of time Scarification Physically altering the seed coat to allow moisture penetration Natural scarification processes: passing seed through GI tract of animals, weathering of coat Artificial scarification processes: hot water bath, sandpaper, etc. Breaks seed coat allowing moisture to enter! Stratification Exposing a seed to moisture and specific temperatures (cold) in order to encourage germination Degrades chemical inhibitors causing dormancy Factors affecting germination Water (moisture) Light (or dark) Oxygen Heat Water (moisture) Penetrates seed coat Endosperm to swell- seed coat splits Dissolves nutrients to initiate germination 3

4 Light (or dark) Can stimulate or inhibit germination Check seed package for planting instructions Oxygen Required for respiration Facilitated with light, well aerated soil mix Propagation by Seed Heat Optimum range for germination Many seeds have wide range Check catalog or seed package for instructions Drives metabolic process Biology Pollination Anatomy Applied Purchasing Transplanting Storing Purchasing Seed Purchasing Seed Choose superior cultivars High quality seed Disease resistant cultivars when available Garden centers Mail order Obtain by mid- February rates Expected percentage of seed to germinate Generally, 65-80% will germinate 60 75% will grow into useful seedlings 60-75% will grow into useful seedlings May affect density of planting 4

5 Indoors Small seeds Long season plants Supplies needed Grow lights Clean containers (with drainage) Sterile seed starting medium Location with proper ventilation and temperature Growing media Loose, uniform, fine texture Mixes labeled for seed starting Pasteurized (sterile) May be low in fertility Containers Any container will do Disinfested Good drainage Adequate root space Containers Compressed peat pellets Peat pots Paper pots Paper pots Plastic cell packs Flats 5

6 Sowing Account for seed germination in timing factor and growing time 2 weeks to germinate, 6 weeks to transplant date - 8 weeks for full development time. Sow in mid-march or April depending on plant species and growing conditions Fill container to within ¼ inch of the top of the rim with moistened seed-starting medium Large seeds directly in pots or cell packs Squash, cucumber, watermelon 2 per pot Use pencil or dibble to make hole for seeds Cover with media related to seed size Small seeds scatter on surface of large cell packs or other containers for later transplant Sprinkle more potting media over seeds or sphagnum moss (sphagnum moss helps prevent damping off) Mix small seeds with sugar or extremely fine sand to help with equal distribution 6

7 Watering Water from below in tray before seeds germinate and when seedlings are very small Allow drying between waterings Helps prevent damping-off Standing water in flats leads to disease problems Don t allow seedlings to wilt Cell damage can occur that is permanent Moisture Plastic covers are useful to trap moisture Retains moisture Remove to promote hardening of tissues Supplemental lighting 3 4 from light source Cool white and warm white fluorescent lights Move lights as plants grow or move plants hours a day Timers are inexpensive and very useful High intensity and quality light less leggy plants Temperature Nights F and 75 F Good rule of thumb-day temperatures 10 degrees warm than night. Cool season crops cooler day/night temps 55 degrees night 65 degrees day Warm season crops higher day/night temps 65 degrees night 75 degrees day Heating mats Fertilization After germination Go ½ rate, avoid burn Two week intervals 7

8 Transplanting Move to larger container when first set of true leaves form Lift seedlings from containers with small flat tool Tease apart tangled plants/roots Handle by true leaves Acclimation Acclimation Plants must develop cuticle Gradual exposure to harsh climates Dry conditions, wind, light intensity, etc. Direct sowing Avoids transplant shock Less work More risk with weather, pests, disease, erosion Direct sowing Know conditions and requirements for seeds Warm- or cool-season crop Average last frost date 8

9 Direct sowing Sow or broadcast into a well-raked bed Free of stones or large debris Cover with a fine layer of soil Gently water to avoid erosion Storing Keep dry Place in airtight container Label and date Store in 40º F, low humidity Open-pollinated: A plant that will grow true to type each year Offspring exactly like the parents Heirlooms Hybrids: The first generation (F1) offspring of two distant and distinct parental lines of the same species Seeds taken from a hybrid may either be sterile or more commonly fail to breed true Beans Beans of all kinds are very popular heirloom vegetables. There are thousand of cultivars, with huge variations in taste, size, color and markings, and climate adaptability. Beans Beans are usually not cross-pollinated. Separate plantings by enough distance to avoid having their vines intertwine. Allow the seed to thoroughly mature on the vine. Pull the entire plant and place it in the shade to dry out for one to two weeks. Bring inside to finish drying if rain threatens. Shell and store in a cool, dry area in a paper bag. Bean and cowpea seeds will keep for three or more years. 9

10 Corn All corn is wind-pollinated and will readily cross with other varieties. Varieties should be widely separated, from 600 feet to over half a mile to ensure purity. You can also save seed by bagging the ears that t you want to save for seed and hand-pollinating them, or by growing cultivars that will be separated by blooming time. You should always grow at least 200 corn plants in a large block when saving seed. Let the seed dry thoroughly on the plant and then dry further once husked. Seed lasts only one year. Cucumbers and Melons There are many different forms of cucumbers that are rarely seen in stores. Cucumbers are cross-pollinated by insects. So if you want to save cucumber seed, plant only one variety. Let the fruits hang on the vine until ripe (skin becomes yellowish and hard). Then handle like the process for tomatoes given below. Lettuce Cut off seed stalks when fluffy in appearance, just before all the seeds are completely dried. Seeds will fall off the stalk and be lost if allowed to mature on the plant. 10

11 Potatoes Potatoes are popular heirloom vegetables. There are many unusual colors, shapes and flavors that are seldom found at the grocery store. Heirloom potatoes are saved from year to year as tubers, and so are very easy to maintain true to name. Peppers, Sweet and Chili Peppers are usually self-pollinating. Insect cross-pollination does occur sometimes, and if it does, hot bell peppers can result, since the gene for hotness is dominant. If grown closer than 500 feet apart, plants must be caged or bagged to prevent spicy surprises in future years. Peppers, Sweet and Chili Peppers should be allowed to ripen until they become red. Cut the pepper pod in half and scrape the seed onto a piece of paper. Spread out the seed and dry thoroughly before placing in a storage container. Wash your hands thoroughly with soapy water after harvesting the pepper seeds, since the residues will burn eyes and lips for hours after contact. 11

12 Squash and Pumpkins Winter and summer squash and pumpkins are all related. Crossing readily occurs between varieties of the same species. No crossing occurs between different species. Grow only one variety of the same species, and separate by ½ mile or hand pollinate to maintain purity. The commonly grown species are: banana, buttercup, cushaw and hubbard squash (Cucurbita maxima); butternut squash (Cucurbita moschata); acorn, crookneck, and scallop squash, zucchinis and most pumpkins (Cucurbita pepo); and Mexican gourd (Cucurbita ficifolia). Squash and Pumpkins When the outer covering of the squash is so hard that it cannot be dented with your fingernail, the seeds are generally mature. Split the squash fruit open, scoop out the seed and wash until all pulp is removed. Spread out on newspaper to dry. Tomatoes Tomatoes are self-pollinators and are usually not cross-pollinated. Only the potato leaf varieties must be separated. Pick fruit from desirable plants when ripe. Cut fruit and squeeze out pulp into a container. Add a little water and let ferment two to four days at room temperature, stirring occasionally. When seeds settle out, pour off pulp and spread seeds in a thin layer to dry thoroughly. Store in an envelope or glass jar in a cool, dry place. Properly stored seeds will remain viable for four to 10 years. Seed Fun, low cost way of obtaining plants Provides a variety of things Know the science and basics Seed for the Vegetable Garden Advanced MGV Training Mike Maddox Rock County UW-Extension 12