Seed collection and preservation
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This document provides information on seed collection and preservation techniques. It discusses when, where, and how to collect seeds, including from natural seed fall, climbing trees, shaking trees, pruning branches, and collecting from felled trees. It also outlines seed extraction, cleaning, testing, storage and preservation methods. The goal of proper seed collection and preservation is to maintain seed viability and quality until they are ready to be sown.
Seed collection and preservation
- 2. Presentation On seed collection and seed preservation Presented by: Faisal Khalid M.Phil semester 2st FORESTRY AND WILDLIFE MANAGEMENT University of Haripur
- 4. SEED The grains or ripened ovules of plants used for sowing. A mature plant ovule containing an embryo. A small dry fruit, spore, or other propagative plant part. The reproductive body of a flowering plant; the mature ovule. A seed is an embryonic plant enclosed in a protective outer covering . Seed is material which is used for planting or regeneration purposes.
- 7. Seed collection Techniques: Agencies for collecting of Seed: Pakistan Forest Institute Forest Department Pakistan Forestry research institute (Faisalabad) Responsible Contractor
- 8. When, Where and How to Collect Seed: Proper Season Plus Tree Skilled Labour Used of proper Tools
- 9. Methods Of Collection: Seed collection is one of the most important steps in the development of an agroforestry system is the proper collection and production of the seed. After selecting and marking good mother trees, several seed collection methods can be used. Collecting from natural seed fall: This is the simplest way to collect seed. It does not require skilled labour. Collection from natural seed fall is suitable for trees with large fruits, pods, and seeds e.g Tectona The following tools will be helpful: Rake, Sieve, Seed container, Large canvas, cloth or plastic sheet. Follow these steps: Clear the ground beneath the tree , spread plastic sheets, Use a rake to gather the seeds and Extract seeds from the litter by sieving. Advantages: Easy method, Time saving, less costly etc Disadvantages: Immaturity, Fungal infection, lose viability or start germinating.
- 11. Climbing trees to collect seed: To use this method, you must have skill in climbing trees and using some specialized equipment. This is the method normally used to collect from standing dry zone trees. The roof of a car may serve as a platformor climb into the crown of the tree and use a saw, large knife or similar implement to cut down seed bearing branches. Well- designed portable ladders provide a quick and safe means of reaching the live crowns of trees. Ladders may be made of light wood, metal or bamboo 6–15 metres in length. For small trees a light wooden or aluminium ladder 6–8 metres long is appropriate.
- 13. Shaking the tree: If natural seed fall is spread over a long period of time, manual shaking of the tree is a useful method to get seeds to fall to the ground at the same time. This makes their collection easier. Before shaking the tree: Clean the ground, or lay down a plastic or canvas sheet. Shake the trunks of trees or low branches by hand. (Higher branches may be shaken using a stick, long pole, hook on rope) Separate seed from the dry pods.
- 15. Pruning off seed bearing branches: When the seed is out of reach for hand picking various pole implements may be used for pruning branches. Select branches with a heavy load of good looking pods. Carefully locate the ground sheets so that pods and seeds will fall onto them from pruned branches. Cut the branches. Collect the pods. Remove the seeds. To use this method you will need: A special pole pruner with shears attached, or, A long pole with a saw or hooked knife attached. Light, rigid bamboo, aluminium or plastic poles 4–6 metres in length can also be used.
- 17. Throwing a rope with weighted end to break off a seed bearing branch: As the last possibility this destructive method may be used to reach high seed bearing branches from the ground. Branches up to 12 metres from the ground can be reached. Skill is required to throw the rope over the selected branch and in the correct position for ease of breakage. For this method we will need: A strong 5 millimetre diameter rope about 25 metres in length; A 400 gram stone, or small bag of sand or soil. Attach the weight at one end of the rope. Throw the weight over the seed bearing branch. Break off the branch by holding the two ends of the rope, and pulling.
- 20. Collecting seed from felled trees: If a tree is to be felled, try to wait until its seed is ripe. Never fell trees just for seed collection. Seed collectors generally aim to sow or dispatch their seed soon after acquiring it. For various reasons, they may need to store the seed for future use. But remember, the longer seed is stored, the greater chance that viability will be reduced or lost. This is also a cheap and commonly used method of seed collection. This method can be very safely practiced where fallings are in progress.
- 22. Rifle: The advantages of using a rifle in order to shoot down seed bearing limbs of tall Eucalyptus are worth mentioning. This technique has also been approved useful for the collection of acacias pods from moist forest in Australia. This system, however, is not practicable in our country.
- 23. Pole implements: Where the crop is out of reach for hand picking, the use of various pole implements may be appropriate. Pole with shears, saws, or hook of various designs attached to one end are commonly used for detaching the fruit or cutting the seed veering .twigs
- 24. Manual collection: This may prove very effective where trees are small and their branches are low enough for the collector to reach them easily from the ground. The use of pruning shears for cutting off thin branches are effective in collecting additional seed e.g. Toot, Shisham, Beri, Kikar, etc.
- 25. Seed extraction Seed is collected while embedded in ripe fleshy fruits, dried fruits, in pods, or as single seeds. OR It is the process of separation or removing out of seeds from the fruits.
- 26. Methods of Seed Extraction: By rolling seeds in the hands By beating, walking, feeding By spreading in the sunlight By watering By floatation
- 27. CLEANING OF SEED: After extraction of seed from fruit, some debris i.e parts of cones, capsules, pods, Some diseased seeds also must be cleaning affect the germination. Seed collection from the field is rarely fit for immediate storage. Drying extraction from the pods (leguminous) and further cleaning are required.
- 28. Pre-cleaning After collection and before storage the seed collected must be inspected to determine it conditions. Moist pods must be spread out to dry and also require treatment with fungicide to avoid further fermentation.
- 29. Methods of Cleaning Water Method Winnowing method Hand picking Sieving method
- 30. DRYING Natural Drying Seeds are spread in a thin layer on beds over the ground. Depending on species, the degree of maturity of the seed and weather conditions. Artificial drying A temperature is 450C for a maximum period of 48-72 hours.
- 31. SEED TESTING Purity Germination percentage Seed availability
- 32. SEED STORAGE/ PRESERVATION Seed storage may be defined as the preservation of viable seed from the time of collection until they are required for sowing. The activity process of keeping something valued alive, intact, or free from damage or decay.
- 33. Importance of Seed Storage: To preserve seeds for interval between collection and time of sowing. To protect seeds from damage by rodents, birds, and insects. To preserve qualities of seeds collected during year of heavy seed crops to furnish a supply during years of little or no crop.
- 34. Factors Influencing Storage Fully ripened seeds will retain viability longer than seeds collected when immature. Seeds of high initial viability will store better than those with low initial viability. Seeds with hard, impermeable seed coats will retain viability longer than soft. Undamaged seed viability better in storage than damaged. Lower the moisture content (i.e. 32%) and lower the temperature (i.e. 40OC), longer viability.
- 35. Others Factors include Temperature Moisture Content Maturity of Seed Oxygen and other factors Longevity of Seed
- 36. Seed Store or Seed Bank Permanent seed store. Seed store should be well ventilated. Cemented and damp proof floor. Guarded openings with wire netting. Other facilities like water, electricity for seed testing stratification.
- 37. Seed Store or Seed Bank
- 38. Store
- 39. Storage Method From species to species . Store only new, mature, healthy and well-dried seeds. Keep them in dry and cool place. Seed easily reabsorb moisture. To maintain dryness. Put moisture absorbing material like dry wood ash, dry charcoal. The drying material up about one-forth of the container space.. Label the containers with the type of seed, place and date of collection If possible, include the initiate percent viability of the seeds. Protect seeds from insects and fungi. Protect from rodents and birds.
- 40. KINDS OF SEED: Orthodox Seeds dried without damage, to low moisture contents (5 – 10%) Can be stored at sub freezing temperature 2 to 5 OC Their longevity increases with reductions in both moisture content and temperature Examples: Pines, Acacia, Eucalyptus, Casuarina,
- 41. Intermediate Seeds those are more tolerant of desiccation than recalcitrant, though that tolerance is much more limited than is the case with orthodox seeds They generally lose viability more rapidly at low temperature Can be stored at sub freezing temperature E.g. Walnut, fir, Poplus, Salix
- 42. Recalcitrant Seeds that do not survive drying to any larger degree, and no long term storage Can’t be stored in air tight containers Storage must be above freezing E.g. Quercus, Aesculus, Mango, Neem
- 43. TYPES OF STORAGE Dry storage Good for orthodox seeds At room temp for few week or months or at cool temp for longer periods Store seed in piles, sacks, or containers Work well in cool climate with low humidity Optimum temp 32 – 41 OF
- 44. Moist Storage Used for recalcitrant seed Used for short period Basic requirement is good ventilation to prevent heating and fungal growth For uniform moisture conditions the seeds are mixed with moist medium, like sand, cloth, charcoal, saw dust Moisture requirement 11 – 40% Temp requirements 32 – 50O F
- 45. To Find Moisture content Seed Moisture Content (%) = fresh seed weight – dry seed weight /Dry seed weight 100
- 46. Storage Procedure Store only new, mature, healthy and well-dried seeds Keep them in dry and cool place to extend their viability Put in some moisture absorbing material. Dry wood ash, dry charcoal, or small pieces of newspaper The drying material should take up about one- forth of the container space
- 48. Use of containers for storage For good seed storage, always use sealed containers. After seed has been dried properly, store it in tin cans, metal boxes, glass jars, or plastic bags or containers with lids that can be seals (pic: ahead) Points to remember when using sealed containers. Never seal the moist seed in container Use airtight container Make sure that the container is clean Open the seed containers only when necessary.
- 50. Care during Storage Store different types of seeds separately (pic: ahead) Regular inspection Use fumigation and pesticides After fumigation clean seed store to remove all dead insects Fill containers completely to reduce possibility of moisture exchange with the air Use porous bags for moist seed Maintain uniform temperature Label the bag or container with name of species, date of collection, locality, germination percentage.
- 52. List of Tree Seeds their seeding period, viability and no. of seeds per Kg. Species Seeding Period Viability No of seed /kg Acacia nilotica May – Jun Upto one year 6600 – 11000 Acacia modesta Dec – Feb Upto one year 32000-36000 Albezzia lebbek Jan – March Upto one year 4940 – 12430 Casuarina equisetifolia June – Dec 3 to 4 months 660000-990000 Cassia fistula June – April Best upto 2 years 5500-6010 Cedrus deodara Sep – Nov - Do - 7050-9110 Dalbergia sissoo Dec – Jan Up to one year 13220 – 15870 Eucalyptus camaldulensis Oct – Feb Upto 2 years 330000 – 660000 Morus alba Mar – may Best when fresh 42300-46800 Pinus helepensis Oct – Nov Upto 2 years 48400-88000 Pinus wallichiana Sep – Nov Upto 18 months 12340 approx Tamarix aphylla Sep – Dec Very low even fresh 481000 approx