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Core Course 5 – Environmental and Natural Resources Management
Exercise 1- Seed Technology and Seed Testing
INTRODUCTION
Seeds is define as a small object produced by a plant from which a new plant can grow. In
addition, it is the beginning of something which continues to develop or grow. Seed is the “source of
life.” In the field of agriculture, seeds commonly used as reproductive material thus unique products
of fertilization and promoting genetic diversity. It is abundant as an economical source of propagules
and relatively easy to handle and store.
Therefore, to effectively utilize this resource it is better to use seed technology in which involves
practices and treatment applied to mother trees, seed stands, seeds, fruits/cones to insure the
production, collection, processing, handling and marketing of high-quality seeds to end-users.
Seed technology can be define as the practices and treatment applied to mother trees, seed stands,
seeds, fruits/cones to insure the production, collection, processing, handling and marketing of high-
quality seeds to end-users. The scopes of this technology are the following:
a) seed source phase f) seed pre germination treatment phase
b) seed production phase g) seed testing phase
c) seed collection phase h) seed certification phase
d) seed processing phase i) seed legislation phase
e) seed storage phase j) seed marketing phase
Meanwhile, seed testing as one of the scope in seed technology is aims to determining the
standard of a seed lot, breaking or lessening dormancy, physical purity moisture and germination and
thereby the forming community to get quality seeds. Seed dormancy has been defined as the
incapacity of a viable seed to germinate under favorable conditions (Bentsink L. and Koorneef M.,
2008). There are different procedures in breaking seed dormancy appropriate for each seed:
Methods of Breaking Seed Dormancy
Various methods have been used by seed scientist and technologists to break the dormancy of seed.
Simple and widely used methods are
A.Scarification
–any treatment i.e physical or chemical that weaknesses the seed coat, is known as scarification.
- is applied when dormancy is imposed by hard seen coat e.g. in legumes – Cajanus cajan
In this method there are various way to break hard seed coat such as:
1. Seeds are either rubbed on a sand paper manually. At the time of rubbing care should be taken that
not to damage the axis of the seed e.g. Green gram & subabool
2. When seed coat is too hard i.e. of woody nature, the seed coat has to be removing completely by
breaking it. E.g Rubber (Havea app) seed India teak wood seed. The pulp as cover of hard testa or
seed coat as outer covering can be removing by depulping.
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3. Soaking treatment: Soaking hard seed coat in concentrated or diluted solution of sulphuric acid for
1 to 60 minutes, it removes seed coat impermeability, e.g cotton seeds, India teak wood seeds etc.
B.Temperature Treatments:
1. When the dormancy is due to embryo factor i.e the seed is incubating at low temperature (0-50oC)
over a substratum for 3 to 10 days placing it at optimum temperature. Required for germination e.g
mustard (Brassica campestris).
2. Some seeds required a brief period of incubation (from a few hours to one to five days) at 40 to 50
o
C before germinating at required temperature. In this method care should be taken that moisture
content of the seed is not more than 15% e.g paddy (Oryza sativa). It can be considered also the
flotation test.
3. Hot water treatment is also an effective method of breaking hard-seedness in legumes. In this
method the seeds are soaked in water at 80 oC temperature for 1 to 5 minutes (depending up on the
type of seed) before putting for germination. It can be considered also in soaking the seeds in ordinary
tap water.
C. Light Treatments:
Some seeds do not germinate in dark thus it provides continuous or periodic exposure of light is
essential e.g. Lettuce (Lactuca sativa) required red light (660nm) or white light is essential for
germination to occur.
D. Treatments with Growth Regulators & other Chemicals:
Endogenous dormancy may be due to presence of germination inhibitors. Application of low level of
growth regulators (i.e Gibberelins, Cytokinins and Etylene etc.) may break the seed dormancy.
Most widely used growth regulators are gibberellins and kinetics e.g seeds of sorghum crop pre
soaking seed treatment with GA3 at the concentration of 100 ppm have been used for breaking seed
dormancy.
Among other chemicals potassium nitrate (0.2%) and thio-urea (0.5 to 3%) are widely used for
breaking seed dormancy in oat (Avena sativa), barley (Hordeum vulgare), tomato (Lycopersicon spp.)
(For prepare 100 ppm solution of GA3, weight 100 mg of GA3 & dissolve in a few drops of alcohol
and make up the final volume (1000 ml) by adding distilled water).
(50 ppm kinetin 5 mg dissolve in few drops of alkaline made with sodium hydroxide and makes the
final volume 100 ml it gives to final concentration of 50 ppm.
Source: http://www.agriinfo.in
The characteristics of high-quality seeds are:
• Collected from the superior/best provenance or source
• High viability (high germinability)
• Vigorous (rapid and uniform emergence under a wide range of environmental conditions)
• High physical purity
• Free from seed-borne disease and pests
Seed species materials to be used/collected
• Pili (Canarium ovatum)
• Cacao (Theobroma cacao)
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• Guava (Psidium guajava)
• Guyabano (Annona muricata)
• Calamansi (Citrofortunella microcarpa ) or calamondin
OBJECTIVES: This exercise aims to:
1. introduce students to be familiar in seed technology
2. enable students to learned the basic activities in seed testing
3. enable them to appreciate seed as source of life
4. produce agroforestry seedlings as planting stocks from seeds
MATERIALS
seed box, garden soil, plastic containers, polybags, soil/potting medium,seeds, scalpel, water
METHODOLOGY
1. In every student collect and prepare 25 seeds of each agroforestry crops mentioned above such as
Cacao, Calamansi, Guava, Guyabano and 50 seeds of Pili. Before collection:
2. Decide on the purpose for which germplasm is required (discussed by Instructor). Find out if
suitable and well-documented germplasm is already available from other sources.
3. Develop a collection strategy-determine the where, when and how of collection
a) Where – find out the geographical and ecological areas where a species grows and from what areas
it can be collected (literature, herbaria, field exploration).
b) When – decide on the best time for collection. This may require a prior visit to a site to identify the
period when seed is mature. Herbarium specimens often give dates of fruiting or collection. Trees
may seed only in certain years and the timing of seed production may vary between years and regions.
For species with a prolonged fruiting season, more than one sampling time might be needed to avoid
collecting only the early fruiting trees.
c) How – estimate the quantity of seed required from the collection, to determine the appropriate
sampling strategy. In addition, decide if seed from individual trees should be kept separate during
collection or bulked to form a single population sample. For research trials, individual tree collections
are sometimes needed, while in other cases a bulk collection from a population suffices. If material is
being collected for immediate distribution to farmers or other users, a bulked collection strategy may
make handling easier.
3.Find out the requirements for handling seed of a species being collected, including necessary seed
treatments to ensure maximum seed viability. If seed is recalcitrant, however, it is necessary to
prepare for immediate planting after collection.
4.Ensure that all necessary equipment for collection is available. Collection from trees may require
special tools, such as pruning saws and tree climbing equipment. Use open-weave collection bags
rather than plastic ones, to allow aeration.
5.Ensure that the necessary permission for collection is obtained. If collections are to be free from
communal or private land, it is necessary to obtain the permission of the head of the community or the
landowner. For large-scale collections, permission must also be sought from the relevant government
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bodies. If collections cross national boundaries, permission for the export of germplasm between
countries may be required.
6. After collection and seed processing please show it to your Instructor for verification before seed
sowing.
7.Prepare seed box or polybags (which ever prefer) to be used as potting medium or in seed sowing.
Seed box will be made from recyclable materials such as plastic containers, wood and bamboo etc.
Sown the seeds in ½ to 1 inch deep in soil depends on the size.
8.Determine the number of days of viability (as earliest germination) of each species. How many days
before seed/s germinated since from sowing?
9.Compute percentage of germination, the formula as follow:
% Germination = (No. of seeds germinated / Total no. of seeds sown) x 100
10. List the number of days (as check ( / ) and count the number of seed germinated per days and per
species (Table 1).
Table 1. Record of Seed Germination
Days 1 2 3 4 5 6 7 8 9 10 ... N Total
No. of / /// /
seeds
germinated
11. Take pictures from seeds being sown to all aspects of germination per day.
General Steps: Seed Technology for Pili
1. Collect the black color (ripened) of Pili fruit
2. Remove the fleshy pulp of seed until testa part was comes out.
3. Cut the testa slightly to easily absorb water in soaking.
4. Decide on the Treatments ( T ) you will use T1 and T2 only to break seed dormancy.
4. Soak the 25 seeds in ordinary tap water for T1 -24 hours and 25 seeds for T2-36 hours, before
sowing.
5. Prepare seed box either reuse plastic containers or wooden materials
6. Use silted soil comes from riverbank as potting medium or in seed box.
7. Use either seed box or polybags depends on the availability.
8. Sown your seeds in 1 inch depth, water everyday and place it in direct sunlight.
9. Water the seed box in the morning and afternoon
Note: The Instructor will discuss the other seeds treatments for the other species. After the seeds being
germinated from seed box or seed beds, transplant the newly young plants into polybags if reached 2-
3 inches in height.
Preparation for seedlings production
1. For potting medium, mix completely composted organic materials or rice hull with garden soil to
improve the soil characteristics such as water holding capacity, nutrient content and soil texture.
2. If possible sterilize soil by boiling soil with water in drums or other convenient containers. The
cheapest way to sterilize soil is the use of solar drying.
3. Loamy to sandy loam soils are the most suitable medium in terms of physical property for raising
seedlings.
4. Liming is used for soils with less than pH 5.
5. Count the number of germinated seedlings it will based for the release of polybags.
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QUESTIONS TO ANSWER:
1. Differentiate epigeal versus hypogeal germination
2. How above crops propagated?
3. What are the economic importance of Cacao, Calamansi, Guava, Guayabano and Pili ?
4. What are the other by products produce from above species.
5. What are the health benefits can be derive from above crops ?
6. What are the different factors to consider in seed germination?
Format of the Report: a) Introduction (make your own), b) Objectives (copy from the exercise) c)
Methodology (past tense from the exercise) d) Results and Discussion (fill up and discuss Table 1
supported with pictures (no pictures of germination will invalidate your report) questions to
answer, computation of percentage germination) e) Conclusion (answer the objectives of the
exercise). Submission of report and produce seedlings will be the last week of the semester.
REFERENCES:
Agri5 (Introduction to Ecological Agriculture) Handout Course 1st Semester AY 2017-2018 College
of Agriculture, NEUST Gabaldon Campus, Gabaldon, Nueva Ecija
Bensink L. and Koorneef M. 2008. Seed Dormancy and Germination. American Society of Plant
Biologists. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243337/
SFI 30 (Forest Nursery) Course Laboratory Manual Silviculture and Forest Influences, College of
Forestry and Natural Resources University of the Philippines College Laguna 4031
Tena V. 2010.Scientific Names Checklist of Agroforestry Species in College of Agriculture, NEUST
Gabaldon Campus, Gabaldon, Nueva Ecija
Tolentino E. 2002. Seed Technology Lecture in SFI 30 (Forest Nursery) Course, Silviculture and
Forest Influences, College of Forestry and Natural Resources, University of the Philippines Los
Banos College Laguna 4031
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