1. Agronomic Principles
AS
Arpitha S
Jr.Msc SST
UNIVERSITY OF AGRICULTURAL SCIENCE, DHARWAD
DEPARTMENT OF SEED SCIENCE AND TECHNOLOGY
ASSIGNED BY
Dr.V.K. Deshpande
Head of Department
Seed Science and Technology
PRESENTED BY
2. GENERAL PRINCIPLES OF SEED PRODUCTION
Production of good quality seed is an exacting task requires high
technical skills and heavy financial investments.
During seed production strict attention must be given to maintai
n
genetic purity and exploit its potentiality in next generation.
In other words, seed production
must be carried out under standardized and well organized cond
ition.
TYPES OF PRINCIPLES
1.Genetic principle
4. Following are some of the
Agronomic principles to be
followed
1 Selection of suitable Agroclimatic regions
2 Selection of seed plot
3 Preparation of land
4
5
6
7
Selection of Variety
Seed and seed source
Seed treatment
Time of planting
6. Selection of agro climatic regions
Variety should be adapted to photoperiod and
temperature of that area.
Moderate rainfall and humidity is good for seed
production.
Dry sunny period and moderate temperature for
pollination.
Ample sunshine, relatively moderate
rainfall & the absence of strong winds
9. Selection of seed plot
1 Seed production plot should have good texture and fertility
2
Should be free from volunteer plants weeds and other crop plants
3
3
Soil should be free from soil borne diseases and ins
ect pests.
The previous crops should not be same crop.
4 The plot should get adequate isolation distance
11. Preparation of Land
The land for seed crop must be prepared well by deep
ploughing and 2-3 harrowing.
Good land preparation helps in improved germination,
good crop establishment and destruction of weeds.
It is also helps in good water management and uniform
irrigation.
13. Selection of Variety
1
The variety should be adapted to agro- climatic conditions of the region.
2
The variety should really be high yielder.
3
The variety should posses other desirable
attributes, namely disease resistance, earliness, grain quality etc.
14. The seeds used for raising seed crops should be
of known purity, appropriate class and invariably
obtained from an authorized official agency
Seed and seed source
Genetic purity for different crops
•Breeder seed :100 %
•Foundation seeds : 99%
•Certified seeds varieties: 98%
•Certified hybrid seeds :95%
•Certified hybrid cotton : 90%
•Certified hybrid castor : 85%
15. Seed treatments : the application of fungicide, insecticide,
or a combination of both, to seeds so as to disinfect and disinfect
them from seed-borne or soil-borne pathogenic organisms and
storage insects
BIOLOGICAL METHOD
CHEMICAL METHOD
PHYSICAL METHOD
19. The seed crops should invariably be sown at their normal planting time.
Depending upon incidences of disease & pests, some adjustments could be made
if necessary.
At time of planting there should be sufficient soil moisture for germination seeds.
Time of sowing or Planting
20. Seed rate
Lower seed rates than usual for raising commercial crop are desirable because they
facilitate rouging operations & inspection of seed crop
26. Shallow sowing in case of small seeds, clay soil and High
moisture content soil.
Deep sowing in case of large seeds, sandy soils and dry soils.
Depth of sowing
27. Rice 3-5 cm
Horse gram 1.5-2 cm
Green gram and Black
gram
3-5 cm
Soybean 2.5-4 cm
Chickpea 3.5-6 cm
28. Isolation:
three types
1. Distance isolation
2. Time isolation
3. Barrier isolation
• Done by providing distance between seed
fields & contaminants.
• Maintenance of isolation distance is varies
with the direction of insect flying or
direction of wind.
• Maintenance of isolation distance is to avoid
mechanical mixtures at the time of
harvesting
• Eg : wheat , rice , barley , sunflower etc
Isolation distance refers to the minimum separation required between crop
varieties to maintain seed purity.
29. Time isolation
Modification of sowing dates between
seed crop and contaminating field.
Eg : Paddy ,maize , sunflower etc
Barrier isolation
Barrier Isolation can be achieved by providing
physical barriers such as barrier
crop/polyhouse/net house/nylon net etc. to
avoid the external crossing or contamination.
Eg : Paddy, wheat, cotton etc
31. Removal of undesirable plants and it is useful to maintain genetic purity
The no. of rouging necessary will vary with the crop and type of seed
production.
-It should be done for both the parents for hybrid seed production
Rouging
Rouging in most of the field crops may be done at any of the following stages as per
needs of the seed crop.
a)Vegetative /pre-flowering stage
b)Flowering stage
c)Maturity stage
32. Off type plant may differ in
Plant character , Plant height,
leaf character, Flowering time,
Maturity, Panicle, Flag leaf
angle, Leaf colour, sheath,
stem
33. Provision of honey bees hives in close proximity to the seed fields of the
largely cross pollinated by insects, ensure good seed set and thereby greatly
increase seed yield and quality.
Supplementary
pollination
Rope pulling in Paddy
34. Mother plant nutrition
N P K and several other minor elements (Mn, Zn, Bo, Mg, S etc) play an important role
for proper development of plant and seed.
Identify the nutritional requirement of seed crops & apply adequate fertilizer.
Timely application of RDF results in maximum seed yield with good quality seed and
better expression of plant characters which facilitates rouging and there by helps in
maintaining higher genetic purity.
35. Irrigation
The irrigation may be required
before planting & at intervals up
to flowering.
One or two irrigations beyond
flowering are
desirable for many seed crop.
In general lighter soils need more irrigation
than heavier soils.
Proper irrigation helps for production of good
quality, disease free seeds and higher seed yield.
37. a)The presence of weed seeds at time of crop
harvest leads to mixing of weed seeds with
crop seeds. In many cases it is difficult to
remove them during the processing of seeds.
b)The presence of weeds in the seed field or
nearby areas may serve as host to number of
diseases. Good & effective weed control is
necessary to obtain higher seed yield with
quality & to avoid contamination.
Weed control
39. Some diseases which are systemic (leave
their spores inside the seed coat) e.g. loose
smut of wheat. If these are not checked
before sowing, seed production will get
infected with spores of such disease and
produce diseased plants in next season.
Some diseases which are non systemic,
leave their spores on seed coat. If not
checked, earlier to sowing, this result in a
greater susceptibility to various seedling
diseases e.g.: damping off
Seed yield & quality are reduced.
Plant protection
40. Management of diseases & pests in
seed crops:-
a)Plant only treated seed.
b)Prepare & adopt appropriate schedule of
spraying for effective disease &insect
control.
c)Roguing of diseased plants & ear heads from
time to time also helps in checking the further
spread of diseases.
41. Some of the important designated diseases in different
crops
42. Harvest the seed crop at the time that will allow
both the maximum yield and best quality seed
Optimum time of harvest is when seed is fully
,
mature when weather damage just begun resulting
in minimum harvest .
losses
,
Harvesting at an early stage the losses due to
threshing and cleaning will be more and leads to
bruising injury
Late harvesting result in increased weather damage &
losses due shattering seeds & lodging of plants in
field.
Harvesting of seed crops
47. Drying of seeds
> In order to preserve seed viability and vigour, it necessary to dry seeds to saf
e moisture
content levels as early as possible without heaping wet seed pods.
48. Storage of seeds
General principles of seed storage:
1. Seed storage condition should be dry and cool.
2. Effective storage pest control.
3. Proper sanitation in seed stores.
4. Before placing seeds in to storage they should be dried to safe moisture limit.
5. Maintain proper temperature and RH.
6. Before storage of high quality seeds, those seeds are well cleaned, treated and then
stored
49. Bulk (open) storage
SEED STORAGE STRUCTURES
Gunny bags Bulk bag seed storage
Bamboo structures Bitumen/ coal tar drum
