Post on 14-Jul-2015
Sorghum ( Open pollinated varieties )
Botanical name – Sorghum bicolor
Family- Gramineae
Origin-Tropical & Subtropical region of Africa & Asia
Sorghum is used for grain, fiber&fodder.
One of the most important staple food for million poor rural
people.
Sorghum is about 70% starch ,so is good energy source.It’s starch
consist of 70 to 80 % amylopectin.
In rank first sorghum production by country U.S. (10,988.00 MT)
in world & India in rank fifth(5,000,00 MT) in world.
Land selected for sorghum seed production should have good
drainage facility so as to avoid water stagnation.
Previous crop in the land should not be of any other variety of
sorghum.
Land should be used sandy loam & well drained soil.
Sorghum is an often crops pollinated crop having 50% cross pollination. Isolation distance should be maintained so as to avoid varietal contamination of seed.
Isolation distance is the distance by which the seed crop is separated from any other variety of the same crop.
Contaminants Isolation Distance (M)
Foundation seed
Certified seed
Other varieties 200 100
Sudan grass 400 400
Fodder sorghum 400 400
Though sorghum is grown as rain fed as well as irrigated
crop in different seasons, appropriate season to produce good
quality seeds is important.
For quality seed production, dry and cool weather is more
favourable than hot and humid weather during panicle
emergence and seed development stage.
For seed production, sowing may be done during June – July
and October – November seasons. Of these, October -
November is more conductive for quality seed production.
Seeds are soaked in 2% potassium dehydrogenase phosphate
solution for 10 hours and then dried back to original moisture
One kg of seeds are to be soaked in 600 ml of leaf extract for 16
hours. Hardened seeds will have the ability to withstand drought
during germination and plant growth.
Good quality seeds should be used to maintain the required crop
stand.
For of land, 12 to15 kg of seed is required. For certified seed
production, foundation seed should be sown.
Seeds with low germination will also be less vigorous and hence
crop growth is very much reduced. Seeds affected by sugary
diseases should be removed.
After the basal application of above fertilizers, ridges of six
metre length are formed at 45 cm distance.
Seeds are sown with a spacing of 15 cm on one side of the
ridge
After the application of 12.5 tonnes of FYM, plough the field
1 to 2 times by harrowing 2 to 3 times&levelling.
Then apply 2 kg of Azospirillum uniformly.
Micronutrient
For zinc deficient and iron deficient soils, 25 kg of ZnSO4 and 50
kg of FeSO4 have to be applied respectively
N (kg/ha) P (kg/ha) K (kg/ha)
Basal application
50 50 50
25 days after sowing
25 _ _
45 days after sowing
25 _ _
After furrow formation, fertilizer should be applied uniformly in the
furrow.
According to the soil condition, irrigation is given once in 7 days or once in
10 days. The following are the important stages in which drought should be
avoided.
Panicle emergence stage Flowering stage Seed maturation stage
a) Weed Management:
Hoeing and Weeding is necessary for controlling of weed.
Weed are also controlled by spraying of 1kg Atrazine(in 700lit of
water)ha after 2-3 day of sowing.
b) Disease Control:
Disease plant should be control Sugary disease of jawor.
Spraying of 0.2% Zineb should be spray after 45 days of sowing.
C) Insect control:
15 kg Thimet ha should be apply in furrow with fertilizer (not with seed)
at time of sowing for contolled Shoot fly .One spray 1.5 kg Thidon/ha
(in 700lit water) should be at 10 to 15 days after germination for
controlling Stem borer.
Growth stages Off-types
Before floweringSelf sown crop plants with different leaf colour, shape and
stem colour
During floweringEarly or late flowering plants and plants with deviant panicle
shape
Before harvestPanicle affects by ergot, fungi and smut and plants with
deviating panicle features
Sorghum crop should be harvested from 40-45 days after 50%
flowering.
At this stage, moisture content will be around 20-22 per cent,
seeds will have black layer at the basal portion.
Seed weight, germination and vigour would also be high. The
seeds harvested before harvestable maturity are immature and
will shrink upon drying.
The harvested ear heads should be dried to bring down the seed
moisture content to 15-18 per cent.
If the seed moisture is below 15% then, seed injury may occur cracking
and above 18% moisture then will be occurrence of crushing injuries.
These mechanical injuries may affect the germination and vigour of the
seed besides paying way for fungal infection.
Seed are dried in sunshine heat.
Harvested Seeds are to be dried to a moisture content of 10-12 per can
Seed yield of 2000 kg/ ha can be harvested.
Seed processing is an operation by which all immature, wrinkled,
broken and small seeds as well as all physical impurities such as
sand, stones, dust, other crop sees and week seeds are removed.
For processing sorghum seeds, sieve of 9/64" diameter can be
used so as to get uniform size seeds.
SEED TREATMENT:
Seed treat to use a safe and non-poisonous chemicals
like Halogen mixture is recommended for treating
sorghum seeds @ 3 g /kg of seeds.
Halogen mixture can be prepared by mixing
bleaching power (calcium oxy-chloride) + calcium
carbonate + agape leaf powder (Albizzia amara)
5:4:1 proportion respectively.
Always, new bags have to be used for packing the
seeds.
Seeds are hygoroscopic in nature which means
they have the tendency to absorb moisture from the
atmosphere
, seeds stored in cloth or gunny bags, loose
viability fast. In such places, moisture vapour proof
containers like polythene (700 guage thickness)
bags can be used.
Storage godown has to be thoroughly cleaned before storing seeds
Seed Moisture should be lowered below 8%, when the seeds
are stored in moisture vapour poof container.
Direct contact of seed bags with the floor or wall is to be
avoided.
Seed bags should be stacked above the wooden pallet.
While stacking, number of bags per row should not exceed 8,
otherwise seeds in the lower bag will deteriorate due to
pressure
Seed certification guarantees the quality of seed as it ensures that the
certified seed.
genetic, physical, physiological and seed health qualities.
It starts from verifying whether seeds were obtained from authenticated
source, verification of isolation distance and inspection during plant
growth, flowering, harvesting, processing and bagging.
seed sample sent to seed testing lab to test physical purity
and germination.
Then certification tag is issued. Colour of the tag is blue
for certified seeds.
seed are certified by the Certification Agency.
Seed details nearer seed certification office may be
contacted.
Cont.
Seed science & Technology
www.tanau.ac.in
Text book of seed technology
Authors: C.N.Chore & S.R.Ghadekar
Seed technology
Authore: A.C.Agrawal