UPLAND AND LOWLAND RICE
PRODUCTION IN TROPICAL
REGION OF NIGERIA
Introduction
Rice (Ory/a saliva L.) is
one of the leading food crops of the world. Demand for rice is rapidly increasing
in West Africa. Nigeria imports more than 80% of its rice requirement. Local
production is low and efforts to increase production are hindered by high input
costs, low prices for rice, and low yields, especially in the uplands. This is
true in most West African nations. There is an urgent need tor cultivars and
production technologies in the both the upland and lowland ecosystems that will
help increase yields at lower monetary costs. Upland rice is mainly grown under
a shifting cultivation system. This involves slashing and burning of virgin
forest to acquire new and more fertile lands. Environmental concerns and
increasing human density are discouraging this practice and research on
permanent cropping of the land is being promoted. One strategy to facilitate
cultivation of the same piece of upland rice field withoul yield loss and
without high input of human labor, fossil energy, feriili/er, and herbicide is
the use of low input rice varieties. These varieties present a major challenge
for research because upland rice often needs a higher level of fertilization
than does lowland rice. The West Africa Rice Development Association (VVARDA)
is developing low input varieties primarily from selections among African
varieties and exotic varieties. In a 3 - year varietal screening exercise,
conducted in the Nigeria, cu WAR 377 B 16 LB LB and WABs6 125, bred by
WARDA were found to be higher yielding and more stable than the commonly used
Asian variety (Peking) aL low fertilizer application rates. The low - input
varieties were also found to have higher NUE than the Asian variety (Peking).
In lowland rice farming, water control is the most important management
practice that determines the efficacy of other production inputs.
Poor drainage that keeps
soil saturated is detrimental to crops and degrades soil quality. In many rice
irrigation systems in Nigeria, water control is highly inefficient. Drainage
mechanisms are dysfunctional or inadequate because farmers believe that rice
grows best when water is supplied in abundance. Poor drainage mechanisms makes
it necessary for farmers to transplant tall, very old seedlings, usually 4 ~ 6
weeks old, and 3 - 4 seedlings per hill. Rice fields are kept continuously
flooded and are flood - free only at time of harvest. This practice is not only
wasteful in terms of water use efficiency, but also leads to leaching of
soluble nutrients, blocks aerobic soil microbial activities and biological
nitrogen fixation as well as slows minerali/ation and nutrient release from the
soil complexes. New management practices that address lowland rice production
constraints in Nigeria are needed. The System of Rice Intensification (SRI),
used in Madagascar, proposes a methodology that has the potential to increase
rice productivity without a high investment in external inputs or introduction
of new cultivars. SRI changes the ways in which plant, soil, water and
nutrients arc managed. In 2000, 2001, and 2002, SRI experiments were conducted
in Nigeria. The SRI water management practices of repeated soil wetting and
drying were found to be beneficial to rice plant growth probably through
increased biological nitrogen fixation, more nutrient availability, profuse
root development, increased tillering, and a high panicle setting ratio leading
to higher grain yields. Grain yields of rice under SRI management are 2 - 3
times higher than the national average in Nigeria.
UPLAND RICE PRODUCTION
Growing Upland Rice in Nigeria
Choice of Land
i.
Select site in ecological zones where
rice is grown traditionally.
ii.
Choose fertile land with good water
retention capacity (contain some clay and/or organic matter i.e. loamy soil),
iii.
If you have to grow rice for one or more
consecutive year on the same piece of land, seek the advice of Soil Survey and
Testing Service of the Institute
of Agricultural Research and Training (JAR&T) or any other reputable
soil-testing unit.
iv.
Grow legumes after rice, and plough rice
residues into the soil as organic matter.
Land Preparation
1) MECHANISATION: (Forest Area)
For newly cleared
areas, stump big trees before the rains preferably from November to February
and remove all stumps, roots and trees before ploughing. Plough once and disc
harrow twice with the first rains from late February to early March to make
good tilt if land is flat. Plough twice and disc harrow once if land is sloppy.
Apply basal fertilizer before final harrowing. Divide the field into plots of
50 or loom2. Construct bunds depending upon the slope, to accumulate
rain water. Level the land to reduce erosion. For consecutive
cropping, take necessary
soil conservation measures in
land preparation.
2) MANUAL CULTIVATION: Clear and
pack bush between November and February, and use hoe
to remove bush and weeds. In the Savannah,
land preparation can
start in February, depending on the rain.
Recommended Varieties
EARLY MATURING
Faro 38 (IRAT 133), FARO 39 (IRAT 144),
FARO 45 (ITA 257), FARO 46 (ITA
150).
MEDIUM MATURING
FARO n(OS 6), FARO 48 (ita 128), FARO 47
(ITA 117), FARO 48 (ITA 301), FARO 49
(ITA 315)
Time of Planting
(i)
In the forest area, plant in
mid-March to mid-April, after 2 to 3 good rains.
(ii)
In the savannah, plant rice
in mid-May to Mid-June, depending on the rains.
SEED RATE
60 kg/ha by dibbling; 50-55 kg/ha by
drilling in rows spaced 30 cm apart; and 80 00 kg/ha by broadcasting.
PLANT POPULATION
In dibbling or direct
seeding, sow seeds 25 x 25 cm to give 160,000 stands/ha. Use a
"pinch" or 4 to 5 seeds paddy per hole. Plant about 3-5cm deep, cover
lightly and press. In drilling method, drill in rows 15-20 cm apart.
Fertilizer Rate and Time of
Application
Undertake soil test before
any fertilizer application. Do not apply any fertilizer on newly cleared land
in the first year.
FERTILIZER RATE
(i) BASAL FERTILIZER OR
FIRST APPLICATION: Where basal
fertilizer is applied, use phosphate and potash fertilizer in deficient soils
at final harrowing before seeding. After bush burning, no phosphate and potash
fertilizer are needed. Apply 100kg of 15-15-15 per hectare (2 bags/ha) as basal
fertili/.er or just at the lime of first
weeding (2-3 weeks after emergence) to facilitate incorporation of fertilizer
into the soil.
(ii) SECOND APPLICATION OF TOP DRESSING: Apply 50 kg (one bag) of Urea per hectare—5 weeks after
sowing. In areas where acidity is high, do NOT use Sulphate of Ammonia but use other
sources of nitrogen e.g. urea.
METHOD OF APPLICATION
By drilling or broadcasting,
ensuring incorporation into the soil. Apply fertilizer at 10 cm from base of
plant (hill application) immediately after a sufficient rain.
(i)
Iron Deficiency: When the soil is deficient in organic matter and iron, the
seedlings turn yellow
then white a
week after germination. They
later die.
• Spray 1% ferrous
sulphate with 0.2% citric acid or lemon at 500 liters/ha once or twice
depending on the recovery of plants.
• Apply iron chelates and
urea in between rows at 25 kg/ha.
(ii) Zinc Deficiency
• Apply 25 kg/ha /inc sulphate (20% zinc) or
• Spray 1% /inc sulphate with 0.5% lime at 500
Itr/ha to the base as symptoms are seen.
WEED CONTROL
Hand Weeding
First weeding should be
thorough and should be done within 2 to 3 weeks after emergence, using hoe
instead of cutlass (The earlier the first weeding is done the better).
Second weeding should be
done 6 to 7 weeks after emergence. Weed a third time, if necessary.
Chemical Control
1)
Pre-emergence: Apply RonstarTM 25(EC) 2-3 days after sowing or just after seeding
at the rate of 4-6 litres/ha. Spray GramoxcTM at 2 Itr/ha when weeds have grown
in the field. DO NOT spray GramoxcTM after the germination of paddy seeds.
2)
Post-emergence: Apply RonstarTM (PL) 14 to 21 days after planting at the rate of
5-6 litres/ha. Use Propanil (Stan 1734), Tamarice or
Propanil-Bentzon (Basagram) 14 to 21 days after planting at the rate of 3 kg
a.i. (10 liter tin) per hectare. With a knapsack sprayer, use 220 ec of
Propanil or Tamarice, except Basagram which should be used at the rate of 150
cc, in 10 liters of water. Any resistant weed species or newly germinating
weeds like corn grass Rottboellia cochinchinensis should be roguecl. A weed-free
seed-bed at planting also contributes to the effectiveness of the herbicides.
Pests
TERMITES
i.
Preventive: Destroy all
dead woods and
plant residues by burning. Locate termite mounds in
surrounding bush and destroy.
ii.
Control: Spray Nogos 50 at the rate of 30 ml per 4.51 (one gallon) of
water. Nine litres (two gallons) of solution are sufficient to destroy a
termite mound.
ARMY WORM
In case of an attack, spray Gammalin 20 or Carbaryl (Vetox 85) at
the rate of 1.68 kg in 225 liters gallons) of water per hectare (i.e. six
levels of empty large match box in 9 liters (2 gallons) of water.
VERTEBRATES
Keep 2 to 3 metre border
round the field free from grass, weed and burn thrash to control rodents. Build
bamboo or palm frond fence (if possible), around the field immediately after
planting. Create openings at. short intervals and place traps in the openings.
If rats and grass cutters become troublesome, kill them with snap traps. Use
scaring devices to control birds. Employ human scarcrs to drive birds from
farms from 6 am to 7 pm first two weeks after planting, and from heading to
harvesting. Use traditional means where it is effective or plant contiguous
fields.
Harvesting
Harvest when 80 percent of
the grains have turned straw colour to avoid shattering.
THRESHING
Thresh immediately after
harvest to avoid losses. Use wacking frames or mechanical devices, but avoid
threshing on bare floor. Thresh on a mat or tarpaulin over concrete floor by
Hailing (i.e. beating rice against the floor, or against a stick or drum).
Thresh carefully and avoid dehusking the grains. Damaged grains become stained
and coloured after parboiling and milling.
Expected Yield
If above recommendations are
followed, and rainfall is adequate, an average yield of 1.5-2.0 t/ha could be
obtained.
Drying
Dry paddy properly to a safe
moisture content of 13-14 percent, by spreading on clean concrete floor, mat or
tarpaulin. Sun-dry slowly for 2-3 DAYS Lo reduce breakage during milling. On a
clear bright day, sun- dry for one day only by spreading paddy thinly on clean
concrete floor, mat or tarpaulin. Use mechanical drier if possible.
Storage
Store in cool, dry
rodent-proof conditions. Infested paddy should be fumigated with phostoxin in
air-tight containers at the rate of one tablet per jute bag (100 kg paddy) or
10-15 tablets per ton of paddy.
Processing
i.
Parboiling: Soak paddy in hot water at yooC for 5 to 6 hours. Discard all
floating empty grains. Parboil rice by steaming soaked paddy put in a jute bag
for 10 to 16 minutes by suspending the bag over steaming water in a drum. Stop
parboiling when rice husks start to split open. Chalky grains or white centers
indicate incomplete parboiling, which may cause breakage of grains during
milling.
ii.
Milling: Mill rice in a two-storage milling machine. Always mill one pure
variety at a time.
LOWLAND RICE PRODUCTION
Major lowland production
constraints
Bio tic
• Weeds
• Insects:
- Africanrice gallmidge (AfRGM)
- Stem borers
• Diseases
- Rice yellow mottle virus (RYMV)
- Blast
- Sheath rot
- Smut
Abiotic
• Drought/flooding
• Low soil fertility (P and N deficiencies)
• Iron toxicity.
• Salinity/alkalinity problems in the
irrigated lowland production
Choice of land
•
Choose fertile land with
good water retention capacity (contain some clay and/or organic matter, i.e.
loamy soil); clayed soils arc most desirable.
•
Heavy soils of valleys andfadamas
are preferred.
•
Consult Soil
Survey and Testing
Service of the Institute
of Agricultural Research and Training (IAR&T), Ibadan or any other
reputable soil-testing unit
if growing rice for
one or more consecutive years on the same piece of
land.
Recommended lowland
varieties
•
Early maturing (<9O-ioo
days): FARO 44 (SIPI) and 'etumbe' (local).
•
Mediummaturing (100-120
days): FARO21, 26, 29, 52 (WITA 4), 57TOX 4004-43-1-2-1, and others.
•
SUAKOKO 8 and FARO 15:
Suitable for iron toxic areas.
•
Late maturing (>12O
days): FARO 10, 12, 13, 16, 17, 19, 24, 28, and others.
•
Gall midge-affected areas:
Cisadane (FARO 51).
Choice of seed
•
Use good
quality seeds with
no insect damage
and no contaminants (weed seeds,
stones, other seed types) with high percentage of viability (>8()%).
Sources to contact for good
quality seed
•
State Agricultural
Development Project (ADP) that includes rice in its production programs.
•
River Basin Development
Authority.
•
Branch office of the National
Agricultural Seed Council.
•
Seed company.
•
Other rice farmers.
•
WARDA-Nigeria.
Seed dormancy
•
Dormancy is the failure of
good quality mature seeds to germinate under favorable conditions. Dormancy of
freshly harvested seed should be broken by using heat treatment at 5O°C in an oven if
available or by placing the seeds on a plastic sheet and covering with itself
or another under direct sunlight for i or 2 days. Acid treatment may also be
used.
•
Acid treatment: soak seeds
for 16 to 24 hours in 6 ml of concentrated nitric acid (69% HNOs) per liter of
water for every i kg of newly-harvested seeds. After soaking, drain acid
solution off and sun-dry the seeds for 3 to 5 days to a moisture content of
14%. Store in dry conditions for sowing.
•
Conduct germination test on
seeds to establish rates to use based on seed viability.
Seed viability testing and
seed requirement
i.
Use only filled grains of
quality for sowing: add water to seeds and discard all empty grains that float
in water.
ii.
When the seed viability is
not known, carry out a simple seed viability test to guide the actual seeds
required for sowing,
iii.
Place moistened tissue paper
(preferably filter paper, if available in a
dish with lid
(use Petri-dish if available)
and put in
100 ramdomly selected filled seeds. Cover and keep the dish at room temperature
for 4-5 days to allow germination.
iv.
Then count the number of
sprouting seeds (only those with shoots >i cm). If 75 germinating seeds are
counted, it means the viability rate is 75%(%germinat:on).
v.
If the seed rate is 80
kg/ha, the actual quantity of seeds to be used for sowing is calculated thus:
Seed required (kg/ha) = 
X % filled grain
X % filled grain
= 
X 1 (assuming 100% filled
grains) = 107 kg/ha
X 1 (assuming 100% filled
grains) = 107 kg/ha
iv. To estimate percentage filled
grains, select at random 100 seeds from the seed lots to be sown and count the
number of filled grains. If 100, it means 100% filled grains.
Seed treatment
•
First, treat selected seeds
with a mixture of insecticide and fungicide. For example, Apron StarTM 42 WS
(thiamethoxam 20 g/1 + difenocona/olc 2 g/1 + metalaxyl-m 20 g/1) at the rate
of one sachet per 4 kg seeds or any available seed dressing chemical before
sowing.
•
Other products can be used:
- PROCOT 4oWS (carbosulfan + carbenda/im
+ metalaxyl-m.
- CALTH1O C 50WS (Lhirain + ehlorpyriphos-ethyl).
• In areas with termite and nematode problems, incorporate
carbofuran (FuradanTM) at the rate of 2.5 kg a.i. per hectare into planting
row. To ensure uniform application, mix Furadan with sand at a ratio of 1:4.
• Soak seeds in water for 24 hours and incubate for 48 hours before
sowing to ensure uniform seedling emergence and good establishment.
Establishment of nursery
Dry bed nursery
•
The nursery bed should be
watered regularly to keep the soil moist but not puddled. Good drainage should
be provided to ensure that the nursery is never flooded.
Wet bed nursery
v Select a good site with well-drained fertile soil exposed to full
sunlight, and conveniently located in an area close to the main field and to
facilities for efficient watering when needed.
v Prepare seed bed at least 7 days but preferably 14 days before the
seeds arc sown.
v Seed bed should be i to i.smwide, 10 m long, 4 to 6 cm above the
ground surface and well leveled.
v Soak the seeds in water
for 24 hours. Spread seeds on the floor. Incubate seeds by covering with
polyethylene bags or raffia palms for another 48 hours for seeds to sprout.
v Spread the sprouted
seeds uniformly on a puddled nursery bed (wet bed nursery) or on a leveled
surface for dry bed nursery. Use seed rate of 80-100 kg/ha depending on
percentage seed viability and grain filling percentage for the actual
requirement.
v Drain the excess water from the nursery bed for about a week. Then
flood to 2-3 cm depth if using wet bed nursery.
v Apply 50 g/m2 of NPK 15-15-15 fertilizer or apply 5 t/ha of rice
husk + bran as mulch/manure. A combination of the two, where available, will
give better seedlings.
v About 5 days after sowing seeds, the nursery beds should be kept
flooded to a depth of 2-3 em. To prevent weeds and also ensure easy pulling of
seedlings, water depth should gradually be increased to a depth of about 5 cm.
v Avoid bird damage during germination by scaring the birds.
v In areas prone to gall midge, apply carbofuran at i kg a.i./ha in
the nursery beds a week before uprooting.
Land preparation
•
In areas with lots of perennial weeds, disc plow the field
immediately after harvest in November/December to expose the rhi/omes (roots)
to the sun.
•
Plow and harrow field Flood the field for about 2 weeks to kill
weeds.
•
Remove water after 2 weeks and mark out field into basins (e.g.
5111 x 5111) with hand hoes.
•
Construct bunds around the field to retain water and suppress
weeds using animal traction, hand hoe, etc.
•
Irrigate or allow rain into
the basins and level properly (hand puddling or with animal traction).
Time of sowing
• Forest zone - March to April.
• Derived savannah - May to June.
• Guinea savannah - June to July.
• Sahel savannah - seed at any time of the year depending on water availability.
• In all eases,
seeding should he
done when rains
arc well established.
Transplanting and spacing
• Transplant seedlings to the well-puddled and leveled main field between
14 and 21 days after sowing.
• Transplant at a rate of 2-3 seedlings per hill, to a depth of 3-4
cm, and at a spaeing of 30 001x30 cm (best for late-maturing eultivars), or 20
x 2Ocm when soil is fertile or sufficient fertilizer is available.
Direct seeding
•
Direct seeding
can be done
in hydromorphic areas
of the
toposcquence.
•
Divide the field into plots
of 50 or loom2 and construct bunds.
•
Apply herbicides to
controlweeds as they can be a problem.
•
Sowsecds at a spacingof20cmbetween
rows andi5-2O cm within rows (between hills) by dibbling.
•
Direct seeding can be done
using pregerminated seeds on wet soils.
Gap filling
Gap fill the empty spaces
with seedlings within 7-10 days after transplanting using leftover seedlings
from the nursery.
Fertilizers
•
Fertilizers supply nutrients
essential for growth, nutrition and health of the rice plant.
•
Fertilizers can be applied
in the form of organic or inorganic (mineral) or both.
•
Organic fertilizer can be in
the form of manure, compost or crop residues.
•
Mineral fertilizers are
manufactured. It is important to apply the right quantity and at the right time
to obtain optimum yields and for environmental protection.
Types of fertilizers
•
Straight (single)
fertilizers: These supply only one primary nutrient (e.g. N, P or K) to the
crop.
Some
examples:
- Nitrogen: urea, ammoniumsulphate,
ammonium nitrate, calcium ammonium nitrate (CAN), and others.
- Phosphorus: single super-phosphate (SSP),
triple superphosphate (TSP), and others.
- Potassium: muriate of potash (MOP;
KCl)
•
Compound fertilizers: these
supply more than one nutrient (e.g. N, P and K) to the crop.
Some examples:
- NPK 15-15-15 (15%N; i5%P2Os; 15%K2O);
- NPK 20-LO-io (20% N; 10% P2Os;
io%K2O);
- NPK 30-10-0 (30%N; 10% P2C>5; o%
K2O);
- Ammonium phosphate nitrate (APN).
Fertilizer applieation
•
Fertilizer should be applied
based on the residual nutrients found after soil testing, the expected yield
and the type of fertilizer materials available.
•
The farmer should strive to
obtain fertilizer recommendations based on the analyses of soil samples. Table
2 can serve as a guide.
•
In situations where it is
not possible to conduct a soil test due to high cost and unavailability of analytical
services, or when the fanner is running out of time because the crop is
subnormal in growth, the general recommendations in this handbook should serve
as a guide.
General fertilizer
recommendation based on Agroeeology
• Humid forest:
Apply 60 kg N, 30-60 kg P2O5
and 30 kg of K2O per hectare
• Savannah:
Apply 60-80 kg N, 30-60 kg
P2O5 and 30 kg KaO per hectare
• Sudan/Sahcl (under irrigation):
Apply 100-120 kg N, 60 kg
P2Os and 60 kg K2O perhectare
Time of application
Basal Application of Phosphorus and
Potassium
•
Apply P and K within one
week before transplanting and work the ferlili/er well into the soil.
Topdressing of N fertilizer (e.g. urea)
•
Apply in three equal doses:
- Deep placement (2-3 cm) at
transplanting.
- Broadcast at aboiitmid-tillering (3-5
weeks after transplanting [WAT]).
- Panicle initiation (i.e. when the
plants are about 'pregnant'; 8 WAT for late maturing cultivars > iso-days or
ealier, (6 WAT) for medium maturing cultivars).
•
Maintain water level on the
field to 3-5 cm at the time of fertilizer application to ensure efficient use
of the applied fertilizer.
Methods of fertilizer
application
The fertiliser can be
applied in two ways:
•
For small areas: in
irrigated system, close the irrigation inlet and drainage
outlet. Then apply the
fertilizer between rows.
•
Irrigate and close the
canals for about 10 days to facilitate nutrient absorption.
•
Drain the field
and apply the fertilizer by broadcasting. The fertilizer should be flooded immediately
to prevent dentrifieation.
Topdressing N from straight
fertilizers (e.g. urea)
General Recommendations:
•
Use 15 to 20 kg N for every
tonne of target (expcetcd) yield.
•
Apply in 2-3 splits for >
60 kg N/ha (>2y2 bags urea); use more splits for late-maturing
cultivars (>12O DAS).
•
Do not apply more than 35 kg
N/ha (iVa bags urea) in a single dose (split) to minimize losses.
•
Use 1RRI Leaf Color Chart (LCC) when available, to guide
in topdressing.
Mixing fertilizers
•
When it is required to apply
two or more elements and the desired compound fertilizer is not available but
the straight fertilizers are available (Annex i), you may weigh and mix the
fertilizers before application. This is particularly important for large
mechanized rice farms.
•
However, note that not all
fertilizers are compatible when mixed. For example, if basal N is necessary and
you need to apply N and P as basal, do not mix ammonium sulphate with rock
phosphate, or urea with super-phosphate. The elements will react with one another
and become less effective. The chart in Annex 2 can serve as a guide for mixing
fertilizers for application to various crops, not only rice.
Iron toxicity
•
Plant tolerant varieties
such as Suakoko 8, FARO 15, ITA 247, 1TA 249.
•
Eliminalc excess iron through
good water management by draining the field.
•
Use balanced nutrients such
as N, P, K, and Zn.
•
Cultural practices such as ridging, organic manure
application, among others.
Water management
•
Maintain the water level in the field up to 5cm from one week
alter transplanting until grain matures.
•
Drain the water a week before harvesting
•
Cracks should not be seen on the field
WEED CONTROL Hand weeding
• Drain water from the field
• Hand weed 14-20 days alter transplanting
• Hand weed again around 30-40 days after
transplanting
Chemical weed control
For pre-emergence in
direct-seeded fields
•
Rice Force and Gramoxone (paraquat) at isoml each in 20 liters of water per hectare sprayed not later than 24 hours after seeding.
Post-emergence application
in both transplanted and direct-seeded fields
• Delmin Forte (2,4-0
amine salt) or Amine Force (2,4-0 amine) plus Propan 360 (propanil) at 200-250
ml (depending on seedling age) or propanil mixed with 50 ml of the 2, 4-D in 20
liters of water per hectare.
Disease control (RYMV, blast, brown
spot, grain discoloration)
•
Use disease
resistant/tolerant varieties to RYMV and Blast.
•
Use good cultural practices
to limit infection of blast and RYMV.
- High nitrogen associated with low
potassium can increase blast damage.
- Split application of nitrogen is
better than one application to reduce blast damage.
- Removing surrounding weeds to destroy
the alternate host of RYMV can reduce the virus infection.
•
Use clean healthy seeds.
•
Treat the seeds 1-2 days before sowing to control seed-borne Pathogens
•
In case (and only in case)
of being in an area conducive to fungal diseases, spray DithaneTM M-45 (80% of
mancozeb) at i.o kg or BenlateTM (50% of benomyl) at 1.5 kg a.i/ha, in 500
liters of water to control rice blast, brown spot and grain discoloration. If
the damage is severe, spray again after 15 days.
Insect control Diopsis species
•
Cultural practices such as
early sowing, narrow spacing of plants and maintaining weed-free fields should be observed to
minimize Diopsis infestation.
•
Synchronize planting
over a large
area to allow
the most; susceptible stage of
rice to escape from Diopsis damage.
•
Use of variety such as WAB
1159-2-12-1.1-6-9-1-2 with highly hairy leaves can trap Diopsis tlioracica larvae.
African rice gall midge
control
Control
•
Early and
synchronized planting of
rice fields can
minimize damage than late planting.
•
Destroy alternative host
plants such as rice ratoons, volunteers and Oryza longistammta.
•
Use of fertilizers: moderate levels of fertilizer (e.g. 60 kg/ha) should be used and
applied in split doses.
•
Movement of seedlings should
be discouraged because
such seedlings can be infested by AfRGM in the nursery.
•
Plant spacing:
narrow
spacing such as
drilling should be discouraged because it provides a suitable
micro-environment for the survival of the exposed life stages of AfRGM.
•
The gregarious
cndoparasitoid (Platygaster diplosisae) and the solitary cctoparasitoid (Aprostocetus procerae)
are the most important wasps (natural enemies)
attacking AfRGM and should be protected on the field.
•
Habitat manipulation
by planting paspalum
grass (Paspalum scrobiculatum)
at the edge of the rice fields can increase the carry-over of parasitoids
from Paspahtm gall midge (Orseolia bonzii) to AfRGM. Such
cultivation can be done in the dry-season to encourage Paspalum
scrobiculatum abundance early in the wet season.
•
Use of traditional Oryza
saliva variety such as TOS 14519.
•
Use of tolerant rice
varieties such asCisadanc , BW348-1, Lcizhung, and others.
•
Use of tolerant lowland
NERICA varieties such as NERIGA L-25, NKRICA L-19, NKR1CA L-29, NERICA L-49.
•
Use of traditional Orijza
glaherrima varieties such as TOG 7106, 7206, 7442, 6346, 5681, and others.
Control
•
Apply DecisTM at i liter/ha
in 500 liters of water to control rice bugs which suck the sap after flowering.
•
Adjust planting date to
allow for manipulation of N. viridula
numbers.
•
Destruction of weed hosts
around rice fields.
•
The green-manuring crop, Sesbania
rostrata, can be used as a trap crop to protect rice against N.
viridula.
Bird control
•
Erect scarecrows randomly in
the field.
•
Scare the bird manually.
•
Tic old VMS tapes diagonally
across and around the field.
•
Install bird nets if
available.
•
Use catapults.
Rodent control
•
Leave an uncropped margin of
1-2 meters around the field.
•
Distribute poison (bait)
mixed with maize, sorghum, millet or rice in bamboo boxes or containers in the uncropped
margins and alleys.
•
Fencing with bamboo or
chicken wire mesh or polythene sheet round the field may deter rats and
grass-cutters.
•
Use of local metal traps.
Rogueing
From heading until harvest, inspect field, remove and destroy
off-type plants and weeds.
The
off-types can be identified through differences in:
• height
• growth cycle
• grain color
• grain shape
• panicle shape
• leaf shape
• leaf base colour
• awn ness
Harvesting
•
The crop is ready for harvest when the grains are hard and are turning yellow/brown.
•
Thai is about 30-45 days after flowering or a month after 50% flowering.
•
Cut the stems with a sickle about 10-15 cm above the
ground.
•
Lay harvested rice crop in upright position for drying before threshing.
Expected yield
•
With good management and use
of improved high yielding variety, 5 lo 6 t/ha paddy is expected.
Threshing
•
Thresh immediately after
harvesting and drying to avoid losses.
•
Use whacking frames or
mechanical devices, but avoid threshing on bare floor to prevent the
introduction of sand, pebbles and other foreign matter.
•
Thresh on a mat or tarpaulin
over concrete floor by flailing (i.e. or against a stick or drum).
•
Thresh carefully and avoid
dehusking the grains.
Winnowing
•
Winnow to separate the chaff
and empty grains from the well-filled matured grains.
•
Remove foreign matter in the
paddy to avoid locali/ed heating spots during parboiling.
Drying
•
Dry paddy properly to a safe
moisture content of 13-14% by spreading in a thin layer (2-3 cm thick) on clean
concrete floors, mats or tarpaulins and turning over periodically.
•
Sun-dry slowly for 2-3 days
to reduce breakage during milling.
•
On a clear bright day,
sun-dry for one day (about 9-10 hrs) only by spreading paddy thinly on clean
concrete floors, mats or tarpaulin.
•
Use a mechanical drier if
available.
•
Caution: avoid drying on bare floors or roadside, the main source of
contamination with sand pebbles, stones and other foreign matter that can
reduce the quality of rice.
Parboiling
•
Parboiled rice
has the advantages
of better storage, cooking quality, being richer in food value,
devoid of unpleasant odor and breaking less during milling.
•
Soak paddy in hot water at
7O°C (hot enough for your
fingers to withstand the heat for about two
seconds) for 5 to 6 hours.
•
Discard all floating empty
grains.
•
Parboil rice by steaming
soaked paddy in a jute bag for 10 to 16 minutes.
•
Suspend the bag over
steaming water in a drum.
•
Stop parboiling when rice
husks start to split open
•
Chalky grains or white
centers indicate incomplete parboiling, which may cause breakage of grains
during milling.
•
Parboiling can be done in
earthen pots or empty petrol drums depending on the quantity of rice.
•
Note: steaming
dexteriscs the kernels and drives the vitamin thiamine and other water-soluble
nutrient's from the testa or seed coal ink) the starchy core.
Milling
•
Milling is the process of
removing the husk or hull from the grain and the bran (pericarp, testa and
aleurone layer) fromthc kernel (brown rice).
•
Greater efficiency in the
miling process results in the milling process results in whole grains with
minimal broken grains to attract premium prices.
•
Mill rice in a two-stage
milling machine.
•
Alwaysmill one pure variety
at a time.
Storage conditions
Good storage practices include:
•
Store at 65% relative
humidity.
•
Store rice at a temperature
within io°F
(s.5°C) of the average monthly air temperature and
below 6o°F (i5.6°C) as long as possible during the year.
•
Design and operate aeration
system to maintain uniform, rice moisture and temperature.
•
Store only well cleaned
rice.
•
Inspect rice regularly
(weekly) during storage.
Control of storage pests
•
Use dried chilli pepper to
keep pests away.
•
Apply 2 tablets of Phostoxin® a.i. aluminium
phosphide in an unsealed envelope per 50 kg
bag of rice grains.
•
Caution: Phosphinc gas is
highly toxic and should not come in direct contact with the rice grains. Wear
protective gloves and nose masks when handling.
•
Treat seeds/grains with
activated silica gel powder to dehydrate possible insects in the bulk.
•
Store grains at extremely
low temperatures (-15 to -20°C) for minimum of 12 hours or high temperatures (above 55°C) for minimum of 3-4 hours.
•
Use of airtight containers
for grain storage
REFERENCES
Dobermann, A. and T. Fairhurst (2000). Rice: nutrient disorders
and nutrient management. IRRI, Los Banos, (The Philippines).
Aduayi, F. A., V. O. Chude, B. A. Adcbusuyi and Olayiwola, S. O., (2002).
Fertilizer use and management practices for crops in Nigeria, 3rd ed. Federal
Ministry of Agriculture and Rural Development, Abuja, Nigeria.
NSPFS (2002). Fertilizers and their use: A pocket guide for
extension
Officers. National Special
Program on Food
Security, Abuja, Nigeria.
Nigeria.
NSPFS (2004).Handbook on soil test-based
fertilizer recommendations for extension workers. Federal Department of
Agricultural Land Resources and National Special Program on Food Security,
Abuja, Nigeria.
