FERTILITY MANAGEMENT IN MULBERRY GARDEN
Sixteen elements are essential for a plant to complete its
healthy life cycle. These essential elements are(
Where a plant gets its
From Air and Water:
Hydrogen, Oxygen and Carbon
From Soil and
Fertilizers: a) Primary Nutrients – Nitrogen, Phosphorous and Potassium,b)
Secondary Nutrients – Magnesium, Calcium and Sulphur,c) Micronutrients –
Manganese, Copper, Chlorine, Molybdenum, Zinc, Iron and Boron. Soil
testing is essential to be conducted for mulberry gardens at least once in
two years to assess nutrient status, subsequently to add proper
fertilizers in adequate quantities. Addition of organic manure can also be
calculated based on fertility data. At the time of planting, it is very
important to see that the cuttings are placed and the soil around is well
compacted. Even the rooted plants obtained from nurseries may also be
planted in this manner.
2. RAISING MULBERRY SAPLING FROM HARD WOOD CUTTINGS
In any perennial crop, initial establishment plays an
important role in subsequent growth and yield and mulberry is not an
exception to this. Mulberry being a vegetatively propagated perennial
crop, in commercial cultivation, to perpetuate the parental characters,
the mulberry garden is generally established through stem cuttings.
Suitable planting methods through cuttings have been evolved for rain-fed
system of cultivation. However, due to variation in soil moisture status,
fluctuations in temperature and non-adoption of recommended methods of
planting by farmers, the initial establishment is not satisfactory and
variation in crop stand, large number of gaps, etc., are the common
features seen in new gardens. As an alternate method, planting saplings
instead of cuttings is very important from the point of above mentioned
2.1 What is sapling?
Sapling is a rooted cutting of specific age, that is,
100-120 days for low or high bush and about 240 days for small trees.
Because of well developed root system, saplings get established quickly
and grow vigorously.
2.2 Preparation of
nursery bed: A flat land nearer to water source is preferred as nursery
site. Well drained land with loamy soil is ideal for nursery. The land
must be ploughed or dug 30-40 cm deep and allowed for weathering in sun
for 2-3 weeks. Land is again ploughed two or more times to bring the soil
to fine tilth. Root stocks, pebbles and weeds should be removed at the
time of ploughing and the land should be leveled.
Divide the land into a number of small units to prepare the
nursery beds. The size of each bed can be kept conveniently. A bed size of
240 cm (L) x 120 cm (B) can accommodate 180 cuttings (row to row 20 cm and
cutting to cutting in a row 8 cm distance) to raise 4 months old saplings.
To raise 6 to 8 months old saplings, the same bed can accommodate only 100
cuttings (row to row 30 cm and cutting to cutting in a row 10 cm
distance). Each bed on all sides should be separated by a bund of 25 to 30
cm width and height and provided with irrigation channel of 25 to 30 cm
width and 15 to 20 cm depth. The following measures are required before
planting cuttings in the nursery bed.
Add 5 pans of organic manure – FYM/sericulture
compost/vermicompost to each bed and mix thoroughly with soil.
In the case of clayey or black cotton soil, add 5
pans tank silt or sand per bed and mix with soil uniformly.
In the case of red loamy or sandy loam soils,
there is a possibility of termite infestation. As a preventive measure,
0.1% Chloropyriphos (5 ml per litre of water) can be sprayed to drench
the soil of nursery beds (2-3 litres per bed).
2.3 Preparation of
cuttings: Plants selected (any popular mulberry variety) for
preparation of cuttings must be healthy and free from scale insect, tukra
infestation, etc. the shoots should be 6 to 9 months old and should have
attained a thickness of 10 to 15 mm diameter. The stout lower portion and
tender, green upper portion of the shoots are not fit to be used as
cuttings. The middle portion of uniform thickness must be used. Cuttings
for raising 3 to 4 months old saplings are prepared 15 to 20 cm long with
3 to 4 good buds. For raising 6 to 9 months old saplings, cuttings are
made about 25 cm size. Sharp knife must be used to get clean cut ends
without damaging the bark.
2.4 Transportation of
cuttings and storing: Cuttings are to be planted immediately after preparation.
Due to unavoidable circumstances, if mulberry cuttings have to be
transported over long distance or stored for 2-3 days, the same should be
done carefully so that the cuttings do not dry. Keep the cuttings in wet
gunny cloth, if they are not planted immediately after preparation.
Dressed shoots are preferred for transportation more than whole shoots or
stems as such, as the volume can be reduced considerably, than prepared
cuttings, which dry too fast. Dressed shoots are transported during cooler
hours, especially during night over long distance. Prepared cuttings, if
required to be stored, should be bundled with all buds in one direction
and kept in wet sand bed with the buds pointing upwards under shade. It
can be covered with a thin layer of hay. The sand bed and hay covering
must be sprinkled with water daily to avoid drying or cuttings. Cuttings
can be stored this way for 2 to 3 days.
2.5 Planting: Nursery beds should be adequately watered and made wet one
or two days earlier to planting. Mark each row at a distance of 20 or 30
cm as required, with the help of a thread. In each row by using a pointed
stick, make small hole at 8 or 10 cm distance, to insert cuttings. To
avoid fungal attack, cuttings may be dipped in 0.2% Bavistin solution for
10 to 15 minutes. Cutting must be planted in the hole in a slightly
slanting position, bud turned up, and exposing only one bud above the
surface of the soil. The soil around the cutting must be pressed firmly,
after planting. In the case of poor rooting varieties, 200 ppm of NAA/IBA
dissolved in 90% ethyl alcohol and diluted can be used to treat the
cuttings before planting. The cuttings should be dipped in the solution
for 6 hours and then used. Cuttings can also be inoculated with VA-mycorrhiza
in the nursery bed to get better survivability and economization of
phosphatic fertilizer. For this 1.0 kg of soil based VAM inoculum/bed is
required. The inoculum can be placed in furrows made for planting cuttings
keeping the spacing mentioned above and the cutting can be planted on the inoculum and furrows be closed. By this
technique, it is possible to save 75% of phosphatic fertilizer once the
plantation is taken up with these inoculated saplings.
2.6 Irrigation: One time irrigation must be provided immediately after
planting. Subsequently, irrigation is given once in 4 to 5 days in the
case of sandy loam, and red soil once in 7 to 8 days in the case of clayey
2.7 Weeding: Nursery beds must be kept free from weeds. At least two
rounds of manual weeding are required, first after 25 to 30 days and
second after 55 to 60 days of planting. Only light harrowing using weeding
sickle or weeding fork must be attempted, taking care not to disturb the
sprouted cuttings. Walking or sitting on the nursery bed should be
application: Chemical fertilizer must be applied in the nursery
saplings attain 20 to 25cms height in about 55 to 60 days after planting,
preferably after the second round of weeding. Following this, 500 g of
ammonium sulphate or 250 g of urea can be applied per bed followed by
2.9 Plant protection: The most common disease noticed in nursery is leaf spot.
Application of 0.1% Bavistin twice at an interval of 15 to 20 days is
recommended. Spraying of 0.1% Rogor to control thrips and 0.1% Metasystax
to control mites are also recommended in case such infestation occurs.
transporting and planting of saplings: Three to four months old saplings are ready for
transplantation to establish bush system of plantation. For tree
plantation or for raising high bush adopting wider spacing and high crown
height, 5 to 6 months old saplings are used. Good saplings attain a height
of 90 to 120 cm in 3 to 4 months and about 150 cm in 5 to 6 months in
Before uprooting of saplings from nursery bed, land
preparation in the proposed plot should be adequately watered for easy
removal. Nursery bed is loosened with the help of crowbar or guddali or
pick axe to a depth of 30 cm and saplings are taken out one by one,
without damaging the main roots. After uprooting, long time preservation
of saplings should be avoided as far as possible and must be taken to the
planting site immediately. If long distance transportation is required,
saplings must be packed in bundles, covered with wet gunny cloth or green
leaves and taken to the planting site during cooler hours. Saplings must
be planted immediately after uprooting and as soon as they are received at
the planting site, in the pits prepared for regular plantation.
2.11 Kissan nursery: Saplings ensure successful establishment of garden. It is,
therefore, a viable proposition to raise saplings on large scale
commercially and make them available to farmers. Saplings can be raised
directly in flat/raised nursery beds. The production cost roughly works
out to be Rs. 0.30 per sapling raised in nursery bed. At selling rate of
Rs.0.50 per sapling, Kissan nursery is a quite profitable venture for the
farmers. Plan of raising mulberry saplings through Kissan nursery on
commercial scale is given in Figure-1.
Figure 1: Seed
multiplication programme for mulberry (to cover 2,700/1,227 acres of area)
1. Two prunings/year – Feb. &
June @ 5 tonnes of seed material/year/acre. Total seed material
from 72 acres in
Two prunings/year – Feb. & June @ 5 tonnes of seed material/year/acre. Total seed material
from 72 acres in
Total seed cuttings available from
360 Tones @ 50,000 cuttings/tonne of
(say 86 acres)
Total area required for Kissan
Nursery @ 2.09 lakh cuttings/acre.
Total number of saplings available @ 75% survival from 1.8
crore seed cuttings.
Area coverage by saplings:
90 x 90 cm spacing with 5,000 saplings/acre.
60 x 60 cm spacing with 11,000
TECHNIQUES OF RAISING SAPLINGS THROUGH SOFT AND SEMI-SOFT WOOD MULBERRY
Low acreage of high yielding mulberry varieties in the
field is mostly due to the non-availability of multiplication materials
i.e., cuttings. At present, only 6 to 8 months old shoots are used for
preparing cuttings. A technology has been developed to use the soft and
semi-soft wood green portion of the shoots as multiplication materials.
However, soft wood (green) cuttings cannot be planted in the farmers’
field directly or in the regular nursery. Saplings need to be raised in
the nursery specially developed for this purpose and 3 to 4 months old
saplings can be supplied to the farmers.
3.1 Preparation of
cuttings: Prepare 15 to 20 cm long cuttings with one or two top
leaves intact. Cut the upper end of the cuttings horizontally above a bud
and the bottom obliquely below a bud. Cuttings must be bundled (20 to 30
per bundle) with lower cuts arranged on the same plane. Dip the base of
cuttings (2 to 3 cm) in 20 ppm NAA for 24 hours. After washing in water,
plant them in the nursery bed.
3.2 Preparation of
nursery beds: Select a site with fertile soil and good irrigation
facility. Sufficient compost or FYM must be mixed with the soil. Make
raised beds of 5 cm high and 120 cm wide. The length of the bed may be
kept at 240 cm, but can be made longer as per the requirement and
3.3 Plantation: Green wood cuttings prepared as above are planted in the
nursery bed. It is advisable to plant in the evening to avoid bright
sunshine. Cuttings are planted at 8 to 10 cm distance from each other in a
row. About 5 cm of the base of cutting is inserted in the ground,
shallower the insertion, better is rooting. After insertion, sprinkle
water and cover the whole bed, as explained below.
3.4 Covering the
nursery beds: Cover the whole bed with transparent polythene sheet
supported with bamboo frames in a dome shaped manner to prevent the entry
of outside air and to maintain high moisture inside the cover. The height
of the cover at the central portion is kept at 50-60 cm above the bed.
Above the polythene cover, gunny cloth is spread to serve as sunshade. The
ideal temperature for rooting is 25-30˚C with light intensity of 2000 lux.
Care should be taken to maintain proper temperature and light intensity.
If the beds are not prepared under the shade of tree, provide another
layer of gunny cloth on the top.
3.5 Maintenance: Not so much watering is required. If the bed appears dry,
irrigate the channel made outside the beds. By seepage, the nursery beds
will be moistened.
3.6 Removal of shade: When more than 10 roots per cutting appear, it is the
right time to remove the shade. Generally, this condition comes after
35-40 days of planting. While removing the polythene sheet, remove one
side one day and the other side on the second day. Fertilizer may be
applied on the day of removing the sunshade and 2-3 weeks later. After 3
to 4 months, saplings are ready for plantation in regular plots. The
methods are the same for uprooting, transport and planting, as in the case
of raising saplings from hard wood cuttings.
3.7 Production cost
and economic viability: The technology is to facilitate fast multiplication of the
limited availability of seed material of improved mulberry varieties. It
also matches where mulberry is harvested by repeated shoot pruning and the
plants do not attain the required maturity for raising saplings following
conventional system. Commercially, it is possible to raise roughly 1.8
lakh saplings in 1 acre in a year costing Rs.0.40 per sapling.
3.8 Precautions: Do not transport green wood cuttings over long distance,
as cuttings will have to be prepared with two green leaves intact, and in
as fresh condition as possible.
TOP WORKING TECHNIQUE TO REPLACE OLD MULBERRY VARIETIES WITH IMPROVED
Many high yielding mulberry varieties have been evolved
recently. The time taken for the establishment of a new mulberry garden is
minimum 6 to 8 months and roughly 2 years to come to the optimum leaf
yield. The technique of bud grafting or top working can be employed to
raise plantation of a high yielding variety (as scion) on the existing
4.1 What is top
Top working is a method of grafting a single vegetative bud
with a piece of bark as scion, on the stock of existing plant. It is also
called bud grafting. Bud grafting is the common vegetative propagation
method followed in temperate regions of the country. This is practiced
when the scion material is scarce and there are initial establishment
problems like poor rooting. The advantages of practicing this method is
that, it helps the farmers not to skip too many crops, as the gestation
period is comparatively very short. The establishment of the grafted
material and the growth is quick enough to compensate the farmer with
immediate mulberry crop portion in the existing mulberry garden, depending
upon the availability of new variety. However, the limitations are high
cost, long time, non-availability of skilled manpower and strict pruning
care in subsequent years. Hence, needs precautions.
4.2 Procedure for top
A source for getting adequate number of buds of
the new mulberry variety for grafting should be ensured. It is ideal to
have a small separate plot of the new variety to ensure this.
Existing plantation should be prepared to do top
working, by cleaning the garden and removing the thinner branches. The
stock branches that are 1.5 to 2 cm in diameter must be selected.
Select the required, mature buds of the desired
Make a slanting cut with a sharp budding knife,
below the bud and lift it upward to about 2-2.5 cm length above the bud
and remove the bud gently.
In a stock branch, select the internodal smooth
portion of stem at height of 25 cm, only to a bark depth. Give another
cut horizontally at the top of the vertical cut, which now appears as a
Gently lift the bark pieces on either side of the
vertical cut for inserting the bud of the new variety, which is
separated and kept ready.
Insert the bud of the improved variety in the ‘T’
cut of the stock and tie the union tightly with polythene strip,
exposing only the bud.
After bud grafting, cut the stock branch a little
above the grafted level.
Irrigate the plot till sprouting of the grafted
bud is ensured.
Remove the sprouting shootlets of the old
variety, regularly. Allow the growth of the grafted buds only.
PACKAGE OF PRACTICES FOR MULBERRY CULTIVATION UNDER RAINFED CONDITION
Mulberry can be cultivated both under soil moisture stress
(semi-arid or rainfed) and irrigated conditions. Specific package of
practices for mulberry cultivation has been developed aimed at improving
both the leaf yield and quality under such stress conditions of rainfed
Package of practices mainly involve use of high yielding
mulberry varieties like S-13 in red loamy soils and S-34 in black cotton
soils, which are adapted to stress conditions. Measures for better
establishment during initial stages of plantation and suitable agronomical
practices emphasizing soil moisture conservation and timely plant
protection measures are essential.
5.1 Establishment of
mulberry garden: Mulberry is a perennial plant. Once it is properly raised
during the first year, it can come to full yielding capacity during the
second year and last for 15 years in the field. There fore it is very
important to estalish the crop initially according to the scientific
methods to obtained best results. To get better mulberry productivity,
following package can be adopted:
5.2 Selection of
land: Flat or slightly slopy land is suitable for mulberry
cultivation. More slopy or steep lands need proper soil conservation
measures through bench terracing, contour bunds and drains. Though
mulberry can be grown practically in a wide range of soils, loamy to sandy
loam and clayey loam soils are preferred. In the case of acidic (pH < 6.5)
and alkaline (pH > 7.5) soils, necessary corrective measures should be
followed through lime or gypsum application, respectively. Mulberry is a
deep-rooted plant and the top soil should be sufficiently deep (60 to 90
5.3 Preparation of
land: Planting should be undertaken during the commencement of
South West monsoon. Therefore, land preparation should start in
pre-monsoon period. Deep digging or ploughing of land to a depth of 30 to
35 cm is recommended, prior to the dry season, making use of the available
soil moisture. The field is then left exposed during the summer, in order
to kill weeds and soil-borne insects. During the pre-monsoon showers, the
soil lumps must be broken and the land must be ploughed repeatedly to
bring the soil to a fine tilth. The land should be leveled, and divided
into plots of convenient size providing the contour bunds for proper
harvesting of rain water.
Pit system of planting with wider spacing should be adopted
for rainfed mulberry. Pits of the size 35 cm (L) x 35 cm (B) x 35 cm
(depth) are dug at 90 x 90 cm spacing. Pits are then filled with a mixture
of soil and FYM (2 kg of FYM/pit). One can use Sericultural compost or
vermicompost in the pit to get better results.
5.4 Planting material
and planting: Varieties S13 and S34 are recommended for rainfed
conditions. Generally, mulberry cuttings are used for planting, but
planting saplings is better. Branches of 8 to 10 months old and 10 to 12
mm diameter are selected for cutting preparation. Each cutting should be
20 to 22 cm length with minimum
3 to 4 healthy buds. The cut should be clean without
damaging the bark or wood. Greenish tender portion or too thick lower
portion of the branches should not be considered for preparation of
cuttings. Three cuttings are planted in each pit with a spacing of 15 cm
between cuttings, in a triangle. Cuttings are placed deep, leaving just
one bud on top, 2 to 3 cm above the ground and the soil around each
cutting should be pressed well to keep the cuttings firm in the soil.
It is risky to resort to direct planting of cuttings, under
rainfed conditions. It is ideal to use 4 months old saplings (one
sapling/pit) under such condition and support it with pot watering during
initial period of establishment. Planting can be timed to receive adequate
rainfall for 1 to 2 months period to the advantage for higher survival,
quick establishment and maximum growth of plants.
5.5 Initial care and
fertilizer requirement: When the new garden is 2 to 3 months old after planting,
inter-cultivation is done by weeding through light digging of the soil and
applying the first dose of NPK @ 25 kg/ha through any complex fertilizer-Suphala/Vijay.
Weeding is again done after another 3 months of first weeding, followed by
application of second dose of nitrogen @ 25 kg/ha either in the form of
urea or ammonium sulphate. This would enable the plants to grow well and
establish fully. Though the plantation may give enough foliage by the end
of 8 to 10 months, it is advised not to take early leaf harvests before
the plants attain full growth, which takes roughly one year under rainfed
condition. The first pruning is done in the following rainy season, after
one year. The plants are cut at a height of 8 to 10 cm above ground level,
with a sharp pruning knife or saw without damaging the stem.
Systematically cultivation practices must be followed from second year of
planting. Ready reckoner for fertilizer requirement for rainfed mulberry
is given in Table 1.
5.6 Maintenance of
rained Mulberry Garden:The scheduled of systematic cultivation practices for
maintenance of rainfed mulberry garden from second year of planting is
given in the following table
Table 2: Scheduled of systematic cultivation practices for maintenance of
rainfed mulberry garden
Leaf yield: By adopting the package of practices for the rainfed
mulberry garden, it is possible to harvest
7 to 8 MT of leaf per
hectare per year during the second year of establishment and 10-12 MT of
leaf per hectare per year from third year onwards.
AZOTOBACTER BIOFERTILIZER FOR MULBERRY PLANTS
The high fertilizer requirement in mulberry cultivation in
mulberry cultivation especially nitrogen (300 kg N/ha/year) is leading to
increased cost of its cultivation. Fertilizers are not only in short
supply, but also expensive and not available in time. Small and marginal
farmers who cannot manure their garden in time in adequate quantity often
harvest poor cocoon crop. Azotobacter biofertilizer, a cost effective
supplement to chemical nitrogenous fertilizers in mulberry cultivation, is
recommended to make sericulture more profitable. Besides, it reduces the
deleterious effect of chemical fertilizers on soil health and also reduces
the water pollution from nitrate contamination through leaching.
6.1 What is
It is a bacterial preparation of live Azotobacter cells
blended with suitable carrier material like lignite/peat in powdered from.
It is capable of supplying nitrogen to the plants through biological
nitrogen fixation and enhances plant growth. It is available in small
polythene packets weighing generally 150-200 g and can be easily handled.
Apply 20 kg Azotobacter biofertilizer/ha/year (to
compensate 150 kg nitrogen) in 5 split doses @ 4 kg each time after
every leaf harvest/pruning and intercultural operations.
Use phosphorous and potash @ 120 kg/ha/year each
in 2 split doses, as per recommendation for irrigated mulberry.
Farmyard manure (FYM) should be applied @ 20
tonnes/ha/year as recommended for irrigated mulberry.
Apply only 150 kg nitrogen./ha/year instead of
300 kg nitrogen in 5 equal split doses @ 30 kg each time after every
leaf harvest/pruning and intercultural operations.
6.3 How to use
Biofertilizer should be used before/after
application of chemical fertilizer over a gap of at least 10-15 days.
Before use, biofertilizer should be mixed
thoroughly with dry powdered FYM (4 kg biofertilizer + 200 kg FYM each
time) and applied in between the rows of mulberry making furrow.
Furrows should be covered immediately after
Irrigation should be given immediately after
application of biofertlizer.
Never mix chemical fertilizer with biofertilizer
Keep biofertilizer away from heat and direct
sunlight and use it before its expiry date.
After application, land must be irrigated
adequately and immediately to save live bacterial cells from
Collect biofertilizer from authentic sources to
avoid spurious material.
Eco-friendly and reduces ill-effect of chemical
fertilizers on soil health.
Long lasting effect and sustainability.
Cuts down cost by 50% in the total application of
nitrogen fertilizer, thereby reducing, at least Rs.700/- per hectare per
year, on fertilizer cost alone.
PREPARATION OF COMPOST USING SERICULTURAL WASTES
Good quality farmyard manure is perhaps the most valuable
organic matter applied to soil to enhance soil fertility and to increase
micronutrients, which are essential for plant growth. Generally, in
sericulture farms, the left over mulberry leaves from rearing bed and
field and other waste including silkworm litter are not properly utilized
in preparing compost of high nutrient value. The traditional method of
preparation of compost is generally not effective. The loose heaps lie
exposed to the sun, with the result the raw organic matter dries up
quickly and does not decompose properly. Hence, it is essential to convert
the sericultural farm wastes into valuable compost, adopting suitable
7.1 Preparation of
compost: The mixed farm wastes can be collected in pits of a
convenient size. Pit size of 3 x 1 x 1 m is adequate to receive farm waste
from 1 acre garden from roughly 2 harvests in 4 to 5 months time. Two such
pits made side by side can be used alternately to compost all the farm
waste from one acre mulberry garden. Each day’s collection of various
sericultural wastes like silkworm litter, left over mulberry leaf, weeds,
etc. should be spread in a thin layer sprinkled with a layer of fresh cow
dung, ashes and water and compacted. At the end of the rearing, the left
over leaves in the garden, along with the young mulberry twigs can also be
added to the pit. Some quantity of chemical fertilizer specially
Superphosphate is also added to enrich the compost
When the pit is filled
and the bed stands 30 to 45 cm height above the ground level, it is then
plastered with a 2.5 cm layer of a mixture of mud and cowdung. A thatched
shed should be provided to protect the compost pit from rain and direct
sunlight. To enhance the decomposition process, lignocellulose decomposing
fungi like Aspergillus sp./Trichoderma sp./ Belaromyces
sp. could also be added along with organic wastes.
7.2 Process of
decomposition: Under above conditions, decomposition is anaerobic which
is mainly a reduction process and high temperature is not generated. The
plant remains, silkworm litter and cattle dung contain water,
carbohydrates, organic acids, lignins and mineral constituents like
phosphates, silicates, etc. during the process of composting, these are
attacked by variety of microorganisms like bacteria, fungi, actinomycetes,
protozoa and worms. As a result of their activities, considerable portions
of the residues, notably the carbon, nitrogen, phosphorous and potassium
are rapidly liberated in available form for plant growth and well
decomposed bulky organic matter is produced. The rate of decomposition
depends upon the nature of the residues and upon the conditions under
which decomposition takes place. During this process, organic nitrogen is
reduced to organic acids and ammonia. The heat generated is sufficient to
destroy all the harmful pathogens present in the material. The nutrient
content of various organic manures is given in Table 2
Nutrient content of
various organic manures
(on air dry basis)
required for satisfactory decomposition
An adequate supply of available nitrogen in the
form of organic wastes.
Adequate moisture. Low moisture (10% and less)
arrests the activities of most cellulose-decomposing organisms while
high moisture content (80-95%) promotes anaerobic bacteria at the cost
of fungi and most actinomycetes.
A fine state of mechanical disintegration.
RAISING MULBERRY GARDEN exclusively for YOUNG AGE (CHAWKI) SILKWORM
Among the several factors that contribute to successful
young age silkworm rearing, supply of highly nutritious mulberry leaves as
feed is a vital one. The larval period and its maintenance is of utmost
importance for the success of sericulture industry since it is the only
feeding stage of the insect. The qualitative and quantitative requirements
of the feed for silkworms differ at different stages of larval period.
While it is generally established that the young age silkworms require
mulberry leaf of higher succulency, moisture and nutrient contents, the
late age worms feed on coarser leaf with less moisture content. Other
important factors determining the success of cocoons crop are the health,
care and hygiene during the young age silkworm rearing-popularly called
the “Chawki Rearing”. Though importance of chawki rearing has been
realized and several Chawki Rearing Centres (CRC) have been established to
serve farmers, the problem of producing quality leaf in adequate quantity
for chawki rearing centres has not been met successfully. To meet the
suitable leaf requirement for exclusive Chawki centres any one of the
training methods explained below may be adopted.
8.1 Eight harvests
schedule per year
8.1.1 Selection of site
and land preparation: Selection of site for establishment of the chawki mulberry
garden is very important. The site must be more or less flat and in an
elevated place, light textured, deep, sandy loam or clayey-loam soil. Site
must be free from nematode and termite infestations and should not be low
lying areas with excess soil moisture. The ideal spacing to be adopted is
60 x 60 cm.
8.1.2 Training schedule: After an establishment period of about one year, the
plants should be pruned at crown (20 cm above ground) during onset of
monsoon. After 35 days of bottom pruning, harvesting of leaf is commenced
for next 10 days (up to 2nd moult). At the end of rearing, the
top terminal bud is to be clipped. Twentyfive days after top clipping,
second leaf harvest as shootlets is to be done for rearing of worms up to
second moult. Thereafter, plants are again pruned at crown (80th
day after 1st pruning). This cycle has to be repeated 4 times
to get 8 crops in a year. Thus, plants are pruned at the crown (20 cm
above ground level) 4 times in a year (after 2nd, 4th,
6th and 8th crops). Individual leaf picking is
recommended for 1st, 3rd, 5th and 7th
crops while the shootlets are to be harvested in 2nd, 4th,
6th and 8th crops for the purpose of rearing.
8.1.3 Manure and
fertilizer schedule: The annual dose is 40 MT FYM/ha to be applied in two equal
splits in 1st and 5th crops. The annual fertilizer
dose is 225:150:150 NPK kg/ha in 8 equal splits @ 28:19:19 kg NPK/ha/crop.
This can be applied as 127 kg Suphala 15 N: 15 P: 15 K plus 20 kg urea per
8.1.4 Irrigation: 1.5 acre inch of irrigation water is to be provided once
in 4-6 days by ridges-furrows method (34,000 gallons of water per acre
Leaf yield: The above technology ensures a high yield of 29 MT of
chawki leaves per hectare per year as against 7 MT/ha of chawki leaves
obtained from common gardens. Almost 100% of the leaves produced are
suitable for chawki rearing.
Leaf quality: Qualitatively the leaves produced by this technology are
superior (about 80% leaf moisture, and by dry weight 25% of leaf protein
and 13% of leaf sugar) to leaves obtained from common garden (76% leaf
moisture, and by dry weight 21% leaf protein and 11% leaf sugar).
8.2 Twelve harvests
schedule per year: Establishment of mulberry garden on sound footing is a
prerequisite for sustained yield of quality leaves per unit area over
several years. Regarding this, the following activities must be carried
8.2.1 Selection of site: The site must be more or less flat and in an elevated
place, light textured, deep, sandy loam or clay loam soil. Site must be
free from nematode and termite infestations. It must have an assured
source of irrigation.
preparation: After selecting the site, the land must be given deep
ploughing/digging. The weeds, root stocks and boulders must be removed. It
must be allowed for weathering for about a month. The ideal soil pH range
is 6.5 to 7.0. If the soil pH is above or below the desirable level,
corrective measures may be adopted by applying required quantity if lime
to acidic soil or gypsum and green manure to alkaline soil. In this
context, soil analysis assumes special significance to test the fertility
and pH of the soil. The organic carbon content should be more than 1%;
adequate quantity of organic matter should be incorporated in deficient
soils. Entire land can be divided into smaller plots of convenient size
with provision for irrigation channels and bunds.
8.2.3 Spacing: Spacing for planting the saplings should be 60 cm between
the rows and 60 cm between the plants in a row (60 x 60 cm). With this
spacing, about 10,000 saplings can be planted in an acre (0.4 ha.) of
8.2.4 Planting material: Healthy, 100-120 days old saplings of 80-90 cm height can
be used for planting. Because of already developed root system in
saplings, plants get established quickly and grow vigorously.
8.2.5 Planting: Planting work can be taken up soon after the onset of
regular South West monsoon. One sapling per pit be placed deep and
straight in the pit/trench by removing the soil. After this, the soil
around the sapling must be pressed firmly. When planting work is over,
adequate irrigation has to be given immediately and in the event of
failure of rain.
and maintenance during establishment: About 1˝ months after plantation, alight weeding/hoeing
must be done. Second weeding must be done around 3 months of planting.
Weeding operations must be thorough and should be regularly carried out.
The plantation taken up during the monsoon period will have
the advantage of receiving fairly distributed rain from June to October.
If there is no rain or not adequate for a period of over 10 days,
supplemental irrigation has to be given. After the cessation of the
monsoon, irrigation has to be given regularly at an interval of 6-7 days,
but this frequency varies depending on weather conditions and types of
soil. About 1.5-2.0 acre inches (34,000-45,000 gallons) of water is
required per irrigation. Irrigation can be given by furrow system and
whenever possible, drip or sprinkler system can be adopted.
Mulberry grows vigorously under assured irrigation and soil
fertility. First dose of chemical fertilizer should be given as booster
dose at the rate of 50:50:50 kg NPK/ha after second weeding and 3 months
of planting. By sixth month, plants would be ready for first harvest of
leaves. After the first light harvest of leaves followed by weeding, a
second dose of chemical fertilizer must be applied at the rate of 50
In the interest of good establishment of the plantation, it
is not advisable to go for regular leaf harvest till the completion of one
year of planting. After 6 months of planting, 3 light leaf harvests can be
made till basal pruning is taken up.
In the event of occurrence of fungal diseases, spraying of
0.1% Bavistin and in case of attack of insect pests, spraying of 0.1%
Metasystox has to be done. Care should be taken to allow required safety
period before harvesting leaf for brushing.
8.2.7 Management of
established garden and leaf harvest: About one year of planting, with good maintenance,
plantation will be established well. Following the good establishment,
regular management and leaf harvests can be initiated. The aim of
developing exclusive chawki mulberry garden is to get suitable nutritious
leaf for chawki rearing continuously. In this direction, the following
cultural operations must be carried out systematically.
The first basal pruning must be at 30 cm above the ground, preferably
during the onset of South West monsoon. Following the first basal
pruning and 3 leaf harvests, at an interval of 15 days, first middle
pruning at 60-70 cm above the ground has to be done. Following this, 3
more leaf harvests can be made. Again the same sequences will follow.
Totally 2 basal pruning and 2 middle cuts must be done in a year. After
about 20 days of each pruning, weak branches can be removed.
After thorough weeding, digging must be done to loosen the soil, to
stimulate the plant growth and to facilitate the application of manures.
Following digging operation, ridges and furrows should be formed.
Yearly twice, bulk organic manure in the form of farmyard manure or
compost should be applied at the rate of 15 tonnes/ha/time and
incorporated into the soil. This may be carried out within 15 days of
each basal pruning. Thereafter (8-10 days), application of chemical
fertilizers should follow. The total annual requirement of chemical
fertilizers is 240: 140: 140 kg NPK/ha. The fertilizers should be
applied in 4 equal split doses corresponding with 2 basal and 2 middle
In light sandy loam soils, more frequent irrigation at 6-7 days’
interval may be found necessary, while in heavy clay loam soils,
irrigation at 8-10 days’ interval may be found adequate. It is also
important that at the above intervals of irrigation, adequate quantum of
water should be supplied as irrigation at a time. It has been estimated
that 1.5 to 2 acre inches of water is required per irrigation.
To improve the leaf quality as well as the productivity, whenever
necessary, plant protection measures must be followed. But, these
measures can be taken up only after pruning and 15 to 18 days before
leaf harvest for brushing.
Leaf harvesting and
From brushing to two feedings after second instar, the silkworms are fed
with young leaves. The leaves to be harvested are from below the largest
glossy leaf, which is yellowish green in colour. The cardinal point is
shoot tip and it should not be removed during any crop. Below the glossy
leaf, about 3 leaves during the first (1-3) and about 3 leaves (4-6)
during the second instar can be harvested. Usually in cool hours
(morning and evening) harvesting has to be done. While harvesting, care
must be taken not to damage the shoots. Due attention must be given to
harvest required quantity of leaves in the shortest time possible from
the plot and to bring that to rearing house immediately. Excess leaf
harvest and longer preservation must be avoided.
Silkworms grow best when fed with fresh mulberry leaves,
which are rich in nutrients and moisture. Under tropical conditions,
driage of leaf is faster. Usually, the leaves are harvested twice a day
and are preserved for successive feedings, depending on the necessity.
During this period, the leaves should be preserved in cool and clean
places in order to preserve their succulency. It is batter to preserve
leaves in a leaf chamber or bamboo basket which is lined with gunny cloth,
that can be kept wet by sprinkling water at frequent intervals. Harvested
leaves must be sprinkled with water in summer season, if necessary.
Alternately, chawki mulberry leaves can be stored in a mud pot, which is
placed in the moist sand and mouth of the pot must be covered with wet
cloth. Also, chawki mulberry leaves can be stored on a flat moist sand bed
covered with wet and clean white cloth. Again after arranging the leaves
on the sand bed, they must be covered with wet white cloth.
8.2.8 Economics: To work out the economics of chawki leaf production, three
models of 0.2 ha (yearly 5,000 kg leaf and 30,000 Dfls), 0.4 ha (yearly
10,000 kg leaf and 60,000 Dfls) and 0.8 ha (yearly 20,000 leaf and
1,20,000 Dfls) have been considered. This consideration is based on
availability of 10,000 kg leaf/0.4 ha (1 acre)/year by 12 crops. Also, as
15 kg leaf requirement/100 Dfls. The cost of chawki leaf production works
out to be Rs 2.60 per kg, with depreciation and Rs.1.77 per kg without
8.2.9 Leaf yield: This method will ensure roughly 25 MT of chawki leaf per
hectare per year in 12 harvests. All the leaves produced are fit for
chawki rearing, unlike in regular mulberry garden where only about 20% of
the total leaf yields is fit for chawki rearing, which is about 7 MT per
year per hectare. Leaf yield in exclusive chawki garden raised is adequate
to rear 1,20,000 layings per year per hectare.
8.2.10 Leaf quality: Qualitatively the leaves produced in chawki garden are far
superior with 75 to 80% moisture content, and by dry weight basis 25% leaf
protein and 13% leaf sugar to leaves obtained in general commercial
garden, with 70 to 74% moisture content, 20 to 21 leaf proteins and 11%
it possible to convert a portion of the existing garden into chawki plot?
The aim in raising exclusive chawki garden is to maximize
chawki leaf production per unit area and improve the leaf quality for
Chawki Rearing Centres. However, there are thousands of farmers to whom
CRC facility are yet to reach or are confident to do themselves the chawki
rearing scientifically. For such individual farmers, improvement of chawki
leaf quality is the prime concern than increasing the quantum of
production. Such farmers can mark a small portion of the existing garden
(roughly 5% of the garden) and provide additional input of FYM, irrigation