Mori-Culture

Today mulberry is cultivated in about 2.90 lakh hectares in India and the stress is upon productivity. Earlier the mulberry production per hectare was around an average of 12,000 to 15,000 kgs of leaf under irrigated conditions. Presently the average production has been tremendously increased due to the adoption of new technology like proper maintenance of mulberry garden and planting high yielding varieties while the average mulberry production per hectare has enhanced from 25,000 kg to 35,000 kgs.

Climate:

Generally the Indian climatic conditions of all states are favourable to grow mulberry. The tropical temperature ranging from 24⁰C. But at low temperature below 13⁰C and above 38⁰C the sprouting of buds and growth of mulberry will be effected. The favourable plantation season for mulberry is early monsoon. However, if abundant irrigation facilities are available mulberry can be planted at any time. The dormant season for growth of mulberry is November to March in temperate zones and rearing could be conducted only during may to October. In the tropical zones and rearing could be conducted only during May to October. In the tropical zones this problem does not arise and mulberry grows all through out the year under favourable conditions. Always plantation season must be selected as per the above specified recommendations; too cold or too hot seasons badly effect the growth of mulberry. The mulberry can grow very well, with in the range of 600 mm to 2,500 mm. Mulberry growth will be considered optimum in elevated areas above 600-700 MSL.

Soil:

Soil matters more in the growth rate of any plant. Mulberry grows in a wide range of soils. Mulberry is a deep rooted perennial plant. Therefore, the soil with good water holding capacity and good air penetration is more suitable. Soils ranging from clayey loam to loamy soils, slightly acidic soils are ideally suitable for mulberry growth, slightly acidic soils ranging the pH from 6.2 to 6.8 reveals healthy growth of mulberry plant.

Propagation of Mulberry:

Mulberry can be propagated in two ways. i. Sexual, ii. Asexual

i. Sexual Propagation:

In mulberry the sexual propagation is through seedlings, particularly the seed propagation carries a varied population, this to utilize in selection and hybridization. For seed germination certain prerequisites are needed to be fulfilled such as selection of quality seed, preparation of land, and the seed should be selected such that can definitely germinate. This is possible only when the seed is subjected to suitable environmental conditions, embryo of seed is alive, and healthy, in internal conditions of seed are favourable for germination.

The fresh seeds will have greater germination rate than the stored once. Seeds must be washed with fresh water until the flesh of fruit is with drawn and dried well, however minimum moisture percentage should be maintained, i.e. at least 6 %. Sowing of seeds may be by way of broadcasting or sowing in lines.

ii. Asexual Propagation:

In asexual type of propagation vegetative plant parts are used. In mulberry the propagation is mainly of three types.

1. Propagation by Cutting.

2. Propagation by Grafting.

3. Propagation by Budding.

In case of mulberry, mostly through "Cuttings" only the propagation is practiced. By asexual method of propagation the inherited characteristics of parent stock can be retained. The desired characteristics can be carried to next generation.

The asexual propagation in mulberry is carried out by grafting, cutting, layering.

MULBERRY CULTIVATION AND PRACTICES:

Mulberry can be cultivated in a wide range of soil. Favourable soils for mulberry growth are sandy loam, loam and clayey loam. The mulberry can be even grown on slopes of hilly areas, which are not prone to water logging. In case of slightly sloppy lands, proper drainage must be provided. No doubt the mulberry cultivation can be practiced in wide range of soils, however the leaf yield is the main factor. To increase the quality of leaf yield per hector all required favourable mulberry cultivation practices should be adopted, because the silkworm is fed by mulberry leaves only. The soil pH, water retaining capacity of field, quality of mulberry variety, temperature, environmental conditions fertilizer/manure application, irrigation practices and soil texture etc., all these factors very much influence on quantity and quality of leaf yield per acre per year.

 

Land should be prepared during early spring or late autumn. In Andhra Pradesh generally the most favourable season for plantation is pre-monsoon. The proposed land should be deeply ploughed during April-May. Since the mulberry is a deep rooted perennial plant and can last even for 10-15 years. The land should be ploughed repeatedly to loosen the soil and all gravel, stones and weed should be removed making the soil fine. In irrigated land the recommended organic manure such as cattle dung compost @20 tonnes per hector or @ 10 tonnes per hectare in rainfed conditions must be applied and mixed with soil by ploughing 2-3 times. Land leveling is also important in case of plains. However, in hilly areas generally the land will be sloppy where pit system is adopted. In hilly areas June/July are the favorable where pit system is adopted in rainfed areas. In case of pit system the pits should be filled with loose soil and organic manure.

Application of fertilizers:

Fertilizers also must be used as per the recommended dosage mainly N.P.K. in case of irrigated mulberry cultivation 120 kgs N,50 kgs of P, and 50 kgs of K per acre help for better leaf yield in Andhra Pradesh. Similarly the recommended dosage of N.P.K will be in the ratio of varied from place to place. Generally N.P.K. will be in the ratio of 2.5:1:1 for irrigated conditions and 2:1:1 of N.P.K for rain fed conditions. In hilly areas the recommended N.P.K. are 100:40:40.

Varieties of Mulberry:

Mulberry variety suitable to that particular area of plantation specifically recommended. For hilly areas high yielding mulberry varieties, K-2, S-54 are recommended. And for the plain areas of Andhra Pradesh, Karnataka M-5 is recommended. The varieties are recommended on the basis of favourable response in the existing environmental conditions.

Spacing:

Either 3’ x 3’ spacing is followed in pit system or 2’ x 2’ system is followed in row system in rainfed conditions, under irrigated conditions, the ridges and furrows are made at a distance of 0.30 to 0.45 m. Mulberry is planted at a distance of 0.10 to 0.15 m between the plants on either side of ridges along the row.

Inter Cultivation:

To eliminate the weeds and to loosen the soil for good aeration, around mulberry plant, light hoeing should be done two months after plantation. This will facilitate the plant to absorb the water freely and plant growth will not be restricted by weeds by competing with mulberry plant for food, nutrition and water.

Pruning:

Pruning of mulberry trees should be done after one year of plantation. By pruning the mulberry branches, leaf yield can be increased and production of leaf can be synchronized with silkworm rearing schedules all through the seasons. Pruning schedules controls the irregular growth of mulberry branches there by save wastage of nutrition and energy. Care should be taken during pruning, bark should not get peeled off since cut wounds do not heal, which leads infections and diseases.

Under pit system of mulberry plantation pruning can be carried once in June and again in November leaving a height of 8-10 cm above the ground level in wider spacing. Further under row systems pruning should be done at a height of 3 to 8 cm above the ground level in closer spacing.

Various methods of pruning are: - (a) fist form (b) Non-fist form.

(a) Fist Form: - Means cutting of mulberry plant each year at one place on main stem. The part gets thick & becomes fist shaped after few years therefore, the name. Easy control of mulberry diseases & pests possible in this method.

(b) Non-fist form: - Pruning done such that 2-3 branches allowed to grow from main stem (basal parts) & secondary branches also develop therefore, non-fist form. Resistance towards disease / pest control comparatively less in this method.

Leaf Harvesting:

Along with leaf production, leaf utilization is also important. Leaf harvesting depends upon type of rearing practice. Leaf harvested by 1) leaf picking, 2) Branch cutting / shoot harvesting. Leaf harvesting in time is very essential as mature leaf contain low nutrient value & silk worms fed upon them become disease susceptible.

Leaf Picking:

In India mostly leaf picking is practiced. However, this is more labour intensive, as availability of labour is not a big problem. Presently this method is being followed by most of the rearers. In a year 5-6 harvests are possible. First leaf harvest takes place after (10) weeks of bottom pruning. The quality of leaves harvested with petiole is better. Where moisture content/nutrient value will not be dried up. Generally the farmer picks up the leaves well in advance and feed to silk worms. Leaves are harvested according to the age of silk worms. Tender leaves are picked up, chopped and fed to chawki worms. As the stage of silkworm advances mature leaves are fed to the worms.

Branch (Cutting) Feeding:

Silk worms fed with mulberry branches hence name – branch feeding. This type of feeding adopted after 3^rd moult of silk worm larvae.

Advantages of Branch Feeding:

A) Cost of labour minimized.

B) Quality (succulency) of leaves maintained (as leaves not detached from branches) for a longer

duration.

C) Bed cleaning process easy & labour saving.

D) Easy to disinfect rearing equipment, if branch feeding adopted in shelf rearing / floor rearing.

E) Easy to preserve & maintain quality.

F) Easy to feed silk worms.

G) Wastage of leaf minimized

H) Hygienic conditions maintained effectively in rearing house.

I) Maximum utilization of mulberry leaves by silk worms.

Whole Shoot Harvest: This type of harvest reduces labour cost. Mulberry branches cut close to the ground level & fed to worms settled for 4^th moult hence, uniformity in maturity of leaf observed. In this type, shoots harvested at an interval of 10 weeks & may extend to another 2-3 weeks depending upon availability of water and favourable climatic conditions. Around 5 harvests possible in this method.

Preservation of Leaf & Leaf Transportation:

Mulberry leaf should be harvested in the early hours of the day, as the day passes the quality of leaves in terms of moisture content comes down due to active transpiration. Hence the leaves are picked up during the morning hours.

Further, the leaves after harvesting should be transported in wet gunny cloth and preserved carefully, either in wet gunny cloth or leaf chamber made up of wood. Frequently water should be sprinkled on the leaf to keep the leaf fresh. However, leaf with water drops should not be fed to silk worms, which results in disease attack.

To keep the nutritive value of leaves qualitatively fresh and for healthy growth of chawki worms always tender leaves (top leaves) should be picked up. As the worms mature, matured leaves should be fed. The leaves always must be succulent, healthy cocoon production and are susceptible to disease attack.

Always fresh leaves are recommended to feed the worms. Longer the preservation, lesser the moisture and the nutrition, hence temperature, humidity and moisture contents in the storage place should be 20^o C–90% of relative humidity and cool, clean with frequent watering.