Working for technological empowerment and sustainable livelihoods at the grass root levels.
 
Selected Replicable Technology Models for Rural Application
Low-Cost Nursery Techniques

Technology

Following is a brief description of the techniques that would be taught to the trainees:

Production of seedlings Producing ready-to-transplant seedlings is currently common only for vegetables. But in the case of other crops such as cotton, castor, arhar, sugarcane or even cereals like rice, bajra and jowar, one can raise seedlings in a nursery and transplant them at the right time.

For woody dicots like cotton, arhar and castor, the seedlings could be produced in plastic bags, while seedlings for most vegetables and cereals can be produced on a bed of soil or sand laid on a plastic film. For optimum results, the soil should have pH of about 6.5. In peninsular India, red (lateritic) soil generally satisfies this condition. If the soil is clayey, it should be mixed with sand or compost, in order to ensure good drainage. The soil is initially drenched with a fungicide solution, to kill pathogenic fungi. Since drenching also causes any weed seeds in the soil to germinate, these should be removed before sowing the crop seed. Incorporating inoculum of Trichoderma viridae also protects the seedlings from soil-borne fungal pathogens. The seed is sown in rows, about 7 to 10 cm apart. The space between the rows is covered by strips pf black plastic film (plastic mulch), which prevents excessive evaporation of water, checks growth of weeds between the rows and, in winter, keeps the soil warm to accelerate germination. The seedlings are fertilized and watered as usual.

Surroundings the seedbed with a continuous skirting of transparent colourless plastic film, about 1 m high, prevents dissipation of the carbon dioxide generated by the plants during the night and enables itsassimilation by the plants during the following day. The growth of the seedlings is also accelerated because of the additional carbon dioxide. The plastic skirting around the beds is later removed so that the plants are exposed to dry air and wind, which hardens them in readiness for sale.

Vegetative Propagation through rooted cuttings Shoot cuttings of most tropical dicot species are capable of producing roots if they are properly treated. Such rooted cuttings have the same genetic constitution, and therefore the same characteristics, as the mother plant. Cuttings of most vines, lianas and herbs, and also those taken from young saplings of trees, root more easily than cuttings from adult tress (i.e. trees that are already producing flowers/fruits). In general, softwood cuttings (i.e. twigs having green bark) root more easily than hardwood cuttings (cut-tings having brown bark). Hormonal treatment of the basal part of the cutting increases the percentage of rooting. The treatment consists of dipping the basal 1 or 2 cm of the cutting for about 10 sec in 4000 ppm solution of indole butyric acid (IBA) or naphthalene acetic acid (NAA) and planting such cuttings in moist sand.

High Humidity Chamber Cuttings placed for rooting can lose moisture of the weather is dry. This can be avoided by keeping the cuttings in an atmosphere having more than 70% relative humidity. If the rooting is conducted in coastal regions, normal atmospheric humidity is itself generally high enough but in inland regions atmospheric humidity can be very low. In such cases, the beds in which the cuttings are planed are covered by a transparent plastic film supported by wire arches forming an enclosed chamber. The atmosphere within this space is very soon saturated by water vapour, indicated by droplets of water condensing on the inner surface of the plastic film. Twigs planted in this chamber remain turgid and fresh for even up to 8 weeks. Using a low-cost humidity chamber of this type dramatically increases the percentage of rooting. For commercial-scale production, the size of the chamber can be increased as required. The only precaution required is to place it in the shade because, if the humidity chamber gets exposed to direct sunlight, it would get so heated up that the twigs would die of heat shock.

Potting Medium Sand-soil mixture is generally quite adequate as potting medium. Sand serves primarily to increase porosity of the soil, therefore the proportion of its use depends upon the clay content of the soil. In black cotton soil, which is extremely clayey, ratio of sand to soil should be 1:1, but if the soil is sandy, there is no need to add sand to the medium. Leaf litter (semi-decomposed leaves) can also be used instead of sand. It is light in weight, has good porosity and, while it decomposes, also provides the saplings with nutrients. If it is plentifully available, the pots may be filled with just the leaf litter. Another substance commonly used nowadays is coconut peat, which however, is quite costly. A similar product can also be obtained by controlled decomposition of dry sugarcane leaves, wheat straw or any other agro-waste, which is locally available.

Peat substitute from agro-waste A silo-like structure about 1m wide and 2 m tall is made by wrapping a black plastic sheet around four vertical bamboo poles. This silo is filled with the target biomass, which has been thoroughly soaked in slurry of cattle dung. The entire mass is kept wet by periodically sprinkling water on it so as to maintain the process of decomposition, which takes place only if the material is moist. Covering the top also with black plastic sheeting helps to conserve the moisture in the pile. As the biomass decomposes, it subsides and therefore requires to be topped up periodically with more biomass treated with cattle dung slurry. Depending on the nature of the agro-waste, the composting process can take anywhere from two to four months. A square hole of about 50 cm side is cut near the bottom of the silo and the composted material removed through this exit port. After each removal, fresh biomass (always treated with cattle dung) should be added to the silo from the top. Once the method has been standardized, the plastic sheet can be replaced by a permanent brick structure or by a large diameter cement pipe.

 
 
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