Nursery is a place where seedlings, cuttings and grafts are raised with care before transplanting.
Advantage of raising seedlings in nurseryIt is very convenient to look after the tender seedlingsIt is easy to protect the seedlings from pests and diseasesEconomy of land usage (duration in the main field is reduced)Valuable and very small seeds can be raised effectively without any wastageUniform crop stand in the main field can be maintained by selecting healthy, uniform and vigorous seedlings in the nursery itself.
Preparation of nursery
Selection of site
Selection of soil
A medium textured, loam (or) sand loam soil is preferred. Soil should be rich in organic matter. Soil depth should be preferably by 15-25 cm.
Types of nursery bed
a) Flat bed b) Raised nursery bed
Preparation of raised nursery bed
Selected soil should be worked well to break the clods. Weeds, stones and stubbles should be removed. Height of the raised bed should be 10-15 cm with a width of 1m and length may be according to the requirement and conveniences. Two parts of fine red earth, one part of sand and one part of FYM can be incorporated to each bed to improve aeration and fertility of the soil. Before preparing the bed, the soil should be drenched wit 4 % formaldehyde or 0.3 % copper oxy chloride to kill the pathogenic spores in the soil.
Advantage of raised nursery bedWater movement will be uniform and drainage of excess water is possible (In the case of flat bed water moves from one end to the other and there is possibility of washing away of seeds).Germination percentage of seeds is normally high. Operations like weeding and plant protection measures are easy.
Media for propagating nursery plants
Several materials and combination of different materials are available are media for germinating seeds and rooting cuttings. A good propagating medium should possess the following characters.
1. Soil mixture
This is the most commonly employed medium for pot plants. It usually consists of red earth, well decomposed cattle manure, leaf mold, river sand and also charcoal in some cases. Soil mixture commonly used for propagation is
Red earth - 2 parts
FYM - 1 part
Sand - 1 part
It is the most satisfactory medium for rooting of cuttings.
It consists of the remains of aquatic marsh, bog or swamp vegetation which has been preserved under water in a partially decomposed state. When such peat is derived from sphagnum, hypnum or other mosses, it is known as peat moss. it is used in mixture after breaking them and moistened.
4. Sphagnum moss
Commercial sphagnum moss is the dehydrated young residue or living portion of acid-bog plants in the genus Sphagnum such as S. papilliosum, S. capillacem and S. palustre. it is generally collected from the tree trunks of the forest species in south Indian hills above 1500m above M.S.L. during rainy period. It is relatively sterile, light in weith and has a very high water-holding capacity. It is the commonly used medium in air layering.
It is very light in weight and able to absorb large quantities of water. This can be used as a rooting medium for air layering and also in pots for raising certain plants.
Container for propagation and growing young plants
1. Earthen pots
They are made of burnt porous clay in various sizes to provide requisite amount of soil and root space to different kinds and sizes of plants. They have straight sides and are made wider at the top than at the bottom to hold the greatest bulk of compost where the feeding roots are and also to facilitate easy removal of soil, intact with roots (ball of earth) at the time of planting or repotting.
2. Seed pan and seed boxes
Seeds pans are shallow earthen pots about 10 cm high and 35 cm in diameter at the top. They have one large hole for drainage in the centre or 3 holes at equidistant from each other. Seed boxes are made of wood, 40 cm wide and 60 cm long and 10 cm deep, with 6-8 properly spaced holes drilled in the bottom.
Against each of the holes is placed a crock with its concave side down. Some large pieces of crock are put over it and also by the side of this crock, some coarse sand 2 or 3 handfuls are sprinkled on the crock pieces forming a thin layer to prevent fine soil from clogging the drainage. Over this, required soil mixture is added. Very delicate kinds of seeds like Cineraria, Begonia, etc. are best sown in these containers.
3. Polythene bags
Small polythene bags with holes punched in the bottom for drainage and filled with a porous rooting medium are used for propagation of cuttings like Jasmines, Duranta, Crotons etc. in the mist chamber. Sometimes, young seedlings which are raised in the nursery are subsequently transplanted in these polythene bags and kept there till they attain required growth for transplanting them to the main field (Papaya, Curry leaf etc.).
4. Plastic pots
Plastic pots, round and square are used to keep mostly indoor plants. They are reusable, light weight, non-porous and they require only little storage space
Tools and implements for nursery work
| Rose can/water can||:||This is used for watering the nursery. Fine spray of water should be used for watering nursery of small sized seeds|
|Digging fork||:||This has prongs of 20 cm long fitted to a wooden handle. This is used for uprooting plants, rooted cuttings, harvesting of tubers etc., without damaging the root system or tubers.|
|Shovel||:||This is a curved steel plate attached to a wooden handle and used for transferring soil, manure etc.|
|Garden rake||:||This is used for leveling lands and collecting weeds. The rake consists of a number of nail like projections from a crow bar provided with long handle|
|Hand trowel||:||This is used as a small tool for making holes for planting seedlings and small plants. This is also useful for removing surface weeds in nursery beds|
|Secateur||:||This is used for cutting small shoots to regulate shoot growth in fruit trees|
|Budding or Grafting knife||:||This knife is used for budding and grafting. This has two blades in which one is with ivory edge used for lifting the bark in budding operation.|
Purposes for which plants are potted are
Pot mixture or potting compost
It is essential for potting of plants. The pot mixture is prepared by suing various ingredients. The proportion of pot mixtures will vary with different kinds of plants.An ideal pot mixture should have an open structure, which allows good drainage and holds sufficient moisture for plant growth and permits excess waster to drain away.Should supply adequate nutrient to the plants during all stages of growthShould be free from all harmful organisms and toxic minerals andShould be light in weight
Potting procedureWet the seedbed before lifting plants. Life with a ball of earth with as much of the root system intact, as possible. Do not pullout seedlings in the hot sun. Do not allow roots or the soil around the roots to dry.Fill up pots by putting some crocks first, then a layer of sand (5-8 cm) and finally pot mixture (8-10 cm).Place the plant with the ball of earth in the centre upon the layer of pot mixture (Place on one side of pots in the case of root stock plants used in inarching)Put pot mixture around the ball of earth, press as you fill up and level off, leaving one inch head space at top. Do not press over the ball of earth. It will break and damage the roots.Set the stem of plant at the same height as it was in the seed bedImmerse pot with plant in a tub of water gently and keep inside water till air bubbles cease to come out. Remove and place the pot under shade of trees.
Repotting is done for changing the soil medium for pot bound plants.
Pot bound condition
When the potted plants are grown for more than one season or one year in pot, the root very soon become a tangled mass and exhaust all the nutrient in the limited soil, besides being circumscribed in the limited place. This stage is known as pot bound condition.
Repotting procedureIt is better to west the potted plant 24 hours earlier to facilitate repotting (removal of plant from pot)The technique to remove the plant with a ball')f each intact is to keep the right hand palm over the soil, allowing the stem of the plant in between the first fingers and turn the pot upside down holding the pot at the bottom with the left hand and gently knocking the rim of the pot on the edge of table or any other hard surface or even on the bottom edge of another inverted pot. The ball of earth comes out of the pot. If for any reason, it fails to come out, break the pot knocking the sides with a stone or fork and free the soil from it.Examine the roots, cut neatly with a secateur, the decayed, dead and dried or twisted roots. Reduce the size of the ball of earth around the roots.Place the plant in the new pot at the same height at which it was in the old pot. Fill up pot with fresh pot mixture and immerse in water.
GeneralThe initial reaction after potting and repotting is wilting. The transpiration loss has to be checked to help plants revive. Hence keep freshly potted plants under shade and "pot water daily".After about ten days under shade, the plants should be gradually exposed to sun by keeping them for some hours under sun and then putting them under shade. The period of exposure can be increased every week until finally the plants can be kept in the open. This process is called "hardening".
1. Dr. N. Kumar. 1997. Introduction to Horticulture. Rajalakshmi Publications, 28/5 – 693, Vepamoodu Junction, Nagercoil. Pp: 15.47- 15.50.