How to transplanting seedlings

Some important aspects of transplanting of seedlings are briefly stated below:

Pulling or uprooting of Seedlings for transplanting: A few hours before pulling up seedlings the bed should be watered well to moisten the root-zone and to soften the soil sufficiently. Seedlings belonging to monocot groups such as rice and onion are pulled and washed to remove soil from the roots (naked) while seedlings belonging to dicot groups such as tobacco, tomato, brinjal and cabbage are pulled up with a lump of soil in the roots. Sowing and Planting 255 Individual seedlings are uprooted with sufficient care so that they do not get damaged except for the tearing of some roots. If seedlings are uprooted in phases, it is better to reduce the density on the principle ()I’ age and vigour by uprooting vigorous seedlings first leaving smaller ones to grow further. If seedlings are uniform in vigour uprooting may be done from one side. Sometimes seedlings are uprooted and transplanted temporarily in vacant portions of the bed or elsewhere to harden them. Seedlings after uprooting should not be allowed to stale. If staling is unavoidable keep them in a moist, cool shady place with frequent watering under, loose conditions or with a lump of moist soil in the roots or in humid chambers. The seedlings should be kept erect otherwise they will bend upward by their negative geotrophic movement. The handling of seedlings before transplanting should be with great care. Any injury to vital parts leads to the death of the seedling. Injury to vital parts may invite disease infestation. During transport seedlings should not be allowed to wilt or pile up which may cause suffocation and damage.

Time for transplanting: Seedlings are transplanted in a well prepared field for raising crop plants. The best time for transplanting is the late hours of the day when the temperature cools down and humidity rises but transplanting can be done at any time of the day if it is cloudy or raining or drizzling or about to rain.

Condition of seedlings: Seedlings with more shoot growth should not be transplanted in dry-hot or chilly months. They should be trimmed to reduce transpirational surface. Overgrown seedlings (with larger and thinner leaves or weak stems) droop or lodge a few hours after transplanting. Such seedlings should be trimmed off from the top by a sharp, clean knife with minimum injury.

Seedling age:Though early seedling age provides for quicker establishment yet the three-to-four-functional-leaf-stage is found to be a more appropriate stage for most of the crops for uprooting, transporting, transplanting and establishment. Such a stage coincides with a plant age of three to ten weeks.

Seedling number per hill: Single seedlings may be transplanted in each spot at predetermined spacing or at the rate of two to three seedlings in each hill.

Plant Density:The number of harvestable plants per unit area depends on various factors. The important factors are species, variety, plant character and the duration, time and method of sowing, fertility status of soil, purpose of cultivation, management practices and method of harvesting.

Placement of seedling: Seedlings should be placed, in such a way that the shoot remains upward and, the root downward. Roots and the sub-terranean shoot portion should not be crooked or tufted as this may delay establishment or cause death. They should be well spread having enough contact with moist soil. The soil around the root may be compacted lightly to provide more root-soil contact and to remove any air gap and consequently the accumulation of more water in the rhizosphere. Otherwise, it may induce the withering or decaying of roots. Sufficient watering in non-plastic soils immediately after transplanting serves the same purpose along with supplying moisture to the root-zone.

Seedling treatment:Seedlings may be treated by dipping the root or immersing it in a solution or suspension for a few minutes for priming prior to transplanting. Such treatments may be to induce establishment and growth or to induce tolerance against insect-pest, and diseases as well as adverse weather and soil conditions.

Water temperature (specially for rice): During transplanting in wet lands the temperature of the standing water should be within the bearable limits (cardinal points) of the seedlings. The depth of water should be as low as possible. Deep water (more than 10 cm) may cause the floating or immersing of seedlings which seriously affects plant population. If the water temperature exceeds 40°C for half an hour or more it is better to drain it out. Deep water not only affects the establishment of seedlings but also impairs tillering. The progress of transplanting should be with the backward movement of the transplanter. Transplanting becomes easy and quick if the transplanter moves to the leeward direction of the prevailing wind. Straight row transplanting ensures a uniform plant population per unit area and subsequent field operations become easy and smooth. In closer spaced crops, for instance rice and onion a skip row after ten to fifteen rows provides a better micro-environment for crop growth. The use of five to ten per cent more seedlings at regular intervals as buffer stock helps to fill up gaps if any, with seedlings of the same variety, age and at the same physiological stage.