After care of Seedlings

After care of Seedlings

After care of Seedlings (1)

The various after care operations to be performed in a commercial forest nursery are discussed below:

Irrigation

Water management may be defined as the scientific regulation of water for the production, conditioning and protection of bare root nursery crops. Water is managed in forest tree nurseries with following objectives

to control available soil moisture to promote the germination, establishment and growth of the crops.

To provide solutions for transporting and infiltrating water soluble fertilizers and leaching excessive salt concentrations.

To protect the crop from excessive atmospheric drought, soil heating, freezing or frost.

To promote germination of weed seed on fallow land.

To minimize potentially polluting losses of fertilizer and biocides

to limit the amount of water for the optimum needed for crop production.

Irrigation in the nursery is one of the most important aspects of nursery management. Care of transplanting seedlings is necessary till they attain appropriate size for planting out. Provision of adequate moisture at all times is essential for a nursery in the tropics. Even in humid equatorial regions, with high well distributed rainfall, one or two days drought can kill young seedlings.

Watering should be adequate and carefully regulated. Continuous watering creates a superficial root system for the plant which cannot stand drought when planted. The excessive wearing is also as harmful as under watering. It may reduce aeration which may also kill Rhizobium, increases damping off, produces pampered and weak seedlings and increases cost of the plants. Watering has to be that level which the soil can retain. Even if cheap water is available, the watering must be more seriously planned. Irrigation may be essential in summer in order to maintain a good growth of seedlings.

Watering may be required every day in hot months of March to may while in September and October the frequency can be reduced to thrice a week. Usually no watering is done during rains. Soil should be maintained moist for several days after germination or pricking out, by watering every day. This frequency reduces as seedlings establishes and require a minimum level usually of two watering per day in early morning and early afternoon. Irrigation requirement varies between tree species. Several species such as teak and bamboo require little irrigation while several other species require more water. After sowing the soil surface should not be allowed to dry out. If the soil becomes dry the seed may dry out too much. The advantages of stratification may be lost, and finally slow and spotty germination my result.

Lack of available soil moisture can reduce germination, survival of seedlings and limit growth of transplants. In addition, many nursery herbicide and granular fertilizers require pit soil to be fully effective. For these reasons a good irrigation system is an important tool in nursery management.

Careful supervision must be done daily because more than one watering per day may be required to maintain proper moisture status during summer days with high evaporate demand. As a rule, fine textured soils require more frequent watering than coarse textured ones. Excessive water promotes per emergence damping off and growth of seed borne fungi by decreasing soil temperature and increasing soil moisture. A correct balance is important. If emergence is much slower than expected and examination of seed reveals that it is rotting, decreasing water and spraying with an appropriate fungicide to prevent further damage can be beneficial.

After germination of seeds in the nursery, the watering regime should be changed in such a way that frequent and shallow irrigation should be replaced with longer periods of irrigation. Soil should be kept In a moisture status of -0.1 and -0.75 bar at a depth of 15 cm for optimum growth and irrigated only when it approaches -0.75 bar. This regime is followed until hardening treatments are begun in mid summer. In the exposed surface of a nursery bed, soil surface temperatures can rapidly rise to over 40°C on warm sunny day. This can damage the root collar area and damage the seedling. To prevent damage, the soil can be cooled by irrigation. Damage is most apt to occur in younger seedlings of species adapted to cool, moist climate. Some nurseries in western countries use air temperature as a guide for determining need for cooling. Soil-surface temperature is usually measured 0.5 to 1 cm below the surface. How long and how often a nursery is to apply with water when critical temperatures are reached varies greatly.

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Vrikshayurveda

Ancient indian science of plant life and plant care: Area of this website provides a comprehensive insight into plants and trees widely used in Vrikshayurveda; methods of plant health, nutritional care and management and biological control measures along with the scope for developing process and products.