Procedure of Introduction

Introduction:

Bringing a new crop, new species of a crop or a wild species of a crop from a region to a new region with different environment is known as introduction. This introduction may occur between two places in a country,  between two countries or between two continents. To adapt the new crop with new environment of the new region is known as acclimatization. For example, East India Company brought many new crops from different places of the world in British-India. They brought Cauliflower, Cabbage and different vegetables from Mediterranean region, Tea and Litchi from China and Mehagani from West Indies. Introduction may be divided into two ways:

1. Primary Introduction
2. Secondary Introduction

1. Primary Introduction:

When an introduced variety is cultivated without changing its genetic characters is known as primary introduction. For example Swarna Dhan.

2. Secondary Introduction:

New improved varieties are isolated by selecting from introduced variety to acclimatize perfectly in the new environment. Besides, hybridization is done with local variety to transfer desired character.

Procedure of Plant Introduction:

1. Collection of germplasm: Germplasm is collected by personally or institutionally after government approval. 
2. Quarantine: Collected germplasm is quarantined to make sure that no foreign pathogen or insects get admit to the region.
3. Cataloging: An entry number is given to the introduced germplasm and the characteristics, source etc. information are recorded.
4. Evaluation: Yield and other criteria are tested by field trial.
5. Increasing number and Distribution: The introduced variety is approved as a new variety and distributed across the country.

Advantage of Introduction:

1. Entirely new crop can be introduced to a new region.
2. A new improved variety of a crop can be selected directly or can be used after hybridization.
3. Variants are found by introduction if the lack of alteration is observed in local varieties.
4. Plants can be collected by introduction to preserve germplasm of a crop.
5. It is a faster and less expensive way to crop improvement.

Disadvantages of Introduction:

1. New fatal diseases may be introduced and outbreak to the new locality. For example Late Blight Of Potato out broke in 1883 in Europe and Banana Bunchy Top Virus was introduced in Bangladesh in 1940 from Sri Lanka.
2. New insects can be introduced along with new species to the new locality. For example, Potato Tuber Moth was found for the first time in 1900 in Bangladesh which came from Italy.
3. New weed seed can admit with new crop. For example, Shial mutra (Chromolaena odorata), Crota (Croton), Taralota (Ipomoea quamoclit) introduced in Bangladesh.
4. Some new crop can destroy the natural equilibriam of the new region. For an example Eucalyptus came from Australia is draining underground water in Bangladesh.