There is a fast rate in the change in the climatic conditions. With the change in the weather conditions, the behavior of plants and the trend in their growth also changes. The growing of temperate fruit crops with low chilling requirement in the sub-tropical areas is being practiced at many places. The sufficient period of rest is important for the deciduos plants to bloom and bear the fruits. The dormancy in these plants is not attained at right time due to warmer sub-tropical climates. Thus, following this plants also show delayed flower and fruit bearing. Thus, manual application of chemicals for the defoliation of these deciduous plants is being practiced at many places to make plants enter into dormancy at right time. Chemicals like Urea, zinc sulphate, copper sulphate, HCN etc showed variable results in induction of dormancy in these fruit plants. Some work pertaining to this has been review under in the article.