Experimental Design for Evaluation of Clones of Casuarina for Windbreak Agroforestry System

Institute of Forest Genetics and Tree Breeding, Coimbatore took an initiative in ideotype breeding to select superior phenotypes of Casuarina which are efficacious for a windbreak agroforestry system. 21 phenotypes of Casuarina were selected by adopting ‘point grading method ’. Trees having more branches were given additional weighted score. On the basis of rooting ability and within clone variation in growth traits, ten clones were short listed for field trials. The total perimeter of the field was divided into two halves. Each half of perimeter was further divided into 20 m long sections. In each section of perimeter, one clone was planted in three rows. Each row is considered as a separate block (Replication) as trees in each row will be experiencing different growing conditions. The spacing between the rows was 1 m and the spacing within rows was 2 m in zig-zag configuration. The check clone was a hybrid clone of Casuarina equisetifolia x Casuarina junghuhniana-a commonly planted clone in Tamil Nadu. By dividing cumulative superiority percentage by 100, a “Cumulative Superiority Index” has been developed for final ranking. As a significant outcome of this experiment, five superior clones have been released for commercial planting with approval of Varity Release Committee of Indian Council of Forestry Research and Education, Dehra Dun-an apex body for approving release of tree varieties in India.