International provenance trial of Neem (Azadirachta indica) in the terai region of Nepal

Abstract

An international provenance trial of Neem (Azadirachta indica A. Juss.) was established in July 1996 at Butwal Research Station of western Terai region of Nepal. It comprised the seed sources of 23 provenances collected from 10 countries including Nepal. A randomized complete block design was used for the experiment with two replications in an area of 1.5 hectares. The objectives of this trail were similar to that of other provenance trials under the International Neem Network. The assessments were made for survival rate, diameter at breast height (DBH), height, crown diameter and straightness of stem at age 5 and age 10. Average survival rates of the provenances in the two assessments were 69.74 and 63.5% respectively. The survival rate ranged from 33% for Kuliyapitiya, Sri Lanka to 92% for Ramannagudu, India. The four provenances Ramannagudu, Sagar, Sunyani, and Lamahi showed ≥80% survival rate. Similarly, Sunyani, Ban Bo, Yezin, Ramannagudu and Doitao showed best performance for DBH. The mean DBH of provenances was 8.74 cm (SD = 2.07). The five provenances namely, Sunyani, Yezin, Ban Bo, Ghaati and Bandia were the best performer for height. The mean height and SD of provenances were 6.29 m and 0.79 respectively. Sunyani had the widest crown diameter at both ages. Ban Nong showed the highest score for the straightness of main stem. Out of the two local provenances of Nepal, Lamahi showed better performance than Geta in many characteristics.