89 KUMAR ET AL Environment & Ecology 28 (4B) : 2753—2755, 2010 © Copyright by MKK Publication 2010 ISSN 0970-0420 Effect of Pre-Sowing Treatments on Seed Germination of Gymnocladus burmanicus Parkinson NARESH KUMAR, SANJEEV KUMAR, BIKRAM SINGH AND DEBASHISH SEN College of Horticulture & Forestry, Central Agricultural University Pasighat, East Siang 791102, Arunachal Pradesh, India E-mail : naresh2020@rediff.com Abstract Gymnocladus burmanicus is a leguminous tree species found in north-east India. Mature pods of this tree species yield soap material and are collected by local people for domestic purposes. The natural regeneration of the species is poor due to the presence of hard-waxy seed coats. Hence, the present investigation was carried out to enhance the germination by giving pre-sowing treatments. Among different pre-sowing treatments, H 2 SO 4 treatment for 15 minutes gave the highest germination (70%) followed by the same acid pre-treatment for 10 minutes (63.67%). The other germination parameters viz., mean daily germination (2.50%), peak value (3.67%), germination value (9.17%) and germination energy (51.00%) were also maximum when the seeds were treated with H 2 SO 4 treatment for 15 minutes. Hot water treatment, also, gave better germination (60.33%) as compared to cold water and urine soaking treatments. The minimum germination (5.33%) was recorded in untreated seeds. Key words : Pre-sowing treatment, Germination, Gymnocladus burmanicus. Gymnocladus is a small primitive genus (Fabaceae : Caesalpinioideae) with only five species of which Gymnocladus angustifolia occurs in Viet- nam, G.. diocus occurs in N. America and the remaining three species namely G.. chinensis, G.. assamicus, and G.. burmanicus are confined to the trijunction of India, China, and Myanmar (1). Gymnocladus burmanicus has been reported in East Siang district of Arunachal Pradesh at 160 to 200 m above mean sea level within geographical limit of latitude 28.06, 28° 4´ 0´´ N and longitude 95.33, 95° 19´ 60´´ E. It is a medium sized tree (average 14.5 m) having compound leaves, pods 12.5–17 × 2.7–3.7 cm, seeds globose, black, shining. It is commonly known as Dekang among the ‘Adi’ a tribal community of Arunachal Pradesh. This tree is culturally and me- dicinally important. The pods of the tree are used in shampoo, soap, dermatological disorders. Adi, a tribal community of Arunachal Pradesh, uses its pods as alternative of soap and for attracting the deer for hunting in traditional ways. Use of this tree among Pasi, Padam, Pangi, Minyong and other ethnic groups of Arunachal Pradesh is also well known (2). Mature pods are largely collected by local people and stored for future use. Deer were found to eat the mature fallen pods. These activities simulta- neously affect its natural regeneration. Presence of hard-waxy seed coat is also one of the major con- straints for its natural regeneration. Keeping in view, the importance of this tree species in the tribal com- munity and problem in its natural regeneration. Keeping in view, the importance of this tree species in the tribal community and problem in its natural re- generation, the present investigation was carried out to improve the seed germination by giving dif- ferent pre-sowing treatments. Methods The present investigation was carried out at College of Horticulture and Forestry, CAU, Pasighat. The matured pods were collected from tree growing in the nearby forest, and healthy and vigorous seeds were used for the study. The different pre- sowing treatments given were : Control (T 1 , without treatment), cold water soaking for 24 hours (T 2 ), cold water soaking for 48 hours (T 3 ), hot water soak- ing and subsequent cooling for 2 hours (T 4 ), soak- ing in cow urine for 48 hours (T 5 ), H 2 SO 4 treatment for 5 minutes (T 6 ), H 2 SO 4 treatment for 10 minutes