Assessing Growth Performance of Tectona Grandis in Nepal

Globally the forest area covers 3,999 million ha (30.6%) of land.About 299 million ha (7%) of this is planted forest which had been increased by 105 million ha since 1990 (FAO, 2016).T. grandis plantation forest constitutes about 4.346 million ha and represents 75% of high tropical hardwood plantation, 83% of which is in tropical Asia (IUFRO, 2018).Teak (Tectona grandis L.F., is a member of Verbenaceae family, one of the most important, widely planted, a valuable hardwoods spp.(Robertson and Reilly, 2006).The success of large scale plantation is mainly due to its relatively fast growth, fire resistance, non-browsability, high survivable rate (Robertson and Reilly, 2006).Besides, it is termite resistance and widely used for boat and ship, building construction, decorative veneer, furniture, handicraft, musical instruments and has been recognized for centuries as a king among timbers due to its durability, workability, attractiveness and strength (KFRI and ITTO, 2003; FAO, 2016, Thapa andGautam, 2007).For most of the countries like Nepal, T. grandis is an introduced species (Jackson, 1994), stands for a good opportunity to produce quality timber and is a major asset for the forest economy.In Nepal, T. grandis plantation had begun from 1960 in Chiliya, Rupendehi (Kayastha, 1974) followed by some block plantation in Sagarnath, Sarlahi and Ratuwamai by Forest Product Development Board.There was a serious problem of great decline suffering from die back in Dalbergia sissoo reported so T. grandis plantation came as alternative of D. sissoo ( Paudel and Sah 2003).T. grandis plantation has been prescribed for more than 60 years of rotation period for Nepal (Amatya and Shrestha, 2016).However, the growth performance is unknown.The growth is generally affected Abstract: The growth of any plant species is important characteristics which determine the yield of the plant.The growth performance of Tectona grandis was not so far assessed in Nepal.Therefore, this study was objectively carried out to assess the growth performance of T. grandis, show the relationship between the growth and soil nutrients and effect of spacing on the growth.Community and private plantations of this spp. in seven Tarai districts of Nepal were selected as study site.Altogether 215 samples were collected applying stratified random sampling.Particularly diameter and height of 8644 plants were measured and the spacing between plants was also recorded.The age of the plantation was noted from plantation report.Meanwhile, 102 soil samples were collected from 0-10, 10-20 and 20-30 cm depths.The increment of basal area, volume, biomass and carbon were analyzed and N, P, K, C, pH and bulk density were evaluated in the lab.The result showed that mean annual stem volume was the higher 171.46 m³/ha in community plantation while it was only 92.61 m³/ha in private plantation.The average soil organic carbon in community plantation was estimated to be 38.29±6.05ton/ha whereas it was only 32.77±2.57ton/ha in private plantation.Total nitrogen was only 0.07% while P and K were 21.23 and 166.04 kg/ha respectively in community plantation.Similarly, carbon and Nitrogen were 0.84 % and 0.06% respectively in private plantation.The P and K were 53.29 and 171.55 kg/ha simultaneously.The pH was 6.50 for community plantation and which was 6.46 in private plantation.The R value of MABAI of T. grandis and carbon was low 0.49 but it was significant (p value = 0.00).It was found that the highest MADI at >3 m spacing with 1.33±0.028cm but it was the lowest at < 2 m spacing with 1.17±0.018cm.This study will be useful to see the rotation and effect of spacing and soil fertility on growth performance.