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ThesisItem Open Access Evaluation of wood quality of selected tropical pines raised in the high ranges of Kerala, for pulp and paper making(Department of Tree Physiology and Breeding,College of forestry,Vellanikkara, 2010) Ajayghosh, V; KAU; Anoop, E VA study entitled “Evaluation of wood quality of selected tropical pines raised in the high ranges of Kerala, for pulp and paper making” was conducted in the College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur during the period 2008-2010. The objective of the study was to evaluate the wood quality of Pinus caribaea Morelet, Pinus patula Schl. et Cham. and Pinus oocarpa Schiede grown in research trials of the Kerala forest department in the high ranges of Idukki district of Kerala. Increment core wood samples were collected at breast height from trees, selected at random, from each plot representing each species belonging to different age levels. These samples were then subjected to intensive investigations to find out radial variation (pith, middle and periphery), species variation and influence of age on different wood physical, anatomical and chemical properties. The study revealed that many of the characters studied were influenced by species and age interaction. Radial variation was also found to have significant difference within the species for characters studied. As a whole, under the present climatic condition P.caribaea was found to perform better with wood properties within the accepted range suitable for pulping and paper making. On the other hand, P. patula and P. oocarpa were also found to be promising species for pulping and papermaking with better derived fiber ratios. However, P. oocarpa had specific gravity value slightly more than that is recommended for pulp and paper making. Studies on chemical composition revealed that P. ooccarpa had better performance with higher cellulose and lower lignin content. So what needs to be determined is the relationship, if any, between wood and tracheid properties of these species and the products which can be manufactured from this renewable resource. For this, more extensive study is needed for which the results of this study could be used as a base line data for future tree improvement aspects of these species with reference to wood quality and to bring out their potential utility for future afforestation programmes and timber utility.ThesisItem Open Access Field performance of arbuscular mycorrhizal fungi on vegetative growth of mahogany (swietenia macrophylla king.) seedlings(Department of Forest Biology and Tree Improvement, College of Forestry, Vellanikkara, 2018) Satyabrata, Nayak; KAU; Santhoshkumar, A VA study was conducted to determine the efficiency of arbuscular mycorrhizal fungi (AMF) on the vegetative growth of mahogany (Swietenia macrophylla King.) seedlings under field conditions at College of Forestry nursery and Instructional farm of Kerala Agricultural University, Vellanikkara, Thrissur district, Kerala during 2015-2017. Three AMF species used in the study were Funneliformis mosseae (Fm), Acaulospora mellea (Am) and Glomus etunicatum (Ge). The study was carried out in two parts. The first experiment was conducted in nursery for three months and the second experiment was conducted in the field for six months. In the nursery experiment, the AMF were applied to the seedlings either individually or in combinations (Fm, Am, Ge, Fm + Am, Am + Ge, Ge + Fm, Fm + Am + Ge) at three different doses (5 g, 10 g and 15 g) and laid out in a factorial CRD with control as 21+1 treatment combinations and three replications. The purpose of the nursery experiment was to choose the best four treatments for out-planting in the main field. It was found that the AMF species used in the nursery significantly influence the biometric characters (height, collar diameter and number of leaves) of the seedlings when compared to control. However, the AMF treatments did not differ among themselves. There was significant differences among different doses of AMF. The seedlings growth increased when the doses of AMF increased. From the result, Fm (15 g), Am (15 g), Ge (15 g) and Fm + Ge (15 g) were chosen as treatments for seedlings for the second experiment. The field experiment was laid out in a randomized block design with five treatments (four chosen treatments from nursery + control) with three replications. The observations like height, collar diameter, number of leaves, photosynthesis rate, stomatal conductance, transpiration rate and leaf temperature were recorded at 30 days interval. Soil nutrient analysis was done before and after the planting of ii the seedlings. Plant’s nutrient analysis were done after the completion of the experiment. It was found that inoculation with AMF, did not result any significant differences in height, collar diameter, number of leaves, stomatal conductance and leaf temperature. However, the AMF had significant influence on photosynthesis rate and transpiration rate on the seedlings at later stages of the experiment. From soil nutrient analysis, it was found that total N, available P, available K and organic carbon content increased with AMF inoculation. The soil pH changed from 5.46 to 5.94. From plant nutrient analysis, it was found, that there were no significant effect of AMF on K and N content of the seedlings. However, the P and C content of the seedlings increased due to AMF. The root colonisation percentage and total spore count were found to be low in all treatments. These values were significantly higher in seedlings inoculated with AMF than the non-inoculated seedlings. From the study, it was concluded that increasing doses of AMF can increase S. macrophylla seedlings growth in nursery. The AMF did not affect the growth of seedling during first six months of field experiment. But, some physiological parameters like photosynthesis rate and transpiration were influenced by the AMF at later stages of the growth. It may be pointed to the fact that AMF experimented could not establish in the field as evidence by low root colonisation percentage. This may be because of the soil reaction which was acidic in nature and was not suitable for AMF to establish since AMF require neutral medium for its better growth and development. Arbuscular mycorrhizal fungi helped in improving the pH of soil along with other nutrient contents (N, P, K and organic C). The seedlings were benefitted from AMF as their P uptake was increased. Further studies are required to identify better native species of AMF for S. macrophylla in acidic ultisols of Kerala.