Browsing by Author "Kunhamu, T K"

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Belowground architecture and carbon stocks of silver Oak (Grevillea Robusta A.Cunn) Trees
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2013) Samritika; Kunhamu, T K
Biomass production and nutrient dynamics in a multipurpose tree based black pepper production system
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2013) Aneesh, S; Kunhamu, T K
A field study was undertaken on a 22-year-old black pepper production system at Livestock Research Station, Thiruvizhamkunnu, Kerala during 2009-10 to evaluate the growth, biomass production, Carbon sequestration and nutrient dynamics in six multipurpose trees used as pepper standards viz. Acacia auriculiformis, Artocarpus heterophyllus, Grevillea robusta, Macaranga peltata, Ailanthus triphysa and Casuarina equisetifolia. Diameter at breast height (DBH), total height and bole height varied significantly between the six species. Maximum DBH was registered by Grevillea robusta (23.06 cm) which was closely followed by Artocarpus heterophyllus (22.12 cm). Mean tree total volume and bole volume production also varied, maximum mean tree bole volume was recorded by Grevillea robusta (0.360 m3) followed by Artocarpus heterophyllus (0.280 m3) and Acacia auriculiformis (0.260 m3). The aboveground biomass was estimated from destructively sampled 12 trees of each species and the belowground biomass was estimated following root excavation of three average sized trees of each species. Species-wise variation in terms of total biomass, aboveground biomass and belowground biomass was observed. Among the black pepper support trees Grevillea robusta recorded highest total biomass production (366 Mg ha -1) followed by Acacia auriculiformis (331 Mg ha -1) and the lowest was recorded in Ailanthus triphysa which is 155 Mg ha-1. The above ground biomass ranged from 264 Mg ha-1 in the case of Grevillea robusta to lowest of 122 Mg ha-1 in the case of Macaranga peltata. Stem wood accounted for maximum contribution to the total biomass in all the species. Maximum root biomass was recorded in the case of Grevillea robusta (63 Mg ha-1) closely followed by Acacia auriculiformis (62 Mg ha-1) and the lowest in the case of Ailanthus triphysa (24 Mg ha-1). Percentage contribution of root biomass to the total biomass varied from 11 to 24 depending on the species. Among different pepper support tree system, the Grevillea robusta based pepper production system recorded highest biomass Carbon stock to the tune of 169.24 Mg C ha-1. However with regard to soil Carbon Acacia auriculiformis based pepper production system recorded highest value (71.39 Mg ha-1) followed by Macaranga peltata (68.64 Mg ha-1) based system while the treeless control plot recorded the lowest carbon stock (38.17 Mg ha-1). Study indicate the overall improvement in site productivity in multipurpose tree based production systems and careful selection of the tree species can bring substantial benefits both in economic and ecological terms to the farmer.
Comparative analysis of carbon and nutrient pools in soils of selected woody ecosystems of central Kerala
(Academy of Climate Change Education and Research Vellanikkara, 2016) Veena Prasad; Kunhamu, T K
Present study entitled “Comparative analysis of carbon and nutrient stocks in soils of selected woody ecosystems of central Kerala, India” was carried out at the Academy of Climate Change Education and Research, Kerala Agricultural University, Vellanikkara, Thrissur during 2015-2016. The study showed that the carbon and nutrient stocks were significantly influenced by the treatments. Soil organic carbon is significantly different in each plantation and was significantly higher than corresponding contiguous treeless soils (p < 0.005). Also there was significant reduction in depth. Carbon stock was higher for mahogany plantation (116.01 Mg C ha-1) followed by homestead (105.41 Mg C ha-1) and teak (103Mg C ha-1). Lower carbon stock was found for mango (76.08Mg C ha-1) and acacia (75.19 Mg C ha-1). Carbon stock for each plantation was significantly higher than contiguous open plot. Similarly highest nitrogen and potassium stock was recorded for mahogany plantation (53.61 Mg N ha-1 and 1030.6 Kg K ha-1) which were significantly different from contiguous open plot. Nitrogen stocks were lower for acacia (26.77 Mg N ha-1) and mango (26.77 Mg N ha-1) but are significantly higher from treeless condition. Nitrogen stock in homestead (30.17 Mg N ha-1) and teak (38.29 Mg N ha-1) was higher than acacia and mango but lower than mahogany. Available phosphorous was lower in all woody ecosystems other than homestead (154.56 Kg P ha-1) with significant reduction across depth. The results of the present study revealed that soil organic and nutrient stock varied significantly with woody ecosystems and slow growing species as well as multi-strata ecosystem enrich soil with carbon and nutrient better than fast growing species like acacia. Also is significantly higher than treeless condition. Enhancing tree cover is thus an efficient method to mitigate global warming. Hence choice of the species and their management conditions are important considerations while designing plantation forestry programs particularly when their carbon sequestration and greenhouse gas mitigation potential are considered.
Diversity, structure and standing stock of timber in the homegardens of Thrissur district, Kerala
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Subu R Unnithan; Kunhamu, T K
Effect of seed biopriming techniques on moisture stress tolerance of sandal (Santalum album L.)
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2024-11-04) Harish Debta.; Kunhamu, T K
Seed priming is a smart, innovative, and effective option for enhancing the germination rate, seed quality, and productive capability of crops. The present study investigated the efficacy of biopriming techniques on the seed germination and seedling growth of Santalum album L. Further, the bioprimed seedlings were evaluated for moisture stress tolerance (drought and flooding tolerance). Five biopriming agents (e.g. Effective microorganisms; Plant growth promoting rhizobacteria (PGPR-I and PGPR-II); Pseudomonas fluorescens and Piriformospora indica) were evaluated in the study. The highest germination percentage was obtained for the seeds subjected to biopriming with Pseudomonas fluorescens for eight days (70.67%), whereas the control seeds had only 28.67% germination. PGPR-I was found to be equally effective in increasing seed germination at higher duration of treatment. Pseudomonas fluorescens and PGPR-I treatment had lower imbibition period to 13 days compared to the control seeds' 24 days. Lowered the mean time of germination (MTG) and increased germination rate index (GRI), germination uniformity and higher speed of germination too were observed with these treatments. Biopriming techniques influenced the seedling growth and biomass production at 90 and 180 days after transplanting (DAT). All the treatments from Pseudomonas fluorescens group effectively enhanced the seedling growth attributes. This was followed by Piriformospora indica and PGPR-I treatments. Among all the priming treatments, Pseudomonas fluorescens for six days was the best treatment for increased biometric growth and biomass in sandal. This was followed by Piriformospora indica treatment for two days. Seed biopriming techniques influenced the seeds' biochemical composition, e.g., carbohydrate, crude fat, electrical conductivity, protein, total soluble sugar and α and β- amylases. Observations during the storage period revealed that seeds deteriorated at 60 and 90 days, with a reported higher electrical conductivity, a decrease in carbohydrate, crude fat content, and protein inactivation. Six-month-old sandal seedlings were exposed to drought and flooding conditions. Leaf samples were used to compare for screening out best performing treatments for moisture stress tolerance, considering physiological and biochemical parameters at three stages. Evaluation was done at three stages: normal stress-free stage, stress (drought or flood) stage, and recovery stage. Multivariate analysis of variance (MANOVA) was performed for each physiological and biochemical parameter at three stages for drought and flood experiment to measure the strength and significance of the relationship between the dependent and independent variables. Piriformospora indica followed by Pseudomonas fluorescens group showed excellent recovery for photosynthetic rate, relative water content, chlorophyll stability index and cell membrane stability index in physiological parameters. Osmotic adjustment (e.g. free amino acids, proline, glycine betaine and total soluble sugar) was found to be significantly higher in seedlings originated from Piriformospora indica and Pseudomonas fluorescens priming suggesting these biotic agents as a potential seed priming agent, in sandal for imparting drought tolerance. Correlation studies suggest that among the sixteen characters (physiological and biochemical) used for the screening study, under drought stress, most of the characters showed a strong negative correlation with canopy air temperature difference (CATD). Under the flood stress, the CATD showed a highly significant negative correlation with net photosynthetic rate (-0.81), stomatal conductance (-0.54) and transpiration rate (-0.79). The study highlights the role of seed biopriming techniques in enhancing abiotic stress (drought and flood) tolerance in sandalwood, a threatened species, due to overexploitation in its natural population. The use of low-cost, environmentally safe seed invigoration techniques, as demonstrated in the present study, will be helpful for nursery growers to ensure better germination and efficient seedling establishment in the field due to the stress tolerance characteristics in this era of environmental unpredictability due to climate change.
Evaluation of biodegradable containers for seedling production in tree nurseries
(Department of Silviculture and Agroforestry ,College of Foresrty,, 2020) Subhasmita Parida; Kunhamu, T K
A nursery trial titled ‘Evaluation of biodegradable containers for seedling production in tree nurseries’ was conducted to develop alternate eco-friendly plant container as substitute for conventional polythene bag based containers at College of Forestry, Kerala Agricultural University, Thrissur. The study involved a three month long preliminary trial to explore the efficacy of various locally available materials for use as container for tree species. Based on the preliminary trial, five better performing container types were screened for detailed nursery trial to further examine their efficiency as containers for tree seedling production. Teak (Tectona grandis) being the widely produced forest planation species in Kerala, the nursery trials were performed with teak as test crop. The locally available materials used as containers for the preliminary trial included cow dung pot, sugarcane bagasse, arecanut sheath, mud pots, bamboo splits, bamboo basket, coco pot, cloth bag, nonwoven bag, bioplastic bag and treated card board. The containers were evaluated for their durability, physical stability to management practices such as irrigation and manuring, survival percent, height and collar diameter of the teak seedlings. It was observed that the bamboo splits based containers had the highest durability and can be used for two seasons while containers made from arecanut sheath, cow dung pot, sugarcane bagasee pot, bamboo basket, bioplastic bag and cloth bag totally degraded within two months suggesting their unsuitability for tree seedling production. In general, the better container types in terms of overall seedling growth performance and physical soundness were nonwoven bag, bamboo split, coco pot, treated cardboard pot and mud pot. These five container types along with coir root trainer (CRT) supplied by Kerala Forest Department were subjected to detailed nursery trial. It was observed that considerable variability existed in seedling growth characters such as height, collar diameter, number of leaves, leaf area, number of secondary and tertiary roots, lateral root length, root length: shoot length ratio, root and shoot dry and total dry weight. Among all container types studied, nonwoven bag grown seedlings showed better growth performance followed by seedlings grown in bamboo split containers while mud pot raised seedlings showed the lowest performance during all the stages of seedling growth. The overall performance of the container types followed the order: nonwoven bag > bamboo split > coco pot > treated cardboard > Coir root trainer (CRT) > mud pot. The cost of production per seedling was Rs 8.3 for non-woven bag, Rs 60.2 for coco pot, Rs 62.0 for mud pot, Rs 11.0 for bamboo split, Rs 12.8 for treated cardboard pot and Rs 25.8 for Coir root trainer (CRT). The Benefit: Cost ratio of raising 3- month old teak seedling ranged from 0.32 – 2.45. The value was highest for seedlings raised in bamboo split pot (2.45) followed by nonwoven bag (2.41) and cardboard (1.56) while it was less than one for all the remaining container types. The trial suggest that further studies are required to develop protocols for the reinforcement of biodegradable containers for increased phys ical strength and durability.
Field evaluation of stump and root trainer grown teak(Tectona grandish L.f.) plantations
(Department of Silviculture & Agroforestry, College of Forestry , Vellanikkara, 2019) Eldhose George; Kunhamu, T K
Teak (Tectona grandis L.f.) stands out to be the most popular commercialtimber species in the tropics by virtue of its matchless combination of properties. Over a century, root- shoot cutting (stump) has been the common nursery productiontechnology for teak across the world. However, the recent decade has seen unprecedented decline in the productivity of teak plantations which could be attributed to diverse reasons. In this context, the efficiency of the stump based planting method for teak hence assume close scrutiny by virtue of the limitation in the root spread and consequent belowground resource acquisition. In this backdrop, a field study entitled “Field evaluation of stump and root trainer grown teak (Tectona grandis L.f.) plantations” was conducted on teak plantations established at Karakkad, Kalady range, Malayattoor forest division, Kerala during 2017-18, to evaluate the influence of planting material viz. stump and root trainer on growth aspects, soil physio-chemical properties and root distribution separately in five and seven-year-old teak plantations. The teak plantations selected for study included; five-year-old (2012 establishment) stump and root trainer grown stands at 3x3 m spacing, seven-year-old (2010 establishment) stump and root trainer based stands at 2x2 m initial spacing. Attempt were also made to study the effect of planting spacing on the growth of teak that was raised from root trainers and managed separately at 2x2 and 3x3 m spacing. Nine random plots of size 20x20 m were demarcated for each of the treatments such that there were 45 experimental plots for observation. Altogether there were three treatment combinations for comparison viz. stump vs root trainer at 3x3 m spacing and five-year-old; stump vs root trainer at 2x2 m spacing and seven-year-old; five-year-old root trainer based teak stands at 3x3 m vs at 2x2 m spacing. Each treatment combinations were analyzed separately with independent t- test. Biometric observations on teak growth showed considerable difference with variable planting material and spacing. Root trainer grown teak stands showed better performance in total tree height (6.68 m at seven-years of age), DBH (9.04 cm at seven-years of age), and mean tree volume (0.031 m3 at seven-years of age) as compared to stump origin stand both at five and seven-years of stand ages. The basal area and bole height showed marginal improvement in root trainer grown stand at five-years of age. Initial spacing showed only marginal influence on total height and bole height with an advantage for stands at 2x2 m spacing as compared to 3x3 m spaced stands. However, DBH, basal area and volume showed discernible improvement in the stands at 3x3 m spacing. Crown diameter showed a nominal increase in the root trainer grown stand than stump grown stand at both ages. However, spacing had great influence on the crown diameter with more spread (2.7 m) by widely spaced stands (3x3 m). Stand LAI also was better for root trainer stand while spacing had poor influence on LAI. Persistence of stem axis and straightness of stem showed limited advantage for stump grown teak origin stand. Also closely spaced teak stands (2x2 m) developed from root trainer stands showed slightly better performance than teak at wider spacing (3x3 m). Attempts to analyze the influence of planting material and spacing on plant leaf nitrogen and soil physio-chemical properties suggested that plant leaf nitrogen concentration was modestly better for root trainer grown trees than stump grown trees. However effect of spacing indicated that widely spaced trees (3x3m) showing significantly higher nitrogen up take than narrow spaced trees. Soil physical and chemical properties were found to be less influenced by the planting material. However, all teak stands irrespective of planting material showed considerable improvement in soil organic carbon and nitrogen concentration and reduction in soil bulk density as compared with respective treeless open plots. Also there was consistent reduction in carbon content and nitrogen with increase in soil depth up to one meter soil depth. The average soil carbon concentration values were 1.15 % and 1.55 % for the root trainer and stump grown teak stands at seven-years of stand age. The corresponding soil carbon stocks were 24.60 Mg ha-1 and 32.85 Mg ha-1 for teak stands at seven-years of stand age. Investigations on root distribution among stump and root trainer grown teak trees revealed obvious advantage in root spread and root intensity for root trainer raised teak stands. Teak trees grown from stump had smaller roots confined to the base of the tree at shallow depths which drastically reduced with increase in lateral distance of soil depth. The presence of prominent multiple tap root systems could be the reason for the high root spread observed with root trainer based teak trees. The trends were the same for small, medium and larger root intensity. Yet another noteworthy observation was that teak trees at closer spacing showed reduction of root spread and restricted the root system at proximal lateral distance while widely spaced trees showed wider root distribution.
Fine root dynamics and associated carbon and nutrient flux in 12 year old acacia mangium at varying stand densities
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Delphy Rocha; Kunhamu, T K
Floristic diversity and regeneration status of moist dedicious forests in Thrissur district, Kerala: reassessment after three decades
(Department of Silviculture and Wildlife Science, College of Forestry, Vellanikkara, 2020) Abhi Jamatia; Kunhamu, T K
Growth and productivity as function of site quality and age in teak plantations of Nilambur, Kerala
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2021) Sankar Thampuran, M V; Kunhamu, T K
Teak has been one among the principal timber species widely used across the world due to its matchless combination of qualities. Kerala has around 76,710 ha of pure teak and 14,440 ha of teak with softwood plantation making up 49.08 and 9.24 per cent respectively of the total plantation area in the state. Despite having the largest share of plantations under teak, the productivity of teak plantations of Kerala are under serious decline and has been a matter of concern in the scientific parlance. Evidences suggest that even in Nilambur, the celebrated land of teak, there has been large scale decline in productivity of teak plantations. However, quantitative aspects of the productivity of teak and the drivers of changes especially in the best teak growing region in Kerala such as Nilambur, is lacking. In this backdrop, a field study entitled “Growth and productivity as function of site quality and age in teak plantations of Nilambur, Kerala” was conducted in selected plantations from Nilambur North and Nilambur South Forest Divisions. The plantations were selected based on the information available from Kerala Forest Department on their age and site quality. Four site qualities (SQ I, SQ II, SQ III and SQ IV) and five age classes (10-20, 20-30, 30-40, 40-50 and 50+) were considered for the study forming a total of 20 plantations (4 site qualities x 5 age classes = 20 plantations). Five sample plots, each of size 24m x 24m were laid out randomly in each of the selected plantations and parameters like total tree height, bole height, diameter at breast height, diameter at crown point and crown width were measured in the field. Also, soil sampling was done in four plantations of different site qualities falling in the mature age class of 40-50. For this, 1 m deep soil pits were dug, one each inside the plantation and in the respective contiguous treeless open. Sampling was done in five depth intervals (0-20, 20-40, 40-60, 60- 80 and 80-100 cm). Thus, a total of 120 samples of soil were collected for analysis. The collected soil was analysed for physical properties like bulk density and particle size distribution/ texture and chemical properties like pH, total Nitrogen, organic Carbon content, available Phosphorus and exchangeable Potassium following standard procedures. 122 The results showed that among the plantations studied in Nilambur, the SQ I plantations showed dominance in all growth parameters of teak while a predictable pattern of change was lacking across the subsequent site qualities. There was large heterogeneity among the plantations in terms of management that had a confounding effect on the potential exploitation of the site resources for optimal growth of teak. Many of the plantations had high density of invaded miscellaneous trees which have increased the effective density and seriously affected the growth of teak. The density of miscellaneous trees varied from 0 to 694 trees per hectare among the studied plantations. The competition with miscellaneous species has created large scale variability within each stand in growth attributes. Normal distribution of diameter classes was observable in the plantations studied due to high effective density. Stand density being a critical factor that decide productivity and product quality in teak plantations, the observed variability in productivity could be attributed to poor adherence to proper density regulation. Also, the productivity of the plantations has been considerably influenced by poor adherence to timely plantation management practices. The Mean Annual Increment varied from 0.56 to 8.70 m3ha-1yr-1 among all the plantations studied. On comparing with the All-India yield table for teak, the plantations showed growth and productivity estimates that were quite different from their assigned site quality. In the age class 40-50, the SQ I plantation showed a height that was corresponding to SQ III according to the yield table, while the SQ IV plantation height corresponded to the SQ II. All the observed soil parameters with in the experimental plots were well within the range required for the optimal growth of teak. However, except for SQ1, we could not observe any predictable change in soil properties across the remaining site qualities. The Bulk density of soil increased with depth, both inside and outside the plantations. The rate of increase of bulk density was higher in the treeless open areas compared to the plantations. Th soil texture remained as sandy loam or loamy sand for all the analysed soil samples. The soil pH varied from 5.17 to 5.98 between the soil samples that were analysed. The organic Carbon content in various layers of plantation soil varied from 0.58 to 2.07 %. Total Nitrogen varied from 0.077 to 123 0.223 %. Available Phosphorus varied from 2.10 to 17.33 kgha-1. Exchangeable potassium varied from 51.82 to 488.30 kgha-1. Attempts to relate the soil properties with the site productivity could not derive meaningful correlations suggesting that the productivity decline might be an effect of poor management rather than depletion of nutrient status. The study suggests that there is an urgent need to revisit and reassess the site quality of the plantations in Nilambur and to give utmost concern for adhering to scientific stand management in timebound manner for deriving optimal productivity from teak plantations of Nilambur.
Growth and productivity of Artocarpusheterophyllus Lam. based agrisilvicultural system under variable stand densities
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2024) Ankita; Kunhamu, T K
Artocarpusheterophyllus Lam. (Jack tree) is a versatile tree species well-suited for the humid tropics, particularly for Kerala, Peninsular India. It is a key component in the traditional homegardens and farmlands of Kerala, primarily valued for the jackfruit, a unique delicacy of the region. Although the tree produces high-quality timber that is in great demand, it is rarely cultivated in Kerala with the primary aim of timber production. In this context, determining the optimal planting density becomes crucial, particularly when the goal includes producing quality timber and utilization of interspaces for integrating compatible intercrops with jack trees. In this backdrop, a field experiment was initiated in 2020 to evaluate the growth performance of jack trees at different planting spacing (3×3 m, 3×4 m, and 3×5 m) under randomized block design (RBD) with four replications, at Suhasini hills, Kerala Agricultural University, Thrissur, Kerala. After the first year of establishing the field, two shade-tolerant herbaceous spice crops viz. ginger and turmeric, were cultivated as intercrops along with black pepper trailed on the jack trees. The growth and productivity of spice intercrops were evaluated consecutively for two years 2021-2022 and 2022-2023 and compared with contiguous treeless control. The data revealed that tree height, crown attributes, GBH, collar diameter and branches increased consistently across all spacing regimes over the study period. Notably, trees planted at 3×3m spacing exhibited the maximum height growth (6.64 m), branch number (39) and crown cover (82.86%). However, the radial growth parameters such as diameter and basal area showed insensitivity to variable spacing regimes for jack during this early period of tree growth. The results from the study showed variable growth trends for black pepper under different tree spacing regimes, though many of such trends were non-significant. It is inferred that the intercropped black pepper is in the early phase of growth (one year) and the systems may take more time for inflicting competitive interactions for resources in short supply. Although all the growth parameters of turmeric and ginger remained non-significant across the planting spacing, there observed sizable variations under tree cover and treeless control. The yield of turmeric and ginger per meter square was not influenced by tree spacing and was comparable to the sole crop yields under treeless control. This is primarily due to the uniform availability of understorey PAR which was above 90% for all the spacing trial plots. However, the projected yield (Mg ha-1) of turmeric and ginger varied significantly with jack tree spacing. For instance, tree spacing 3×5 m recorded maximum (turmeric:15.83 Mg ha-1 and ginger: 11.69 Mg ha-1) while the tree spacing 3×3 m registered the minimum (turmeric: 7.41 Mg ha-1 and ginger: 5.71 Mg ha-1). The tree spacing exhibited insignificant effect on curcumin and oleoresin content of turmeric and ginger, during both the years respectively. The jack woodlot site and contagious control showed modest differences in soil bulk density and pH across the spacing during the two sampling periods. However, the soil under all spacing regimes noticed significantly higher organic carbon (3×3 m (0.667 %) > 3×4 m (0.661 %) > 3×5 m (0.641 %) than open treeless condition (0.56 %). The variation in the concentration of primary (N, P, K) and secondary nutrients (Ca Mg and S) across the tree spacing regimes and the comparable nutrient concentration in treeless open conditions depicted the considerable influence of trees in modifying soil-physico attributes of soil. Across all the spacing, tap root length did not show significant differences, although spacing at 3×3 m recorded the highest average length of 2.43 m followed by 2.36 m at 3×4m and 2.05 m at 3×5m. However, the trends were reverse with lateral root length which showed an increase with increasing tree spacing with highest lateral root length at 3×5m (275.25 cm). It was observed that leaves, twigs, stems and roots exhibit significant differences in biomass production across spacing with mean component biomass increased with increasing tree spacing. The results clearly revealed that wider spacing significantly enhanced carbon accumulation in component parts than the closer spacing at mean tree level and stand level. Results indicate promising trends toward optimizing the combined productivity of jack trees and understorey crops managed at variable planting spacing. The plentiful availability of resources including understorey light and nutrients may have created a non-competitive growth ambiance for intercrops which could be the reason for the marginal effect of tree spacing on growth and yield attributes. Therefore, it is concluded that jack tree has complementary interactions with intercrops during 2nd and 3rd year of growth. However, long term studies are required to get the more concluding results on tree growth, crops interactions and soil fertility changes.
Litter dynamics of selected multipurpose tree species used as pepper standards
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2005) Bino George; Kunhamu, T K
A field trial was conducted at Livestock Research Station, Thiruvazhamkunnu, Kerala during August 2002 - August 2003 to characterize the litter dynamics and nutrient flux associated with seven MPTS used as support for black pepper. The study covered quantification of litter production, litter decomposition, nutrient release pattern through litter route and the changes in soil properties and site productivity in terms of pepper yield. The pepper support tree species under study included, Casuarina equisetifolia J.R. & G. Forst, Macaranga peltata (Roxb) M.-A, Ailanthus triphysa (Dennst.) Alston, Artocarpus heterophyllus (Linn), Acacia auriculiformis (A. Cunn.) ex Benth, Grevillea robusta (A. Cunn.) ex R. Br. The experiment was superimposed on a pre-existing, fourteen- year- old pepper stand in a Randomized Block Design with three replications. Generally, moderate levels of litter production has been shown by different pepper support trees under investigation. Annual litter yield was maximum for Artocarpus (4653.63 kg ha-1) and Macaranga (4550.88 kg ha-1), while Ailanthus (2221.25 kg ha-1) yielded minimum. Nutrient level in litterfall varied between species. Maximum N content was associated with nitrogen fixing trees such as Acacia and Casuarina. The leaf litter decomposition rate was generally faster for all the species with almost 90 per cent mass loss within three months. Artocarpus showed faster rate of litter decomposition while Macaranga and Ailanthus were relatively slow decomposers. Unprecedented heavy mass loss was registered by Casuarina, Grevillea and Acacia from their litterbags owing to physical nature of the litter. All the selected tree species showed a characteristic biphasic pattern of litter decomposition. Decay coefficients ranged from 0.73 (Casuarina) to 0.19 (Macaranga). The exponential equations relating mass loss over time were worked out for all the species. The lignin content of the leaf litter was found to excerpt negative influence on the rate of litter decomposition. The general order of nutrient in terms of their releasing capacity from the decomposing litter was K>P>N. Acacia and Artocarpus registered faster rate of nutrient accretion. Changes in soil properties such as moisture content, pH and bulk density was marginal on account of the presence of tree species. Leguminous species like Acacia was found to improve the soil N content. Maximum rainfall interception was attributed to Artocarpus followed by Macaranga. The yield of pepper in terms of dry berry weight was maximum for Acacia (2.56 t ha-1) and Artocarpus (1.91 t ha-1). Better physical suitability, high lopped out turn and nutrient turnover potential suggest these species as ideal candidates for trailing pepper. However, the general reduction in soil physical and chemical properties and reduction in the yield of black pepper for each standard over years suggest a declining trend in the productivity of this system, probably induced by the ageing of the stand as well as the heavy management practice followed.
Long term effect of thinning on productivity and wood properties for twenty year old Acacia mangium wild stands
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Suresh Ramanan, S; Kunhamu, T K
Nutrient content and decomposition of leaf biomass of selected woody tree species
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 1994) Kunhamu, T K; Gopikumar, K
A detailed study was conducted at the College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala during 1992-94 to compare the rate of decomposition and nutrient release pattern of leaf biomass of five forest tree species namely, Schleichera oleosa (Lour.) Oken, Pongamia pinnata (L.) Pierre, Macaranga peltata, (Roxb) M.–A., Terminalisa paniculata Roth and Bridelia retusa (L.) spreng. The experiment was laid out in a typical home Garden. Generally, all the species under study showed a faster rate of leaf biomass decomposition. Among the various species tested, B. retusa and T. paniculata showed faster rates of leaf biomass decomposition while P. pinnata exhibited relatively a slower rate. The initial leaf nitrogen content and C:N ratio could not establish a direct relationship with rate of decomposition. However, in all the species, lignin content was found to exert a profound influence on mass loss patterns. All the species showed a faster mineralisation of nutrients in accordance with the mass loss pattern. Among the nutrients, potassium followed a faster rate of mineralisation. A relatively good trend for N mineralisation also has been reported for M. peltata, T. paniculata and B. retusa during the course of the study. Generally, Ca, Mg and S exhibited lower rates of mineralisation. T. paniculata and B. retusa followed an efficient release pattern for all the nutrients while P. pinnata showed slower rates of mineralisation with regard to most of the nutrients.
Optimization of fertilizer regimes and understorey productivity in four-year-old Swietenia macrophylla King stands
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2018) Vikas Kumar; Kunhamu, T K
Performance of selected medicinal herbs under typical homegarden and pure coconut plantation
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2015) Niyas, P; Kunhamu, T K
Soil carbon stocks and microbial status in the selected woody ecosystems of Thrissur District, Kerala
(College of Climate Change and Environment Science,Vellanikkara, 2021) Aiswarya Soji Joseph; Kunhamu, T K
Studies on the growth and propagation of selected bamboos in Kerala, India
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2022-04-30) Amani Khalil Alahmad; Kunhamu, T K
With the increasing demand for wood and wood products, tree plantation activities are expanding at faster rate across the world. The present scenario demand planting of tree species that offer better economic returns while contributing to the ecological resilience of the agroecosystems. In this pursuit, bamboos are excellent group of plants that serve the dual purpose effectively. Bamboos are the arborescent grasses belonging to family Poaceae. India is the second richest country of bamboo genetic resources after China. Kerala is one among the major diversity centers of bamboo in the country and 22 species of bamboos under seven genera have been recorded from this region. In Kerala bamboo grows in forests and agroecosystems. The edaphic and climatic conditions of Kerala permit the cultivation of diverse species of bamboos. Though bamboos exhibit fast growth, it varies considerably with species and local conditions. However, information on the productivity of bamboo especially in the humid tropical conditions of Kerala are limited. In this backdrop a field study has been designed to evaluate the comparative growth performance of six bamboo species of high economic and ecological importance to Kerala viz. Bambusa balcooa, Bambusa tulda, Bambusa vulgaris, Dendrocalamus asper, Dendrocalamus brandisii, Dendrocalamus longispathus. The study also probed into the suitable vegetative propagation techniques for selected three bamboo species Dendrocalamus longispathus, Dendrocalamus brandisii, Bambusa balcooa. The field trial was carried out in an existing bambusetum established during 2018 located in Instructional Farm adjoining the College of Forestry campus, Vellanikkara, Kerala, India. Each of the selected six bamboo species were grown in randomly allocated blocks. There were 20 clumps per block at a spacing of 5x5 m. Periodic growth observations were made for clump height, clump circumference, culm girth, intermodal length, and number of culms. Propagation trial was carried out in the nursery separately for the three selected bamboo species viz. Bambusa balcooa, Dendrocalamus brandisii and Dendrocalamus longipathus treating their culm cuttings with various concentrations of NAA and IBA. The experiment was laid out in factorial CRD with three replications. The hormonal combinations were 0, 100, 250 and 500 ppm of both NAA and IBA which were tried separately for the three bamboo species. The hormone treated culm cuttings were planted in nursery beds and all routine observations were taken. There was considerable variation in growth and productivity among the six bamboo species under study. Bambusa vulgaris and Dendrocalamus brandisii were the toppers in terms of clump height, clump circumference and culm girth while Bambusa tulda showed relatively poor growth for these parameters. Among the species, the highest internodal length was observed for by Dendrocalamus brandisii and Dendrocalamus longispathus while Bambusa tulda recorded the shortest internodal length. Number of culms per clump was highest for Dendrocalamus asper while it was the lowest for Bambusa balcooa. Overall, among the six species under study, the promising bamboo for humid Kerala would be Bambusa vulgaris, Dendrocalamus brandisii and Dendrocalamus asper. Among the bamboos, the growth hormonal effects were highest for Dendrocalamus longispathus followed by Bambusa balcooa and the lowest for Dendrocalamus brandissi. Hormonal treated culm cuttings of Dendrocalamus longispathus showed significant improvement in plant height, leaf number, number of roots, root length and rooting percentage while the performance was poor in the untreated control. In general, IBA showed significantly better response to plant height, leaf number and rooting percentage for D. longispathus. Dendrocalamus brandissi showed poor performance for most of the growth parameters except for root weight. However, apparently better response were observed for sporting percentage and rooting percentage with IBA at 250 ppm. The response of untreated control was very poor. Bambusa balcooa showed significantly better performance for NAA for number of leaves (250 ppm), number of roots (250 ppm) and root weight (100 ppm). IBA 250 ppm showed better influence on collar girth and root length of B. balcooa non treated cuttings (control) showed very poor response to all growth parameters. Overall, the propagation study reveals that growth hormonal treatment of culm cuttings of Dendrocalamus longispathus and Bambusa balcooa give promising results for their mass multiplication in nursery conditions.