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ThesisItem Open Access Biomass production and root distribution pattern of selected fast growing multi-purpose tree species(Department of Silviculture and Agroforestry, College of Forestry,Vellanikkara, 1994) Jamaludheen, V; KAU; Mohankumar, BA randomized block design experiment involving nine fast growing multi – purpose trees (Acacia auriculiformis A. Cunn. ex Benth., Casuarina equisetifolia J.R. & G Forst., Leucaena leucocephala (Lamk.) de wit. Var. K 8, Ailanthus triphysa (Dennst.) Alston, Emblica officinalis Gaertn, Artocarpus heterophyllus Lamk., Pterocarpus marsupium Roxb., Paraserianthes falcataria (L.) Neilson and Artocarpus hirsutus Lamk.) Initiated during June, 1985 was used for the present investigations. The objectives of the study included quantifying the biomass production potential of nine selected fast growing multi-purpose tree species grown under short rotation intensive cultural systems; characterising the root distribution pattern of these trees and also elucidating the extent of nutrient loss through harvest, besides characterising litter dynamics. Acacia and paraserianthes recorded the highest growth rates in terms of height, radial growth and biomass yield. Biomass production decreased in the order: Acacia > Paraserianthes > Casuarina > A. heterophullus > Emblica Pterocarpus > A. hisrsutus > Ailanthus > Leucaena. The most important component of total biomass undoubtedly, was the bole while foliage contributed least to biomass yield. Nevertheless foliage, in general registered the highest N, and K contents. Among the species, Leucaena had the highest N concentration followed by Paraserianthes and Pterocarpus. For P and K concentrations, Pterocarpus and A. hirsutus registered the highest concentration. A one – to – one correspondence between nutrient accumulation and biomass yield was however, lacking because of wide variations in elemental concentrations among species and also among tissue types. Bole fractions, in general, did not account for more than 50 % of total nutrient export from site. Altering the rate of nutrient removal in products is one of the most important design criteria in planning for sustainable plantion. N-fixing tree plots generally had a higher soil N status. Casuarina, Emblica and Pterocarpus plots were having higher P levels. Acacia, Paraserianthes and A. hisrsutus plots registered markedly higher K level. The amount of litterfall was maximum for Acacia and the minimum for Pterocarpus. Litterfall also followed a unimodal distribution pattern with a distinct peak during the November – January period and the period of lean fall was during May-August. Litter dynamics accounted for bulk of the nutrient inputs into the system. The retranslocation of mineral nutrients from senescing leaves to younger leaves and /or other tissues prior to abscission was obvious. Leucaena, Paraserianthes, Pterocarpus, Acacia, Alinathus and Emblica formed examples of high (> 1.5%) detrital N content. Generally the wet period (June – August) was characterised by increased concentration of N in litter. Litter P did not follow a consistent pattern with respect to seasons. However, a characteristic decline in litter K concentration was noticed during the rainy season. Mass disappearance of litter samples followed a negative expontential relationship. Leucaena litter, having the highest initial N content, decomposed compeletely in the shortest period (9 months). Root system studies suggest that A. hetrophyllus, Emblica and Paraserianthes are perhaps unsuitable for intensive mixing and close planting in agroforestry as they possess shallow and highly spreading root system. Ailanthus is perhaps a better candidate species for the above purpose as it possess relatively lower lateral root spread and at the same time having a deep tap root system. Root activity paatern of Artocarpus hisrsutus revealed that more than 75% of fine roots responsible for water nutrient absorption is concentrated in the 75 cm radius around the base of the tree. Recovery of 32P declined as depth of application increased. The combination of lowest lateral distance (75 cm) and depth (30 cm) accounted for more than 30% root activity.ThesisItem Open Access Conservation strategy for Hopea parviflora Bedd. species through storage of seeds usinhg cryopreservation techniques(Department of Silviculture and Agroforestry, College of Forestry,Vellanikkara, 2001) Ani, J R; KAU; Sudhakara, KA detailed study was conducted at College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala during 1998-2000 to standardize the conservation strategy for Hopea parviflora Bedd. species through storage of seeds using cryopreservation. Diameter of seeds collected at seven weeks after anthesis was found to be higher than that at sixth week. Physiological maturity of the propagules is attained between five and six weeks after anthesis. The propagules were subjected to different relative humidities, vacuum and dry air for different durations as a pretreatment for cryopreservation studies. In 100 to 46.6 per cent relative humidities, the moisture content and the leachate conductivity of the propagules were found to increase with duration compared to the initial value. Equilibrium moisture content of Hopea parviflora propagules was found to lie between 75.6 to 30 per cent relative humidities. Germination parameters of seed and seed without seed coat were not decreased significantly due to desiccation by relative humidities, vacuum or dry air, but that of embryonic axes was considerably reduced as rapid drying might have been effected due to 30 and 20 per cent relative humidities and also due to vacuum and dry air with duration. High culture contamination was observed in vacuum and dry air treatments. After cryopreservation techniques, the propagules invariably failed to regenerate but could retain green colour for two to three days.ThesisItem Open Access Viability of hopea parviffora seeds with reference to temperature , medium of storage and microencapsulation techniques(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 1996) Sunilkumar, K K; KAU; Sudhakara, KA detailed study was conducted at College of Forestry, Kerala Agricultural university, Vellanikkara, Thrissur, Kerala during 1994 – 95 to study the effect of temperature, storage medium, fungicide and microencapsulation of zygotic embryo (synthetic seed) on the storage behaviour of Hopea parviflora seeds. Storing the dewinged seeds with a moisture content below 30 per cent resulted in rapid decline in seed viability due to dehydration injuries irrespective of storage temperature. Sand and neemcake was inappropriate as a storage medium because sand favoured early germination of the seeds in storage condition itself and neemcake caused severe desiccation injuries. Storing fungicide treated winged seeds collected just before natural seedsheding, at 100 C retained high germination percentage upto 40 days. Sythetic seeds were also successfully stored up to 1 month at 100C without significant reduction in germination percentage. Two ppm and three ppm ABA was observed to be helpful for maintaining higher germination percentage of synthetic seeds during storage.ThesisItem Open Access Nutrient content and decomposition of leaf litter of Acacia mangium Willd as affected by season and field conditions(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 1995) Ramakrishna, Hegde; KAU; Gopikumar, KA detailed experiment was conducted at the College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, during the period from 1993 to 1995 to study the nutrient content and pattern of leaf litter decomposition of Acacia mangium Wild. During south west monsoon and north east monsoon seasons. The experiment was conducted both in home garden and open area. The rate of decomposition was faster in all the study situations. The initial nitrogen, lignin, C:N ratio and lignin : nitrogen ratio of leaf litter were found to exert profound influence on the rate of decomposition. The decomposition rate was found to be a function of time, soil moisture and soil temperature. The nutrient release pattern in almost all cases followed a characteristic biphasic model with an initial rapid phase followed by a slower latter phase. Among the different nutrients, potassium showed a faster rate of mineralisation in most of the situations while calcium and nitrogen mineralised slowly. Among the several mathematical models tried to predict the absolute amount of nutrients in the residual mass, the second order hyperbolic function was found to be good fit in most of the cases. Though the PH was not altered significantly by the decomposing litter mass, the content of most of the nutrient elements is found to be drastically influenced.ThesisItem Open Access Functional dynamics of an agrisilvicultural system involving coconut palms, Multipurpose trees and kacholam(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 1997) Sureshkumar, S; KAU; Mohankumar, BA factorial experiment involving coconut (Cocos nucifera L.) and three multipurpose tree species (Ailanthus triphysa (Dennst.) Alston., Grevillea robusta A. Cunn. and Vateria indica L.) in two planting geometries (single and double hedge) was established in an existing coconut plantation (14 years old) at Vellanikkara in June, 1992. Kacholam (Kaempferia L.), a herbaceous medicinal plant was introduced in this trial as a floor crop in May 1995. Monocultures of coconut and kacholam were also maintained. Objectives of the study included evaluating suitability of interplanting multipurpose trees in coconut plantations, assessing the consequential changes in growth of multipurpose trees productivity of coconut and kacholam and inter alia characterise the above and below ground interactions between field and tree crop components. Coconut yield was not adversely affected by interplanting multipurpose trees until the multipurpose trees were about 4 years old. Multipurpose trees exhibited wide variations in their growth and crown characteristics. Consequently the light availability beneath the canopy was highly dependent on the multipurpose tree species. Availability of photosynthetically active radiation (PAR) was inversely proportional to the stand leaf area index. Available PAR ranged from 18-45 % and 22-45% of that in the open at 50 and 150 cm above ground level respectively. Planting geometry did not influence this parameter significantly. Kacholam grown in the open (sole crop) exhibited better growth as compared to kacholam grown in association with coconut and multipurpose trees. Nevertheless, rhizome yield (at final harvest) was comparable in all the situations. Tissue nutrient content of kacholam was also independent of multipurpose trees. The results suggests the moderate shade tolerant nature of kacholam, which can be highly useful in intercropping. However, no strong relationship could be established between light availability and rhizome yield. Multipurpose trees exhibited considerable root activity in the coconut rhizosphere, as evident from the data on 32P recovery. However, competition for nutrients between the two components was not evident, probably due to the juvenile nature (4 years old) of the multipurpose trees. Even at this stage, the three multipurpose trees exhibited discernable difference in foliar 32P activity. Cross-feeding of kacholam by coconut roots scavenging kacholam beds was noticed. Three to four years of tree growth did not alter the soil nutrient status very substantially. An increase in soil pH and available potassium was, however, observed. Nevertheless, kacholam cultivation resulted in a modest decline in soil nutrient status.ThesisItem Open Access Litter dynamics of selected multipurpose tree species used as pepper standards(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2005) Bino George; KAU; Kunhamu, T KA 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.ThesisItem Open Access Effect of seed size on the germination and seedling performance of teak (Tectona grantis Linn. f.)(Department of Silviculture & Agroforestry, College of Forestry, Vellanikkara, 2004) Jijeesh, C M; KAU; Sudhakara, KA detailed study was conducted at the College of Forestry, Vellanikkara to investigate the effect of seed size on seed characters and germination vigour and the effect of seed size and time of germination on seedling performance of teak (Tectona grandis Linn.f.) during 2001-2003. Most of the fruits were belonging the grades between 9 to 18 mm. 12-15 mm size grade recorded the highest proportion by number as well as the weight per kg of the sample lot compared to 15-18 mm, 9-12 mm and 6-9 mm grades. Size, volume and weight of the individual seeds not differed between the plantations studied. The average emptiness value of the seeds decreased with the increase in seed size. The number of empty, one, two, three and four 'true seeded' seeds increased with increase in seed size grade. The crude oil content of the true seeds ranged between 42 to 33 per cent by weight and that of soluble and total carbohydrate content ranged from 6.42 to 5.12 and 10.72 to 9.61 per cent by weight and these were found to increase with increase in size grade. The insoluble carbohydrate content of 'true seeds' was ranging from 4.5 to 3.8 per cent by weight and it varied significantly between the plantations and Cherupuzha plantation recorded the maximum amount. Protein content of the seeds ranged from 3.7 to 3.6 per cent by weight and it did not vary significantly between the plantations as well as size grades. Poly acrylamide gel electrophoresis of proteins at ph 7 gave similar banding pattern (two bands with Rm values 0.09 and 0.19) for different size grades in all the plantations. Storage of the seeds for one year significantly reduced the germination Size grade of the seeds used to conduct the nursery studies significantly influenced the germination percentage of the seeds as well as the vigour index of the seedlings. The effect of seed size grade and time of germination on seedling characters was significant at all stages of growth of the seedlings with the exception of taproot length, specific leaf area and chlorophyll a content of the seedlings. The seedlings belonging to 15-18 mm grade seeds recorded largest height, collar diameter, internodal length, length of longest lateral roots, leaf area, number of lateral roots, stem dry weight and chlorophyll b and total chlorophyll content at different stages of growth. Seedlings belonging to 9-12 mm seed grade recorded the lowest values of these characters. The leaf, stem and total dry weight of the seedlings at 270 and 360 DAP were found to increase with the increase in size grade of the seeds. Seedlings belonging to 9-12 mm grade showed higher RGR and NAR values compared to that of the seedlings belonging to 15-18 mm and 9-12 mm seed grades in first to fourth week germinants. There was no definite pattern in variation of number of leaves, and root:shoot ratio among the of the seedlings due to size grade of the seeds. With regards to time of germination of the seeds, seedlings obtained from the first week germinants recorded the largest height, internodal length, collar diameter and leaf area at all the stages of growth. Other characters did not show any definite trend due to time of germination. Significant differences due to seed size was absent in all the attributes related to the growth potential of the stumps prepared from 180 days old seedlings. However, the effect of time of germination of the stumps was significant in the number of lateral and tertiary roots per stump and length of the first, second and third longest lateral root. Dry weight of the lateral roots was found to increase with the increase in seed size grade of the stumps obtained from 360 days old seedlings. With regards to time of germination, the stumps obtained from the first to fourth week germinants varied significantly in the number of sprout, length of the second sprout, number of leaves, lateral and tertiary roots per stump and length of the first, second and third longest lateral roots.ThesisItem Open Access Development of storage techniques for thampakam (Hopea parviflora Bedd.) seeds(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2002) Shaji, M; KAU; Sudhakara, KA detailed study was conducted at College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala during 1999-2001 to develop a suitable storage technique for the seeds of Hopea parviflora Bedd. species through synthetic seed and cryopreservation technology. Moisture content of intact seeds/ seeds without seed coat/: excised embryonic axes decreased with increase in intensity and duration of desiccation levels and only the seeds without seed coat showed significant difference in moisture content due to maturity levels. Leachate conductivity was not significantly affected due to maturity levels of intact seeds and excised embryonic axes. But seeds without seed coat showed significant difference in leachate conductivity due to maturity levels and it was higher at seven weeks after anthesis. Increasing the duration of desiccation significantly increased the leachate conductivity of intact seeds/ seeds without seed coat! embryonic axes. Germination parameters of intact seeds and seeds without seed coat were not affected significantly by increased desiccation. However, excised embryonic axes showed significant difference in germination parameters when the intensity and duration of desiccation was increased. The synthetic seeds developed from these desiccated axes also showed significant difference in their germination parameters. Synthetic seeds stored at 4°C retained maximum viability after four weeks, compared to those stored at 200 C and 27 0 C. When stored at 27 0 C, the synthetic seeds developed from six weeks mature embryos retained viability up to three weeks whereas those at seven weeks after anthesis retained viability up to two weeks only. After cryopreservation, the propagules invariably failed to regenerate but could retain green colour for two to three days.ThesisItem Open Access Evaluation of fuelwood characteristics, physical and mechanical properties of selected agroforestry tree species(Department of Silviculture and Agroforestry, College of forestry, Vellanikkara, 2001) Shanavas, A; KAU; Mohankumar, BAn experiment to evaluate the fuelwood value, and physical and mechanical properties of selected agroforestry tree species was conducted at the College of Forestry, Vellanikkara. The study involved determination of the fuelwood value of 48 species/materials and assessment of the physical and mechanical properties of three promising multipurpose trees having local importance, viz., Acacia auriculiformis, Acacia mangium and Grevillea robusta. Variations abound in the calorific values of agroforestry species and their tissue-types. Ash content, specific gravity, chemical composition and moisture content of tissues are primary factors affecting calorific value; while species and tissue-types, may exert a secondary control. Ash content and moisture content had a negative correlation with calorific value, whereas specific gravity exerted a positive influence. Based on the range in calorific values and fuelwood value indices obtained, different species and tissue-types could be broadly divided into three categories: high, medium and low. Calorific value of different tissue fractions decreased in the order: heartwood> sapwood > bark. Mean ash percentage of tissue-types followed the order: bark> sapwood > heartwood. Variations of ash content along bole height followed the order: branchwood > top > bottom > middle. Mean specific gravity of tissue-types followed the order: heartwood> sapwood > bark. For sample positions it followed the sequence: bottom> middle> top> branchwood. Wood moisture content increased from bottom to top along tree height and for tissue-types, it followed the order: bark < heartwood < sapwood. Coconut shell recorded the highest fuel value index (FVI) which was approximately 25 times greater than the highest value for tree species (Casuarina equisetifolia). Physical and mechanical properties of Acacia auriculiformis was significantly supenor to that of Acacia mangium and Grevillea robusta. The physical and mechanical properties were affected by both species and sample positions. Wood specific gravity increased from inner to outer sample positions along radial direction except for Grevillea robusta, which followed the order: outer < inner < middle. Moisture content decreased from inner to outer sample positions in Acacia mangium; while Grevillea robusta exhibited a divergent trend. Variations in shrinkage along radial direction followed the same trend as that of moisture content but was inconsistent with that of specific gravity. Most of the strength properties followed a trend similar to that of specific gravity. On a final note, specific gravity, work to limit of proportionality in static bending, work to maximum load in static bending, compressive stress at limit of proportionality in parallel to grain, compressive stress at limit of proportionality in perpendicular to grain and end-hardness of Acacia auriculiformis were greater than the values reported for teak. The physical and mechanical properties of Acacia mangium and Grevillea robusta except for shrinkage were less than that of teak.
