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2012 - 201920
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Subject: Silviculture and Agroforestry × End date: 2019 × Start date: 2010 ×
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    ThesisItemOpen Access
    Impact of seed priming techniques on germination and seedling performance in sandal (Santalum album L.)
    (Department of Silviculture and Agroforestry, College of Forestry,Vellanikkara, 2019) Chithra, P; KAU; Jijeesh, C M
    Santalum album L, known as the East Indian Sandalwood is a semi-root parasitic tree native to South India and it is one of the most precious and valuable among Indian forest trees. The poor rate of germination coupled with long germination period is the major constraints in the regeneration of sandal. Present study was conducted to assess the impact of seed priming techniques on the germination and seedling growth attributes of sandal at College of Forestry, Vellanikkara, Thrissur. The effect of different duration and concentration of priming agents viz. water (Hydropriming for 3, 6, 9 and 12 days), Pseudomonas fluorescens (Biopriming at 25, 50, 75 and 100% for 2, 4, 6 and 8 days), Polyethylene Glycol 6000 (Osmopriming at 5, 10, 15 and 20% for 3, 6, 9 and 12 days) and MnSO4 (Chemical priming at 0.4, 0.6, 0.8 and 1.0 M for 3, 6, 9 and 12 days) on seed germination and subsequent seedling growth in sandal were studied. The non- primed seeds were kept as control. Primed seeds were stored for one day and one month after the completion of priming processes and the germination and seedling growth were observed. The germination was obtained only in the seeds stored for one day after priming process and the seeds stored for one month failed to germinate. Results indicated that the hydropriming of the seeds could not improve the germination of the sandal seeds compared to control. Biopriming significantly increased the seed germination and the highest germination percentage (88%) was recorded in the seeds subjected to biopriming for 8 days at 100% concentration, which was 1.9 times higher compared to control. The highest germination recorded in osmopriming was 78%. The chemical priming with MnSO4 at different concentrations for 3 days also recorded the higher germination (88%) comparable to biopriming. Electrical conductivity was the highest in the leachates of seeds hydroprimed for 12 days (1.96 dS cm-1) and was the lowest in seeds subjected to biopriming (0.03 dS cm-1). The leachate conductivity of the seeds subjected to osmopriming treatments (1.69 dS cm-1) was comparable to that of the hydropriming treatments. Although the different concentrations and duration of MnSO4 reduced the leakage of solutes from the sandal seeds, the electrical conductivity was higher than that of the biopriming treatments. Hence, biopriming treatments were the best in reducing the leakage of solutes from the cells leading to better membrane integrity and stability. Biochemical analysis of the primed and non-primed seeds indicated that the hydropriming treatments recorded significantly lower carbohydrate, protein and crude fat content compared to control.
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    ThesisItemOpen Access
    Productivity of tree fodder banks in selected homegardens of central Kerala
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2019) Anush Patric; KAU; Asha, K Raj
    The field study entitled “Productivity of tree fodder banks in selected homegardens of Central Kerala” was carried out as three separate experiments in selected small, medium, and large scale homegarden with livestock component in Arimboor panchayath, Thrissur, Kerala during 2018-2019. The study aimed to assess the forage yield and nutritive value of five fodder tree species viz. Mulberry (Morus indica), Agathi (Sesbania grandiflora), Moringa (Moringa oleifera), Gliricidia (Gliricidia sepium) and Calliandra (Calliandra calothyrsus) under hedgerow planting (45 x 45 cm spacing) in homegardens; and to explore the short term changes in soil nutrient status of homegardens with tree fodder integration. The treatments were laid out in randomized block design replicated four times. The trees were harvested at 1m height and at the interval of two months during rainy season and three months during summer season The result revealed that all the tree species established well in the homegardens after planting. Initial growth of Agathi and Calliandra was faster in terms of plant height, whereas Gliricidia showed excellence in lateral branching. In general, coppice parameters were better for Gliricidia followed by Agathi and Calliandra. The annual green and dry forage yields were higher for Gliricidia (24.27 & 4.39 Mg ha-1) and Calliandra (16.38 & 4.60 Mg ha-1) respectively followed by Agathi and Mulberry. The yield from Moringa was comparatively poor. Seasonal fodder yields were higher for rainy period than summer. Forage quality also differed among tree species. Calliandra (22.57 %) and Gliricidia (19.99 %) fodder had more crude protein content and yield followed by Mulberry (16.74 %). Crude fibre content was lower in Gliricidia, Calliandra and Mulberry than other species. Mulberry (7.93 %), Moringa (7.61 %) and Agathi (7.12 %) had higher ash content, whereas Moringa and Mulberry had higher P and K content. Dry matter content was significantly higher for Calliandra (30.40 %) and Mulberry (28.73 %). Higher leaf-stem ratio was observed in Mulberry (2.09) and Gliricidia (2.05), followed by Calliandra (1.67). In general, Gliricidia and Calliandra had higher forage yields and protein content, followed by Agathi. Mulberry showed intermediate performance with respect to yield and quality. Moringa was inferior in forage yields but rich in quality attributes like ash, minerals and P content. Comparing homegardens, yield performance of fodder banks was higher in medium homegarden (MHG) followed by large (LHG) and small homegarden (SHG). Whereas reverse trend was observed in quality attributes of fodder. Survival count of the trees after one year of planting was significantly higher in Mulberry (80.06 %) and Calliandra (71.13 %), followed by Gliricidia (44.35 %), whereas survival was drastically lower for Agathi (31.55 %) and Moringa (31.55 %). Inspite of poor yields of Mulberry in the initial year, higher persistence of Mulberry indicates its better performance in the subsequent years. Comparing different homegardens, survival percentage was higher for SHG (59.47 %) and MHG (54.46 %) followed by LHG (41.07 %). Low survival in LHG was due to waterlogging during rainy season. In general, the soil organic carbon, N and P content improved with fodder tree integration in SHG and MHG. There was no visible changes in K content. Soil N and P levels also improved in LHG whereas SOC showed a declining trend. Comparing tree species, Agathi plots showed more soil improvement with higher SOC and NPK levels whereas soil depletion was more evident in Moringa with respect to carbon, P and K, and in Calliandra in terms of carbon and nitrogen. PAR transmittance ranged from 50.10 % in SHG to 52.75 % in MHG and LHG which were on par. PAR transmittance levels in various tree plots ranged from 45.50 – 58.57 % with no statistical significance. A marginal reduction in transmittance was observed in Mulberry (45.50 %) when compared to other species. The economics of fodder bank cultivation in homegardens varied significantly with respect to tree species. Gliricidia fodder banks generated higher returns and B: C ratio (1.28) whereas all other species showed B: C ratio of less than one. The initial cost for raising fodder banks in homesteads is high whereas the forage yield in the initial year of planting is comparatively less as trees are under the establishment phase. Hence, in conclusion, fodder trees like Gliricidia, Calliandra, and Mulberry with good yield/persistence are found to be ideal for hedgerow planting in the understorey of homesteads. Agathi is not amenable to heavy pruning, hence frequent replanting is a management option due to its faster growth. Cultivation of Moringa should be confined to light intensive as well as dry areas of homesteads. Moreover, pruning of overhead trees in homesteads to enhance understorey light regimes can further elevate the yield levels of fodder banks. Scientific cultivation and management of multispecies tree fodder banks and feeding mixed forages will provide quality and balanced nutrition to enhance livestock production at minimal cost in homegardens.
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    ThesisItemOpen Access
    Comparative performance of mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) under diverse management regimes in a coconut based fodder production system
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2016) Reshma, M Raj; KAU; Asha, K Raj
    The research project entitled “Comparative performance of mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) under diverse management regimes in a coconut based fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2015-2016. The main objective of the study was to assess the influence of plant density and pruning frequency on forage yield and nutritional qualities of mulberry and subabul intercropped in coconut gardens; and to explore the soil fertility changes associated with these intercropping systems. The treatments consisted of two fodder tree species; mulberry and subabul, under three levels of plant density (49,382 plants ha-1, 37,037 plants ha-1 and 27,777 plants ha-1) and three levels of pruning frequency (8, 12 and 16 weeks interval) in all possible combinations with split plot design replicated thrice. The results revealed that both subabul and mulberry produced comparable dry fodder yields under coconut plantation. However, significant variation was noted with regard to proximate composition. The CP content in fodder biomass was significantly higher and CF % lower in subabul than mulberry. However, mulberry had higher ash (6.70 %) and P content (0.58 %) than subabul. Leaf- stem ratio was found to be comparable in both the tree species. Comparing plant densities, highest density yielded more dry matter (12.48 Mg ha-1yr-1) than the lowest one (7.32 Mg ha-1yr-1), with higher leaf-stem ratio (1.34). Total N, CP and P content increased and CF % decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning interval had no significant influence on fresh fodder yield, whereas dry yield was higher for 12 and 16 week intervals. However, leaf -stem ratio was higher at 8 week interval, indicating more foliage production than stem fraction when harvested at shorter intervals. Pruning frequencies had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks yielded fodder with maximum CP (18.51 %), and phosphorus content (1.1 %), and least CF content (41.91 %) compared to 12 and 16 weeks. Ash content (8.70 %) in fodder was significantly higher at the longest interval of 16 weeks. Comparing interaction effects, for both mulberry and subabul, planting at the highest density (49,382 plants ha-1) and pruning at shortest interval (8 weeks) yielded the maximum fodder (11.05 & 12.17 Mg ha-1yr-1 dry yields for mulberry and subabul respectively) with superior quality (T1 & T10). B:C ratio was also found to be higher in the above systems.Intercropping subabul and mulberry in coconut garden under different management practices produced significant changes in some soil parameters after the initial year of establishment. In comparison to the sole coconut plot, soil properties like OC, pH, EC, WHC and available N, P, K content significantly improved in the high yielding treatment combinations of T1 and T10. Comparing T1 and T10, all soil parameters excelled in T1 except available N content, which was higher in T10.Hence, in conclusion, forage yield and nutritive value of mulberry and subabul underneath coconut garden could be optimized at the cheapest levels by adopting a tree density of 49,382 plants ha-1 and pruning interval of 8 weeks. In comparison, subabul yielded more dry matter and CP, whereas mulberry was superior in ash and mineral content. Establishment and proper management of these tree fodders in coconut garden and feeding mixed fodders thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.
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    ThesisItemOpen Access
    Selection and evaluation of superior planting materials of Ailanthus triphysa (Dennst.) in Thrissur
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2018) Abijith, R; Jamaludheen, V
    A nursery and field experiment was conducted to evaluate the superior performance of selected candidate plus trees of Ailanthus triphysafrom the Thrissur District, Kerala. The demand of this timber was very much increased because of its fast growing nature and diversity of utilizations. Hence, the tree improvement of this species is the need of the hour that might result increased quality and reduced rotation time. The possible gain expected through the phenotypic selection can also be directly utilised by the tree growers. The candidate plus trees were identified and selected by adopting the comparison tree method. The seeds collected were used to study the germination parameters at tree nursery of College of Forestry, Kerala Agricultural University. The initial growth performances of the progenies of the selected CPTs were evaluated at nursery in a completely randomised design and also at the field in a randomised block design and the data were statistically analysed using Analysis of Variance technique. The progenies of the selected CPTs showed significant variation in their initial growth parameters. The highest germination per cent of 83.50 was exhibited by CPT-11 and the lowest of 67 per cent by CPT-1. After the six months of observation in the nursery, CPT-11 attained the maximum height of 88.67cm and lowest height by CPT-5 (76.33cm). The maximum plant height (99 cm) and girth (21.04 cm)in the field was also exhibited by CPT-11. The CPT-11, CPT-10 and CPT-9 were the top performers compared to other selections. The CPT-1 was the inferior in the nursery and also in the field. The CPTs that exhibited superiority in germination percentage, germination value and mean daily germination also exhibited distinctively superior growth in the nursery and in the field. In fact, the identification and selection of superior quality planting materials of Ailanthus triphysahas a greater role in the tree improvement. The single tree selection is the best method for the production of superior progenies and this can be useful for the future afforestation and seedling production for getting high quality timber with short rotation period. From this study we recommend CPT-11, CPT-10 and CPT-9 for achieving these objectives.
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    ThesisItemOpen Access
    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; KAU; Kunhamu, T K
    Extensive field study was carried out to investigate the effect of fertilizer treatment and intercrops on the growth and productivity of 4-year-old Swietenia macrophylla King. The study was carried out in a S. macrophylla plantation that was established at Mala, Thrissur during 2009 at a spacing of 2.5 x 2.5m. The fertilizer cum intercropping trial was superimposed on the existing S. macrophylla plantation in a split plot design with fertilizer levels as main plots and intercrops as sub plots during two consecutive years (2014-2016). The various N, P, K fertilizer combinations were viz. F1: 0:0:0; F2-50:25:25 (68:78:26 g per tree); F3- 100:50:50 (136:156:52 g per tree) and F4-150:75:75 (205:234:78 g per tree) kg ha-1 year-1 N, P2O5 and K2O; equivalent to 0:0:0, 50:10.75:20.75, 100:21.5:41.5 and 150:32.25:62.25 kg ha-1 per year elemental N, P and K, respectively. The fertilizers were applied to the mahagony trees at a basal ring of 50 cm radius just after the pre-monsoon rains. The various intercrops selected were shade tolerant ginger (Zingiber officinale Roscoe), wild turmeric (Curcuma aromatic Salisb) and turmeric (Curcuma longa L.). There were total 16 combinations of treatments with three replications (total 48 plots). The main plot size was 40 x 10 m and sub plot 10 x 10 m. The growth observation of the S. macrophylla tree after the fertilizer application showed consistent increase with increasing fertilizer dosage. Tree growth in terms of height, diameter, basal area and volume showed characteristic increase with increase in fertilizer levels. For instance, the stand basal area increased from 8.69 (F1: unfertilized) to 14.87 m2 ha-1 (F4: heavily fertilized). Similarly the tree volume also showed increase with fertilizer application. The difference in basal area for the higher fertilizer regimes were on par (F3, 14.50 m2 ha-1 and F4, 14.87 m2 ha-1) suggesting F3 as the optimal fertilizer regime if basal area production is the objective. However, the volume production was the highest under F4 regimes (105.28 m3 ha-1) which was significantly different from F3 (93.31 m3 ha-1). Hence tree management at F4 fertilizer regime would be ideal for optimal volume production for S. macrophylla. The biomass production results also showed positive response to applied fertilizers. Total mean tree biomass production was in the order 52.24, 60.62, 64.32 and 83.62 kg per tree for F1, F2, F3 and F4 fertilizer dosage regime respectively. The corresponding stand level biomass (per ha basis) was in the order 83.59, 97.00, 102.91 and 133.80 Mg ha-1 for F1, F2, F3 and F4 fertilizer dosage regime respectively. The highest fertilizer dosage plots showed almost 60 per cent increase in biomass production as compared to unfertilized control. Among the biomass components, stemwood represented almost 50 % of the total biomass production for all fertilizer regimes followed by roots which accounted almost 18 % of total biomass production. Branchwood biomass represented roughly 14-15 % of total biomass. Biomass accrual by the various components in the decreasing order was: stemwood> roots> branch wood >leaves>twigs. Mean tree and stand level carbon sequestration showed positive response to fertilizer application for 6 year old S. macrophylla. The total mean tree carbon stocks ranged from 29.1 kg (F1) to 46.66 (F4). The total carbon sequestration on per hectare basis was 74.66, 57.24, 54.31, and 46.56 Mg ha-1 for fertilizer regimes F4, F3, F2 and F1 respectively.Among the various biomass components, stemwood accounted bulk of the biomass carbon which was roughly 50% followed by roots (17 %). Nutrient partitioning S. macrophylla suggests that in general, nitrogen and potassium concentrations decreased in the order leaves > stem > branch > roots > twigs for N, P and K. However, tissue phosphorus concentration followed the order branches > leaves > roots > twigs > stem. Various components stored considerable amount of nutrients in their biomass. The total N stock in the standing biomass ranged from 0.428 (unfertilized control) to 0.716 Mg ha-1 (F4; heavily fertilized). The stock of phosphorus in the biomass was 0.174 (unfertilized control) to 0.223 Mg ha-1 (F4; heavily fertilized) while the corresponding stock for potassium was 0.090 (unfertilized control) to 0.144 Mg ha-1 (F4; heavily fertilized). Root distribution studies using logarithmic spiral trench technique in 6-year-old S. macrophylla showed increase in rooting intensity with fertilizer application for total roots and root class <2.5 mm. Fine root (< 2.5 mm) represented approximately 58 to 62 % of the total roots. Hence the increase in fine root count in high fertilized plots suggest higher nutrient uptake and there by higher tree growth for S. macrophylla. The present study showed the maximum foraging zone for S. macrophylla was at rhizosphere volume of 2.17 m lateral distance and 40 cm soil depth. At the present stocking this leads to considerable overlapping of the rhizosphere of S. macrophylla and intercrops and thereby limits the prospects of intercropping. Hence the possible optimal spacing suggested for 6-year-old S. macrophylla would be 5.5 m x 5.5 m for effective intercropping. Effect of intercrop on the tree growth in all the fertilizer treatment plots suggested non-significant response. Despite the overwhelming effect of fertilizer on tree growth and yield, the presence of intercrop had only very modest influence on tree growth. Interestingly some of the S. macrophylla tree growth variables were marginally better in the intercropped plots suggesting possible complementary interaction between the intercrop and trees for applied fertilizers. The intercrops viz. ginger, wild turmeric and turmeric showed better growth in fertilized plots as compared to unfertilized control. Also the biometric growth and rhizome yieldswere higher in the treeless open control plots as compared to S. macrophylla intercropped plots. Nevertheless the growth differences were lower in the heavily fertilized plotsas compared to open control. The better growth and rhizome yields during the second year for all the three intercrops was due to improvement in understory light regimes consequent to uniform tree pruning.
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    ThesisItemOpen Access
    Performance of calliandra (Calliandra calothyrsus meissn.) under diverse mangement regimes in a coconut based hedge row fodder production system
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Anu Sagaran, K; KAU; Asha, K Raj
    A study entitled “Performance of calliandra (Calliandra calothyrsus Meissn.) under diverse management regimes in a coconut based hedge row fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2014-2015. The main objective of the study was to assess the influence of management practices like tree density, pruning height and pruning frequency on initial growth, forage yield and nutritional qualities of calliandra intercropped in coconut gardens under humid tropical conditions of Kerala. The treatments consisted of three levels of plant density (27,777; 22,222 and 17,777 plants ha-1), three levels of pruning frequency (8, 12 and 16 weeks interval) and two levels of pruning height (0.5m and 1m) in all possible combinations laid out under factorial randomized block design with three replications. The results revealed that various management practices had a profound influence on the forage yield and quality aspects of calliandra when grown as an intercrop in coconut garden. Comparing plant densities, highest density stand (27,777 plants ha-1) yielded 55 percent more forage (11.73Mg ha-1yr-1, dry basis) than the lowest density (17,777 plants ha-1), with higher foliage fraction. Quality parameters of forage like crude protein, ash, dry matter, phosphorus and potassium content increased and crude fibre content decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning at the prolonged interval of 16 weeks yielded more total forage, but the majority of the fodder comprised of stem fraction as indicated by the poor leaf-stem ratio. Leaf –stem ratio of fodder harvested at 8 and 12 weeks showed an increment of 125 percent over that of the 16 weeks interval, indicating more foliage production than stem fractions when harvested at shorter intervals. Pruning frequencies also had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks and 12 weeks yielded fodder with maximum crude protein, phosphorus and potassium content when compared to 16 weeks. Ash and dry matter content in 99 fodder was significantly higher at the longest interval of 16 weeks. Crude fibre content of forage increased sharply from 28.33 to 49.98 percent by prolonging the harvest interval from 8 to 16 weeks thereby adversely affecting the palatability of the forage. Pruning height showed more prominent influence on forage yield of calliandra than the nutritive parameters. Dry fodder yield increased from 8.11 to 10.81 Mg ha-1yr-1 with increasing pruning height from 0.5 to 1m, with a higher leaf-stem ratio for taller stocks. Similarly there was a significant improvement in CP yield from taller stocks (1.67 Mgha-1 )when compared to shorter ones (1.23 Mgha-1) The interaction effects of plant density, pruning height and pruning frequency had no significant effect on yield and quality parameters of callianrda. The highest yielding combination (13.39 Mg ha-1dry basis) was found to be D1H2F2 (27,777 plants ha-1 + pruning height 1 m + pruning interval 12 weeks ) with higher foliage fraction and better nutritive parameters, compared to all other management levels, which were inferior either in forage yield or nutritive value or palatability of forage. On the whole, the study revealed that forage yield and quality of young stands of calliandra underneath coconut garden could be optimized at the cheapest level by adopting a tree density of 27,777plants ha-1, pruning height of 1m and pruning interval of 12 weeks. Moreover, based on the growth and yield performance and quality aspects, it is found that calliandra is a promising fodder tree, which can be successfully integrated with the existing coconut gardens of Kerala. Establishment and proper management of calliandra in coconut garden at appropriate management levels thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.
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    ThesisItemOpen Access
    Forage yield, soil fertility and carbon dynamics of calliandra (Calliandra calothyrsus meissn,) in coconut plantation
    (Departament of Silviculture and Agroforestry , College of Forestry, Vellanikkara, 2017) Jilna Joy; KAU; Asha, K Raj
    A study entitled “Performance of calliandra (Calliandra calothyrsus Meissn.) under diverse management regimes in a coconut based hedge row fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2014-2015. The main objective of the study was to assess the influence of management practices like tree density, pruning height and pruning frequency on initial growth, forage yield and nutritional qualities of calliandra intercropped in coconut gardens under humid tropical conditions of Kerala. The treatments consisted of three levels of plant density (27,777; 22,222 and 17,777 plants ha-1), three levels of pruning frequency (8, 12 and 16 weeks interval) and two levels of pruning height (0.5m and 1m) in all possible combinations laid out under factorial randomized block design with three replications. The results revealed that various management practices had a profound influence on the forage yield and quality aspects of calliandra when grown as an intercrop in coconut garden. Comparing plant densities, highest density stand (27,777 plants ha-1) yielded 55 percent more forage (11.73Mg ha-1yr-1, dry basis) than the lowest density (17,777 plants ha-1), with higher foliage fraction. Quality parameters of forage like crude protein, ash, dry matter, phosphorus and potassium content increased and crude fibre content decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning at the prolonged interval of 16 weeks yielded more total forage, but the majority of the fodder comprised of stem fraction as indicated by the poor leaf-stem ratio. Leaf –stem ratio of fodder harvested at 8 and 12 weeks showed an increment of 125 percent over that of the 16 weeks interval, indicating more foliage production than stem fractions when harvested at shorter intervals. Pruning frequencies also had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks and 12 weeks yielded fodder with maximum crude protein, phosphorus and potassium content when compared to 16 weeks. Ash and dry matter content in 99 fodder was significantly higher at the longest interval of 16 weeks. Crude fibre content of forage increased sharply from 28.33 to 49.98 percent by prolonging the harvest interval from 8 to 16 weeks thereby adversely affecting the palatability of the forage. Pruning height showed more prominent influence on forage yield of calliandra than the nutritive parameters. Dry fodder yield increased from 8.11 to 10.81 Mg ha-1yr-1 with increasing pruning height from 0.5 to 1m, with a higher leaf-stem ratio for taller stocks. Similarly there was a significant improvement in CP yield from taller stocks (1.67 Mgha-1 )when compared to shorter ones (1.23 Mgha-1) The interaction effects of plant density, pruning height and pruning frequency had no significant effect on yield and quality parameters of callianrda. The highest yielding combination (13.39 Mg ha-1dry basis) was found to be D1H2F2 (27,777 plants ha-1 + pruning height 1 m + pruning interval 12 weeks ) with higher foliage fraction and better nutritive parameters, compared to all other management levels, which were inferior either in forage yield or nutritive value or palatability of forage. On the whole, the study revealed that forage yield and quality of young stands of calliandra underneath coconut garden could be optimized at the cheapest level by adopting a tree density of 27,777plants ha-1, pruning height of 1m and pruning interval of 12 weeks. Moreover, based on the growth and yield performance and quality aspects, it is found that calliandra is a promising fodder tree, which can be successfully integrated with the existing coconut gardens of Kerala. Establishment and proper management of calliandra in coconut garden at appropriate management levels thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.
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    ThesisItemOpen Access
    Autoallelopathy of selected multipurpose tree species and the effect of their leachates on Agricultural test crop
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Neenu, P; KAU; Jamaludheen, V
    A study carried out in the tree nursery of College of Forestry, Vellanikkara, Thrissur to assess the autoallelopathic effect of selected multipurpose trees and the effect of their leachate on agricultural test crop. The study on allelopathy is very essential in agroforestry as it effect the yield and performance of the trees and crops grown together and is essential to make judgment on the compatibility of trees and crops. The allelopathic effect of different tree part leachates such as leaf leachate, bark leachate and root leachate of selected trees viz., Acacia auriculiformis, Acacia mangium, Ailanthus. triphysa, Grevillea robusta and Swietenia macrophylla on the germination and growth of their own seedling and an agricultural test crop cowpea (Var. Anaswara) were studied. The soil for the pot culture experiment was collected from well established plantations of the MPTs and is used as potting mixture with sand in equal proportion. The pots were irrigated with leachates of different tree parts of these trees by soaking the tree part in water for 24 hours in 1:10 w/v concentration. The monthly variation in nutrient status of the soil used for pot culture experiment and the variation in the physicochemical properties of leachates at six intervals is also estimated. The effect of tree part leachates considerably varied among the germination and biomass production in both allelopathic and autoallelopathic studies. The observations on the germination per cent in allelopathic and autoallelopathic study revealed greater inhibition in the pots treated with leaf leachate in all tree species, except for S. macrophylla. With regard to biometric observations and biomass production also, S. macrophylla performed as the best compared to other selected species investigated for autoallelopathy. In case of the test crop also, it showed a better growth in pots treated with the leachates from S. macrophylla. The physicochemical analysis of the leachate of tree parts used to irrigate the pots showed increasing trend in total solid, electrical conductivity, total phenol, total carbohydrate and a decreasing trend in pH upto 36 hours. The physicochemical analysis of leachates for total phenol showed a greater concentration in the leaves than the bark and root. Results converge to the generalisation that among the five selected tree species the effect of auto allelopathy is negligible in case of S. macrophylla. The better growth performance of the test crop in S. macrophylla tree part leachates shows the compatibility of the test crop with the tree than the other selected tree species.
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    ThesisItemOpen Access
    Productivity, carbon and nutrient stocks in mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) based high density fodder production system in coconut
    (Department of Silviculture and Agroforestry College of Forestry, Vellanikkara, 2018) Acsah Rose, John; KAU; Asha K Raj
    The research programme entitled “Productivity, carbon and nutrient stocks in mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) based high density fodder production system in coconut”, was conducted at Instructional farm, College of Horticulture, Vellanikkara during 2017-18, to evaluate the influence of tree density and harvest interval on forage yield, carbon and nutrient stocks of three- years- old mulberry and subabul fodder banks in coconut garden. The study also examined the variation in coconut productivity and soil fertility changes associated with fodder bank integration in coconut plantations. The treatments included intercropping of fodder tree species like mulberry and subabul-1 at three levels of tree densities (49,382; 37,037 and 27, 777 plants ha-1 ) and three levels of harvest intervals (8, 12 and 16 weeks) in all possible combinations with randomized block design replicated thrice. The study indicated that annual fresh fodder yield from fodder tree banks per hectare of coconut garden in the third year of intercropping was significantly higher in mulberry (33.93 Mg ha-1 yr ) than that of subabul (20.14 Mg ha-1 yr ). Forage yields of tree banks increased from 18.97 to 35.04 Mg ha yr from lower to higher density classes, and were also found to be higher (33.98 Mg ha-1 yr ) for medium harvest interval of 12 weeks than longer or shorter intervals. Comparing the cumulative effects of stand management practices, forage yields of mulberry and subabul stands showed drastic variation which ranged from 16.40 to 63.38 and 9.33 to 30.96 Mg ha-1 yr-1respectively under various management levels, there by indicating the critical role of proper management for productivity enhancement from tree fodder banks. Maximum yield was obtained from the highest density stand (49,382 plants ha-1 ) and at medium harvest interval of 12 weeks in both the tree species. In general, fodder tree intercropping and various management regimes showed no significant influence on coconut productivity. However, a slight decrease in nut yield was observed under very high fodder tree density (49,382 plants ha-1 ), especially with that of mulberry, there by pointing out the need for crop specificnutrient and moisture supplementation to prevent competition and yield loss in coconut under high density intercropping. Intercropping of fodder trees and various management practices resulted in significant enhancement in total biomass production and carbon storage potential of coconut plantations (82.70-108.48 Mg ha-1 ) than that of coconut monoculture system (75.35 Mg ha-1 ). The intercropped fodder trees have fixed additional carbon to a maximum of 33 Mg ha-1 in the plant biomass and in soil up to 40 cm depth, thereby making considerable contribution for reducing atmospheric carbon dioxide levels. Significant difference was observed in nutrient uptake by the two fodder tree species, tree density and harvest schedule. N, P and K uptake was found to be significantly higher for mulberry (70.77, 4.80 and 38.22 kg ha-1 ) than that of subabul (51.62, 2.97 and 24.45 kg ha-1 ). N, P and K uptake enhanced by 81, 113 and 96 per cent from lower to higher densities. The nutrient uptake was higher in the medium interval of 12 weeks when compared to shorter or longer intervals. In general, intercropping practices in coconut have overall improved the fertility status of soil compared to coconut monoculture. However, proper nutrient supplementation should be ensured while adopting very high tree densities to avoid any possible competition with coconut palms. Fodder tree species and tree density had significant effect on soil properties like pH and water holding capacity (WHC) in mulberry and subabul plots intercropped in coconut plantation. Soil pH was observed higher in subabul (4.84) than mulberry (4.58). Water holding capacity (WHC) was observed higher in mulberry plots (53.96 %) than that of subabul (50.84%). Comparing the economics of tree fodder integration in coconut garden, significantly higher B: C ratio was obtained from mulberry (2.94) than subabul (2.54). B: C ratio showed an increasing trend (2.26 to 3.05) from lower to higher density classes. The highest B: C ratio (3.07) was obtained from 12 weeks harvest interval.Hence, the present field study clearly demonstrates the possibility of integrating mulberry and subabul fodder banks in coconut gardens of Kerala to enhance quality forage production, so as to minimize farmer’s expenses on feed cost. Adoption of ideal stand management practices viz., tree density of 49,382 plants ha-1 and 12 weeks harvest interval, can generate higher forage yields from limited land area. Moreover, the intercropped fodder trees have fixed additional carbon to a maximum of 33 Mg ha-1 , thereby making considerable contribution for reducing atmospheric CO2 levels to minimize global warming. Thus, establishment and proper management of mulberry and subabul fodder banks in coconut garden is a low cost technology to enhance quality forage production in humid tropics, and a promising strategy for climate change mitigation via carbon sequestration.