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20183
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Subject: Silviculture and Agroforestry × End date: 2018 × Start date: 2018 × Type: Thesis × Thesis Type: M.Sc ×
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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
    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.
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    ThesisItemOpen Access
    Understorey productivity of selected fodder grasses in mature coconut and rubber plantations
    (Department of Silviculture and Agroforestry, Vellanikkara, 2018) Rose Mary Jose; KAU; Jamaludheen, V
    A field experiment was conducted at Vellanikkara, Thrissur, Kerala from May 2017 to February 2018 to assess the understorey productivity of four fodder grasses viz congosignal (Brachiaria ruziziensis), guinea (Panicum maximum) and two hybrid napier cultivars CO-3 and CO-5 when grown under mature coconut (Cocos nucifera L.) and rubber (Heavea barsiliensis Muell. Arg,) plantations, which are the two prominent land use systems in Kerala. The biophysical attributes influencing the productivity of these land use systems and the biochemical changes in the products of understorey crops were also studied. Growth parameters of understorey fodder crops varied remarkably among these land use systems. The fodder grasses grown in coconut plantations showed an increased plant height, leaf area index, leaf area ratio, and leaf weight ratio as compared with treeless open plot. However, the number of tillers per clump and number of leaves per clump showed a decreasing trend when grown as understorey crops in mature coconut and rubber plantations. Rubber grown fodder grasses expressed substantially poor performance both in growth and yield attributes. Regarding fodder production, open grown fodder grasses consistently showed maximum biomass dry weight throughout the harvests. On comparing with the open, the rubber plot showed a substantial reduction of 91.35% in the total biomass dry weight from all harvests whereas the reduction was only 39.02% under coconut plantations. Mean mid day (12–1p.m) understorey photosynthetic Photon Flux Density (PPFD) were 1342.5 moles μ m -2 sec -1 in rubber and 1575 μ molesm -2 sec -1 in coconut, with respective understorey PAR transmittance of 39.84 % and 56.08% of full sunlight. The understorey crops in coconut and rubber showed an increased chlorophyll-a, chlorophyll-b, and total chlorophyll content and leaf moisture content over treeless control. The maximum crude protein value was noticed in the rubber (11.97%) grown fodder grasses and was on par with open while 124 coconut (9.29 %) accounted the least crude protein content. The understorey crops showed a decreased crude fibre content as compared to open. The maximum leaf nitrogen content was observed in the rubber plot (1.92%) and this was followed by open plot (1.87%). The lowest nitrogen content was observed in the coconut plot (1.49%). No noticeable changes were observed in foliar phosphorus and potassium content across both land use systems. The soil analysis revealed that the organic carbon and available nitrogen content of the top soil were increased under both the tree based cropping systems as a result of understory intercropping. However, on comparing with the initial values of different soil properties studied, only modest changes were observed in the soil properties in general across both the land use systems and treeless open plot. It is concluded that the coconut based fodder production systems with these grasses are almost comparable, in terms of growth and yield, to the open areas and hence recommended for farmers adaption. This practice of integrating fodder grasses in coconut plantations gains immense importance in Kerala, where mature coconut plantations forms one of the extensive and prominent land management system. Thus, judicious use of the vast area of interspaces under these matures coconut plantations for fodder production is very ideal especially in the state of Kerala. The best proven combination of land use system and the fodder grass in a coconut based intercropping scenario was the cultivation of CO-3 fodder grass under matured coconut plantations. However, the rubber based fodder production system is not at all feasible and further conclusive studies may be done for affirming more reasons for such a substantial reduction of growth and yield in rubber based system.