A COMPILATION OF POTENTIAL ALTERNATE SHADE TREE SPECIES FOR TEA PLANTATIONS

Tea (Camellia sinensis) is a shade loving plant, which is usually grown as amono crop, under a canopy of shade trees throughout its life. Variousphysiological functions of tea are facilitated by shade, leading to sustain itsvigour, yield and quality of the final produce. The 'tea - shade tree'ecosystem is manipulated to possess a microenvironment resembling forestcharacteristics. Of the four different tea growing agro-climatic regions in SriLanka, the recommended shade trees are confined to eight species: Grevillearobusta, Albizzia moluccana and Albizzia chinensis as high shade and Acaciapruinosa, Acacia decurrens, Erythrina lithosperma, Calliandra calothrysusand Gliricidia sepium as medium shade. One species each from the twocategories is usually grown at each location; pollarding and periodic loppingof high and medium shade respectively are practiced to ascertain the optimalshade levels of 10-40%. In order to achieve ecological, environmental andeconomic stability of the system and sustainable productivity per unit areaover monocultural systems, exploitation of more number of species is of vitalimportance. This also imparts direct benefits of harbouring natural enemiesof pests, moisture retention, nutrient and energy trapping, soil erosioncontrol, biomass energy and organic matter addition and indirect benefits ofC sequestration and opportunities for 'fair trade labeling' and eco tourism,biodiversity improvement, floral and aesthetic values and income generation.The present exercise explored the alternative species considering climaticsuitability and natural habitat, growth rate, plant height, root characteristics,pollarding/ lopping ability, stem and branching characteristics, canopyarchitecture, leaf characteristics such as angle, size, shape, orientation andshedding. In addition, competitiveness with tea for water and nutrients,biomass production, nitrogen fixation, availability of information onpropagation and other silvicultural practices, harbouring pests and diseases oftea, food, timber, fuel wood values etc. were considered. Initial databaseresulted in over 230 potential species with native and introduced originsexcluding trees for intercropping and diversification purposes. The mostprobable species identified in the initial exercise were Adenenthera pavonina,Adina cordifolia, Albizzia odorissima, Alstonia macrophylla, Alstoniascholaris, Bauhinia racemosa, Bauhinia variegata, Berrya cordifolia, Bhesa zeylanica, Cananga odo rata , Canthium montanum, Carallia brachiata,Cassia javanica, Cassia spectabilis, Cedrella odorata, Chukrasia tabularis,Dalbergia sissoo, Elaecarpus amoenus, Elaeocarpus glandulifer,Enterolobium cylocarpum, Erythrina edulis, Erythrina fusca, Erythrinapoeppigiana, Erythrina variegata, Filicium decipiens, Khaya senegalensis,Macademia temifolia, Mallotus tetraeocevs, Mangifera zeylanica, Micheliachampaca, Muntingia calabura, Parkinsonia aculeata, Paulownia fortunei,Peltophorum dasyrachis, Pentaclethra macroloba, Pongamia pinnata,Pterocarpus indicus, Sapindus emarginatus, Tecoma stans, Temstroemiagymnanthera and Trema orientalis, which belong to the families Anonaceae,Apocynaceae, Bignonaceae, Elaeocarpaceae, Euphorbiaceae, Fabaceae,Magnoliaceae, Meliaceae, Paulowinaceae, Proteaceae, Rhizophoraceae,Rubiaceae, Sapindacea, Theaceae, Tiliaceae and Ulmaceae.The species will be exposed to further screening processes and pilot scalefield evaluations at the Tea Research Institute and different tea growing areasrespectively, prior to releasing the most promising selections for field use.

Comparative dynamics of tea (Camellia sinensis L.) roots under organic and conventional management systems with special reference to water use

Comparative measurements were carried out in the on-going, long-term organic and conventional comparison “TRI OR-CON” trial at the Tea Research Institute of Sri Lanka. The tea was grown organically using tea waste (TW), neem oil cake (NOC), compost (COM) as soil amendments using IFOAM guidelines, which were compared with tea grown conventionally (CONV) with recommended synthetic inputs. Responses of the tea yield, root system and mass volume sap flow were studied. The tea bushes showed comparable responses between all the treatments, the differences of which were not statistically significant: They exhibited similar yield, root distribution, growth, extension rates, mortality, mass volume flow of water and water use efficiency (WUE). The organically grown (ORG) tea bushes invested more roots in deeper soil layers than the CONV bushes. The results showed that in terms of plant growth, managing tea organically is as equally feasible as managing tea in the conventional manner

Restoration of Tsunami affected Landscape and Plant Diversity in Dharmapala Park in Galle

Approximately 6 ha. of Dharmapala Park in Galle City has traditionally been maintained as a recreation area for children and adults. Owing to significantly poor horticultural attention and maintenance for many decades and the Tsunami hit, most of the lower level trees, shrubs and landscape designs as well as a few buildings and structures have been damaged. Many large trees seemed dying due to prolonged exposure to salt concentra tions in the ground and due to age, over shading and competition, termite and wood rot damages, poor drainage facilities and dumping of city garbage etc. Sky view of the park did not appear a recreational park but looked overcrowded and not harboring a diverse and fascinating array of flora arranged or managed systematically. Therefore, rehabilitation of degraded and eroded landscape status of Dharmapala Park was recognized by the local authorities. We attempted to improve the landscape status purely on the basis of adaptability to the inherent soil and land parameters and environmental conditions by choosing compatible vegetation types, strengthening architecture in par with culture and traditions of Southern Sri Lanka and existing architectural models historic to Galle Fort and other structures. Whilst restoring, improving and enhancing biological, eco logical and esthetic values, architectural and landscaping designing was aimed at accommodating requisites for future beneficiaries i.e. demonstration of ecological and biodiversity conservation and urban forestry etc. for educational, leisure and recreational purposes. Dumping yards were completely removed and the original soil organic matter status of 0.6 – 1.1 % was improved by land filling with soil sources having more than 1.5 % organic matter. Thinning out of branches, removal of old trees, shrubs and plants in unwanted places, tree surgeries and treatments of diseased and damaged tree por tions were completed to establish the proposed landscape designs. Walk ways for jogging and pets, steps, open spaces with playing, and historic exhibition facilities were systematically arranged with improved drainage and erosion control measures while the open theatre area was renovated attractively. The dominated and over crowded vegetation by Mudilla (Barringtonia asiatica L) and exotic trees and plants of about 40 species including Pinus, Casurina and Cypres etc. with little or no ecological, aesthetic or landscaping significance were changed into a variety of different canopy architectural beauty by introducing more than 120 different species of plant and tree species and turfs to give beauty and attraction for the users with cool and peaceful satisfaction. Introduction of new species was based on assuring different colour i.e. dark and light green, yellow, pink etc., diversity, size, appearance and shade horizontally and vertically during different seasons in the year, protection of the Park from sea breeze using tolerant hedge tree species and easy and less mainte nance of vegetation. In a sample survey, the visitors expressed full satisfaction of the present developments. We propose therefore to impose strict entry requirements avoiding misuse and a nominal levy in view of sustenance of the Park status and its facilities for the beneficiaries. This would also help attract both local and foreign visitors of any ag

Fotossíntese e fotoinibição em mogno e acariquara em função da luminosidade e temperatura foliar Photosynthesis and photoinhibition in mahogany and acariquara as a function of irradiance and leaf temperature

A fotoinibição pode ser intensificada por fatores de estresse como alta temperatura. O objetivo deste trabalho foi determinar os efeitos da luminosidade e temperatura na fotossíntese e na recuperação da fotoinibição sob baixa irradiância em mogno (Swietenia macrophylla King) e acariquara (Minquartia guianensis Aubl.). As plantas cresceram sob baixa irradiância: 0,20 (acariquara) e 1,43 mol m-2 dia-1 (mogno). A fotossíntese líquida e as características da fluorescência foram avaliadas em duas irradiâncias, 1.000 e 1.700 mmol m-2 s-1 , e duas temperaturas foliares, 32 e 38ºC. A 32ºC, a fotossíntese máxima (Amáx) foi maior em mogno do que em acariquara. Em mogno, a exposição a 38ºC causou redução gradativa na fotossíntese, sendo a taxa fotossintética após 50 min similar à encontrada em acariquara. A 32ºC, o aumento na irradiância, de 1.000 para 1.700 mmol m-2 s-1 , intensificou a fotoinibição, mas Amáx não foi alterada. Em 1.700 mmol m-2 s-1, o aumento da temperatura, de 32 para 38ºC, não afetou a fotoinibição. Após 72 horas em baixa irradiância, a recuperação da fotoinibição foi de 80% em acariquara e 89% em mogno. Não houve efeito da temperatura da folha na fotoinibição.<br>Photoinhibition may be exacerbated by stress factors such as high temperature. The aim of the work was to determine the effects of temperature and irradiance on photosynthesis and photoinhibition in mahogany (Swietenia macrophylla King) and acariquara (Minquartia guianensis Aubl.). Also to assess the effect of irradiance and temperature on the recovery from photoinhibition at low irradiance. Sapling were grown at low irradiance: 0.20 mol m-2 day-1 (mahogany) and 1.43 mol m-2 day-1 (acariquara). Photosynthesis and fluorescence characteristics were assessed in plants subjected to two irradiances 1,000 and 1,700 mmol m-2 s-1 , and two temperatures, 32 e 38ºC. At 32ºC, light saturated photosynthesis (Amax) was greater in mahogany than in acariquara. Mahogany plants exposed to 38ºC showed a consistent decline in carbon uptake, and after 50 min both species showed the same photosynthetic rates. In saplings exposed to 32ºC, increase in irradiance, from 1,000 to 1,700 mmol m-2 s-1 , exacerbated photoinhibition, but without reducing Amax values. At 1,700 mmol m-2 s-1 , the rise in temperature, from 32 to 38ºC, did not increase photoinhibition. After 72 hours at low irradiance, recovery from photoinhibition was 80% in acariquara and 89% in mahogany. There was no effect of leaf temperature on photoinhibition