สืบค้นงานวิจัย
Seasonal Changes in Xylem Sap Flow Rate in Mature Rubber Trees
K. Annamalainathan - ไม่ระบุหน่วยงาน
ชื่อเรื่อง (EN): Seasonal Changes in Xylem Sap Flow Rate in Mature Rubber Trees
ผู้แต่ง / หัวหน้าโครงการ (EN): K. Annamalainathan
บทคัดย่อ (EN): Sap flow measurement is a precise technique to study the tree water relations and to quantify whole-plant water use. The water usage of grown up rubber tree is not thoroughly studied so far. Sap flow measurements can provide an accurate method for determining the transpiration water loss from any plantation crop. The quantum of water loss in a tree depends on canopy size, physiological condition and soil and atmospheric factors. There is also an increasing interest in water and carbon fluxes at the canopy-atmosphere interface in the confert of global climate. The experimental site was located at Rubber Research Institute of India (RRII), Kottayam, Kerala at an altitude of72 MSL, longitude 76o 34’ E and latitude 9o 32’ N. Xylem sap-flow was measured in two rubber clones, namely RRII 5 and PR 255 of 19 year age with a mean girth of 78 and 82 cm, respectively at 150 cm above bud union. The terrain was mainly with gentle slope and the soil was laterite. Granier’s TDP probes with 80 mm length were inserted in main trunk at the breast height and the probes were connected to data logger. The data were downloaded every week and the mV signal was converted to flow velocity (V). Rate of flow of xylem sap through the trunk was recorded round the clock continuously for two years. The diurnal and seasonal differences in the trend of sap flow rate were very evident which responded to the ambient weather conditions (such as intensity of sunlight temperature, rain fall etc.) In the morning hours, as the sun light intensity increased there was a corresponding sharp increase in sap flow rate which attained maximum level around mid day. In the evening as the light intensity declined, the sap flow rate also declined. However, the rate of decline in the sap flow with respect to reduction in sunlight intensity in the late afternoon was lower than the rate of increase in sap flow with increase in the light intensity in the morning hours. Even during the mid day, when there was a sudden reduction in sunlight intensity due to a passing cloud, sap flow rate did not show any immediate concomitant reduction. The wintering phenomenon in Hevea generally starts from later part of December and completes by January. During defoliation period the sap flow rate declined drastically (from 40 litre/day/tree to 7 litre/day/tree). New foliage was started appearing from third week of January onwards. The sap flow rate slowly increased concomitant with the onset of new flush of leaves and attained maximum rate of flow after second week of February. The maximum and minimum rate of sap flow per day was observed during December and February, respectively. Sap flow rate during summer season was smaller than post-monsoon season. Significant positive relationship existed between T max and sap flow rate during pre-monsoon periods with saturated soil moisture. Taking a mean water consumption of 221/day/tree and assuming there are 400 trees/ha, the water consumption through transpiratory pull works out to be around 1.5 mm/day..Taking the long-term average rain fall in the region (3000 mm/year), it can be seen that the water loss due to transpiration by the trees amounted only to 12% of the annual rainfall.
บทคัดย่อ: ไม่พบข้อมูลจากหน่วยงานต้นทาง
ภาษา (EN): en
เผยแพร่โดย (EN): การยางแห่งประเทศไทย
คำสำคัญ (EN): xylem sap flow rate
เจ้าของลิขสิทธิ์ (EN): การยางแห่งประเทศไทย
หากไม่พบเอกสารฉบับเต็ม (Full Text) โปรดติดต่อหน่วยงานเจ้าของข้อมูล

การอ้างอิง

K. Annamalainathan. "Seasonal Changes in Xylem Sap Flow Rate in Mature Rubber Trees". ไม่ระบุหน่วยงาน. ม.ป.ป.

K. Annamalainathan. "Seasonal Changes in Xylem Sap Flow Rate in Mature Rubber Trees". ไม่ระบุหน่วยงาน. ม.ป.ป.. Print.



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Seasonal Changes in Xylem Sap Flow Rate in Mature Rubber Trees
K. Annamalainathan
การยางแห่งประเทศไทย
ไม่ระบุวันที่เผยแพร่
Sap Flow and Water Status in Adult Rubber Trees POTENTIAL OF INCREASING THE PLANTING DENSITY OF RUBBER IN SRI LANKA RUBBER FACTORY EFFLUENTS TREATMENT WITH UASB –STABILIZATION POND- OXIDATION DITCH METHOD STUDY ON THE POTENCY OF SERRATIA BACTERIA USED TO CONTROL WHITE ROOT DISEASE IN RUBBER The Role of Myanmar Rubber Planters and Producers Association (MRPPA) in Natural Rubber Development and its Recent Activities Effect of Temperature Constraints on Photosynthesis of Rubber (Hevea brasiliensis) JDM88 AGRO-VENTURES RUBBER BASED FARMING SYSTEM FEASIBILITY OF RUBBER (Hevea brasiliensis Mull. Arg.) CULTIVATION IN THE EASTERN PROVINCE OF SRI LANKA; A NON TRADITIONAL AREA FOR RUBBER IDENTIFICATION OF SUITABLE SPECIES AND GENOTYPES FOR CUT FOLIAGE CULTUVATION ON RUBBER LANDS SUPPORTS OF THE VIETNAM RUBBER ASSOCIATION FOR RUBBER INDUSTRY
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