Consideraciones técnicas para el establecimiento y manejo del cultivo del caucho (Hevea brasiliensis) en la Orinoquia Colombiana

Author(s):  
Alfonso Martinez
Keyword(s):  
2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Hanifa Marisa

An investigation had been done to Tetragonula (Tetragona) sp nest at Indralaya, South Sumatra to describe the Tetragonula sp nest that use streetlight pole as nest medium during April - May 2019. Purpossive sampling is used to select the target nest. Two streetlight pole found be used by Tetragonula sp as their home. The coordinate of location, heght from ground surface, diameter of streetlight pole, air temperature and humidity, and floral species around nest, were noted. Spot coordinate are S 30 14’ 19.2498’’ and E 1040 39’ 15,3288’’ ; 1,5 m above the ground surface, 12 cm diameter pole, highest air temperature was 35 o C at daylight (April and May 2019), 80 – 90 % humidity at April-May 2019; which Switenia macrophyla, Hevea brasiliensis, Zea mays, and Citrullus lanatus floral species are planted around. Air temperature in the pole is very high, around 40 0 C during daylight.


2015 ◽  
Vol 3 (2) ◽  
pp. 232
Author(s):  
Hendra Wiguna ◽  
. Supijatno
Keyword(s):  

<p><em><span style="font-family: Times New Roman;">Penelitian dilaksanakan untuk mempelajari dan mengidentifikasi manajemen penyadapan tanaman karet. Kegiatan magang dilaksanakan di Perkebunan Karet Simalungun, Sumatera Utara pada tanggal 10 Februari hingga 9 Juni 2014. Manajemen penyadapan ditujukan untuk menjaga kontinuitas dan meningkatan produksi karet alam sesuai dengan umur ekonomis tanaman. Persentase populasi tanaman siap sadap rata-rata       per-hanca di PT BSRE pada tahun tanam 2005 dan 2009 adalah 96.82%. Konsumsi kulit sadapan antara penyadap kelas A dan kelas B pada sistem sadap tarik ½ S d/3 dan sadap sorong ¼ S d/3 tidak berbeda nyata dan belum sesuai dengan standar penyadapan perusahaan. Faktor pendidikan dan pengalaman kerja penyadap mempengaruhi produksi cuplump pada sistem sadap tarik ½ S d/3, sedangkan faktor usia tidak mempengaruhi. Faktor pendidikan, usia, dan pengalaman kerja penyadap tidak mempengaruhi produksi cuplump pada sistem sadap sorong ¼ S d/3. Manajemen bidang sadap dan penggunaan zat stimulansia di perkebunan karet ini bersifat spesifik klon. Penyakit kering alur sadap (KAS) klon seri PB nyata lebih tinggi pada tahun tanam 2005 dibandingkan pada tahun tanam 2009, sedangkan penyakit KAS pada klon PB 330 dan DMI 35 tidak berbeda nyata pada tahun tanam sama. </span></em></p>


2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Boshi Zhao ◽  
Zhiming Yu ◽  
Yang Zhang ◽  
Chusheng Qi

AbstractBlue staining on rubberwood (Hevea brasiliensis) is a common kind of defect. There currently exists much research focused on the prevention and control of blue staining. However, little research has been concentrated on the utilization of blue staining for green dyeing. The research conveyed in this paper primarily used Lasiodiplodia theobromae to dye rubberwood, and used scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR) to analyze the commission internationale eclairage (CIE) L*a*b* value of color, the contact angle, the pH value, 24-h water absorption, mass loss ratio, and compressive strength in increments between 5 and 40 days. The results found that the color of rubberwood became darker and more uniform, and that the surface dyed with fungi can reach a super-hydrophobic state. With the increase of time, the pH value of rubberwood changed from acidic to alkaline. Furthermore, hyphae entered the wood mainly through vessels for their large pore diameter, and reduced water absorption. Mass loss ratio increased gradually between 5 and 40 days. The research in this paper concludes that the microorganism was an effective method of wood dyeing, and lays a foundation for further research.


1991 ◽  
Vol 266 (24) ◽  
pp. 15944-15948
Author(s):  
H.I. Lee ◽  
W.F. Broekaert ◽  
N.V. Raikhel ◽  
H. Lee

2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.


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