31
JoTEC (Journal of Tropical Estate Crops), 1(1) (2023): 31-34,
JoTEC (Journal of Tropical Estate Crops)
Available online http://ojs.uma.ac.id/index.php/jotec
Latex Production of Rubber Plants Based On The Physiological Aspects
Yayuk Purwaningrum1), Yenni Asbur1), Junaidi2), Atminingsih2) & Chairani Hanum3)
1)Department of Agrotechnology Faculty of Agriculture-Universitas Islam Sumatera Utara, Indonesia
2)Sungei Putih Research Center - Indonesian Rubber Research Institute, Indonesia
3)Department of Agroecoteknologi, Faculty of Agriculture – Universitas Sumatera Utara, Indonesia Received: Desember 28, 2022; Accepted: Maret 01, 2022; Published: April 12, 2023
Abstract
Indonesia's rubber production is still lower than Thailand's rubber production, even though the area of Indonesian rubber plantations is wider. One of the determining factors is the superior clone. Indonesia has produced several superior clones, as the output of ongoing research. However, the tapping factors which include the length of the tapping groove, the frequency of tapping, and the use of stimulants are very decisive factors to obtain high production. These factors must also consider the physiological parameters of latex, namely the levels of dry rubber, sucrose, inorganic phosphate, and thiol. The dynamics of the content of these latex compounds can be used as an indicator of the tapping system applied and production projections. The condition of the plant canopy and climatic elements (especially the dynamics of rainfall) are the main determining factors in implementing a productive and profitable tapping system.
Keywords: Clone; Physiology; Tapping.
*Corresponding author:
E-mail: [email protected]
ISSN xxxx-xxxx (Online)
Yayuk Purwaningrum, Yenni Asbur, Junaidi, Atminingsih & Chairani Hanum,Latex Production Of Rubber Plants Based On The Physiological Aspects
32 INTRODUCTION
The Directorate General of Plantations noted that the export value of rubber in 2013 reached 2.7 million tonnes with a selling value of US$6.9 billion, and then in 2014 it reached US$4.7 billion. In 2015 the area of rubber plantations in Indonesia was 3.6 million hectares with production in 2015 of 1,036 ha/year, still lower than Thailand's production which reached 1,600 ha/year (Directorate General of Plantations, 2020) On the other hand, several superior clones as a result of research have been obtained to be able to increase national rubber production.
Several types of clones that are widely used in Indonesia have been differentiated based on their physiological characteristics. Slow starter (SS) clones, for example, include RRIM 921, BPM 1, and PR 261, and their production is initially low, and production will increase due to good quality recovered skin. (Siregar.
2008, dalam Sumarmadji dan Tistama, 2011). On the other hand, based on research results apart from fertilization, efforts to increase production are also carried out using stimulants. In addition, the use of stimulants is used to reduce labour in the wiretapping process. This paper describes aspects of rubber tapping and its relationship with latex physiology, using some references.
Clone Aspects
Several types of clones that are widely used in Indonesia have been differentiated based on grouping, including SS, such as BPM 1, RRIM 921, PR 261, and GT clones. According to the research results, SS clones are clones with low to moderate metabolism, having specific characteristics including being responsive to stimulant administration, relatively more resistant to exploitation pressure and the recovered skin is generally thick so it has the potential to be utilized. One of the clones, namely RRIM 921, has a large stem diameter (70-100 cm), dark green
leaves, stable production and resistance to tapping groove drying (KAS). The metabolism in the RRIM 921 clone is low, the plant roots are firm. The weakness of this clone is that it produces dry rubber content (KKK) (Wibowo, 2019).
Tapping
Basically, tapping is the activity of breaking or injuring the latex vessels so that the latex drips out of the latex vessels into a receptacle mounted on a rubber rod.
Rubber tapping must pay attention to tapping a depth. The deeper the cut, the more latex vascular bundles are cut.
Therefore, tapping should be done as deep as possible, but should not touch the cambium layer because it will damage the selected skin. If the tapping is too shallow, fewer latex vascular bundles are cut so that the amount of latex obtained is limited. To obtain good tapping results, tapping must follow certain rules to obtain high production, while still paying attention to plant health factors. Before tapping, it is necessary to know the readiness or maturity of the rubber tree to be tapped. The rubber skin to be tapped must be cleaned first so that soiling of the latex can be prevented as early as possible.
According to the results of the study, at a skin depth of 0.5 mm from the cambium layer, the skin has the highest number of latex vessels, namely approximately 80 latex vessel rings. While the recommended incision depth is 1–1.5 mm from the cambium layer, because at a depth of 0.5 mm the skin is very prone to damage to the cambium and will affect further production. The research results show that the consumption of skin with S/4 tapping is less than S/2. The time to cut S/4 slices is shorter and the KKK of latex is higher.
The results of Hasyim's research (2018) concluded that the tapping of the upper tapping field resulted in the consumption of skin per tapping varying greatly, depending on the height of the tapping area. At the beginning of tapping the top
JoTEC (Journal of Tropical Estate Crops), 1(1) (2023): 31-34
33 panel, the consumption of skin per month is 2.5- 3.0 mm. Even though tapping on the top panel consumes thicker skin, it is necessary to set a maximum limit for the consumption of skin that is allowed on the tapping of the top panel. The maximum consumption of leather per year varies according to the tapping frequency. With a low tapping frequency, the consumption of skin per year is less (S/4 = 30 cm/year), compared to S/2 with skin consumption of 50 cm/year. Tapping with short slices (S/4) upwards, combined with an effective stimulant is expected to optimize production in the upper tapping field. Skin consumption with S/4 slices with a 45o slope is less than with S/2. The time to cut S/4 slices is shorter and the latex dry rubber content (KKK) is higher.
Stimulant
Stimulant is formula made with various vitamins and growth regulators.
Experiments in the long term will be very beneficial for determining the extent of the impact or benefits of the use of stimulants to increase production, KKK and KAS.
Tapping in the lower tapping area is recommended to use a stimulant with a concentration of 2.5%, tapping intensity d/3 (every three days) to maintain continuity of production and plant health.
Exploitation systems in rubber plants continue to be carried out to find the most appropriate method to produce high latex production and avoid physiological stress.
It was further concluded that the use of stimulants on mature rubber trees is already an integral part of the tapping system, especially on large plantations.
The use of stimulants aims to increase the production of latex and extend the drying period of rubber latex. Latex stimulation is generally carried out on mature rubber plants to increase latex yields to obtain additional benefits. The material commonly used for stimulation by topical means is a stimulant with the active ingredient then with various trademarks.
This active ingredient emits ethylene gas
which, when applied, will seep into the latex vessels. Inside the latex, gas vessels absorb water from the cells around it. This water absorption causes turgor pressure to rise which is accompanied by the swift flow of latex.
Latex Physiology
Dry Rubber Content
Dry rubber content is the solids content of rubber per weight calculated in units of a per cent (%). The dry rubber content determines the selling price of rubber. The handling of the results in both latex and excellence largely determines the value of the KKK. Some field factors that can affect KKK include tapping techniques, climate (especially rain), plant canopy conditions (leaf fall or leaf growth stages in the crown), clone type, and stimulant use techniques. Classification of garden latex quality based on dry content, namely quality I with a minimum KKK of 28% and quality II with a minimum KKK of 20% or below 28%. The KKK value is a measure of the quality of latex because this value describes the amount of water content in the latex.
Sucrose content
Sucrose content is a potential latex raw material and is closely related to the level of exploitation applied. Sucrose content in latex vessels decreased with increasing exploitation intensity. The threshold value for sucrose is 4 mM. If the exploitation intensity is increased so that the sucrose content is below 4 mM, it will cause vacancies in the latex constituent materials. From the results of the study, it was concluded that the level of sucrose in latex is strongly influenced by the metabolic rate in the tissues. In mature plants, low sucrose levels indicate that the assimilate metabolism is very intensive, so carbohydrate reserves are depleted for rubber production. Conversely, high levels indicate less active plant metabolism. High sucrose levels can also mean that laticifer
Yayuk Purwaningrum, Yenni Asbur, Junaidi, Atminingsih & Chairani Hanum,Latex Production Of Rubber Plants Based On The Physiological Aspects
34 cells are no longer functioning or degenerating.
Inorganic Phosphates
High levels of latex inorganic phosphate indicate active latex metabolic activity or vice versa. The increase in latex metabolic activity is influenced by several things such as climate, injury, and stimulation. Physiological characteristics of latex such as inorganic phosphate, thiols and pH are important factors in rubber biosynthesis. According to research results, the levels of Pi (Inorganic Phosphate) describe the availability of energy in the cells of the latex vessels to convert sucrose into rubber particles. The optimal range of inorganic phosphate (Pi) levels is 10-20 mM. If latex has a Pi level of 20 mM it means the plant is experiencing over metabolism or disease attack. This is consistent with the opinion which states that Pi is an indicator of metabolic activity, in this case describing the ability of plants to convert raw materials (sucrose) into rubber particles. Inorganic phosphate (Pi) levels can also be used as an indicator of latex energy and metabolism. Pi levels describe the availability of energy in latex vessel cells to convert sucrose into rubber particles (Atminingsih, 2016)
Thiol
According to Sumarmadji and Tistama (2011), optimal thiol levels range from 0.4-0.9 mM. Increasing the intensity of exploitation affects the increase in thiol levels, but if the intensity of exploitation is excessive, the thiol levels will be very low.
Thiols are a control parameter concerning KAS and reflect the ability of plants to prevent susceptibility to latex physiology.
The function of thiols is to activate enzymes that play a role in environmental stress conditions, and thiol status shows the response of plants to exploitation pressure. Thiol levels are inversely proportional to the intensity of exploitation. The higher the exploitation
intensity, the lower the thiol content. Thiol content also influx
CONCLUSIONS AND
RECOMMENDATIONS Conclusion
The diversity of latex yields is strongly influenced by the conditions of the leafing phase which are in line with changes in the pattern of monthly rainfall/rainy days. A significant decrease in latex yields occurred during leaf fall and the formation of young leaves.
Suggestion
Tapping on rubber plants is recommended by paying attention to environmental conditions and plant conditions. The use of stimulants should be stopped when the plant sheds leaves.
enced by several factors including the exploitation system, season and plant age.
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