Increased Rubber Production Research Articles

Green productivity analysis of raw rubber production

Rubber is a well-known commodity that has been cultivated for a relatively long time in Indonesia. Rubber plays an essential role in contributing foreign exchange incomes, job opportunities, and providing industrial raw materials. In 2014, Indonesia became the second-largest rubber producer after Thailand, with a rubber yield of 3,979 tons. Increased rubber production is linear to the environmental damage that occurs so that productivity improvement tools based on environmental or green productivity are needed. This research aims to determine the factors influencing productivity level and improvement efforts by considering the environmental performance indicator. The method used is the Environmental Performance Indicator (EPI). Two expert respondents filled the weighted result, i.e., academician and head of waste treatment. The selection of alternative improvement using Benefit-Cost Ratio (BCR). The result is Multi Soil Layering (MSL) which could save the cost of IDR 253,651,626.2 per year or 70% water savings. This alternative can increase productivity by 11.12% from 76.13% to 85.25% and raise the EPI value of 0.766 from 0.201 to 0.967.

Rubber in East assures the perceived benefits; a case study showing increased rubber production, amelioration of the climate and improved rural livelihood

With the development of agronomic protocols to cultivate rubber in the prevailing conditions in the Eastern province and identification of land availability, the Ministry of Plantation Industries has launched an accelerated programme to establish 10,000 ha of rubber in this region. In addition to the increased rubber production, improved environment with forest cover and enhanced rural livelihood are expected. Proven evidence is required for the success of the programme; hence, as a case study, this was aimed to assess the potential of achieving the perceived benefits using firstly reached two rubber smallholdings to latex harvesting stage in Helakomana GN division. Latex yields to predict the potential rubber production in the region, changes in crop microclimate and evidence for changes in farmers’ livelihood were evaluated. Basically, this programme has the potential of producing 15,000 MT of dry rubber annually with smallholder participation. A farmer having a hectare of mature rubber receives an average monthly income of about LKR 35,000. Income generated from rubber has empowered farmers to reap the benefits of recent infrastructure development in the region and to meet other family needs. Crop environment has been improved by rubber cultivation with 3.70C reduction in air temperature and moderate level %RH during the day time. This has provided better working conditions for farmers and would have an effect on regional climate once the targeted extent of rubber is grown. Rubber canopy has also protected the surface soil moisture.

Night temperature, rubber production, and carbon exchange in guayule

Guayule ( Parthenium argentatum Gray), a native of the Chihuahuan desert, produces the majority of its rubber during the winter months. Increased rubber production is thought to be induced by cold night temperatures, but the factors involved in rubber induction are not completely understood. The purpose of this study was to answer three questions about rubber production in the winter: (1) how do immature plants (<180 days) respond to cold night temperatures?; (2) how is rubber production in mature plants (≈1 year) related to night temperature?; and (3) what is the relationship between carbon exchange and rubber production under cold night temperatures? Plants were grown in differentially heated enclosures over three consecutive winters. The warm-night plants were exposed to simulated summer night temperatures and the cold-night plants to ambient winter night temperatures. Plant responses to different night temperatures were monitored by measuring growth, carbon exchange, fresh and dry weight, and resin and rubber production. Immature plants exposed to cold nights had higher rubber concentration than the warm-night plants only in the first year, which had the lowest night temperatures. For the mature plants, dry weight was not significantly different between treatments, but rubber concentration and yield were significantly greater in the cold-night than the warm-night plants. Plants in both treatments had similar carbon exchange rates. Therefore, the similarity in dry weight between treatments was most likely due to increased growth in the warm-night plants and increased rubber deposition in the cold-night plants. Rubber concentration was significantly related to night temperature in both mature and immature plants and appears to be stimulated most by temperatures below 10 °C.

Tapping Masculinity: Labor Recruitment to the Brazilian Amazon during World War II

Tapping Masculinity: Labor Recruitment to the Brazilian Amazon during World War II

Increasing the profitability of traditional, planted rubber agroforests at the Tapajós river, Brazilian Amazon

The planted rubber agroforests of the Tapajós region in eastern Pará State, Brazilian Amazon, are a traditional land use practice of intermediate intensity between extractivism in natural forest and plantation agriculture, and thus of potential interest especially for inhabited conservation areas and Extractive Reserves. We measured rubber production of five groves of 23–40 years of age on representative soil types and landscape positions of the region during one tapping season and tested options for improving rubber production in a series of on-farm experiments. The groves contained 650–700 rubber trees with a dbh >10 cm ha −1, plus variable numbers of smaller rubber trees. Rubber trees contributed 72–97% to the total basal area of the groves. Average dry rubber production per grove varied between 30 and 75 g per tree per week, with an average of 50 g. Income from rubber tapping at the present level of productivity was unlikely to exceed one Brazilian minimum salary for most farmers. Stimulation of the latex flux with a conventional chemical stimulant, ethephon, increased rubber production per week by up to 38%, but the response was highly variable between groves. The attempt to substitute the chemical stimulant by a locally produced, biological product was unsuccessful. There seemed to be considerable potential for improving tree health while increasing rubber production per unit time through the use of improved tapping practices, especially for old trees. From the two tapping knives and methods that are used in the region, the Amazonian method gave significantly higher yields per tree than the southeast Asian method; this adds to better protection of the trees from panel diseases and therefore greater longevity of the groves. Stem diameter, crown form and crown position of the rubber trees were all significantly related to rubber production, suggesting that too early tapping (which reduces growth) and excessively dense stands should be avoided; however, the predictive power of these variables was poor, and this may explain why farmers are reluctant to thin their stands and believe that mature rubber trees are not negatively affected by a secondary forest environment. Even in groves with low average productivity some very high-yielding trees were found, with the most productive ones attaining 250–300 g of dry rubber per tree per week. This points to a considerable value of these traditional agroforests as genetic reservoirs, and to opportunities to establish more productive groves through a rigorous process of seed and plant selection, without the need to drastically alter the traditional agroforestry practices.

Ethrel (Ethylene Releaser)-Induced Increases in the Adenylate Pool and Transtonoplast ΔpH within Hevea Latex Cells

The treatment of rubber tree (Hevea brasiliensis) bark with chloro-2-ethyl phosphonic acid (ethrel), an ethylene-releasing chemical, induced, after a lag period of 13 to 21 hours, a marked increase in the total adenine nucleotides (essentially ATP and ADP) of latex cells. This rise in the latex adenylate pool was concomitant with a marked decrease in the [ATP]/[ADP] ratio without significant changes in the adenylate energy charge. The apparent equilibrium constant for the adenylate kinase, which appeared to behave as a key enzyme in maintaining the adenylate energy charge in the latex, was considerably reduced, probably as a consequence of the alkalinization of the latex cytosol induced by the treatment with ethrel. To reduce the "sink effect" and activation of the metabolism induced in Hevea bark by regular tapping, the latex was collected by micropuncture (few drops) at increasing distance (5-50 centimeters) above and below an ethrel-treated area on the virgin bark of resting trees. The effect of ethrel was shown to spread progressively along the trunk. The increase in the adenylate pool (essentially ATP) was detectable as early as 24 hours after the bark treatment and was maximum after 6 or 8 days, 5 centimeters as well as 50 centimeters above and below the stimulated bark ring. The correlative vacuolar acidification and cytosolic alkalinization, i.e. the increase in the transtonoplast DeltapH, induced in the latex cells by ethrel were shown to be concomitant with the rise in ATP content of the latex. This suggests that the tonoplast H(+)-pumping ATPase, which catalyzes vacuolar acidification in the latex, is directly and essentially under the control of the availability of its substrate (i.e. ATP) in the latex. The results are discussed in relation to energy-dependent activation of metabolism, and increased rubber production, as induced by the stimulation of rubber trees with ethrel.

Isozyme markers in breeding guayule ( Parthenium argentatum) for increased rubber production

Isozyme markers in breeding guayule ( Parthenium argentatum) for increased rubber production

Rubber production of salt-stressed guayule at various plant populations

The hypothesis that increasing the plant population of guayule (Parthenium argentatum) to compensate for the reduced plant canopy size caused by soil salinity coupled with an anticipated enchancement of rubber production under the moderate environmental stress imposed by salinity was tested in a field plot experiment in the Imperial Valley of California. Irrigation waters having electrical conductivities (EG i ) of 1.2, 3.2, 6.5, and 9.4 dS/m were applied for 4 years to plots having plant populations of 28,000, 56,000, and 84,000 plants per hectare. The influence of salinity on rubber and resin production was independent of plant population. The salt tolerance threshold, maximum average salinity level of the root zone measured as the electrical conductivity of saturated soil extracts (\(\overline{\overline {{\text{EC}}}} _e \)) without yield reduction, was 7.5 dS/m; beyond this threshold, rubber production was reduced 6.1% per unit increase of soil salinity. The salinity values were averaged through the root zone from planting to harvest. The average rubber content — 7.9% — was altered little by treatment or harvest age for 2- to 4-year-old plants. Resin content averaged 8.4% but increased salinity and increased plant population increased the resin content slightly in some cases. Dry matter production of shoots for the nonsaline treatment was 259 kg/ha/month for pollarded (clipped) shoots after 31 months, 203 kg/ha/month for shoots harvested after 43 months, and 401 kg/ha/month for the 24-month period after pollarding. Combining the shoot mass after 31 and 55 months gave an average growth rate of 321 kg/ha, supporting the recommendation for pollarding. Monthly growth rates for the lowest salt treatment (3.2 dS/m) were about 10% less than for the nonsaline treatment (1.2 dS/m). The hypothesis tested was proven to be false because neither increased salinity nor increased plant population increased rubber production.

Smallholder Modes of Agricultural Production in the South Pacific: Prospects for Development

Smallholder Modes of Agricultural Production in the South Pacific: Prospects for Development

Increased Rubber Production from Thickly Seeded Guayule1

Agronomy JournalVolume 38, Issue 7 p. 589-613 Article Increased Rubber Production from Thickly Seeded Guayule1 Omer J. Kelley, Omer J. KelleySearch for more papers by this authorH. R. Haise, H. R. HaiseSearch for more papers by this authorL. C. Markham, L. C. MarkhamSearch for more papers by this authorA. S. Hunter, A. S. Hunter Soils Technologist, Assistant Soils Technologist, Assistant Soils Technologist, and Associate Soils Technologist, respectively.Search for more papers by this author Omer J. Kelley, Omer J. KelleySearch for more papers by this authorH. R. Haise, H. R. HaiseSearch for more papers by this authorL. C. Markham, L. C. MarkhamSearch for more papers by this authorA. S. Hunter, A. S. Hunter Soils Technologist, Assistant Soils Technologist, Assistant Soils Technologist, and Associate Soils Technologist, respectively.Search for more papers by this author First published: 01 July 1946 https://doi.org/10.2134/agronj1946.00021962003800070003xCitations: 3 1 Contribution from Special Guayule Research Project, Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration, U. S. Dept. of Agriculture, Salinas, Calif. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume38, Issue7July 1946Pages 589-613 RelatedInformation

Effects of Temperature on Rubber Accumulation by the Guayule Plant

1. Young greenhouse-grown plants of guayule showed marked difference in rubber formation according to the temperature conditions to which the plants were subjected. 2. Plants grown in the greenhouse or outdoors in the summer contained in general 0.50% or less rubber. When such plants were transferred to a greenhouse at a constant temperature of 80⚬ F., rubber concentration either remained at the initial low level or dropped slightly. 3. Similar plants subjected to an 8-hour day at 80⚬ and a 16-hour night at 45⚬ or 40⚬ increased in percentage of rubber. This increase amounted to 0.7-1.0% over a period of 1 month. 4. Night temperatures of 50⚬ appeared to be less effective than night temperatures of 40⚬-45⚬ in causing increase of rubber percentage. Night temperatures of 55⚬-60⚬ were ineffective. 5. Young plants continued to respond to night temperatures of 45⚬ with increased rubber production over a period of 4 months. 6. Older plants, which had already been subjected to one winter in the field, responded to low night temperatures in a manner qualitatively similar to that of young plants. The older plants, however, were more effective in rubber accumulation than the young plants, both at high and at low night temperatures.