Smallholder Rubber Plantations Research Articles

Rainforest transformation reduces parasitoid wasp diversity—Can the enrichment of flowering vegetation alleviate this?

Abstract In Indonesia, the rapid expansion of oil palm and rubber plantations replaces large areas of tropical rainforest. Rainforest transformation alters the diversity and composition of parasitoid wasp communities, but appropriate management strategies to buffer their decline in rainforest transformation landscapes are not yet developed. Here, we studied the effects of rainforest conversion to smallholder rubber and oil palm plantations on parasitoid wasp species richness, abundance and species composition. We also conducted a flowering vegetation enrichment experiment using the flowering weed Asystasia gangetica in all land‐uses to investigate potential mitigation effects on parasitoid wasp diversity and composition. Rainforest transformation to rubber plantations caused a large decrease in species richness (46%) and abundance (59%) of parasitoid wasps. Community structure of parasitoid wasps differed between forest and monoculture habitats with more habitat‐specialised species in forest and a higher proportion of common species in the monoculture. The experimental flowering vegetation enrichment increased parasitoid wasp species richness by 18% and abundance by 127%. Enrichment also enhanced the presence of unique parasitoid species in plantation and furthermore increased differences in community composition between rainforest and plantations. However, the enrichment experiment was confounded by time, meaning that a multi‐year experiment with targeted controls is necessary for statistically more reliable statements. Our study shows the effect of rainforest transformation to oil palm and rubber plantations on parasitoid wasp communities. Although providing additional flowering vegetation in plantations seems to potentially mitigate diversity loss, further research is needed to confirm and to investigate the mechanisms how flowering plants alleviate negative effects of rainforest transformation on parasitoid communities. Thereby, efficient conservation strategies for parasitoids wasps and their biological control services can be developed for rapidly changing tropical landscapes.

Types of land use in Sei Nahodaris Village, Panai Tengah District, Labuhanbatu District using the Horton infiltration model

The aim of this research is to establish an infiltration rate model for land uses including smallholder rubber plantations, rice fields, and shrubs. The infiltration rate data was analyzed using the Horton equation model. Every ten minutes, the water level drops. The results of the research show that the infiltration rate model on smallholder rubber plantation land is is f = 7.2 + (10 – 7.2) e 2.64t, whereas on small oil palm plantation land it is It is f = 7.98 + (10 – 7.98) e−2.68 t on smallholder latex plantation land; f = 9.13 + (10 – 9.13) e−5.20 t on rice fields; and f = 4 + (10 – 4) e−2.96 t on bush land. In smallholder rubber plantations, the infiltration rate is classified as moderate at 2.06 cm/hour; in rice fields and smallholder plantations, it is relatively slow, namely 0.87 cm/hour and 1.87 cm/hour, respectively. The infiltration rate in bush land is relatively fast, namely 6.56 cm/hour. With an infiltration rate of 1.87 cm/hour on smallholder oil palm plantations and 0.87 cm/hour.

Kajian Nilai pH Tanah pada Berbagai Toposekuen dan Kelas Lereng yang Berbeda pada Lahan Perkebunan Karet Rakyat di Kecamatan Pelepat Ilir, Kabupaten Bungo, Jambi

Soil pH value either with KCl solution or with H2O are two important indicators needed to describe soil acidity. This study aims to determine the distribution of soil pH values in smallholder rubber plantations with different land topography classes in Pelepat Ilir Subdistrict, Bungo Regency, Jambi Province. The study used a survey method with a toposequence concept approach at a semi-detailed level, where observation points were made based on the upper tread polypedon, middle tread polypedon, and lower tread polypedon at each level of percent slope 15-24%, 8-15%, and 3-8%, and flat tread polypedon at a percent slope of 0-3%. Ten composite soils were taken from a mixture of 3 individual soil samples at each polypedon using a soil drill at a depth of 0-30 cm from the soil surface. Soil pH value analysis was conducted in the laboratory on each composite. The results showed that the pH value of the soil with 1:2 H2O solution was very acidic, and acidic for 1:2.5 KCl solution. The distribution of soil pH values showed that the lower slope had a higher pH value than the middle slope, and the upper slope had the lowest pH. Soil pH values decreased as the slope increased, and soils with flat topography were considered more fertile than those with high slopes. This result can be a recommendation in determining liming and fertilization doses, where higher doses are required for high slope soils than flat soils for optimum agricultural yields.

Kajian Nilai pH Tanah pada Berbagai Toposekuen dan Kelas Lereng yang Berbeda pada Lahan Perkebunan Karet Rakyat di Kecamatan Pelepat Ilir, Kabupaten Bungo, Jambi

Soil pH value either with KCl solution or with H2O are two important indicators needed to describe soil acidity. This study aims to determine the distribution of soil pH values in smallholder rubber plantations with different land topography classes in Pelepat Ilir Subdistrict, Bungo Regency, Jambi Province. The study used a survey method with a toposequence concept approach at a semi-detailed level, where observation points were made based on the upper tread polypedon, middle tread polypedon, and lower tread polypedon at each level of percent slope 15-24%, 8-15%, and 3-8%, and flat tread polypedon at a percent slope of 0-3%. Ten composite soils were taken from a mixture of 3 individual soil samples at each polypedon using a soil drill at a depth of 0-30 cm from the soil surface. Soil pH value analysis was conducted in the laboratory on each composite. The results showed that the pH value of the soil with 1:2 H2O solution was very acidic, and acidic for 1:2.5 KCl solution. The distribution of soil pH values showed that the lower slope had a higher pH value than the middle slope, and the upper slope had the lowest pH. Soil pH values decreased as the slope increased, and soils with flat topography were considered more fertile than those with high slopes. This result can be a recommendation in determining liming and fertilization doses, where higher doses are required for high slope soils than flat soils for optimum agricultural yields.

Conversion of Rubber Land Into Palm Oil and Its Effect on Production in North Sumatra

This study aims to analyze the conversion of rubber land to oil palm and its effect on production in North Sumatra. Today many rubber farmers are turning their land into oil palm plantations. So that the famous commodity from North Sumatra, namely, palm oil, is no longer rubber. Whereas previously the rubber plant (Hevea brasiliensis) as a plantation plant that was integrated with the culture of the people of North Sumatra Province had environmentally friendly properties. This study uses descriptive qualitative research methods. Data were collected by observation, interviews, literature study, and document analysis. The results show that smallholder rubber plantations have been the mainstay of the economy of North Sumatra Province since a century ago. Although there has been a change from Rubber Land to Palm Oil Land, currently North Sumatra accounts for 33% of the total national natural rubber production. North Sumatra is the second largest natural rubber producer after South Sumatra.

Rubber Plantation Smallholders’ Management Model in Traditional Farming Practices in North Sumatera, Indonesia

The study is aimed at determining the role of various social-economic variables on the income of rubber plantation smallholders and help develop the plantations in North Sumatra, Indonesia. It uses descriptive methods to assess such variables. The results show the number of dependents, education, land status, seed sources, seed quality, planters, fertilization, farmer age, land area, and the age of rubber plants to determine their income by 45.2%. Also, the land status, area, and fertilization become the primary determinants of revenue in the smallholder's rubber plantation business, though their business is still managed traditionally. Traditional cultivation patterns prove that farmers try to improve land in order to boost revenues. High education does not support the increase of income when the approach to cultivation remains traditional. Efforts to encourage productivity can be made by optimizing the inputs to the land. Keywords: Management model, traditional farming, smallholders, rubber plantation

Pestalotiopsis sp. infection causes leaf fall disease of new arrivals in several clones of rubber plants

Abstract. Damiri N, Pratama Y, Febbiyanti TP, Rahim SE, Astuti DT, Purwanti Y. 2022. Pestalotiopsis sp. infection causes leaf fall disease of new arrivals in several clones of rubber plants. Biodiversitas 23: 3943-3949. This study aims to investigate the response of rubber clones commonly cultivated by farming communities to infection with the new leaf fall pathogen of Pestalotiopsis in rubber plantations. The study was conducted in smallholder rubber plantations, laboratories and greenhouses Department of Pests and Plant Diseases, Faculty of Agriculture, Sriwijaya University. The study consists of two stages. The first stage was a survey of the leaf fall disease of Pestalotiopsis in smallholder rubber plantations in Banyuasin Regency. The second stage was testing the isolates of Pestalotiopsis sp. against several rubber clones in the greenhouse using the Randomized Block Design (RBD) method, with six treatment clones and six replications. Each replication consisted of three polybags. The treatments tested were rubber plant clones aged four months, namely rubber clones PB 260, RRIC 100, IRR 112, IRR 118, BPM 24 and PB 340. The inoculated leaves were rubber leaves aged 10 days after opening. The results showed that Pestalotiopsis leaf fall disease in 10 smallholder rubber plantation areas in the field showed that new leaf fall attacks caused by the Pestalotiopsis fungus on smallholder rubber plants ranged from 80 to 100 percent with a decrease in production between 20 to 50 percent. All clones planted were susceptible to this new disease, which resulted in a very significant reduction in yield. The treatment of Pestalotiopsis sp. inoculation on six rubber clones significantly affected the severity of Pestalotiopsis new leaf fall disease. Effect of Pestalotiopsis sp. the number of rubber leaves that fall is very significant. The rubber clone that experienced the most leaf fall due to disease was PB 340 although the percentage of leaf fall was not significantly different from the treatment of PB 260 but significantly different from the treatment of clones RRIC 100, IRR 112, IRR 118 and BPM 24. The percentage of Pestalotiopsis leaf fall experienced by clones PB 340 reached 47.19% while the RRIC 100 clone was only 4.98%.

Agroforestry rubber networks and farmers groups in Phatthalung area in Southern Thailand: A potential for an innovation platform?

The study took place in southern Thailand, in Phatthalung province, and is part of “Heveadapt,” a Franco-Thai research project. The aim of this project was to show how smallholder rubber plantations can adapt and remain sustainable in the face of variable climatic conditions and deep changes in socio-economic context. Among the various types of cropping systems, agroforestry practices were identified as promising. Rubber agroforestry systems (AFS) are economically more productive than rubber monocrop plantations and give more flexibility to smallholders, in particular when rubber prices are low, which has been the case since 2013. However, adoption of AFS during the mature period of the plantations is very low in Thailand. The policy to boost rubber agroforestry practices still needs to be developed with all local stakeholders. The objectives of the study were to identify the possibilities and capacities to use current AFS dynamic networks as a basis to set up a rubber agroforestry innovation platform. The research team studied: i) farmers’ collective organizations, groups or networks with rubber AFS partially or entirely and ii) the social dynamic enabling the sharing of knowledge and know-how. An individual producer’s grid, with original farmers or strong knowledge with ease of sharing, was also studied. The role of local institutions involved in the promotion of rubber AFS was also analyzed. This allowed us to design an innovation platform and to define activities that suit the socio-economic context of Phatthalung province. The main aims of the platform are to promote cooperation among innovative producers and the transmission between them of knowledge and know-how about rubber AFS. This could an efficient tool that Thai rubber institutions could set up to encourage the adoption of rubber AFS by farmers.

Market-Based Strategy to Anticipate Covid-19 Pandemic in Smallholder Rubber Plantations in Riau Province, Indonesia

The coronavirus pandemic had disrupted almost all businesses in various sectors, one of which is the plantation sector. Smallholder rubber plantations in Riau Province, Indonesia have faced the very tough challenges of the coronavirus pandemic. Efforts that could be made were marketing rubber products by implementing market-based strategies, namely market strategy, marketing mix strategy, customer value and marketing performance. This study aimed to analyze the effects of market strategy, marketing mix strategy, and customer value on marketing performance in smallholder rubber plantations in Riau Province during the Covid-19 pandemic. Data collection was carried out using 45 respondents as heads of smallholder rubber plantation farmer groups in Riau Province. Data analysis used structural equation modeling-partial least square (SEM-PLS). The results show that market strategy and marketing mix strategy had a significant direct effect on customer value. Customer value had a significant direct effect on the marketing performance of smallholder rubber plantation farmer groups in Riau, while the market and marketing mix strategies had an indirect effect.

Preparing Households for the Oil Palm Replanting Program: Is an Empowerment Program Needed?

This article describes a new idea of how the level of intervention in household empowerment policies is based on an empirical study of the magnitude of the negative impact of the smallholder palm oil replanting (SPR) program. One of the negative impacts is the temporary loss of income (TLI) for farmer households due to the cessation of production of oil palm fruit bunches. This study aims to analyze the magnitude of the impact of the SPR program on household and regional economies as a basis for making decisions on the intensity level of community empowerment programs. The household survey research was conducted in three village centers for smallholder rubber plantations in Jambi Province, Indonesia: Purwodadi Village, Dataran Kempas, and Sungai Keruh. The research result shows that the average potential TLI in each household is IDR 2,364,644/month (equivalent to 74.55% of the oil palm household income or 39.78% of the regional economy) if replanting palm oil is carried out. Purwodadi Village is the village most vulnerable to regional economic disturbances due to the high potential for TLI, reaching 99.43% of the oil palm household income and 67.06% of the regional economy. The level of TLI is influenced by factors of age and area of old oil palm plants, the proportion of households that will undergo the replanting process of oil palm, and the level of dependence of regions on oil palm farming. Based on the research results, it can be concluded that there is still a need for innovation and expansion of empowerment programs to encourage household readiness in facing the community oil palm rejuvenation program.

Direct financial cost of weed control in smallholder rubber plantations

Abstract A survey was conducted to provide information on weed types, control strategies, and their estimated costs to smallholder rubber outgrowers in Western Ghana. A total of 80 farmers with rubber trees aged 1–4 years were randomly selected for the study. This represents 10.2% of the total number of farmers (783) who fall within this target group in the districts. The results show that smallholder rubber plantation farmers are dealing with diverse weed species, most of which are reported as global weeds. Chromolaena odorata, Scleria boivinii, and Mimosa pudica were the most reported species. Manual weeding and application of herbicides are the major control methods adopted by the farmers in the study area with a small percentage (16%) also using cover cropping. The two major control methods cost farmers an estimated average amount of Ghc 618.24 ± 26.25 (US $140.51 ± 5.91) for one-time weed control per hectare. The average estimated cost of one-time manual weeding per hectare was higher than that of herbicide application per hectare. This estimated amount is only a fraction of the total economic cost of weeds to the farmers. The farmers are likely to spend more if, for example, the costs of yield loss due to weeds are captured. The study thus indicates that the cost of weed management is high for rubber outgrowers and essentially farmers are investing heavily in weed management to keep weed competition on-plantation relatively low. Given that the core objective of rubber growing is to maximize profits, this study recommends the application of herbicides to control weeds in rubber plantations since average estimated cost of herbicide application per hectare was lower than one-time manual weeding per hectare. This recommendation should, however, be weighed against the possible environmental impact of herbicides, which was not assessed in this study.

Looking for indicator bird species in the context of forest fragmentation and isolation in West Kalimantan, Indonesia

In the context of Borneo’s drastic landscape fragmentation, we assessed the role of diverse forest and land uses—swidden agriculture, mixed garden, smallholder rubber and oil palm plantations—in determining (1) diversity levels and composition of bird species in different vegetation types; (2) the potential for bird species to act as indicators of habitat quality; and (3) the agricultural matrix’s contribution to preserving forest-dependent species. Field campaigns across West Kalimantan sites were conducted during both rainy and dry seasons, using mist nets and 10-min point count recordings along transects. We used four diversity indices, non-metric multidimensional scaling (NMDS) and the Indicator Value index (IndVal) for our analysis. Our results endorsed the general trend found across the tropics of a significant reduction in bird species richness, from the complex natural and old secondary forest structures to the simplified monoculture habitats. We recorded 10,519 individuals across 214 bird species, representing almost 90% of Borneo’s lowland forest species. NMDS differentiated intact forest from forest fragments and land under different agriculture uses. Eighty percent of the bird species preferred an intact forest environment. Industrial oil palm sites were the most ‘avoided’ vegetation type. Using IndVal, we found six indicator species significantly associated with forest, three indicator species for depleted forest, one for mixed garden, and none for oil palm plantation. Farm-dependent species richness was strikingly low, and species had little conservation value as per IUCN standards; industrial oil palm plantations were poorest in bird species. Notable exceptions were traditional mixed gardens and old fallows associated with swidden agriculture, when in proximity to forest. These traditional agroforestry systems have higher conservation value than industrial and smallholder monoculture plantations, however, their long-term preservation is uncertain, and monitoring programs are lacking that can contribute to long-term biodiversity conservation and ecosystem service maintenance. More data are needed to determine the viable population sizes for the bird indicator species identified in our study. Such knowledge on population trends can be used to monitor habitat quality and health of forest agriculture landscape mosaics and improve the effectiveness of management, conservation and monitoring in future.

Fruit trees and herbaceous plants increase functional and phylogenetic diversity of birds in smallholder rubber plantations

Rubber plantations are widespread in mainland South-east Asia. Intensive monocultural rubber cultivation practices predominate, which negatively impact biodiversity. Some plantations are managed as high-yielding agroforests, where the integration of fruit trees and other plant species marginally enhances crop diversity relative to monocultures, providing benefits for species richness of some taxa without compromising yields. A key question is whether these high-yielding agroforestry systems also support enhanced functional and phylogenetic diversity relative to monoculture. Focusing on birds in rubber monocultures and agroforests in two provinces of Southern Thailand, we study plantation habitat structure and wider landscape characteristics to identify effects on functional and phylogenetic diversity metrics. Functional diversity, phylogenetic diversity and evolutionary distinctiveness of birds were comparable between rubber monocultures and intensive agroforests. The density of fruit stems and taller herbaceous plants within agroforests positively influenced functional and phylogenetic diversity, and evolutionary distinctiveness. Functional and phylogenetic diversity was higher in landscapes with a greater proportion of fruit orchards, but was lower in landscapes with a greater proportion of degraded natural forest patches. Our study suggests that the integration of fruit trees and maintaining taller herbaceous plants within rubber plantations could help support bird diversity at evolutionary and functional levels. Small patches of degraded forest in areas dominated by agriculture may need time to generate positive spillover effects on the functional and phylogenetic diversity of birds within rubber plantations. Better management of existing rubber plantations could sustain higher diversity, while offering food security and alternative revenue streams.

A review: The development of double row spacing to improve land productivity and income of rubber smallholders

Low prices of rubber has been a serious problem to rubber smallholders in Indonesia. Rubber-based intercropping systems offers a practical solution to this issue and increasing overall productivity of intercrops, for example upland rice and maize. This study reviewed the suitable spatial arrangements in rubber planting to long term impact based intercropping systems. A field experiment was established in a smallholder rubber plantation in Tanah Laut Regency, South Kalimantan with area of 50 ha. Two planting patterns of rubber PB 260 clone were tested: (1) single row planting pattern (SR) by 6 m x 3 m, and (2) double row planting pattern (DR) by 18 m x 2 m x 2.5 m. The experiment showed that girth of rubber trees in the SR system at the first tapping year was slightly larger than in DR system, even though statistically it was not significant. The latex yield per tree of SR and DR systems were similar, however, latex yield per hectare of SR system was higher than DR system due to a higher tree population in SR system. The DR system was technically suitable for long term intercropping, because when rubber tree can reached 8 to 9 years old and light penetration was more than 80% at distance from the rubber row. The total area required for rubber, upland rice and maize grown in monoculture to produce an equivalent of a one hectare of rubber-upland rice-maize intercrop is 1.87. This means the intercropping has an advantage compared to monoculture.

Patterns and causes of conversion of smallholder rubber plantation to oil palm (case in Batik Nau sub district, Bengkulu Utara Regency)

Batik Nau Subdistrict has the largest rubber plantation in North Bengkulu Regency, namely 3,779 hectares, but much of it has been converted to oil palm plantation. The conversion occurred quite massively, namely 393 hectares or 10.4 percent in 2019. This study aims to determine the patterns and causes of the conversion of smallholder rubber to oil palm in the Batik Nau Subdistrict. The research was conducted in three rubber production center villages in Batik Nau Subdistrict from January to March 2021 through in-depth interviews with 10 key informants. The data extracted relates to the patterns and factors causing the conversion of rubber to oil palm. In addition, secondary data collection and field observations were also carried out to confirm the results of the interviews. The data were processed descriptively. The results showed that there were two conversion patterns, namely direct conversion and gradual conversion. The main causes of conversions are low rubber prices and inefficient use of labor. In developing rubber farming the people must pay attention to the availability of labor in the family.

PENGARUH PEMBERIAN EKSTRAK KULIT MANGGIS SEBAGAI STIMULAN LATEKS PADA TANAMAN KARET (Hevea brasiliensis Muell. Arg.)

Low productivity of para rubber trees in Indonesia can be anticipated by the application of technology in the downstream sector, especially in terms of tapping such as by the application of latex stimulants. The objectives of this study were to determine the effect of alternative stimulants sourced from household waste such as climacteric fruit peels that is mangosteen peel extract and obtain its concentration that gives the best effect on the latex production of rubber plants (Hevea brasiliensis Muell. Arg.). The reserach was carried out for five months at a smallholder rubber plantation in Dharmasraya District, West Sumatra. This study was designed using Randomized Block Design (RBD) that was repeated four times. The treatments were: without stimulant, mangosteen peel extract 3 ml application-1, mangosteen peel extract 4 ml application-1, mangosteen peel extract 5 ml application-1, and mangosteen peel extract 6 ml application-1. The results showed that the application of mangosteen peel extract as latex stimulants was able to increase the latex production when compared to without stimulant. Its application at 5 ml application-1 was able to produce the highest latex volume of 151,04 ml tapping-1 and without symptoms of tapping panel dryness.

Plants Diversity in Small Rubber Plantations at Segamat, Johor

Species richness in rubber plantations varies considerably with regards to production and management activities. This research was conducted to identify the diversity and richness of common plants in rubber plantations at Segamat, Johor. To answer the question of how rubber plantations owned by local smallholders affects the plant diversity, quadrat random method with 5 x 5 m plotting site was established in three different aged of rubber plantations at Segamat area which are Kg. Sedeng, Kg. Logah and Kg. Jawa. Each of the locations consisted of 10 sampling quadrats making a total of 30 quadrats. The results showed there are a total of 41 species belonging to 36 genera and 24 families in the 30 plots of the three plantations. The most dominant families were Rubiaceae, Euphorbiaceae and Asteraceae. The plants diversity were documented in rubber plantations at different location to record the number of species, the species evenness, similarity index, species richness, abundance parameter and important value index (IV i ). As for all three locations, the plants species were moderately diverse as the value of Shannon Diversity Index (H’) moving closer to Hmax but all the plotted area within three location showed higher evenness in species distribution. Based the result from density and frequency of abundance parameter, Asystasia gangetica species was the common species in all plantations. For the IV i , there was only one species with absolute dominance (higher than 10%) which was Asystasia gangetica with value 13.62% for overall location at Segamat, Johor. In conclusion, the most common species in the smallholder rubber plantations at Segamat, Johor was Asystasia gangetica, Bridelia tomentosa, Ageratum conozoides, Caryota mitis and Melastoma malabathricum. The rubber plantations adopting a minimal or natural management approach were dominated by common weed species and invasive plants. Despite the benefits of maintaining high species diversity for sustaining the gene pool, improving management practices is beneficial to improve yield and productivity.

Simultaneous Equation Model for Economic Calculation of Households of Independent Rubber Farmers in Mineral Land in Kampar Regency, Riau Province

Rubber is a plantation crop which is mostly a source of community income in Kampar District. As a source of household income, rubber farming is managed by households independently. This study generally aims to design models and government policy strategies in the development of smallholder rubber plantations on land typology mineral land conditions on the economic decision making of rubber farmer households. Specifically, this study was conducted with the aim of analyzing the characteristics of independent smallholders and internal and external dominant factors that influence the allocation of working time, income and household expenses of rubber farmers. This research was conducted using a survey method located in Kampar District. The data used in this study consisted of primary data obtained using the interview method. Samples were taken by simple random sampling method with 60 rubber farmers. Descriptive analysis and Economic Decision Model of Rubber Farmer Households using the simultaneous equation model approach with the Two Stages Least Square (2SLS) analysis method were performed to answer the research objectives. The results showed that only internal factors of farm households are responsive to household economic decisions. There are no external factors included in the model that are responsive to the economic decisions of rubber farming households in Kuantan Singingi Regency regarding the aspects of production, working time allocation, income and expenditure of rubber farming households. From the aspect of production, no responsive internal or external factors were found, but the biggest effect was the number of productive rubber stems. From the aspect of work time allocation, internal factors that are responsive to influence are the total outpouring of farmer work, outpouring of farm family work in businesses and the workforce of farmer households. Furthermore, from the aspect of farmer's household income the responsive internal factors that influence it are the farmer's household income in the business. then what influences household expenditure is outflow of work in business, farmer education, wife education and total rubber farmer income. The policy implications of increasing rubber prices and outpouring of family work in the business have the most positive impact. While the increase in wages for workers outside the family has a negative impact on the household economy.

Characteristics of rhizobacteria on healthy and white rot - infected rubber trees

White root disease is an important disease in rubber plants caused by the fungus Rigidoporus microporus. The severity of white root disease in smallholder rubber plantations is up to 15%. Various controlling technique has not been effectively eliminate this disease. To develop an integrated white root disease management, a comprehensive study including the ecology and rhizobial characteristic of rubber tree is needed. This study was aimed to describe the characteristics of rhizobacteria on healthy and infected rubber trees. The results showed that the population of antagonistic and non-fluoresence bacteria was higher in the rhizosphere of healthy rubber plants, vice versa. The observation of bacterial morphology showed that the bacterial community was more diverse in the rhizosphere of healthy rubber than the rhizosphere infected by R. microporus.

Hamparan perak paddy local cultivar performance applicated with biochart and planting distance as multiple crop between row of one year old hevea

The low price of natural rubber in last 10 years has the impact on low income of the smallholder rubber plantation. Intensity of tapping and management of Hevea crop had decreased. In other side, space between rows of Hevea could be managed to produce food when Hevea in Immature Periods, hence could be beneficial to the smallholder rubber plantation. This research evaluated paddy land local cultivar, Hamparan Perak, which produce the red rice, applied by biochart created from Hevea seed shell. Research was conducted with 12 combination treatments in 1x1 m2 plot size. Bicohart with 0 kg/plot, 0.5 kg/plot, and 1.5 kg/plot, combined with planting distance 20x20 cm, 25x25 cm and 30x30 cm of Hamparan Perak cultivar. Results found that biochart had significant effect on amount of panicles, but it was not significantly different effect on growth and yield. Planting distances had significant effects on crop height and amount of tillers but were not significantly different on 1000 grain weight and grain yield. Biochart has long term effects, hence it will be valuable for Hevea. The research still continue to the known growth and yield of paddy land due to the growth of Hevea canopy.