By K S Nayar :

A reputed Plant Breeder (erstwhile Deputy Director, Rubber Research Institute of India), Dr. Mallinath Priyadarshan is specialised in breeding Hevea rubber for sub-optimal environments. As a consultant, he offers advice and expertise to organisations and plantations to help them improve their business performance that includes plantation management, strategy, IT, finance, marketing, HR, labour issues and supply chain. He has authored several scientific papers and chapters that appeared in journals and books of international repute. Dr. Priyadarshan owns rich expertise as he has worked in Tripura for eighteen years. He has also served as Deputy Director, Central Experiment Station (RRII), Chethackal. He may be contacted on e-mail: [email protected] and Tel: +91-9496236226. In a wide-ranging interview to Rubber Asia, Dr. Priyadarshan says plantations can be profitably run only if the planter scientifically nurtures around 400 trees, harvests the trees and processes the latex without any additional manpower. He should also ensure the quality of plant material. Tapping trees twice a week (if not once a week) is a meticulous practice along with organic farming and water conservation.
EXCERPTS from the interview:

FAO says in the context of rising demand for rubber wood, there is no reason to distinguish between forestry plantations and other estate crops. It has also said that from an environmental point of view there is no difference between an intensively managed rubber plantation and an intensively managed acacia or pine plantation. As a renowned rubber consultant, what are your views on how plantation companies can turn growing rubber into gainful business?

This is a burning question. Let us consider the environment impact first. For instance, in Tripura (India), 63,323 ha was under rubber as per 2013 statistics. It was 574 ha during 1967. It may rise to 85,000 ha by 2025.
In Vietnam, the total area under rubber increased from approximately 77,000 ha in 1976 to about 4,65,000 ha in 2005. Vietnam’s target for rubber development is 7,00,000 ha or even more.
Cambodia has granted permission to expand its plantation into Kampong Thom Province through clearing over 6,000 ha of forests. Collectively, more than 1,000,000 ha of rubber have been planted in the last several decades in non-traditional rubber growing areas of China, Laos, Thailand, Vietnam, Cambodia, and Myanmar.
By 2050, the area of land dedicated to rubber (and/or other monoculture plantation crops) in these areas could quadruple, largely by replacing lands now occupied by evergreen broadleaf trees and swidden-related (shifting cultivation) secondary vegetation. For all this, the justification is to reduce the production-demand gap and to ensure income to low-income groups.
Accepted; but the science of rubber cultivation is prime. Under all these circumstances, water is the pivotal factor for cultivation of any species and human sustenance. Water-use efficiency in rubber has been studied in Bueng Kan, Thailand, and Kampong Cham, Cambodia. Studies show spatially, mean annual rubber ET increases strongly with increasing net radiation (Rn) across the available rubber plantation observation sites, unlike non-rubber tropical ecosystems, which reduce canopy conductance at high Rn sites.
If this is true, it is a matter of great concern. High water use by rubber raises concerns about the potential effects of continued expansion of tree plantations on water and food security in Montane Mainland South East Asia (MMSEA). Here, the demarcation of rubber areas is a must, and has to be done by legislation.
Remember, rubber is domesticated and the forest cover is native. Cultivation of domesticated species is to be restricted and should not be at the cost of native species. Growing other tree species with rubber is no option, since the structure of rubber roots is so intense that they never allow any other species to come up along.
Growing Acacia and Pine in the periphery can work as wind shields along with wood-yielding species like Shorea robusta, Artocarpus hirsutus, Gmelina arborea, Dipterocarpus alatus, Macadamia integrifolia, Vitex parviflora, Swietenia macrophylla, Pterocarpus indicus (kindly refer internet for local names). Persea americana (Avocado) and Garcinia mangostana (mangosteen) can be good additions. I must vehemently say that FAO must review/rethink its stand “Rising demand for rubber wood.”
Swidden has long been the dominant farming in MSEA. Today, the ecological bounty of this region is threatened by the expansion of settled agriculture, including the proliferation of rubber plantations. In the current conception of REDD+ (United Nations Collaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries), landscapes involving swidden qualify almost automatically for replacement by other land-use systems because swiddens are perceived to be degraded and inefficient with regard to carbon sequestration.
However, swiddening in some cases may be carbon-neutral or even carbon positive, compared with some other types of land-use systems. Scientists of East-west Centre, Honolulu, Centre for International Forestry Research, Indonesia and the Department of Geography, National University of Singapore have demonstrated how agricultural policies and institutions have affected land use in the region over the last several decades and the impact these policies have had on the livelihoods of swiddeners and other smallholders.
They explored whether incentivizing transitions away from swiddening to the cultivation of rubber will directly or reliably produce carbon gains. They argue that because government policies affect how land is used, they also influence carbon emissions, farmer livelihoods, environmental services, and a host of other variables.
A deeper and more systematic analysis of the multiple consequences of these policies is consequently necessary for the design of successful REDD+ policies in MMSEA, and other areas of the developing world. REDD+ policies should be structured not so much to ‘hold the forest boundary’ but to influence the types of land-use changes that are occurring so that they support both sustainable livelihoods and environmental services, including (but not limited to) carbon.

How plantation companies can turn growing rubber into gainful business is really a painful question. With clear rubber policy very far in countries like India, this remains unanswered. How the companies are going to disburse the exorbitant labour wages plus other incentives in the coming years?

Can the decline in natural forests cost-effectively be addressed by promoting rubber plantations as a means to strengthen rural economies by providing jobs that are directly related to rubber tapping and utilization of rubber wood to make furniture etc.?
There should not be any decline in natural forests. Vehemently, there is no alternative for natural forests. Biodiversity is biodiversity and its conservation is essential for the harmonious coexistence of plants, animals and human beings. Under no circumstances, this subtle fabric of nature be ruptured.
On the other hand, every effort – concerted, holistic, sustained and multi-pronged – must be exercised to increase biodiversity. The so called ‘rural economies and providing jobs’ are man-made and should be addressed through alternative means by policy makers. Political will power is essential to do this.
To be frank, I have never come across an authentic and scientific comparison of wood of teak and rubber. Is it wise to increase diversity by cultivating as many number of forest trees or to have mono culture? The choice is left to you! Check whether the rubber wood market is thriving well?

Can India replicate the success achieved through attractive market-driven demand for wood as experienced by small-holders in the Philippines, Nepal, Laos and Thailand? What are your suggestions in the Indian context where planters are abandoning rubber?

What could be the rate of population increment in these countries? India is with 441 persons/square km as against Philippines with 337 persons. Philippines’ GDP is $292 billion which ranks 40th in the world and India is with $2.1 trillion that ranks 7th in the world. 101 million people living in the Philippines make it the 12th most populous country in the world while India with 1.31 billion makes it the second most populous country. 26.96% is under forest in Philippines (it was 22% in 1990) and 23. 77% in India (it was 21.5% in 1990) Laos with 81.3% of forest cover is well ahead. Thailand has 32.1%. The Vietnamese government gives 50 years renewable use rights over degraded areas to individual farmers in an attempt to stimulate private investment in reforestation. Is this possible in India? Is it possible to stop encroachment of forest land in the Western Ghats or to wrench back the encroached land? Is a stern legislation possible in this regard in India?
I would bring your attention to the environment crisis of cardamom hills. When the pepper boom happened in 1980’s, forest cover was denuded under which cardamom use to thrive and pepper wines were raised. Pepper was devastated by quick wilt and the end result was increased inhabitation of these areas. How much area we lost due to pepper boom? Any statistics?
The Western Ghats, one of the global biodiversity hot spots, lost 35% of the forest cover in last 90 years as per study by Indian Space Research Organisation’s (ISRO) National Remote Sensing Centre in Hyderabad. In 1920, it was 95,446 square kilometres (73.1 %). It reduced to 61,511 square kilometres in 2005 (47.1%). It remained unchanged till 2013. This shows how much alarming the situation is. Forest cover in Idukki district was 280,000 hectares during 1950. What is remaining now? Approximately 92,000 hectares.
Rainfall has reduced from 6,500 mm to roughly 2,500 mm. What is next? Tell me, is it possible to have indiscriminate constructions in Europe and America or even in China? From one of the poorest countries some 30 years back, how China grew to be world’s second largest economy today? Strong political will power is needed to address these policy issues relating land use reforms.
Now, about your question on abandoning rubber. Traditional rubber planters stand with rubber. Those who abandon rubber when the prices come down are doing so at their own behest. Vicissitudes in price are not a reason to abandon a crop.
Is it wise to have multiple cropping systems? The answer is yes. Having rubber along with coffee and cocoa is indeed a wise idea. But the planter should have competence and knowledge to manage such crops together. Rubber grows in acidic soils while coffee needs basic soils. Root competition is great and going for an intercrop may not be wise. Instead, one can have separate areas for the crop. If shade is required, wood trees can help. But, one should have multi-tier of wood trees, with different age groups. All these require meticulous planning and hard work.

As a consultant to plantation companies, can you explain the impact of private corporate involvement to significantly increase the plantation area, mechanization of tapping and harvesting operations to increase productivity, use of improved planting stock etc.?

As I said earlier, rubber is becoming or has become a small holder’s crop. How to pay the exorbitant wages if the rubber prices are not getting increased? Several experiments on mechanized tapping knife are in the store. Let us wait and see what happens. One of the mechanized tapping systems being experimented in Thailand seems to incur high investment .The rubber injector under investigation with stimulation stems offers great promise .
And now about using improved planting stock: I wish to draw your attention to an article by Michael Le Page on Farmers may have been accidentally making GMOs for millennia that appeared in the New Scientist (March 7, 2016). The first sentence of the article is: “We have been accidentally genetically engineering plants – and eating GMOs – for millennia.”
This was written based on a report on Cell-to-cell movement of mitochondria (appeared in Proceedings of the National Academy of Sciences -PNAS- USA). The stock-scion interaction in Hevea rubber has been a puzzle for the scientists all over. It will remain as a puzzle as long as the stock is an open pollinated seedling.
What we must do is to bud-graft a given clone (say RRII 105) onto micro-propagated (tissue cultured; true to the type) plants. Trees born from bud-grafting RRII 105 onto open pollinated seedlings must also be raised. Also, a third population with trees born out of bud-grafting RRII 105 onto the seedlings of RRII 105 must also be raised.
Comparison of all these three populations may yield some insights into the intricacies of stock-scion interactions. Remember, this study must involve extensive application genomics. Always, poly-cross seedlings shall be better stocks.

What are the key plantation management practices that you would recommend to shore up the earnings of rubber growers, including the small holders?

Rubber is no longer a crop of landlords. A planter who scientifically nurtures around 400 trees, harvests the trees and processes the latex can only thrive in the years to come. The vicissitudes in rubber prices have transformed the tapper’s wages unaffordable. Monthly wages in Kerala (India) is US$143. Monthly wages in Vietnam is around US$155; Laos US$111; and Nepal US$ 95.
A small holding should have all crops; annual and perennial. One can have vegetables, flowering plants, rubber, fruit trees and even medicinal plants. Such kind of activities include soil management, water-use protection, crop nutrition, crop health and protection. If animal husbandry is involved, related activities like biogas production could sustain oneself. Such farmers do not go to market to procure his needs.

There had been reports that the plantation sector had suffered due to poor quality planting stock materials, use of sub-optimal or outrightly wrong materials as well as species. As a researcher, who has done extensive work on tree breeding/biotechnology, what are the measures that should be taken to breed quality rubber trees in view of the fact it is a lengthy process that cannot capture non-additive genetic variations particularly because of inbred lines suffer from inbreeding?

First, we must ensure quality plant material to the planters. Purity of clones is prime. For this, research has to go far ahead, applying molecular diagnostics to verify the authenticity of plant material supplied to the planters. Outlets/nurseries as authorized by the government must only be permitted to supply clones to the planters. As already yield differences due to stock-scion interactions and soil conditions are conspicuous, one cannot afford to give chance to accept fraudulent plant materials.
Now, about your question on non-additive genetic variation and inbreeding. Hevea rubber is believed to be cross-pollinated with a mixed reproductive system in which the self-pollination rate is 22%. Most of the time, the stock seedlings selected are from monoclonal plantations. Poly-clonal seedling stock is always advisable to ensure genetic diversity. All those breeding tools for annual crops cannot be used in tree breeding. Capturing non-additive genetic variation is indeed difficult. The only option is to exercise juvenile selection.
Transcriptome analysis of bark is an upcoming area for marker assisted selection during juvenile stage that can revolutionize breeding Hevea rubber. RNA sequencing of bark validated 78 SNPs in 36 genotypes. This new dataset represents a powerful information source for rubber tree bark genes and will be an important tool for the development of microsatellites and SNP markers for use in future genetic analyses such as genetic linkage mapping, quantitative trait loci identification, investigations of linkage disequilibrium and marker-assisted selection. Characterization and cross-amplification of microsatellites from wild Hevea species has augmented the possibility of transferability of these microsatellites to Hevea brasiliensis.
A comparative evaluation between self-rooting juvenile clones (JCs) and bud-grafted (donor) clones (DCs) at transcriptome level gives invaluable leads. Genes, especially encoding epigenetic modifications, are differentially expressed in JCs and DCs. Genes involved in carbohydrate metabolism, hormone metabolism and reactive oxygen species scavenging were
up-regulated in JCs of CATAS  7-33-97 and Haiken 2, indicating that the JCs provide sufficient molecular basis for the increased rubber yield.
Comparative trial between self-rooting JCs and DCs proved self-rooting JCs exhibited better performance in rubber yield. Such investigation clearly indicate the intricateness of stock-scion interactions. No doubt, such investigations can gain a perfect juvenile selection system in Hevea in the years to come. Scientists at the Chinese Academy of Tropical Crops at Haikou must be congratulated for such advancements.
The Hevea genome has now been published three times over. Yet not everyone comes up with the same findings. Rahman et al (2013) do not offer the newest Hevea genome, and the honour goes to the RIKEN team of Japan, working in collaboration with Universiti Sains Malaysia (USM) for a more comprehensive genome analysis (Lau and his colleagues).
However, the most comprehensive genome to date comes from the Chinese Academy of Tropical Agricultural Sciences (CATAS) group. CATAS declares the genome size as 1.47 Gb (Tang and colleagues), whereas USM and RIKEN/USM both give the figure of 2.15 Gb. Despite this discrepancy, it is noteworthy that the CATAS assembly captures practically all the USM sequences contained in a purportedly larger draft genome.
It appears that CATAS has done a better job of fitting contiguous sequences into a smaller number of scaffolds. Thus, while USM has a scaffold N50 of only 67.2 kb, CATAS weighs in with a massive scaffold N50 of 1.28 Mb. Despite three published Hevea genomes now in the public domain, the discrepancies between the reports have the logic that the last word is still not yet in.

What are the management reforms that should be introduced in the rubber plantation sector that in the short and medium term will make plantations more attractive for farmers?

Conserve water….water……water. Hevea rubber needs more water to sustain and yield more. Run away water must be captured in check dams.
Strictly, twice tapping/week must be adopted, if not weekly tapping. There are smallholdings that tap six days a week in Kanyakumari district, Tamil Nadu. Such planters must be educated amply on the need to undertake low-frequency tapping. Conversion of sucrose to rubber particle takes 36 to 48 hours. The need to give rest for the tree is imminent.
Practise organic farming. No use of chemical fertilizers. We lack studies on plant growth-promoting rhizobacteria, arbuscular mycorrhizal fungi and endophytic bacteria. Such microbes colonize in plant roots and induce plant growth. Research needs to be focused on these aspects. Under the Indian scenario, the road map to follow can be:
1) Benefits of rubber have to reach areas other than Kerala, Tamil Nadu and the North-eastern states. Vast areas of Chattisgarh, Jharkhand, Odisha, and north Bengal can be tapped for this purpose.
2) Available manpower, skilled force, expertise need to be redeployed in these areas to popularize rubber cultivation.
3) Areas with 2,000 mm rainfall can be delineated and soil environment can be analysed with the assistance of state-owned Soil Survey Department.
4) Location-specific clones, GAPs (Good Agricultural Practices), and fertilizer recommendations (if needed) and resistance schedule shall be disseminated among stake holders through training classes.
To implement the aforesaid schedule, strong administrative/political will and motivation are required. This is essential to ensure the benefits of rubber reaches the poor people in new areas.