This paper is primarily concerned with decomposition of the major contributory factors for the transplantation of natural rubber from Brazil to the South-East Asian colonies of Europe during 1850 to 1910. The analysis is contextualized to capture and reconstruct the missing links in the debate on the process of transfer of rubber from its natural habitat in the Amazon basin to South-East Asia. The conventional wisdom on the theme has been focused on the three region-specific factors, viz. organization of rubber production, supply of labour and plant diseases. However, a centralized system of research and development support provided by the colonial powers of Europe through a network of Botanical Gardens had been pivotal in providing a sustainable platform for transplantation of rubber from the Amazon basin. The unrivalled role of colonial Botany evolved by the network of Botanical Gardens is underlined by the commercialization of plantation rubber within two decades of the Wickham rubber mission in contrast to the stagnation of the interlocked wild rubber extraction system for about a century. In sum, R and D inputs provided by the colonial powers had been the centripetal force leading to the dynamic growth of a cost competitive Asian plantation rubber and gradual exit of the wild rubber from the world market.

Clones derived from selected ortets were tested in a field trial at the experimental farm of the Hevea Breeding Sub-Station at Nettana in Dakshina Kannada district of Karnataka. Fifteen clones were planted in the trial. Girth and yield of the clones were recorded. Girth increment during the immature and mature phases, yield of the clones over the first four years, long term yield over 11 years and yield in the BO-1 and BO-2 panels were analyzed to identify the superior clones in the trial. Girth at opening and tappability attained by the clones were also recorded. Clones with superior yield during summer, monsoon and post-monsoon seasons, and those with stability in growth and yield were selected. Drop in the rate of girth increment due to crop harvest and drop in the summer yield were also determined. Highest mean monthly yield was recorded during November. The highest yielding season was post-monsoon. In this trial, seven clones viz. Ayr 2, Pai 17, Pal 15, CES 42, CES 70, Alk 47 and CES 1/2 were identified for their improved attributes over the check clones. High yield and high girth were recorded in Ayr 2 and Pai 17. Alk 47 was identified as a potential timber-latex clone. Five clones were medium yielders with high girth (Pal 15, CES 42, CES 70, Alk 47 and CES 1/2). These clones were found superior to RRII 105 in the non-traditional Dakshina Kannada district of Karnataka

India’s rubber sector has been endowed with the unique feature of a well-developed natural rubber (NR) production and rubber products manufacturing segments since the 1940s. A remarkable degree of domestic market orientation of both the segments had been protected from external competition till the early 1990s. India’s Regional Trade Agreements (RTAs) assume importance for the trade sensitivity arising from higher shares in the total value of external trade in rubber and rubber products (47.2 %) and in the negative balance of trade (278.6 %) during 2014-15. Among the total 23 trade agreements signed by India, tariff reduction/ elimination commitments for rubber and rubber products are covered only under 11 agreements. This paper is concerned with (i) India’s tariff policies on rubber and rubber products under the RTAs and (ii) the impact of the same on India’s balance of trade in rubber and rubber products. Analysis of time series external trade data for the past 15 year period from 2000-01 to 2014-15 revealed that India provided ample protection to its NR production segment under various RTAs except Asia Pacific Trade Agreement (APTA) and less developed countries under the South Asian Free Trade Area (SAFTA). However, the total value of imports of NR under RTAs grew at the rate of 39.5 per cent and the negative balance of trade during 2014-15 was US $ 785.35 million. At the aggregate level, India’s exports and imports of rubber and rubber products under the RTAs grew at the rates of 16.8 per cent and 26.3 per cent, respectively during the period under review. The magnitude of the emerging trends is evident from a higher negative balance of trade with the RTAs (US $ 1469 million) than with the world during 2014-15. The results of the study underlined the need for a comprehensive policy package for India’s rubber sector rather than segmented ad-hoc measures from a long-term policy perspective.

Expansion of rubber cultivation in India to non-traditional areas has necessitated selection of clones suitable for drought prone regions. Ortet selection from polycross seedling populations established at the Regional Research Station of the Rubber Research Institute of India (RRII) in Dapchari, Maharashtra, in the drought prone North Konkan led to selection of 13 elite plus trees which gave promising yield under rainfed conditions. The 13 ortets were cloned and evaluated for their yield potential under the favourable agro climatic situation in the Central Experiment Station of RRII in the traditional rubber growing region of Central Kerala. Evaluation of the clones for yield, growth and the structural and physiological components of yield over six years of tapping in panel BO-1 under a S/2 d3 6d/7 system of tapping without stimulation led to the identification of two clones viz. D 111 and D 37 which were superior for most of the traits. Ortet clone D 111 gave a very high yield of 90.8 g t-1t-1 in panel BO-1 and had the highest summer yield of 64.4g t-1t-1which was significantly superior to the check and the rest of the ortet clones. This was followed by clone D 37 (62.7g t-1t-1) which was comparable to the check clone RRII 105 (63.9 g t-1t-1) in terms of annual mean yield in panel BO-1 and was superior to the check clone in summer yield which was as high as 44.1g t-1t-1. Four more ortet clones viz. D 236, D 95, D 35 and D 173 with yield of more than 50.0g t-1t-1were on par with the high yielding check clone RRII 105. While D 111 also possesses high summer yield, D 37 was found to be a high girthing clone. Both these clones are promising in terms of yield components like a high number of latex vessel rows and high volume of latex. No incidence of tapping panel dryness was observed in these clones after six years of tapping. No association was found between the yield of the original ortets in Maharashtra and that of their respective clones in Kerala as evidenced non-significant correlations.The variation in yield of ortets and their clones is discussed with reference to earlier reports along the same line suggesting G x E interaction as well as random effects attributable to variation in latex yield between the main trunk and the branch propagated by bud grafting of axillary buds onto heterogenous rootstocks.

Soil organic matter quality and carbon mineralization in soils under immature rubber with Pueraria phaseoloides, banana, and pineapple and mature rubber were studied in a farmer’s field in Kottayam district of Kerala state, India. It was found that water soluble carbon (WSC) and hot water extractable carbon (HWEC) were significantly higher in immature rubber with Pueraria and banana than the other two systems. Among the four systems studied, immature rubber with Pueraria had significantly higher particulate organic matter carbon (POMC) followed by mature rubber, immature rubber with pineapple and immature rubber with banana. Total carbon also showed significant variation among the systems and it decreased in the order immature rubber with Pueraria > immature rubber with banana > mature rubber > immature rubber with pineapple. An incubation experiment was also conducted to study the soil carbon mineralization in these systems. There was ignificant difference in carbon decomposition rate among the systems studied. The rate of carbon mineralization was in the order, immature rubber with Pueraria > immature rubber with banana = immature rubber with pineapple > mature rubber. Carbon mineralization is positively influenced by WSC, HWEC and POMC and these parameters can be used as soil quality indicators in rubber based systems. The study indicated that vegetation and management practices in rubber plantation influenced soil organic matter quality and carbon mineralisation. Among the immature systems studied rubber-Pueraria system showed more nutrient supplying potential and mature rubber plantation showed carbon sequestration potential.

Clonal nursery evaluation technique is being successfully adopted in recent years to reduce the time span of breeding in Hevea. This paper reports the performance of 48 half-sib progenies in clonal nurseries in two different agro-climatic regions, namely Padiyoor in North Kerala and Chethackal in Central Kerala by evaluating three important juvenile parameters viz. girth, yield on test incision and yield on test tap. Clones in general showed 26.7 per cent lower girth and 32 per cent lower yield in Padiyoor compared to Chethackal, indicative of the effect of climatic stress existing in Padiyoor. Out of the 15 top performing clones at Chethackal, nine clones were among the top 15 at Padiyoor also (HS 96/263, HS 96/34, RRII 430, HS 96/145, HS 96/329, HS 89/80, HS 96/274, HS 89/215 and HS 89/78). Hence, these clones can be considered stable and may have the potential for cultivation in varied agro-climatic conditions. Half-sib progenies from PB 255, PB 260, GT 1, RRII 203, PB 28/83 and PB 217 maintained superiority in the clonal population of progenies reconfirming the prepotency of the parent clones. Correlation analysis showed that initial girth up to six months was not correlated with final girth. But, girth from 12th month onwards was highly correlated with girth in subsequent years and hence, clones with good growth potential can be identified from the very first year itself. Yield on test incision was not correlated with girth at any stage in both the locations. But it was highly correlated with test tap yield at 24th month at Chethackal and 24 and 48 months at Padiyoor. Girth recorded in plants from 18th month onwards showed significant correlation with yield at Chethackal and Padiyoor except in the final test tap yield at Padiyoor. Yield on test tapping at 24th month was highly correlated positively with final test tap yield (48 months) in both the locations. Hence, test tap yield at 24th month itself can be used for the identification of a potentially high yielding clone.