Performance of <i>Hevea brasiliensis</i> on Haplic Ferralsol as Affected by Different Water Regimes

Abstract

<b>Problem statement: </b>Rubber has been grown more than a century in South East Asia, who&#13; has been the largest producer of natural rubber. Demand of natural rubber increases steadily due to&#13; increasing demand particularly from developing countries. Water has been a limited and invaluable&#13; resource especially in agriculture. This resource has to be used wisely and there is a need for a detailed&#13; study pertaining to water requirement of rubber plants. This study provides details about rubber plants&#13; growth in relation to water stress. <b>Approach: </b>Two new latex timber clones from Malaysia Rubber&#13; Board (MRB), RRIM 2005 and RRIM 3001 were used in this study with soil from Haplic Ferralsol&#13; used as planting media. Five levels of treatment were used; plants irrigated for every 2, 5, 10 and&#13; 15days and everyday which acted as control. The experimental design used was a Completely&#13; Randomized Block Design (RCBD) with four replications. <b>Results: </b>Results showed treatment well&#13; watered for clone RRIM 2025 (T6) had most the turgidity with high mean value in stomata&#13; conductance and chlorophyll content. RRIM 2025 also more resist to water stress compared to RRIM&#13; 3001. All plants in treatments with extreme different in water regimes cannot survive and dead due to&#13; severe stress. <b>Conclusion:</b> This study found rubber clones RRIM 2025 and RRIM 3001 cannot survive&#13; with acute deficiency of water. Rubber cannot be planted in dry areas with low water regimes which&#13; will retard the plant growth and plant will die under severe water stress

Current trends of rubber plantation expansion may threaten biodiversity and livelihoods

“…1a). The environmental tolerances indicated by the model are in agreement with existing literature on agricultural trials (Mokhatar et al, 2011;Nair et al, 2010;Priyadarshan, 2003aPriyadarshan, , 2003bPriyadarshan, , 2011Priyadarshan et al, 2005;Rao et al, 1998): the species, in its original form, has limited tolerance to frost and high temperature seasonality, it requires at least 6 months in the year with rainfall >60 mm per month, it cannot withstand <20 mm rainfall during the driest quarter nor mean windspeeds of >4-5 m s À1 , and it favours areas with approximately 6 h of sunshine per day, and 27 8C during the rainy reason. Most of the historically suitable environmental space (60% AE5) is located in tropical South America where H. brasiliensis is native, but large-scale production is no longer commercially viable due to the occurrence of a fungal pathogen (Microcyclus ulei) (Priyadarshan et al, 2005) and higher costs of labour.…”

“…We then used a species distribution modelling approach, whereby the native rubber records were combined with environmental layers to produce a spatially explicit model of habitat suitability for rubber. We explored a range of modelling methods using the R library 'dismo' of which MaxEnt (Phillips and Dudik, 2008) produced results that were closest to areas known to be historically suitable for rubber (Li and Fox, 2012;Priyadarshan et al, 2005), and response curves that were in closest agreement with existing literature on agricultural trials (Mokhatar et al, 2011;Nair et al, 2010;Priyadarshan, 2003aPriyadarshan, , 2003bPriyadarshan, , 2011Priyadarshan et al, 2005;Rao et al, 1998). The final model achieved a mean Area Under Curve (AUC) of the receiver operating characteristic of 0.97 (AE0.014 SD) under 10-fold cross-validation.…”

Gas exchange in young Hevea brasiliensis (Willd. Ex A. Juss.) Müll. Arg. (Euphorbiaceae) plants in Antioquia (Colombia)

“…Therefore, it is probable that rubber plants will have a better adaptation to the water supply -both of the soil as well as of the environment-in San Roque. The aforementioned suggests that in San Roque rubber plants have a higher stomatal control in relation to the entry and release of gases (flow); this allows the plants to be more efficient to capture carbon and in water consumption, since, as Mokhatar, Daud and Arbain (2011) have mentioned, in evaluations of rubber plants subjected to different irrigation levels, the reduction in stomatal conductance -caused by the closure of the guard cells-forces the stomata to decrease the transpiration rate, even though the photosynthetic rate is affected.…”

Current Classification of the Bacillus pumilus Group Species, the Rubber-Pathogenic Bacteria Causing Trunk Bulges Disease in Malaysia as Assessed by MLSA and Multi rep-PCR Approaches

“…Malaysia is the world’s fifth-largest rubber producer that contributes more than 90% of global rubber production ( Fox and Castella, 2013 ; Malaysian Rubber Board, 2020 ). The RRIM 3001 superclone rubber tree ( Hevea brasiliensis ) is the new high producing rubber clone introduced by Malaysian Rubber Board (MRB) to fulfill the demand for planting materials and produce a remarkable return of natural rubber production ( Mokhatar et al, 2011 ). This clone generated a high yield of rubber production for three years of tapping and documented the topmost girth increment after six years of planting with an average of 10.6 cm/y ( Nurmi-Rohayu et al, 2015 ).…”