The present study was undertaken to assess the agro-climatic suitability of left wing extremism (LWE) affected states of India for cultivating natural rubber (NR). Monthly means of maximum temperature, amount of rainfall, number of rainy days, potential evapotranspiration, hot degree days, vapour pressure deficit and aridity index were used in the present analyses. Variations in these parameters in the LWE affected districts of Odisha from Kottayam and Kanyakumari districts which have more congenial conditions for NR cultivation were first estimated. No district fell within a variability of up to 20 per cent from Kottayam and Kanyakumari districts when all the above parameters were taken together.  When aridity index (AI),

which is a function of air temperature, wind speed, vapor pressure deficit, solar radiation and rainfall alone

was considered, Ratnagiri district in Maharashtra was at par and four districts in West Bengal were within

20 per cent variability of Kanyakumari district. It was also found that between periods 1901-1955 and 1956-

2002, there was no significant variation in AI in the study areas. Earlier studies have shown that favorable limits of climate parameters for NR cultivation are: annual rainfall ≥1500 mm, rainy months ≥6, monthly maximum temperature ≥360C, monthly minimum temperature ≥100C and A  ≥0.50.   Considering these parameters as the normal climate tolerance limit (CTL), we found that 10 districts in LWE affected regions

fall within these normal limits. By relaxing the CTL favourability by 10 and 20 per cent from the normal, a total of 29 and 76 districts, respectively could be identified.  Maximum number of districts were from Odisha and West Bengal. Identification of suitable districts for growing NR using the AI and CTL approach should be taken with abundant caution even as it is not known how stressful it would be to grow NR

commercially in a district where the AI or CTL is 10 or 20 per cent different from the normal range. Moreover, the east coast states, particularly Odisha are prone to frequent cyclonic storms almost every year. Therefore, results from the present study could be used only as a general indication. Ecological Niche Modelling and Geo-spatial approaches could be used in conjunction with the present analyses for identifying suitable

areas for cultivating NR with greater confidence.

A field survey was conducted to assess the extent of adoption of various agronomic practices in the rubber growing regions of Kerala, Kanyakumari, Karnataka, Goa and Maharashtra.  Primary data was collected by a well-structured questionnaire with a series of questions related to the adoption of agronomic practices recommended by the Rubber Board of India by interviewing a total of 10760 farmers.  In all the rubber growing regions of South India, majority of the growers used polybag plants of clone RRII 105 as the planting material and planting was done in pits of size 75 cm3.  Land preparation operations like digging pits and making terrace were done manually in the entire rubber growing regions of Goa, whereas it was

83, 76 and 92 per cent in Kerala, Karnataka  and Kanyakumari, respectively and the use of earth movers becoming common in these regions. In Maharashtra, more than 90 per cent of the rubber growers followed mechanical mode for land preparation. More than 86 per cent of the rubber growers in South India adopted manual method of weed control both in immature and mature rubber plantations.  Only less than 2.4 per cent of the growers applied herbicides in rubber plantations. Banana was the widely accepted intercrop in all states especially in Tamil Nadu (94%) and Goa (100%). In Maharashtra around 50 per cent of the farmers adopted pineapple intercropping where as in Kerala, Karnataka and Tamil Nadu, the percentage of adoption was 11, 9 and 3, respectively. Construction of terraces for conserving soil and water was the widely accepted conservation practice in all states and combination of conservation practices for controlling soil erosion was followed only in Kerala, which shows the need for concerted efforts to increase the adoption of integrated soil and water conservation practices in NR plantations particularly in the context of increasing drought and cost of cultivation.  The observations from the present study will be useful in identifying areas where further institutional intervention is needed and also stress the importance of renewed extension efforts for diffusion of the recent technological innovations.

Proteolytic enzymes are commonly used as a hydrolytic agent for the reduction of protein content in natural rubber (NR).  In the present an attempt has been made to standardize a method to reduce the protein content of NR latex using a novel proteolytic enzyme. The NR latex was treated with very small quantities of the enzyme and then creamed for six hours.  The cream portion was removed and coagulated and this rubber had nitrogen level similar to conventional deproteinised natural rubber (DPNR), but with higher initial plasticity (P0) and plasticity retention index (PRI). Though the technological properties of the DPNR

produced were slightly low, they were well within the process limits.  The advantage of this method is production of DPNR with better properties in a short period of time.