Cover crops for Rubber plantation: Benefit aplenty but not in practice

     In middle of the March,2013, I happened to visit three rubber plantation in the Dhalai district of the state. Those plantations were in the road side of the national high way therefore, I could make it possible to inspect on my way to north Tripura district for my personal visit.
      Rubber plantations, which I referred above, were of 2 to 3 years old, cleanly weeded and topography of the land is sloppy.
      After inspection of the rubber plantation what come to understanding is; young seedlings are suffering from excessive heat due to scorching sun which was further escalated by soil temperature surrounding the rubber seedling.
      Soil seems to be excessively dry due to lack of any coverage either through natural vegetation or mulching of the soil surrounding the seedlings.
      After visiting these three rubber plantations, what I felt is; the concept of cover crops raising in the rubber plantation is either not known or adopted by the growers. The general scenario in the state also reflects the same trends that I have observed with my little observation.
        Raising or growing of cover crop preferable leguminous crops has been advocated by the Rubber board and it’s to provide the following benefits:
      1.Enhancing soil fertility through fixation of atmospheric nitrogen through leguminous crops
      2.Increasing the biomass content of the soil through growing of cover crops
      3.Decreasing the soil erosion through growing of cover crops
      4.Suppressing the weed growths in the plantation through growing of cover crops
      Despite these ample benefits, practically in field level it’s not implemented by all growers.  The resultant affect for not taking up this easy to use concept are very much felt by the growers that has been  observed the way  expenditure incurred  for weed management by the small rubber growers.
      The process of growing leguminous cover crops is very easy due to availability of seed material from the rubber board with affordable rate and also locally available cover crops of the state.
      The most popular and easy to grow cover crop is Pueraria and locally available cover crop is Mucona.
      As general practice, seeds of the cover crops are sown after onset of pre-monsoon shower in patches between the rows of the rubber seedling.
      Based on the nutrient condition of the soil, fertilizer like phosphorus is applied while sowing of cover crop seeds.  Within a year, cover crops establishes in the plantation successfully with profuse growth.
      Benefits as narrated above, these leguminous crops, fixes atmospheric nitrogen with the help of rhizobium bacteria that lives in the root system of the cover crops which helps in increasing nitrogen content of the soil in the plantation.
      Cover crops that sheds dry leaves helps in increasing the biomass content of the soil thereby improving overall soil condition of the plantation.
      Cover crops,  as rubber plantation is carried out in hill and sloppy topography helps to reduce the soil erosion due to it’s thick canopy so is preventing the removal nutrient rich top soil of the rubber plantation.
      Another felt need for every rubber grower is; minimizing the expenditure in weed management of the plantation, Tripura which receives fairly good amount of rain fall due to south west monsoon also helps in uncontrollable growth of weeds in the rubber plantation.
      Rubber growers have to spend a good chunk of money in weed management in the initial year of rubber plantation. Cover crops if taken up in the plantation as advocated by the rubber board can substantially reduce the extra expenditure through growing of cover crops.
      However, one important point that should be taken into consideration is cover crops should not compete with the rubber seedling therefore; cover crops should not allow for growing in the periphery of the seedlings to avoid competition. A distance of 2-3 meter is maintained around the rubber seedling for avoiding competition between rubber seedling and cover crops.
      In Tripura, the time for new rubber plantation has already started, new growers are busy with field preparation and planting of rubber seedling with the onset of monsoon rain that is expected to arrive from the month of June but the concept of cover crops should also be their one of the agenda for raising rubber plantation successfully and economically.
      N:B:  Suitable cover crops for Tripura, per ha seed  rate and details procedure for seed treatment for  ensuring successful germination may be referred in rubber board of India.

Rain Guard: Should you consider?

      Rainy season in Tripura is 02(two) months away from now. South-West monsoon used to arrive in the state in the month of June and stays up to August.
      South-West monsoon is very essential for rubber trees as it gives much needed moisture for rejuvenation and growth of the rubber plants. A good and healthy rubber tree in the plantation means good productivity.
     However, continuous rain, torrential rain do also impacts negatively on the productive days in a year. Rainy days are not suited for latex tapping.
     Rain in the morning is no no for rubber tree tapers to go for tapping due to washout and dilution of natural rubber latex due to rain water.
     More number of rainy days means loss of many tapping days. Loss of many tapping days means reduction of total yield of rubber plantation.
     Fewer yields finally reflect the total profit of the rubber plantation owners.
    In Tripura, rainy season stays roughly for 02(two) months with varying intensity of rainfall due to prominent monsoon the south-west monsoon.
    In the given period of monsoon, average loss in tapping days should not be less 25-30 days. 25-30 days of loss in tapping days is quite significant in terms of loss of marketable product the dried rubber sheets or natural rubber latex.
   Are there any way out to minimize the loss of many productive tapping days?
   There’s a process by which loss of many tapping days due to rain can be minimized. It is by way of using protective cover called rain guard or rain gutter in the panel of the tapping portion of the rubber tree.
    By using rain guard or rain gutter, rain water which falls to the later collection cup either through tree trunk or directly from leaves is prevented.
    Rain guard is popular in Malaysia, the top natural rubber producer in the world.
    Rain gourd is also available in the rubber growing belts in the western ghat hills region of India.
   The product is easy to use and available in affordable rates.
   The idea is: rain water doesn’t fall in the latex collection cup that would cause dilution of natural rubber latex and washout of collected latex from the cup.
   So, what’s to be done? Very simple process, Rain guard or rain gutter is like a rectangular transparent polyethylene sheet which is sealed or pasted at one end just above the marked portion of tapping panel (graphically indicated below) and bottom end or portion is kept open in such a length that it covers the latex collection cup and also facilitates tapers for making incision on the bark of the rubber tree for tapping as graphically represented below:

     

                                          

                                                  Tapping Panel 

                                         

                                           Tapping Without Rain Guard 

                                         

                                                Use of Rain Guard 

    It’s seen that the technique is quite simple and can be performed by anybody with little technical know how and product is also available in affordable: rate.
     So, why rain guard is not popular in Tripura?
     In Tripura, rain guard or rain gutter is not popular and practiced in field level. Although, there’s report that it was also tried in the state but there’s no sign of popularity and adoption seen now-a-days.
    As a concept also, the matter is not discussed among the growers community and, even in the public domain too.
     Does it indicate that rubber growers are not loosing any tapping days due to rain?
    May not be because in the given rainy season of 02(two) months from June to July which sometimes extends up to August, there’s bound to be loss of many tapping days.
    And, loss of tapping days is bound to be within the range of 25-30 days and in that case approximate loss to the rubber plantation owners will be as follow:
    1. Area of plantation: 1(one) ha.
    2. Nos. of productive rubber tree: 450 nos.
    3. Average latex yield per plant: 80 ml.
    4. Loss of tapping days: 25-30 days
    5. Total latex loss: 900 liters to 1080 liters (80ml x 450 nos. x 25 day, 80ml x 450 nos. x 30 days)
   6. Total loss of dried rubber: 240 Kg to 288 Kg Sheet (Conversion, 3.75 liters of latex=1kg of dried rubber sheet)
   7. Total gross monetary loss: 36000 to 43200 (Rate of 1kg dried rubber sheet = 150)
      Looking to the above approximate calculation, it’s seen that total gross economic loss is within the range of 36000 to 43200 (in Indian currency) if the loss of total tapping days is within 25-30 days.
     The loss is quite significant and the amount of loss would escalate in case of big plantation owner.
     So, there’s every reason to consider for rain guard.
     Now, coming to the investment aspect towards setting up of rain guard or rain gutter, the cost of the material is quite reasonable.
     It’s available within 25-50 (in Indian currency) for setting up of rain guard of one rubber tree.
     In the above line, if numbers of rubber tree is 450 than the total investment for setting up of rain guard will be within 11250 to 22500 (in Indian currency).
    That means, even after investment of 11250 to 22500 towards setting up of rain guard or rain gutter, rubber plantation owner can still save 24750 to 20700 from a rubber plantation of 450 nos. rubber trees.
    This indicates the significantly safeguarding the profit which otherwise would have lost in absence of any protective mechanism like rain guard or rain gutter.
    However, looking to the whole aspect of rubber plantation, it transpires that there are still many aspects that need to be looked into and addressed at grower level for maximizing the profit and also well managing the rubber tree and rubber plantation.
    For this to happen, our growers’ needs exposure, awareness and tips for realizing all required aspects.
    N.B: For considering the rain guard, grower should look into their previous year’s log book that would give than the real picture of nos. of loss of tapping days.
     They can asses based on the previous tapping data whether or not rain guard is feasible to their condition or not.
     For growers, wanting to go for rain guard should see pros & cons of rain guard and get the expert suggestion.
     Average latex yield per rubber tree, rate of dried rubber sheet and latex to marketable dried rubber sheet are based on the data randomly collected from grower which may vary according to season.
     Numbers of rainy days and period of rainy season may vary according to climatic condition.