A comparative  study  on the economics of Apis cerana indica F. and  A. mellifera  L. was carried out in the rubber smallholding  sector on the basis of a sample survey covering 24 beekeepers identified  from  six different  locations.   It was  found  that  beekeeping  with  A. cerana  indica yielded  honey in the range of  2 to 17 kg per hive per year during  a period of 11 years from 1988 while  A. mellifera  yielded  5 to 60 kg per  hive per  year in a period  of six years  from 1993.  A comparative  analysis of the cost and  income indicated  that the cost of maintenance of A. mellifera  was  almost  four  times more in 1994, 1995 and  1996, 3.5 times more  in 1997 and  3.4 times more in 1998 than  that of A. cerana indica.  The income from A.  mellifera was eight,  ten, five, three  and  four  times more in 1994, 1995, 1996, 1997 and  1998  respectively than  that of A. cerana indica.  However,  inconsistency has been observed  in the honey  yield from both  types  of apiaries and  the profitability of beekeeping  due  to various  factors such as weather,  bee forage plants, diseases  to bees and  the vigour  of the colonies.   At current prices, culturing of A. mellifera was found to be more profitable than A. cerana indica. However, for the marginal  and  small beekeepers  A. cerana indica is more suitable  due  to lower  initial investment.   A. mellifera requires  higher initial investment and suits more to large organised beekeepers.

Growth  and  initial yield of ten Hevea clones were studied  under  the agroclimatic conditions of Assam in North East India.  RRIM 600 exhibited the highest girth in juvenile stage closely followed by PB 235 and  RRII 118.   At the immature stage, PB 235 showed the highest girth closely followed by RRIM 600 and   RRII 118.   RRIM 600 showed the highest girth  after the commencement  of tapping  during  mature stage also, closely followed by PB 86 and RRII 118. Poor growth as well as low rubber yield was observed in all the ten clones during winter months characterized by low temperature from December to March combined with the wintering and refoliation stresses. High DRC of latex, low dry rubber yield and high plugging index were observed in all ten clones during May to August.  An increasing  trend  in the yielding pattern  was observed from August  onwards  in all the clones with a maximum in November. RRIM 600  had  the  highest  yield for  the  first  three  years  of tapping  followed  by  RRII 105 and  PB 235 with  minimum  in  Gl 1.

An alternative approach to evaluate yield performance of Hevea clones was devised by developing a commercial yield performance index (CYPI) which incorporated certain yield characteristics and managerial factors which influence the relative profitability either directly or indirectly. The incorporated  variables  are extent  of immature  phase, share  of field coagulum  (FC) in yield, tapping  intensity, yield per tree, number of trees tapped  per unit area and  the pattern of yield  profile.   The CYPI was worked  out for 19 clones for the first 10 years of tapping and  compared  with mean yield indices (MYI). Except in three clones viz., GT 1, PB 217 and PB 5/51 the relative positions in ranking according to MYI got shifted when ranked according to CYPI.  Though RRII 105 obtained the highest MYI, the first rank with regard to CYPI was achieved by PB 260 by virtue of its relatively early tappability.  The shifts in rankings   were compared and the contributing factors were identified. The CYPI along with other characteristics such  as susceptibility  to diseases and  tapping  panel dryness,  proneness  to natural  damage, timber  yield, etc. may  be considered  in the  comparative  evaluation  of clones.

Attempts  were made  to study  the effects of temperature  and vapour  pressure  on major yield components  of Hevea brasiliensis in humid  and  dry sub-humid  climates.   Initial flow rate  (F) is positively  and  plugging  index  (P) and  dry  rubber  content  (Cr) are  negatively  correlated with yield in both the climatic regions. Maximum temperature (T_max)showed a negative correlation and  minimum  temperature  (T_min) and Vapour  pressure  (VP) positive  correlations  with initial flow  rate,  whereas  T_max correlated  positively with  P and  Cr.

With the use of financial tools of analyses, such as pay back period, net present value (NPV), internal rate of return (IRR) and  benefit cost ratio  (BCR), the costs and  returns  analysis  of rubber production in large estates in Nigeria was undertaken.   The annual output  per hectare for 26 years coupled  with  costs and  revenue  were discounted  at 25 per  cent discount  rate. A positive net value  of  N 5888.56 was  obtained.    The internal  rate  of return  was  38.56 per cent while the pay back period  was 12-13 years of plant  life which  is five to six years after maturity.  The period for recapitalisation was between 26^th and 27^th year which is twelve years after the capital invested  has been fully paid.   On the other hand, the benefit cost ratio was  4.15.

The dissolution of four indigenous   and two imported rock phosphates in an acid   soil was studied for   a period of 120 days.   As the amount of rock phosphate applied increased, an increase in available P content was noticed. A reduction in P availability   was noted during the 60 to 75  day  period after the addition  of P in the form of rock phosphates.   The highest P availability was from Gafsaphos  among  the  rock phosphates  studied.    All indigenous P sources in general showed similar dissolution pattern.