COCONUT PLANTER'S MANUAL. 1£ 



and the deficit will be made up by water taken up by the roots at 

 night when transpiration is at a minimum.) In the mornings and 

 evenings water does not avaporate ;is fast as it is brought in and the 

 leaflets tend to spread out: so in the evening their width will be as- 

 great as in the early morning, showing that any shortage of water 

 experienced during the day 1ms been made up. 



It has been found that, under normal conditions, a leaflet eva- 

 porates about 10'8 grams of water in a day. Allowing 150 leaflets 

 per- frond and 25 fronds to the tree, the whole tree will evaporate 40 5 • 

 litres or about 9 gallons per day, through its leaflets. But taking the 

 very lowest record loss, viz., 28 litres per day, the annual transpi- 

 ration per tree would be represented by 10,220 litres, equivalent to 

 about 2,250 gallons. 



The plant foDil taken up by -means of transpiration will, under 

 the most favourable conditions, make up for the loss in nuts andi 

 leases removed off the land, and meet the requirements of the tree- 

 for its growth. Allowing a loss of 16 leaves per annum and calcu- 

 lating 8'5 per cent of each leaf as ash and nitrogen, the loss of matter 

 taken up in solution by the roots will be about 4,080 grams. Again 

 with each nut the tree loses of ash and nitrogen 33*84 grams in the ■ 

 husk, 3'36 in the shell, 13'83 in the kernel, 5'97 in the milk, or a 

 total of 57 grams. Supposing the tree produces only 20 nuts a year, 

 the loss of plant food per tree per annum through the nuts would be 

 1,140 grams, or a total loss in leaves and nuts of 5,220 grani^ 

 (between 11 and 12 lb.) This would need 10,220 litres (about 2,250 

 gallons) of water as already calculated. In old leaves (from eight 

 months old to time of fall) transpiration is greatest. During severe 

 drought the old leaves drop faster than usual, and in this way, the- 

 tree is saved loss through transpiration at a time when the reduction i 

 of evaporation is an urgent matter. 



It is in the leaf that the mysterious change from inorganic into < 

 organic matter takes place with the formation, first, of starch and 

 sugar, and later of the oil that we find in the nut. For this the 

 presence of sunlight is essential. As already stated it is through the 

 stomata that oxygen passes into the leaves and carbonic acid passes 

 out, according to a process of respiration which is similar to that in 

 animals : while through the same openings carbonic acid gas is taken 

 up from the air, the carbonic being retained to meet the requirements 

 of the plant, and oxygen given out which purines the atmosphere. 



