Edible Products. 



60 



should be capable of immediate check, and the cause ascertained at once and 

 remedied, if a garden is to be kept up to the mark under the high pressure 

 conditions of modern tea planting. 



Accompanying the decline in yield the appearance of the wood on a bush 

 usually changes. There are grey lichens on the stems of nearly all tea bushes, 

 but they only occupy part of the surface; in unhealthy plants these licheus seem 

 quickly to spread over the whole, giving the wood a peculiar greyish appearance 

 which is generally described by the term ' hide bound.' Though this term has no 

 definite scientific meaning, yet in a ' hide bound ' bush the bark always seems 

 distinctly harder than on a thoroughly healthy plant. The most character- 

 istic feature is, however, the fact that leaf growth seems to cease in large measure 

 except from the younger wood on the top of the bushes. The result is that a 

 'hidebound' bush always looks hollow, and while it may appear fairly vigorous 

 on the top, an examination below indicates the unhealthy condition in which it 

 really is. The usual and often the right prescription for such bushes would be 

 heavy pruning. This is not, however, always the case as will be realised later. 



We have described the most obvious signs of an unhealthy deteriorating 

 bush, and the special causes which produce such unhealthiness must next be 

 considered. Deterioration in tea, apart from incorrect management, must be due 

 either to exhaustion of the land, or exhaustion of the bush, and it has been 

 a common subject of discussion among planters as to which is usually first 

 noticeable. It seems now clearly proved that the question does not admit of a 

 definite and generally applicable answer. In many cases, and in my experience 

 notably in the Duars, the bushes show signs of being worn out long before the soil 

 could be considered exhausted. In others, the marvellous results obtained by 

 adding manure to the land, without any further treatment, show beyond cavil 

 that the bushes would yield and continue in good health if only the soil was rich 

 enough, or the plant fuod present in an available condition. I am strongly of 

 opinion that in by far the greater proportion of cases it is the exhaustion of the 

 soil, coupled with incorrect treatment of one sort or another, which brings about 

 the first decline in the value of areas of tea. At any rate it is no use touching the 

 bush until one is certain that the soil is in good enough condition to enable the 

 bushes to respond to the treatment. But how to ascertain whether there is 

 anything wrong with the soil ? 



In the first place, it should be made certain that the drainage of the land 

 is satisfactory. This, I think, can be done on the spot by three or four tests. These 

 tests concern (1) the moisture in the subsoil in the cold weather, (2) the depth of the 

 subsoil water in the drains, (3) the rapidity with which the heavy rains disappear 

 through (not over) the soil on a piece of flat land. With regard to the first of these 

 matters, it can easily be tested by digging a hole two feet deep, weighing say, 

 ten pounds of the damp soil at the bottom of the hole, drying it in a warm place near 

 the boiler for say two days, and reweighing. Now the maximum amount of water 

 which ten pounds of different classes of dried soil can take up when saturated 

 is approximately as follows : — 



CAUSES OF DETERIORATION. 



DRAINAGE. 



Sandy soil 

 Light loam 

 Medium loam 

 Heavy loam 

 Clay soil 



2"25 pounds. 



