THE ACID LIME FRUIT IN HAWAII. 



5 



TILLAGE. 



The lime tree makes the same demand upon the soil as do other 

 trees of similar size and the fertility of the soil should therefore be 

 maintained. The soil should be thoroughly tilled to keep it in a 

 suitable condition of aeration and free from weed growth. Such 

 tillage will result in conservation of soil moisture, improvement in 

 texture, and an increase in the productivity of the soil. 



FERTILIZING. 



To produce the most profitable crop lime trees must be properly 

 nourished. In Hawaii many lime trees do fairly well without till- 

 age, irrigation, or fertilizers of any kind; nevertheless, the fruiting 

 capacity of trees reaching a high degree of productivity becomes ab- 

 normal through intensive -cultivation, and heavy bearing can be 

 maintained only by furnishing the trees with an abundance of plant 

 food. This may be given in the form of a fertilizing material, either 

 as farm manure or commercial fertilizer, or better still, the two may 

 be used in combination. 



Locations naturally differ in soil and climatic conditions and each 

 should be studied separately so that its needs may be determined. As 

 a rule the soil is deficient in humus wherever citrus fruits are grown 

 commercially. Farm manure should be applied to such land or a 

 leguminous cover crop should be grown to furnish green manure. 

 Many growers utilize both. 



Farm manure is one of the best general fertilizers. It supplies the 

 soil with a large quantity of organic matter, which, upon decaying, 

 improves the texture of the soil and makes readily available for crop 

 use the mineral fertilizer constituents in the soil. Farm manure 

 should be well distributed over the soil and then immediately turned 

 under. 



Green manure is furnished by growing and plowing under some 

 leguminous crop, such as velvet beans, cowpeas, pigeon peas, mungo 

 beans, and the like, which enrich the soil in nitrogenous matter. 



Excess of nitrogen in the soil is indicated by vigorous growth of 

 the trees, dark-green foliage, and a small amount of fruit having 

 a thick rind and very fibrous pulp. Liberal applications of potash 

 with the nitrogen tend to produce greater fruitfulness, thinness of 

 rind, and less fiber. 



Trees which it is desired to have grow rapidly but which have 

 not attained bearing age require relatively large amounts of nitrogen 

 and much less potash than do those producing heavy crops. Trees 

 bearing heavy crops require a fertilizer having high percentages of 

 both potash and phosphoric acid. 



In general fruit culture young trees are thought to require phos- 

 phoric acid, potash, and nitrogen in the proportions of 6, 8, and 4 

 per cent, respectively, and fruiting trees in the proportions of 8, 12, 

 and per cent, respectively. 



■ Table 1 shows the kinds and amounts of constituents that might be 

 used to make a ton of fertilizer. 



