152 STATE BOARD OF HORTICULTURE. 



Stable Manure of Doubtful Utility. — Barn manure is largely 

 used by many growers, who still hold to the tradition that 

 chemical manures are injurious to the plants. The benefits of 

 barn manure in an orange-grove are in serious question. The 

 fruits produced by nitrogen from this source are usually large, 

 coarse, thick-skinned, with abundant rag, and of inferior 

 flavor. If barn manure is used— and most growers have a 

 limited quantity and desire to use what they have — it should 

 be spread over the grove lightly, so that each tree receives only 

 a small amount. Where such manure is depended upon as 

 the main element of fertilization, liberal dressings of potash 

 should be occasionally applied; this will tend to correct the 

 evils of an overbalanced nitrogeneous fertilizer. What has been 

 said as to the effect of barn manure on the quality of fruit 

 applies equally to the effects produced by muck, cottonseed 

 meal, blood and bone, tankage, etc. 



In general, organic fertilizers do not stimulate fruiting to the 

 same extent as the mineral fertilizers. It is probably better 

 economy to apply such fertilizers to annual crops, cereals, 

 garden truck, etc. 



Mineral Nitrogen. — The mineral nitrogen manures, nitrate 

 of soda and sulphate of ammonia, apparently stimulate pro- 

 duction of fruit more than organic manures, and yet promote 

 a fair general growth. The fruit produced by fertilization with 

 these salts, used in correct proportions with the other elements 

 which it is necessary to apply, is usually of good qualit}^, being 

 solid, juicy, and rich, with thin skin and little rag. Sulphate 

 of ammonia has the effect, growers testify, of sweetening the 

 fruit to a considerable extent. There seems to be little doubt 

 as to the correctness of this view, but why it is so remains 

 in question. The sweetening is probably more marked if 

 there is a slight deficiency in potash. The use of very large 

 quantities of either sulphate of ammonia or nitrate of soda 

 may result disastrously, acting as "chemical poison," killing 

 the trees outright and causing them to throw off their leaves. 



Sulphate of ammonia has been very widely used among 

 orange-growers. Nitrate of soda has been but little used thus 

 far, but is apparently growing in favor. Its insecticide and 

 water-attracting properties are probably much greater than 

 those of sulphate of ammonia. 



