384 ANNUAL REPORT OF THE Oft. Doc, 



food is needed, a good fertilizer is one carrying about 30 pounds 

 actual nitrogen, 50 pound actual P205, and 25 to 50 pound K20 

 per acre. In many cases, the smaller amounts of K20 will doubt- 

 less give better net returns than the larger, though there are some 

 soils where this is apparently not the case. In certain of our cul- 

 tural methods experiments, a fertilizer similar to this has very good 

 results, especially in connection with tillage. In some cases in 

 connection with sod or mulch treatments, however, it has seemed 

 probable that the nitrogen was haidly sufficient in the above form- 

 ula, though this is a point that will have to be determined more or 

 less by local trial. The nitrogen can, of course, be furnished by 

 manure or leguminous jjlants to a greater or less extent, if this is 

 found desirable. 



In a few of our orchards, moreover, uo form of fertilization has 

 as yet produced a material response. This we consider due to the 

 presence of other limiters, of which improper moisture supply is 

 frequently important: though there are many other possible limiters. 



The existence of such orchards emphasizes the need of local tests 

 before making large and regular expenditures for fertilizers. These 

 tests can be readily made by treating one part of the orchard and 

 leaving the remainder unfertilized. In the case of most young or- 

 chards, or in any orchard that is doing well in growth and fruiting 

 and retains a thrifty foliage well through late August and Septem- 

 ber, it is doubtless safest to fertilize only a small portion of the or- 

 chard for two or three years and leave the larger part unfertilized. 

 The fact that the trees are well loaded in a given year, however, is 

 no sufficient reason for omitting the fertilizer that year. In fact, 

 that is one of the best reasons and times for applying a proper fer- 

 tilizer rather liberally, in order to prevent the total absence of a 

 ciop the following year, and in the long run to tend to steady the 

 annual production. 



In case of the reverse conditions, — old orchards or those not re- 

 taining a thrifty look throughout the season or not growing and 

 bearing satisfactorily, — it is best to reverse the procedure, and fer- 

 tilize the larger portion, leaving only a small block to test the value 

 of the treatment. In all cases, however, we strongly advise the use 

 of a check until the real value of the treatment is well established. 

 It is neither desirable to throw away money by too much liberality 

 in the treatment of crop, nor to fail to realize its possibilities by 

 too niggardly a treatment. Either course is an economic blunder, 

 and the latter is especially deplorable because its effects is to de- 

 crease the productivity of the whole nation. 



The time of application also we consider important, especially 

 in the case of the nitrates. While our evidence is by no rueans com- 

 plete on this point, yet we believe that it is quite possible to make the 

 applications either too early or too late for satisfactory results. In 

 fact, we have some evidence, from the work of certain orchardists, 

 that leads us to believe that very distinct harm may be done by ap- 

 plying nitrogen too near to the fruit-setting time, especially in the 

 case of peaches. Other evidence indicates that nitrates applied too 

 early in the season may be wholly lost to the trees. 



So that all things considered, we feel that nitrates should be ap- 

 plied not earlier than petal-fall in apples and probably not later 



