EXPERIMENT STATION BULLETINS. 575 



food was available for fruit productiou. These facts tend to show that 

 the small average productiou in the sprayed orchards of this State is 

 due primarily to a starved or half-starved condition of the trees, due 

 to poor orchard management. With favorable weather conditions many 

 of the orchards might have set a good crop but due to a poorly nourished 

 condition of the trees they were not able to withstand such adverse 

 conditions for fruit setting as existed during the flowering period of 

 1919. 



In Michigan the center of apple production has been gradually shift- 

 ing northwestward ; in other words, it has been gradually coming under 

 the control of the fruit grower, in distinction to the general farmer. 



The new plantings of the fruit growers, however, have not increased 

 the total production of the State, so that while the population of the 

 cities and towns or consuming centers has been growing at a rapid rate, 

 there is no increase of production or plantings, especially since 1914. 

 It is probal)le that tlie 1!)2<) census report v>'ill show little, if any, in- 

 crease in acreage of api»les throughout the country as a whole since 

 1910 ; the new plantings being hardly sufficient to replace the old trees. 

 The present shortage of nursery stock means that it will be several years 

 before enough new plantings can be made to make any material increase 

 in production, while it will be many years before the new plantings will 

 be sufficient to balance the increased population of the consuming 

 centers. These facts should form a reasonable basis for expecting fair 

 prices for apples for at least the next few years. 



The prospect of good prices for fruit during the next few years should 

 make the problem of orchard management, to insure maximum produc- 

 tion, of serious concern to every grower. The exceedingly small average 

 production of even the sprayed Michigan orchards shows that the imme- 

 diate problem of the average grower is one of improving his cultural 

 practices to increase his yields of marketable fruit. A study of this 

 problem first directs one's attention to the factors that influence the de- 

 velopment and condition of the fruit spur. 



FRUIT SPURS AND THEIR DEVELOPMENT, 



We may, for convenience, classify fruit spurs into three general groups, 

 insofar as their development is concerned: (1) those of a short, slight 

 growth, without sufficient development and vitality in them to produce 

 a fruit bud; (2) those of slightly stronger growth with a fruit bud of 

 only sufficient vitality to flower but not to set fruit; (3) those of a 

 stronger spur growth with a plump, vigorous fruit bud alile to set and 

 mature fruit. 



Most of the spurs on a non-productive apple tree belong to the first 

 group. The history of trees producing such spurs frequently shows a 

 rather satisfactory growth in the earlier years, especially during favor- 

 able seasons ; comparative early bearing of the trees continued for a few 

 seasons, after which a cessation of growth occurred and then of fruit 

 production; the tree had exhausted the food supply within reach of the 

 roots to such an extent that further growth and production was in- 

 hibited. This is the present condition of many Michigan apple orchards 

 and usually is the characteristic condition of neglected orchards. (See 

 Fig. I.) Severe winter pruning is often resorted to by the grower to 

 "re-invigorate" such trees, often resulting in temporarily restoring their 



