Orchard Pests and their Control 373 



peach-yellows. There is no premature ripening of fruit, no clusters 

 of small branches, and the trees may bear yellow foliage for a 

 number of years and eventually recover, something unheard 

 of with peach-yellows, where death is swift and sure. Instead 

 we find pale yellow or greenish yellow foliage, stunted growth, 

 small fruit, bare branches with small clusters or rosettes of leaves 

 at the end, and eventually dead branches and finally dead trees. 

 " In all localities which have come under our observation, the 

 affected trees occur on marly land, which is described on page 19. 

 It is true that many orchards of vigorous trees may be found 

 growing in this kind of soil, but it is also true that it is more difficult 

 to keep the trees in good condition. In many of these orchards 

 the culture has not been suited to the conditions, consequently 

 the supply of available plant-food has been depleted, and the 

 ground has become so compact that it is almost impossible for 

 the absorbing roots to develop. When for any reason the soil 

 conditions become uncongenial, it is impossible for many absorb- 

 ing roots to form, consequently malnutrition results. The tree 

 responds promptly, and the yellow foliage is the signal of distress. 

 The importance of understanding the nature of plants as set 

 forth under the heading of " The Orchard Plant " (page 53) 

 should now be apparent to all; Had these growers fully under- 

 stood the delicate nature of their trees, much of this loss and 

 worry might have been avoided. 



As to the remedy, it should be understood that marly land is 

 not the best for orchards, but it has been made to grow profit- 

 able fruit plantations. As has been intimated, good culture must 

 be practiced; when yellow foliage appears, the grower must 

 change and improve his methods. We would recommend first 

 that the ground be plowed late in the fall to a depth of at least 

 six inches, and deeper if practical. In the spring plant some 

 leguminous crop, as red clover. Do not cut any of the crop for 

 hay, but return it all to the soil. Plow this material under in the 

 fall, and repeat the process the following season. It may be 

 advisable later on to allow the crop to stand for two seasons before 

 plowing, but this must be determined by the conditions. In all 

 cases the irrigation furrows must be kept open so that the water 



