78 



THE MONTHLY BULLETIN. 



soil, then the hard-pan may be broken, np by blasting and walnuts grown 

 successfully. 



Although the walnut is deep rooted and is considerably resistant to 

 drought when grown on proper roots, plenty of soil moisture is necessary. 

 One should not wait luitil the tree shows lack of moisture before irrigat- 

 ing. The time of irrigation depends somewhat on the rainy season, but 

 those who have the best results and the largest crops of well-filled nuts 

 are those who begin irrigation early — say in ]\Iay — and irrigate three or 

 four times, three or four weeks apart, giving a thorough cultivation after 

 each irrigation and not allowing the trees to check up in their growth. 

 Of course different soils will require more or less deviation from this 

 rule. AA-'alnuts are sometimes grown without irrigation, but unless 

 planted upon soil on which it is easy to retain moisture by cultivation, 



Fig. 32. — Comparison in tne nursery of 

 of first summer's growth of first genera- 

 tion iiybrid with trees that are not hybrids, 

 but all grown from nuts of the same tree. 

 The slieet used as a background is 7 feet 

 high, showing the height of the hybrid trees. 



These hybrids were procured by hand 

 poUenizing. The smaller trees are from nuts 

 that were not pollenized. About 60 per cent 

 of these are hybrids. 



more or less irrigation is always beneficial and profitable. Where the 

 trees do fairly well without irrigation, they grow much more rapidly, 

 come into bearing earlier and give much largei- crops with water. 



On the other hand, if you do not have good drainage or there is a 

 great amount of moisture constantly standing near the surface, the trees 

 will not do well. It is hazardous to grow walnuts on land where the 



