154 



1916 ANNUAL REPORT 



ticularly valuable trees. They were likely to appear suddenly and spread 

 rapidly in spite of the care exercised to check them. Sometimes with 

 the use of Bordeaux paste, after very careful removal of all diseased tis- 

 sue, the trouble was overcome." 



Summary. — That a Pythiacystis, similar to Pythiacystis citrophthora, 

 may, under certain conditions become at least a wound parasite of avo- 

 cado trees, is shown by these tests. The fungus was isolated from two 

 different specimens, was grown in pure cultures, was introduced into avo- 

 cado trunks at two different seasons and produced effects similar to 

 those on the trees from which it was isolated. It was twice recovered 

 in cultures from the inoculated trees, in one case six weeks and in an- 

 other three months after the inoculation. 



The same preventive and control measures as used for Pythiacystis 

 Gummosis of Citrus will probably apply to this disease, though few ex- 

 periments of this kind have as yet been tried out. 



FOUR YEARS' EXPERIENCE WITH BUDDED AVOCADO TREES 

 By J. T. Whedon, Yorba Linda, California 



I planted my first avocado trees at South Santa Anita, in the spring 

 of 1912. The cold winter of 1912-13 convinced me that I would have 

 to find a warmer climate to make a success of the avocado business, 

 which I had decided to engage in. 



On April 1, 1913, I sold out and relocated at Yorba Linda, Orange 

 county, in May, 1913. I planted 77 trees that summer and finished 

 planting five acres in March, 1914. The trees planted in March, 1914, 

 did much better than those put out in mid-summer, 1913. 



Yorba Linda is located on rolling ground and about 20 miles in an 

 air-line from the ocean. My place is at an elevation of 500 feet, and the 

 trees are planted 24 feet apart on the equilateral system, irrigating 

 better on account of the lay of the land. 



I lost six Harmans, and two Tafts, from sunburn and one Harman from 

 wind when first put out in 1913, because they were not properly protected 

 from the sun and wind. 



All trees set out in 1914 and since are staked, shaded from the noon- 

 day sun, and the trunk protected, for the first year, with paper mattress, 

 such as newspapers are printed on. The second year the trunk is protected 

 with whitewash, (Wickson formula). After the second year, if trees are 

 not headed out too high, they will protect themselves from sunburn. I 

 am now letting all of my trees branch out low, as it protects them against 

 the wind, of which we have considerable, and sunburn, gives a larger 

 and stronger trunk, and holds the moisture much better than when kept 

 trimmed up. 



I think 24 to 30 inches is as high as any avocado tree should be 

 headed out, and this heading out should be done in the nursery on all 



