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13 1822 01677 8425
UNIVERSITY OF CALIFORNIA PUBUCATIONS
COLLEGE OF AGRICULTURE
AGRICULTURAL EXPERIMENT STATION
New Control Methods
LIBRARY FADL in
972 9
T Thrips and Peach Tree Borer
Earl L. Morris
Sprayed lor Thrips.
Unopmycd.
BULLETIN No. 228 (Berkeley, Cal.)
SACRAMENTO :nd Wm. Richardson - - Superintendent ok Statk Printinu 19 12
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UNIVERSITY OF CALIFORNIA SAN DIEGO
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3 1822 01677 8425
UNIVERSITY OF CALIFORNIA PUBUCATIONS COLLEGE OF AGRICULTURE
AGRICULTURAL EXPERIMENT STATION
New Control Methods
'car Thrips and Peach Tree Borer
Earl L. Morris
- '" v^'. r-7»««-'i«..«33i«» :f^ t^3-V "
Sprayed {or Tlirips.
BULLETIN No. 228
(Berkeley, Cal.)
SACRAMENTO Friend Wm. Richaboson - - Superintendent of State Printing
1912
Benjamin Ide Wheeler, President of the University.
EXPERIMENT STATION STAFF.
E. J. WiCKSON, M.A., Director and Horticulturist.
E. W. HiLGARD, Ph.D., LL.D., Chemist (Emeritus).
W. A. Setchell, Ph.D., Botanist.
LiEROY Anderson, Ph.D., Dairy Industry and Superintendent University Farm Schools.
M. E. Jaffa, M.S., Nutrition Expert.
R. H. Loughridge, Ph.D., Soil Chemist and Physicist (Emeritus).
C. W. WOODWORTH, M.S., Entomologist.
Ralph E. Smith, B.S., Plant Pathologist and Superintendent of Southern California
Pathological Laboratory and Experiment Station. G. W. Shaw, M.A., Ph.D., Experimental Agronomist and Agricultural Technologist, in
charge of Cereal Stations.
E. W. Major, B.Agr., Animal Industry.
B. A. Etcheverry, B.S., Irrigation Expert.
F. T. Bioletti, B.S., Viticulturist.
W. T. Clarke, B.S., Assistant Horticulturist and Superintendent of University Exten- sion in Agriculture.
John S. Burd, B.S., Chemist, in charge of Fertilizer Control.
J. E. CoiT, Ph.D., Assistant Pomologist, in charge of the Citrus Experiment Station Riverside.
George E. Colby, M.S., Chemist (Fruits, Waters and Insecticides), in charge o] Chemical Laboratory.
H. J. Quayle, M.S., Assistant Entomologist.
H. M. HalLj Ph.D., Assistant Botanist.
C. M. Haring, D.V.M., Assistant Veterinarian and Bacteriologist. E. B. Babcock, B.S., Assistant Agricultural Education.
W. B. Herms, M.A., Assistant Entomologist.
W. T. HoRNE, B.S., Assistant Plant Pathologist.
C. B. LiPMAN, Ph.D., Soil Chemist and Bacteriologist.
A. J. Gaumnitz, Assistant Agronomist, University Farm, Davis. N. D. Ingham, B.S., Assistant in Sylviculture, Santa Monica.
T. F. Hunt, B.S., Assistant Plant Pathologist.
P. L. McCreary, B.S., Chemist in Fertilizer Control.
E. H. Hagermann, Assistant in Dairying, Davis.
R. M. Roberts, Farm Manager, University Farm, Davis.
B. S. Brown, B.S.A., Assistant Horticulturist, University Farm, Davis. J. I. Thompson, B.S., Assistant Animal Industry, Davis.
J. C. Bridwell, B.S., Assistant Entomologist. L. Bonnet, Assistant Viticulturist.
F. C. H. Flossfeder, Assistant in Viticulture, University Farm, Davis. P. L. HiBBARD, B.S., Assistant Fertilizer Control Laboratory.
C. H. McCharles, M.S., Assistant Agricultural Chemical Laboratory.
B. A. Madson, B.S.A., Assistant Experimental Agronomist. Howard Phillips, B.S., Assistant Animal Industry, Davis.
Walter E. Packard, M.S., Field Assistant Imperial Valley Investigation, El Centro L M. Davis, B.S., Assistant in Dairy Husbandry, University Farm, Davis. S. S. Rogers, B.S., Assistant Plant Pathologist, Plant Disease Laboratory, Whittier H. A. RuEHE, B.S.A., Assistant in Dairy Husbandry, University Farm, Davis.
C. O. Smith, M.S., Assistant' Plant Pathologist, Plant Disease Laboratory, Whittier
E. H. Smith, M.S., Assistant Plant Pathologist.
C. L. ROADHOUSE, D.V.M., Assistant in Veterinary Science.
F. M. Hayes, D.V.M., Assistant Veterinarian.
M. E. Stover, B.S., Assistant in Agricultural Chemical Laboratory.
W. H. VOLCK, Field Assistant in Entomology, Watsonville.
E. L. Morris, Field Assistant in Entomology, San Jose.
E. E. Thomas, B.S., Assistant Chemist, Plant Disease Laboratory, Whittier.
A. B. Shaw, B.S., Assistant in Entomology.
G. P. Gray, M.S., Chemist in Insecticides.
H. D. Young, B. S., Assistant in Agricultural Chemistry, Plant Disease Laboratory
Whittier. A. R. Tylor, B.S., Assistant in Plant Pathology, Plant Disease Laboratory, Whittiei L. T. Sharp, B.S., Assistant in Soils. W. W. Cruess, B.S., Assistant in Zymology. J. F. Mitchell, D.V.M., Assistant in Veterinary Laboratory. W. B. Boys, Assistant Cerealist. M. E. HoLTER, B.S., Assistant Soil Chemist.
Anna M. Lute, Scientific Assistant, United States Department of Agriculture. J. C. Roper, Patron, University Forestry Station, Chico. E. C. Miller, Foreman, Forestry Station, Chico.
D. L. Bunnell, Secretary to Director.
NEW CONTROL METHODS
FOK" Tin;
PEAR THRIPS AND PEACH TREE BORER.
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[Introductory Notes. — The present Bulletin gives the pi-aetical results of studies on the two most serious pests in the Santa Clara Valley. They were conducted by Mr. Morris under the auspices of the Experiment Station. Very decided progress was made towards the control of these insect.s, both of which extend into other parts of the State and are causing much concern at the present time.— ('. W. Woodwohtii. I
LIME SPRAY FOR THRIPS (Euthrips pyri).
This paper is based on an experiment in a pear oi-chard belonging? to W. C. Bogen on San Tomas Road, near San Jose, ('idifornia. It was possible to make this experiment, which extcMich^d over two seasons.
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Fig. 1. — Whitewashed tree coming out into full bloom.
368
UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION.
solely through the hearty cooperation of Mr. Bogen, who at all times gave freely of his time, money and counsel.
The period covers the fruiting season of 1910 and 1911. The writer had observed that in some instances pear trees sprayed with a heavy solution of home-cooked lime-sulphur, which contained a large excess of lime, were freer from attacks of thrips than pear trees in the same
Fig. 2.-
-Unspi-ayed trees at blossoming time. This tree is adjacent to tlie one sliown
in figure 1.
orchard which were not sprayed. From previous experiments it seemed highly improbable that sulphur in chemical combination with the lime was the active agency. The only other possible agency was the free lime which Avas sufficient to make a thin whitewash. Acting on the above suggestion in the spring of 1910, we sprayed four rows of pear trees, thirty-one trees in a row, and three trees on each of the next
Bulletin 228] pear thrips and pp:acii trkk borkr. 369
two rows, making in all one huiulrcd tliirt}' trees. This was six trees more than one sixth of the orchard, and the adjacent unsprayed trees made an excellent check. The application was made witli a hand pump, without constant agitation, with the result tluit the last wiiitt'wash sprayed from the tank was much thicker than the first. The last trees sprayed, especially the last six, which were in unsprayed rows, were covered with a very thick, heavy whitewash. This application was made when very few blossom buds were open sufficiently to admit tlie llirips. At the time of full blossom it was very apparent that the nund)er of blossoms was in direct proportion to the amount of whitewash. The trees which had a thin coating of whitewash had very few blossoms; those which had a ver}' thick coating of whitewash had abuiulanc(! of blossoms. Fig. 1 shows thickly whitewashed trees in full I)lo()m. Fig. 2 shows adjacent unsprayed trees with very few blossoms, the blossom buds having been destroyed by the thrips. The amount of fruit corresponded to the amount of blossom.
The season of 1911 the experiment was repeated on a larger scale. Between one and two weeks before the time for the buds to open. Mr. Bogen sprayed a large number of trees verj- thoroughly with thick whitewash. Time is a great factor in the control of thrips, and we had hoped to show from this experiment that the whitewash A\()uld have the same beneficial effect when applied a week or more before the buds open as when applied at the time of opening An exceedingly heavy downpour of rain washed the lime from the buds and defeated our plans. By the time the orchard was again dry enough for spray- ing, the buds Mere just beginning to open and conditions were ripe for duplicating the experiment of the previous season.
About one half of the orchard was used for the experiment. It con- sisted, including checks and sprayed trees, of seven rows, thirty-six trees to the row. The same material was used as in the previous experi- ment. Two rows were sprayed, one row unsprayed, two sprayed, two unsprayed, with this exception, that in the one unsprayed row of trees seven trees were spraj-ed bj^ mistake.
The results were the same as the previous year. All the sprayed trees, including the seven in the unsprayed row, came into full blossom. The unsprayed trees blossomed very feebly. The fruit corresponded very closely to the blossoming. The spraj^ed trees averaged eight times as much fruit as the unsprayed trees. Fig. 3 shows sprayed and unsprayed trees at picking time. Fig. 4 shows the fruit from a sprayed and an unsprayed tree.
We used eighty (80) pounds of quicklime for one hundred (100) gal- lons of spraying material. The whitewash was strained through one fourteenth (1/14) inch mesh wire screen and the same sized screen u.sed on the suction hose of the pump. The ordinary Bordeaux no/zles
370
UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION.
Fig. 3. — Trees at harvest time ; the lower one was whitewashed and carries fruit.
Bulletin 228]
PEAR THRIPS AND PEACH TKEE UdUKU.
371
worked well. But it was necessary to enlarge slightly the opening in llio disks of Vermorel type nozzles. We found it very important to have the lime properly slaked. Good lime properly slaked is of creamy con- sistency, with a negligible amount of grit. It forms a smooth, uniform, creamy coating on the tree. An attempt to use improperly slaked limr will usually result in complete failure. No amount of written inslruf tion will teach one to slake lime. The laiowledge must come from actual work with some one who has had the experience.
In orchard practice we found it convenient to have our slaking vat, which was 6 by 4 by 1 feet, elevated about three feet, with one end slightly lower than the other. In the lower end we arranged a sliding door through which the whitewash flowed by gravity into a containing
(Unsprayed. ) (Whitewashed.)
Fig. 4. — Fruit at harvest from treated and untreated trees.
vat. The lower vat was shorter, narrower, and deeper than the slaking vat to facilitate the removal of the material to the spray tank. Between the two vats we arranged a piece of window screen, of one fourteenth inch mesh, supported by chicken fencing, through which the whitewash passed in flowing from the slaking vat.
The cost of material ranges from one (1) to one and one half (1^) cents per gallon, depending upon the cost of lime and labor. One application proved sufficient to protect the blossoms and permit setting of fruit. We did not find it necessary to spray a second time for larva\ although in the first experiment enough larvje appeared to lead us to believe that in some cases a second spraying would be necessary with some good contact spray.
372
UNIVERSITY OF CALIFORNIA EXPERIMENT STATION.
ASPHALTUM TREATMENT FOR THE PEACH TREE BORER.
The western peach tree borer (Sanninoidea pacifica) is an insect of much economic importance in the horticultural district about the southern arm of San Francisco bay.
The investigations upon which this paper is based were made in most part in the peach orchard of the J. H. Flickinger Company, Berryessa, California. They have extended over a period of four years. The results have not been verified for other districts.
The adult borers are slender, blue-black, day-flying moths, about one inch long. They are seldom seen and very rarely recognized by the orchardists. They issue more or less from February to September, but
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Pig. 5. — Work of the peach tree borer.
the mass of them appear about the middle of July. They place the eggs on the trunk of the tree from the ground up two feet, one to twenty-five eggs in a place. These are very small and generally escape notice. They hatch in a few days.
The newly hatched larvge, or "worms," which are difficult to find, usually enter the bark at or near the ground. The new burrow is marked at first by light brown bark dust, which in a few hours dis- appears, after which it is nearly impossible to find the opening. The larvae grow rapidly, work their way through the bark, and spend most of their life between the bark and wood, where they may do great
BlLLETIX 228]
PEAR THRIP9 AND PEACH TREE BORER.
373
damage by boring long distances, often completely girdling the trees. Gum flows as a result of this injury and is a fairly reliable indication of the presence of the large "worms." Unfortunately there is nothing to show the presence of the small "worms."
The full-grown larvce are about one inch long and the diameter of a slate pencil. They have white bodies and dark brown heads. When ready to pupate, they seek places from which the moths can easily issue and construct about themselves cocoons from the chewed-up wood and bark. The cocoons are light brown capsule-shaped bodies, slightly larger than the "worms." They may be found under the bark, in tlie bark, or in the ground an inch or more from the tree.
The usual method of combating the peach borer is to dig out the "worms" during the winter season, but often the knife causes more damage than the borers, especially if the digging must be done con-
FiG. 6. — The asphaltum treatment for the peach tree borer.
«ecutive years or by careless workmen. In the fall the soil is removed from the base of the tree to a depth of six or eight inches and the borers dug. In the spring they are dug again and the soil replaced. The second digging is necessary because in the fall manj^ of the "worms" are too small to be found.
Many preparations are being used on the trunks of trees ; some to keep the moths from depositing eggs, some to prevent the "worms" from entering, some to kill the "worms" after they have entered. None of these have been wholly satisfactory. Experiments along these lines by the writer led to the use of hard asphaltum, grades "C" and "D." with good results. This was applied early in the spring to badly infested trees from which the borers had not been dug. It was found that a thick heavy coating prevented both the issuance and the entrance of about 95 per cent to 98 per cent of the insects, the degree of efficiency •depending upon the thoroughness of the application. Asphaltum does
374 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION.
not penetrate, crack, deteriorate, or bind the tree, since it yields to the slightest pressure. Four years of experimenting have not shown the least injury.
The material is applied warm with a brush from five inches below to five inches above the ground. It is easier to apply two or more coat- ings than to try to put on more at one time than will adhere firmly. The first coating will harden very quickly and the second can be applied without loss of time. Two coatings are generally sufficient unless the bark is very rough. But in any case a thick, uniform covering is abso- lutely necessary for the best results.
Borers are seldom uniformly distributed over an orchard. Small blocks of trees here and there may be badly infested and the most of the orchard comparatively free from the pest. In such cases it is not necessary to treat all of the trees with asphaltum, but it is necessary to examine them carefully, for in no other way can the true conditions be known.
A convenient way to handle the asphaltum is to mount an iron kettle on the running gear of an orchard truck and suspend beneath it a sheet- iron apron as a fire box. Keep hard asphaltum in the kettle all the time so that the melted asphaltum will not get too hot to carry in small con- tainers and apply directly to the trees.
We have also used asphaltum to a limited extent for covering wounds and for grafting. And although our experiments are not completed, we believe it may become very useful as a dressing for tree surgery.
SUMMARY.
In the fall throw the soil away from the trees and dig the borers. In the spring dig the borers again and apply a thick coating of asphaltum and replace the soil. Examine the trees each subsequent year to remove borers and to repair any thin or broken places in the asphaltum coating.
STATION PUBLICATIONS AVAILABLE FOR DISTRIBUTION.
REPORTS.
1SJ6. Report of the Viticultural Work during the seasons 1887-93, with data resiiud- ing the Vintages of 1894-95.
18LI7. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viti- cultural Report for 1896. '
1902. Report of the Agricultural E.xperiment Station for 1898-1901.
VJ03. Report of the Agricultural Experiment Station for 1901-03.
J:^04. Twenty-second Report of the Agricultural E.xperiment Station for 1903-04.
BULLETINS.
print. Endurance of Drought in Soils of
the Arid Regions. . 128. Nature. Value, and Utilization of
Alkali Lands, and Tolerance of
Alkali. (Revised and Reprint,
1905.) 133. Tolerance of Alkali by Various
Cultures. 147. Culture work at the Sub-stations. 162. Commercial Fertilizers. (Dec. 1,
1904.)
167. Manufacture of Dry Wines in
Hot Countries.
168. Observations on Some Vine Dis-
eases in Sonoma County.
169. Tolerance of the Sugar Beet for
Alkali.
170. Studies in Grasshopper Control.
171. Commercial Fertilizers. (June
30, 1905.) 174. A New Wine-cooling Machine.
176. Sugar Beets in the San Joaquin
Valley.
177. A New Method of Making Dry
Red Wine.
178. Mosquito Control.
. 179. Commercial Fertilizers. (June, 1906.)
181. The Selection of Seed- Wheat.
182. Analysis of Paris Green and
Lead Arsenic. Proposed In- secticide Law.
183. The California Tussock-moth.
184. Report of the Plant Pathologist
to July 1, 1906.
185. Report of Progress in Cereal In-
vestigations.
186. The Oidium of the Vine.
187. Commercial Fertilizers. (Janu-
ary, 1907.)
188. Lining of Ditches and Reservoirs
to Prevent Seepage and Losses.
189. Commercial Fertilizers. (June,
1907.)
190. The Brown Rot of the Lemon.
191. California Peach Blight.
192. Insects Injurious to the Vine in
California.
193. The Best Wine Grapes for Cali-
fornia ; Pruning Young Vines ; Pruning the Sultanina.
194. Commercial Fertilizers. (Dec,
1907.)
No. 195. 197.
198. 199. 200.
201.
202.
203.
204.
205.
206.
207. 208. 209. 210.
211.
212. 213. 214. 215.
216.
217. 218. 219.
220.
221.
222. 223. 224.
225.
226. 227.
The California Grape Root-worm.
Grape Culture in California ; Im- proved Methods of Wine-mak- ing ; Yeast from California Grapes.
The Grape Leaf-Hopper.
Bovine Tuberculosis.
Gum Diseases of Citrus Trees in California.
Commercial Fertilizers. (June, 1908.)
Commercial Fertilizers. (Decem- ber. 1908.)
Report of the Plant Pathologist to July 1, 1909.
The Dairy Cow's Record and the Stable.
Commercial Fertilizers. (Decem- ber, 1909.)
Commercial Fertilizers. (June, 1910.)
The Control of the Argentine Ant.
The Late Blight of Celery.
The Cream Supply.
Imperial Valley Settlers' Crop Manual.
How to Increase the Yield of Wheat in California.
California White Wheats.
The Principles of Wine-making.
Citrus Fruit Insects.
The House Fly in its Relation to Public Health.
A Progress Report upon Soil and Climatic Factors Influencing the Composition of Wheat.
Honey Plants of California.
California Plant Diseases.
Report of Live Stock Conditions in Imperial County. California.
Fumigation Studies No. 5 ; Dos- age Tables.
Commercial Fertilizers. (Oct. 1911. J
The Red or Orange Scale.
The Black Scale.
The Production of the Lima Bean.
Tolerance of Eucalyptus for Alkali.
The Purple Scale.
Grape Vinegar.
d
CIRCULARS.
No. 1. Texas Fever.
7. Remedies for Insects. 9. Asparagus Rust.
11. Fumigation Practice.
12. Silk Culture.
15. Recent Problems in Agriculture. What a University Farm is For. 19. Disinfection of Stables.
29. Preliminary Announcement Con-
cerning Instruction in Practical Agriculture upon the Univer- sity Farm, Davis, Cal.
30. White Fly in California.
32. White Fly Eradication.
33. Packing Prunes in Cans. Cane
Sugar vs. Beet Sugar.
36. Analyses of Fertilizers for Con- sumers.
39. Instruction in Practical Agricul- ture at the University Farm.
46. Suggestions for Garden Work in California Schools.
4 8. Butter Scoring Contest, 1909.
50. Fumigation Scheduling.
No. 52. Information for Students Con- cerning the College of Agricul- ture.
55. Farmers' Institutes and Univer- sity Extension in Agriculture.
58. Experiments with Plants and Soils in Laboratory, Garden, and Field.
60. Butter Scoring Contest, 1910.
61. University Farm School.
62. The School Garden in the Course
of Study.
63. How to Make an Observation
Hive.
64. Announcement of Farmers' Short
Courses for 1911.
65. The California Insecticide Law.
66. Insecticides and Insect Control.
67. Development of Secondary School
Agriculture in California.
68. The Prevention of Hog Cholera.
69. The Extermination of Morning-
Glory.
70. Observations on the Status of
Corn-growing in California.
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