bettewFruit 



"^"^ The Pioneer Horiicaliural Jourtih of the Pacific Northwest 



Entered •» second-cl.ss matter April 22, 1918, at the Postoffice at Portland, Oregon, under act 



of Congress of March 3, 1879 __^ 



Vol. XVI 



Portland, Oregon, April, 1922 



Number 10 



Pests of the Strawberry Industry 



S 



TRAWBERRIES are subject to only 

 a few diseases in northwestern dis- 

 tricts, but of insect pests there are 



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quite a few that are already well established 

 and have proven serious. This does not 

 mean that the strawberry industry is 

 doomed, as there is usually relief in sight. 

 In all cases it does not inean that absolute 

 control methods are present, but when cer- 

 tain methods are used and followed the 

 industry can go on. 



First and foremost, be sure and have your 

 plants inspected in the field before setting 

 out a new patch. Second, be sure that the 

 patch you are setting is free from the dis- 

 eases and pests by knowing past history and 

 conditions of crops grown there. Also, if 

 your neighbor's patch or your own patch is 

 infested, protect your new one from them. 



Leaf Spot — Our most common disease 

 of the strawberry throughout this district 

 is the leaf spot. The disease makes its ap- 

 pearance on the leaf caly,x and fruit stems. 

 The spots are very small, deep purple or 

 red, and are usually first in evidence on the 

 upper surface of the leaves. Eventually 

 they become gray or white in the center. 

 The cause is a fungus which lives within 

 the leaves throughout the year, remaining 

 within the leaf during the winter. 



Control measures are these: Plant only 

 healthly plants, procured, if possible, from 

 fields where the disease is not present. In 

 any case, all diseased leaves from plants 

 should be picked off before planting. The 

 common practice of mowing off and burn- 

 ing leaves after harvest is beneficial, as it 

 destroys the leaves with the fungus in them. 

 If the trouble is serious, use Bordeaux mix- 

 ture 4-4-50. Spray first before blossom- 

 ing; second, after blossoming, and tliird, 

 after harvest. 



Rhizoctonia — The Rhizoctonia is a soil 

 fungus which works in the soil and works 

 its chief injuries by causing rots of the stem 

 under the ground or by rotting off roots. 

 The roots are rotted off and the top of the 

 plant shows the effects by the outer leaves 

 dying first, leaving the center leaves green. 

 These often die soon also. Often the leaves 



B?/ C. O. Weiss 



District Horticultural Inifector, Everett, Washington 



keeping the weeds down and also mulchmg 

 to keep the fruit from the ground. 



STRAWBERRY Root Weevil— The 

 strawberry root weevil is by far the 

 most injurious insect pest of the strawberry, 

 in Washington. Just recently the serious 

 nature of the pest has been brought into 

 prominence because qf the quarantine issued 

 by the department of agriculture of the 

 state of Washington, which prohibits any- 

 one from selling, bartering or giving avvay 

 strawberry plants that have not passed in- 

 spection. 



The strawberry root weevil was undoubt- 

 edly introduced from Europe. The first 

 report we have of it in this country is in 

 Massachusetts in 1852. Since that time it 

 has spread steadily westward and also north- 

 ward. It was reported from Wyoming in 

 1893, from New Mexico in 1894, from 

 Minnesota in 1895, from Montana in 

 1897, and from W.ishington in 1904. 

 When we consider the fact that this insect 

 cannot fly, but must almost depend entirely 

 on outside agencies for transportation, its 

 spread seems fairly rapid. 



In a survey I have made, this pest has 

 been found in many communities of Sno- 

 homish, Skagit and Whatcom counties. 



Destructiveness — Strawberry root wee- 

 vil is a pest both as a beetle and a grub. 



I There is excellent fromise that | 



I this season zi-ill be a favorable one for | 



I strau'berr-j grozvers of the Northzvest. | 



I Reforts indicate that the flants have \ 



i come through the winter in the best | 



I of condition, in nearly every district, | 



I and greater cannery capacity than | 



I ever before zc-ill be a helfful rnarket- | 



I ing factor. For the good of the | 



i industry it behooves every grozver to | 



I be on the alert for diseases and fests | 



I inimical to the strazvberry. The ex- | 



I cellent resume on fests and control | 



I measures here fresetited by Mr. | 



I Weiss is that he gave recently before | 



I the Western Washington Horticul- | 



I tural Association convention. \ 



i i 



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turn reddish and then brown when dying. 

 There is no remedy except the rotation 

 of crops to reduce the amount of fungus in 

 the soil. There is one significant fact in 

 connection with Rhizoctonia on strawber- 

 ries that should be noticed. When this 

 fruit is put on ground following potatoes, 

 the Rhizoctonia is almost always quite 

 severe. So do not follow potatoes with 

 strawberries directly, but let some other 

 crop intervene. Potatoes are always very 

 subject to, and often severely troubled with 

 Rhizoctonia, and when they have been in 

 the soil leave a residue of the disease behind 

 them. For the control of the Rhizoctonia, 

 start a rotation, using crops known to be not 

 affected by the fungus such as grains, 

 grasses and clover. 



Fruit Rots — Fruit rots result from the 

 berries coming in contact with the damp 

 earth and becoming rotted on the lower 

 side. Sometimes other areas in the fruit 

 become rotted. One form of rot that does 

 this is the gray mold or Botrytis mold. 

 Often the affected areas will become 

 covered with a mass of gray mold. This 

 trouble may spread and involve the whole 

 fruit cluster. 



Control of this trouble consists in avoid- 

 ing a wet location, obtaining good drainage. 



The beetles feed on the foliage, strippmg 

 and ragging it in a characteristic manner. 

 The grubs, however, are by far the more 

 injurious. They feed on the entire root 

 system of the strawberry. The smaller 

 grubs are usually found feeding on the 

 fibrous rootlets, often devouring them en- 

 tirely or barking them so they die. A 

 seriously infected plant m.iy be kicked out 

 with the foot or easily pulled up, often 

 with the fibrous root system eaten away. 



Undoubtedly a portion of the grubs feed 

 close to the main tap root and their feed- 

 ing there will sometimes girdle the crown. 

 The larger grubs are often found buried in 

 the tap roots and this food seems to give 

 them a more pinkish cist, giving rise to the 

 common belief that two species of larvae 

 are present. 



The beetles may be present in a patch 



