Page 38 



BETTER FRUIT 



February 



ENTRY NO. 4~THE CUSHMAN POWER SPRAYER, WHICH WON THE GOLD MEDAL IN 

 THE POWER SPRAYER CLASS, AT HORTICULTURAL CONGRESS, COUNCIL BLUFFS, 1910 



beneficial results of such a fungicide as 

 bordeaux. Foggy conditions, however, 

 produced decidely different results from 

 rain. The deleterious substances dis- 

 solved in rain water are largely washed 

 ofif the foliage by the rain itself, whereas 

 dew usually merely wets the foliage and 

 then dries up. There is very little of 

 the washing process. Thus each time 

 dew collects upon the foliage a small 

 amount of spray material is apt to dis- 

 solve, if it is at all soluble in atmospheric 

 moisture, and with the alternate wetting 

 and drying of the foliage, and no actual 

 washing ofif, extremely minute quantities 

 of a toxic substance may eventually 

 accumulate in sufficient amounts in the 

 leaf to cause injury. This is no doubt 

 the explanation of the extreme sensitive- 

 ness of apple foliage in this section to 

 spray materials in general, and is prob- 

 ably the explanation of certain difficulties 

 that have been met with in the apple 

 mildew investigation. 



The solution of the mildew problem in 

 Pajaro Valley may be of more than local 

 value, for new and non-injurious fungi- 

 cides are much needed east of the Rocky 

 Mountains, and it is hoped that the 

 exacting conditions of this section will 

 lead to the development of something 

 usueful in those localities where similar, 

 but not so severe, climatic conditions 

 prevail at times. 



Since the soluble sulphides are out of 

 the question, if sulphur is to be used at 

 all it must be in an insoluble form, and 

 at present the matter is sifted down to 

 the use of sulphur itself. But while 



PLANT LICE 

 Green Apple Aphis: 1, Young stem mother; 2, 

 Adult stem mother; 3, Adult apterous viviparous 

 female, second generation; 4, Young female, sec- 

 ond generation; 5, Winged viviparous female of 

 third generation; 6, Pupa of preceding; 7 and 8, 

 Apterous male and female. Woolly Apple Aphis: 

 9, Apterous viviparous female; 10, Fall migrant; 

 11, Overwinter young. Black Peach Aphis: 12, 

 Adult apterous viviparous female; 13, Young 

 female, first instar; 14, Alate female; 15, Chrysopa 

 sp. and eggs; 16, Cocoon of preceding. 



ground sulphur is effective against the 

 mildews of other plants and in other 

 localities, the finest grades obtainable are 

 of practically no use here. In the work 

 previously done by Mr. Volck it was 

 found that when lime-sulphur solution is 

 added to a solution of copperas, or iron 

 sulphate, a flocculent, black, muddy mass 

 precipitates, which is ef?ective in con- 

 trolling mildew. This discovery has been 

 followed out by an extensive series of 

 experiments during the past two seasons, 

 and it appears that the virtue of that 

 material lies principally in the large 

 amount of precipitated sulphur which it 

 contains in addition to the black iron 

 sulphide. This sulphur is of the same 

 nature as the finely ground article used 

 for grape mildew, but is far finer than 

 anything that can be produced by grind- 

 ing. In addition, a number of other 

 sprays have been prepared containing 

 sulphur in an extremely finely divided 

 form, and all have possessed the virtue 

 of mildew control, and also have the 

 very desirable property of stimulating 

 the growth of the tree. 



To somewhat counteract these good 

 qualities we have two bad features that 

 accompany sulphur sprays. First (and 

 again probably due largely to the sensi- 

 tiveness of the trees in this valley), if 

 the spray is too heavily applied it is apt 

 to cause a dropping of the fruit and, to 

 some extent, the foliage. Second, the 

 fruit having a deposit of spray material 

 on its exposed side is more susceptible 

 to sunburning when a period of hot days 

 comes. The foliage dropping that accom- 

 panies the use of these sprays is of no 

 serious consequence, since the growth 

 stimulated more than makes up for the 

 loss, and it is hoped that a method of 

 entirely eliminating the damage to the 

 fruit will be eventually worked out. 

 During the past season a considerable 

 amount of commercial spraying with this 

 so-called iron sulphide spray was done 

 in this valley, and the results are encour- 



aging. The method of preparing the 

 spray and the times for application will 

 be discussed in the bulletin to be issued 

 later. 



The problem is not yet finished, but 

 it is hoped in the end to have a satis- 

 factory method for the control of mildew 

 worked out. 



Figure 1 — Western Tent Caterpillar: a, Female 

 moth; b, c, Males; mm, Apple twig with egg 

 masses; f, Cocoon; 3, Egg masses of American tent 

 caterpillar, life size. Figure 2 — Cottony Maple 

 Scale: a, Scales mostly hidden by secretion, life 

 size. Figure 3 — Codling Moth: a, Wings closed; 

 b, Open; enlarged about one-fourth. Figure 4 — 

 Apple showing white egg of codling moth (under 

 letter /), life size. Figure 5 — Fruit Tree Leaf 

 Roller: a, Moth, wings open; b, Closed; c, d, Egg 

 patches, hatched; all life size. Figure 6 — Pear 

 with Howard's Scale: The young appear as minute 

 white specks; life size. Figures from photographs 

 by the author. Photographs by C. P. Gillette, Fort 

 Collins, Colorado. 



