October, ipip 



BETTER FRUIT 



Page p 



Iree itself producing over 300 pounds. 

 If a tree of that age is not producing 

 over 100 pounds there is something 

 wrong, either a lack of a pollenizcr 

 or a lack of a pollen carrying agent, 

 namely, bees. 



\Vhat method of procedure must we 

 follow to introduce the pollenizer into 

 the orchard, and how far apart should 

 the pollenizer be? In orchards al- 

 ready established the trees must either 

 be budded or grafted. If the trees are 

 under six years they may be budded. 

 The cherry tree buds very readily. It 

 may also be grafted at that age, graft- 

 ing into one year old wood, using a 

 whip graft. If the trees are eight 

 years or older a cleft graft would be 

 preferable, not cutting into larger 

 than three-inch wood, as it will take 

 longer for the graft union to heal 

 over. If the tree is an old one a few 

 small limbs should be left to take up 

 the surplus sap, which might other- 

 wise drown the grafts. It might be 

 well to paint a band of tanglefoot 

 around the trunk to prevent ants from 

 crawling up the tree. The ants herd 

 aphids in the tree like they were a 

 bunch of goats and usually select ten- 

 der grafts for their pasture. Should 

 the grafts become infested with aphis 

 they will make very little growth that 

 season. Vigorous trees only should be 

 grafted; grafts will not grow on a 



gumosis infested tree. In three years' 

 time the tree will have formed a new 

 top, that is, a top which will produce 

 an abundance of blossoms. As to the 

 distance apart that the poUenizers 

 should be, it would not be safe to have 

 any self-sterile tree further than 75 

 feet from a pollenizer, as the yield 

 rapidly falls off where the trees are 

 at a greater distance. Some growers 

 have made it a practice to graft but 

 one limb in a tree. It is a mistake not 

 to graft over the whole tree, with the 

 exception of a few small limbs, be- 

 cause if only one or two limbs are 

 grafted, the resulting growth will be 

 very disappointing. A single graft of 

 this nature stands no chance of get- 

 ting its share of sap so does not make 

 a growth of over a foot or so when it 

 should grow three to five feet. If 

 the varieties are mixed in the picking 

 box the fruit stands a chance of being 

 rejected by the canneryman. If the 

 whole tree is Waterhouse there will be 

 no chance of mixing the varieties. 



Needless to say, bees in abundance 

 should be a part of every orchard. 

 Enough bees should be provided to be 

 able to pollenize the whole orchard in 

 a few hours, if necessary, for during 

 rainy sijrings there may not be more 

 than a few hours of sunny weather in 

 which the bees can carry on their im- 

 portant work. 



The Fatality of Crown Gall in Apple Orchards 



By J. M. Van Houten, Iowa 



IF you were building a house to live 

 in for forty years, would you build 

 it of plaster or bricks? Would you 

 situate it in the valley near the floods 

 or on the proverbial rock, high and 

 dry? 



In a similar way, if you were plant- 

 ing out an orchard, would you plant 

 one comparable to the plaster, that 

 would stand up only a few years, or 

 would you make one like the brick, to 

 last for a long time? 



Crown gall has been known for a 

 long time but its injury to apple trees 

 has not been known for long and what 

 is known now is still more or less 

 vague. Back in 1910, at the conven- 

 tion of the National Nurserymen's As- 

 sociation held in Denver, members of 

 that body became agitated in regard to 

 the amount of damage caused by this 

 growth and appointed a committee for 

 investigational purposes. Mr. E. S. 

 Welch, president of the Mount Arbor 

 Nurseries of Shenandoah, Iowa, hap- 

 jjcned to be a member of this com- 

 mittee. 



By securing co-operation of aulhoii- 

 ties at the Iowa Experiment Station at 

 -Ames, he has carried on experiments 

 at his place which when finished, will 

 no doubt be of great value to orchard- 

 ists as well as nurserymen. 



In the spring of 1012, the first plant- 

 ing, consisting of .SIO trees affected 

 with crown gall and 246 normal trees, 

 was made. There were two varieties, 

 .lonathan and Wealthy, there finally 



State College of Agriculture 



being 200 of the latter infected and 

 210 of the former, their totals being 

 326 and 330, respectively. 



It seems strange that crown gall in- 

 fected apple trees showed more life 

 than those that were supposed to be 

 healthy, but such was true, for at the 

 end of five years, more of the infected 

 trees were alive than the normal ones. 

 However, conclusions cannot satisfac- 

 torily be drawn from this, for in the 

 severe winter of 1916-1917, the stand 

 of infected trees was reduced to 91 

 per cent while 95 per cent of those 

 trees in the healthy block were still 

 standing. Perhaps the more satisfac- 

 tory conclusion might be drawn from 

 the latter fact. 



Different varieties of apples have 

 been known to vary in susceptibility 

 to disease. The same is true of crown 

 gall. While the experiment itself es- 

 tablished conclusively the fact that 

 Wealthy is more susceptible than Jon- 

 athan, it has been generally recognized 

 that hardier varieties are more seri- 

 ously affected with crown gall. Take 

 such varieties as the Patten Greening, 

 Brilliant, Okabena, Eastman, Anisin, 

 Wolf River, Tolman, Sops of Wine, the 

 Ben Davis group, Winesap and Jona- 

 than and Wealthy as well, are known 

 to be particularly susceptible to crown 

 gall. Other varieties as Duchess of 

 Oldenberg or Hibernal are seldom in- 

 fected with the disease. The various 

 varieties of crab are heavily struck. 



The fact that Wealthy is more sus- 



ceptible than Jonathan was borne out 

 by infections. Soil on which the ex- 

 periment had been carried on had had 

 infected trees in before, so that the 

 bacteria which spread the disease 

 were present in the soil. Some trees 

 of each variety, free from infection, 

 were planted, and investigation 

 showed that 62 per cent of the wealthy 

 became infected while only 12 per 

 cent of the Jonathan succombed. 



Trees can recover from crown gall, 

 but of course are stunted from being 

 held back by the disease. From those 

 trees that were infected when planted, 

 it was found that 81 per cent of the 

 Wealthy had thrown off the disease 

 in five years, while 31 per cent of the 

 Jonathan had recovered. This goes 

 further to prove the greater hardiness 

 of the latter variety. 



Effects of Galls. 



Galls were found to be of two vari- 

 eties, the hard gall and the soft gall. 

 The hard gall is woody, and seems 

 more like a dead body, as if the gall 

 were dead or lying dormant, while the 

 soft gall or hairy root, is a more lively 

 body and seems to be more actively 

 growing. Perhaps the fact that of the 

 infected Jonathans that recovered, 36 

 per cent of the Jonathans were of the 

 hard galls and only 29 per cent of the 

 soft, may indicate a more active 

 growth in case of the soft galls. 



This hairy root, a form of soft gall, 

 is peculiar. When a tree is planted 

 out, it seems to make a good growth, 

 due to the large number of sap roots 

 which are put out from the gall. How- 

 ever, if the gall is located in a position 

 as to directly interfere with the flow 

 of sap, it will later stunt the tree. 



Galls act on trees by interfering with 

 sap flow. In this manner, a gall on 

 the main root is more serious and 

 more of a detriment than one on some 

 side roots or secondary feeders. When 

 the sap flow is cut off, the tree is 

 stunted as was shown in the experi- 

 ment b>- reduction in twig growth and 

 growth of trunk diameter. 



Our grandfathers used to girdle or 

 partially cut off the sap flow of the 

 trees to throw them into fruitfulness. 

 Crown gall does the same in a modi- 

 fied way, thus throwing the infected 

 trees into fruitfulness early. This was 

 shown by the fact that in five years, 

 those trees which were known to have 

 been infected, showed blossoms and 

 fruit spurs while normal trees were 

 still making their younger growth. 



Galls that were formed on stock and 

 union seemed to be equally harmful, 

 being both on main feeding portions 

 of the tree. Galls on secondary roots 

 naturally seemed to be less harmful 

 than those on main roots. 



The experiment as carried on at 

 .Shenandoah, of course, has not had 

 time to run to trees of bearing age, 

 but does cover that kind of stock 

 which would be planted out by the or- 

 chardist or grown by the nurseryman. 

 Crown gall is dangerous. It is quar- 

 antined from interstate shipment in 



Continued on page 2'1. 



