Page Ten 



BETTER FRUIT 



June, 1922 



spheric and climatic changes. Immersion 

 in a film of water will cause pollen to 

 germinate somewhat and we may consider 

 moisture the worst enemy of pollen that 

 we have. 



Germination or growth of a pollen grain 

 occurs within a short time after immersion 

 in a suitable liquid. It has been found that 

 90 per cent of the pollen will be germ- 

 inated in four hours at 65 to 70 degrees F. 

 and a little less at 50 degrees. As light or 

 darkness has but little effect on germina- 

 tion of the pollen, the main thing is to 

 have a period of time long enough for the 

 catkin to dry out and the pollen to be 

 shed. Therefore, if there comes a period 

 of comparatively dry weather followed by 

 light rain, but not heavy rains, we may ex- 

 pect pollination to take place. The surface 

 of the psitil is very rough and it would un- 

 doubtedly require a rather heavy rain to 

 wash off the pollen. 



Pollen grains are resistant to cold tem- 

 peratures until they are subjected to the 

 extreme temperatures such as those of 

 December, 1919. Exposure to temperatures 

 of zero for 96 hours only reduced the 

 germinability or viability of the pollen 

 about 12 per cent. From this we can 

 deduce that frosty weather is of less mo- 

 ment than rainy weather. However, when 

 we consider the season of 1921 and its 

 excessive rainfall and then see the average 

 crops of filberts that have been produced 

 we are fairly sure of a good crop of filberts 

 under any but the worst conditions. 



After considering the catkin and the 

 pollen what of the pistillate flowers.' The 

 pollen may be washed off the pistils, but 

 it is doubtful if any other extensive injurv 

 from rains can take place. 



The pistillate flowers are more suscep- 

 tible to low temperatures than is the pollen. 

 Where pollen was little injured at zero 

 in 96 hours, the pistillate flowers had 90 

 per cent of the stigmas or three-fourths to 

 one-half of the pistil that is exposed killed. 

 A temperature of 1 5 degrees killed 20 

 per cent in 12 hours and 25 per cent in 24 

 hours. Thus, it appears that the pistillate 

 flowers are much more susceptible to low 

 temperatures than the catkins. It would 

 seem that it might be wise to avoid some of 

 the worst frost pockets instead of advocat- 

 ing the planting of filberts anywhere west 

 of the Cascade mountains, irrespective of 

 air drainage. During the last ten years we 

 have had temperatures below 1 5 degrees. 



The main question, then, is one of pol- 

 lination. In all of the literature available, 

 little or nothing is said of pollination. E. 

 A. Bunyard of England s,iys, "No work 

 has yet been done to test the self -sterility, 

 or otherwise, of nuts, but judging from 

 large orchards, one would assume that the 

 commonly grown varieties are quite self 

 fertile." Other references than this one 

 amount to little, so it can be assumed that 

 the pollination question is not a serious one, 

 either from the fact that European growers 

 generally have planted more than one 



variety, or that the varieties there are really 

 self- fertile. 



nr^F.STS carried un during the past two 

 A years have not shown any variety of 

 filberts that was self-fertile. On the 

 Barcelona this past year 306 pistillate 

 flowers were sacked and allowed to self- 

 pollinate. Two nuts resulted; 112 

 Daviana flowers were selfed with no nuts 

 resulting. Seventy-two Duchilly were 

 selfed with the same results. One-thousand 

 and seventy-three pistillate flowers of 

 thirty-one separate varieties, in addition to 

 those mentioned, were also selfed and 

 twelve fruits resulted or about one per cent 

 of the blossoms set fruit. 



(liant Daviana filliert, 16 years old. 2i feet tall 



nnd having spread of 20 feet. CCuts by courtesy 



(Oregon Gtower.) 



To check the percentage of fruits borne 

 from self-pollination, counts were made of 

 blossoms that were wind pollinated. These 

 were made in different orchards and on 

 different varieties. In one orchard it was 

 shown that il per cent of the blossoms set 

 fruit. In another 5 7 per cent of the 

 blossoms set fruit. This would indicate 

 that the one per cent set from self pol- 

 linated blossoms would not form more than 

 a small per cent of the crop. 



Further work is necessary, but it would 

 seem from last year's work that the filbert 

 sets fruit on a very high percentage of its 

 blossoms. One thing, then, that must be 

 considered is the necessity for continually 

 producing vigorous new wood, as this wood 

 is most productive of both types of flowers. 



Since all varieties are self-sterile It must 

 then be a problem of cross-pollination. 

 With other fruits we find that some varie- 

 ties cross-pollinate to good advantage, while 

 others are inter-sterile. This condition 

 exists in the filbert. Taking the Barcelona 

 we find that all of the common varieties 



will cross-pollinate it to a certain extent; 

 some more, some less. There are some 

 lesser known varieties such as the Fertile de 

 Coutard that arc entirely inter-sterile. 



One of the best pollinators is the Cos- 

 ford, a variety little known. This resembles 

 the Daviana. The Du Chilly has uniformly 

 given good results and, due to the fact that 

 it is a good commercial variety, is un- 

 doubtedly one of the best for this purpose. 

 The one drawback comes from the fact 

 that it blooms considerably later than the 

 Barcelona. 



With the Du Chilly, the varieties that 

 have been recommended by the different 

 growers all work fairly well. Again the best 

 results for last year were with little-known 

 varieties. Further tests are necessary to 

 show whether or not they are enough 

 superior to warrant attempting to propagate 

 them to any extent. None of them that 

 gave the best results on the Barcelona or 

 Du Chilly are heavy enough bearers to be 

 really commercial varieties. 



This brings us to the question of inter- 

 planting. Before taking that up we must 

 consider how far the pollen will be carried 

 and also the proportion of pollenlzers to 

 plant. 



Some trees were stripped of their cat- 

 kins and left to wind pollinate. Those 

 over 100 feet distant bore less than one 

 per cent nuts. Although light, the pollen 

 evidently does not carry very far. In 

 observations in the field it seemed that 

 trees plant 40 to 60 feet from a pollenizer 

 bear good crops, though the ones at 60 feet 

 sometimes appear light. From evidences at 

 hand it would seem that the trees should 

 be more than two trees distant, from the 

 pollenlzers, that is when planted 20 to 25 

 feet apart. This can be accomplished in 

 one way by planting in every third tree 

 in every third row; one pollenizer to 8 

 of the regular variety. Thus this would 

 give eight Barcelon.is and one Du Chilly. 



In seasons when the blooming time of 

 Barcelona and Du Chilly are wide apart it 

 is doubtful if the Barcelona receives full 

 benefit of the pollenizing ability of the 

 Du Chilly. An examination of the pistil- 

 late flowers last season showed that the 

 stigmas of many Barcelona flowers had a 

 dead, washed-out appearance before the Du 

 Chilly was ready to shed pollen. Under 

 these conditions it would seem advisable to 

 have an earlier pollenizer. 



The earlier blossoms would be taken care 

 of by the early blooming variety while the 

 later blooms would be pollenized by the 

 Du Chilly. This would give vigorous, 

 viable pollen for both early and late 

 blossoms. The last pollen of the season 

 is less viable than the earlier pollen. The 

 question of blank nuts is a large problem 

 some years and is unquestionably connected 

 with some phase of pollination. A pol- 

 lenizer that would come between the Du 

 Chilly and Barcelona and pollenize both 

 would give almost ideal conditions. There 

 are several varieties that are good for one 

 of the varieties and fair on the other. 



