Winter killing of the wood and catkins is probably the limiting factor in growing filberts in Western New York. Satisfactory varieties must possess catkins hardy enough to provide sufficient pollen for pollination purposes. There must also be very little killing of the wood or the crop will be reduced in proportion to the amount of wood that is winter injured. Several years observations in the Station filbert orchard at Geneva have shown a great variation in hardiness of filbert varieties. With some varieties the catkins are severely injured each winter, with others, very little injury occurs. Because of this great variation in hardiness we must accumulate as much data as possible concerning the ability of varieties to withstand our winters, especially the mild winters, before we are in a position to make definite variety recommendations.

Last winter, 1932-33 was especially hard on filberts, in fact, much more winter injury was experienced than at any time since the Station orchard was set in 1925. It was a good season to separate the hardy and tender sorts. Throughout the winter the weather was exceptionally mild and favorable for that type of winter injury due to early growth activity. In a normally cold winter catkin killing as a rule is not very serious, except on a few tender varieties. Although catkin killing was so serious at Geneva, S. H. Graham of Ithaca, who is growing a number of varieties on an exposed location where winters are more severe than at Geneva, reports that his trees suffered less catkin injury than at any time since he has been growing them. Catkin killing does not seem to be due to extreme cold during the winter and rarely are the catkins injured before late February or early March. Injury may be severe even though the temperatures are not lower than the catkins are thought to endure when in bloom. Apparently the injury may be due to the cumulative effect of dessication throughout the winter months, this effect becoming apparent shortly before the catkins bloom. Catkins forced into bloom prior to late February bloom normally and without apparent injury.

The data on winter injury of catkins is being accumulated for two purposes. First, it is being used as a basis for recommending varieties as pollinators; and second, it is being used in selecting parents for breeding hardy varieties.

The amount of winter killed catkins is determined by observation during the blooming season in late March. All catkins that fail to open, or open weakly and shed no pollen, are considered winter killed and the proportion that are killed is expressed in per cent.

Based on the amount of winter injury of catkins during the winter 1932-33, I am making four groups. First, those varieties in which all, or practically all the catkins were killed. In the varieties suffering such severe catkin injuries, much of the wood was killed, but this will be treated separately.

The varieties in this group are Nottingham, Early Prolific, Garibaldi, Kentish filbert, Pearson's Prolific, Princess Royal, the Shah, Webb's Prize Cobb, Bandnuss, Barr's Zellernuss, Berger's Zellernuss, Grosse Kugelnuss, Heynicks Zellernuss, Lange von Downton, Multiflora, Sickler's Zellernuss, and a Corylus rostrata brought into cultivation from a glen a few miles away. The planting of varieties in this list is not recommended.

The second group includes those sorts in which 50 to 90 per cent of the catkins were killed. The varieties are Barcelona, Daviana, Fertile de Coutard, Montebello, Cannon Ball, Duke of Edinburgh, Duchess of Edinboro, Prolific Closehead, Red Skinned, Kadetten Zellernuss, Kaiserin Eugenie, Kunzemuller's Zellernuss, Liegel's Zellernuss, Prolifique a coque serree, Romische Nuss, Schlesierin, Truchsess Zellernuss, Voile Zellernuss, Kruse, and Littlepage, a variety of Corylus americana from Indiana. Some wood killing occurred among the varieties in this group. None of these varieties should be depended upon for pollination purposes.

The third group includes those varieties experiencing 20 to 50 per cent winter injury. The varieties are Kentish Cob, Italian Red, Bollwiller, Red Aveline, White Aveline, and Vollkugel. These varieties may be planted with caution if too much dependence is not placed upon them as pollinators.

In the fourth group are those with less than 20 per cent of catkin injury. These are Clackamas, Cosford, Minna, Early Globe, English Cluster, Medium Long, Oregon, Purple Aveline, Red Lambert, White Lambert, D'Alger, Althaldensleber, Ludolph's Zellernuss, Luisen's Zellernuss, Neue Riesennuss, Eickige Barcelonaer, and Winkler and Rush, the latter two being varieties of Corylus americana. Varieties from this group and the third group should be used as pollinators and as parents in breeding work to develop catkin hardy varieties.

Winter killing of the wood has not been as extensive nor as serious as catkin killing. It is usually slight and confined to a few varieties but during the past winter 1932-33, many varieties killed back severely.

The varieties are grouped according to the amount of winter injury of wood. Varieties in which more than 50 per cent of the wood was killed are Nottingham, Early Prolific, Garibaldi, Princess Royal, Webb's Prize Cob, Bandnuss, Grosse Kugelnuss, Jeeves Samling, Kaiserin Eugenie, Multiflora, Kurzhullige Zellernuss, Lange von Downton, and the Corylus rostrata previously mentioned.

Varieties experiencing from 20 to 50 per cent of wood killing were Barcelona, Red Aveline, Montebello, Berger's Zellernuss, Einzeltragende Kegelformige, Heynick's Zellernuss, Prolifique a Coque serre, Sickler's Zellernuss, Voile Zellernuss, and Russ.

In the following varieties from 5 to 20 per cent of the wood was winter-killed: Minna, Bollwiller, Duchess of Edinboro, Pearson's Prolific, The Shah, Barr's Zellernuss, Kunzemuller's Zellernuss, Liegel's Zellernuss, Romische Nuss, Schlesierin, Truchsess Zellernuss, Vollkugel and Littlepage.

Varieties which are not injured at all or less than five per cent were Clackamas, Cosford, Daviana, Early Globe, English Cluster, Kentish Cob, Fertile de Coutard, Italian Red, Medium Long, Oregon, Purple Aveline, Red Lambert, White Aveline, White Lambert, D'Alger, Cannon Ball, Duke of Edinburgh, Kentish filbert, Prolific Closehead, Red Skinned, Eckige Barcelonaer, Kadetten Zellernuss, Ludolph's Zellernuss, Luisen's Zellernuss, Kruse, Neue Riesennuss and Rush and Winkler.

It is evident from this data that although many filbert varieties are subject to serious winter injury, there are still a number to choose from that are sufficiently hardy under western New York conditions.

Variety Notes

The Station variety collection has grown considerably since I discussed filberts before you in 1929. At that time the collection consisted of 28 varieties; today there are under test at Geneva 99 varieties of Corylus avellana, five varieties of Corylus americana, five Jones seedlings, and six species of Corylus, or a total of 115 forms.

Later observations on the original orchard have indicated that the original variety recommendations should be modified. Certain varieties imported from Europe and renamed, or were misnamed when imported, and that have been disseminated by nurseries are apparently identical with certain German varieties recently imported by the Geneva Station. Preliminary observations indicate that some of these recently imported German sorts are worthy of further attention.

Barcelona which was the most productive variety during the first few years has been falling behind in yields the past two seasons. This, coupled with the winter killing of wood and catkins last winter, makes Barcelona a doubtful variety to plant.

Italian Red in 1932 averaged nearly eight pounds of nuts to the tree, the heaviest yield of any variety in the orchard. The crop this year promises to be satisfactory and one of the largest in the orchard, in a season when varieties generally are very light. S. H. Graham of Ithaca reports that "Italian Red has been the best and most regular bearer of any of the European filberts" that he has tried.

Kentish Cob averaged five pounds per tree last year and Cosford over four pounds. The latter variety is catkin hardy and should be in every planting. White Lambert and Red Lambert, still light croppers, possess very hardy catkins and for that reason deserve trial.

Oregon, Purple Aveline, and English Cluster bear heavy crops, but are difficult to husk and the nuts too small for market. For home use they should be very satisfactory.

Among the newer nuts fruiting last year for the first time, Neue Riesennuss, originating in Germany in 1871, is promising. It is one of the largest in the Station collection, is a bright light brown in color with slightly darker stripes, and last winter experienced very little catkin injury and no wood injury. As yet nothing is known of its productiveness in this country, but in Germany it is said to be productive.

Some of the nuts distributed in this country by Mr. Vollertsen of Rochester are proving identical with some of the German sorts recently imported by the Station. I do not intend to suggest now that the name of the varieties in this country be changed to those of the varieties with which they are identical. Later when all of these imported varieties are in full bearing the matter of changing names will be brought to your attention again.

Red Lambert (of Vollertsen) is identical with Beethe's Zeller, and Italian Red (of Vollertsen) is identical with Gustav's Zeller. Minna (of Vollertsen) is not the Minna of German descriptions.

Filbert Breeding

The breeding work with filberts is following two lines. Hardiness of wood and catkin is of prime importance and to develop varieties satisfactorily in these respects those varieties that have proved hardy are being crossed with different sorts that have desirable nut and tree characters. Hardiness is also being sought by crossing the Rush native hazel with varieties of Corylus avellana. 535 trees from this cross, made by Mr. Reed, are now growing in a fruiting plantation at the Station, and several hundred more from other crosses are in the nursery row. With this wealth of material coming along, it is reasonable to assume that the day is not far distant when satisfactory varieties will be available for northern planting.