O1EQN A 00 00 3 0 4 OLI297 I E Ci / E $1.00 41:49 I9S I121 Growing Hazelnuts in Ore;.,

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PUBLICATIONcurrent most THIS For http://extension.oregonstate.edu/catalogExtension Circular 1219 I May 1985 Oregon State University Extension Service Contents

Economic importance 3 Managing a hazelnut orchard (continued) Cropvalue ...... 3 Covercrops ...... 11 Geographic distribution ...... 3 Training and pruning ...... 12 Marketingaids ...... 3 Wound dressings ...... 12 Production costs ...... 3 Sucker control ...... 12 Locating the orchard ...... 4 Orchard nutrition ...... 13 Suitable soils ...... 4 Neworchards ...... 13 Determining soil suitability ...... 4 Potassium (K) ...... 13 Magnesium (Mg) ...... DATE. 13 Hazelnut varieties ...... 4 Lime...... 13 1,3 Nut development ...... 5 Nitrogen(N) ...... Mature orchard nutrition ...... 13 Floral initiation and development...... 5 Fertilizer needs OFand application ...... 13 Pollination ...... 6 Nitrogen(N) ...... 13 Pollinizer requirements ...... 6 Phosphorus (P) ...... 13 Pollinizer spacing and placement ...... 6 Potassium (K) ...... 13 Boron(B) ...... 14 Blanks, brownstain, and developmental dropouts...... 7 Insects...... 14 Blank formation ...... 7 OUT Brownstain ...... 7 Diseases...... 14 Flower cluster losses ...... 7 Orchard sanitation ...... 14 Growing and selecting planting stock ...... 7IS Bacterial blight ...... 14 Eastern filbert blight ...... 15 Method of propagating...... 7 Control...... 15 Propagating from suckers ...... 8 Graftedtrees ...... 8 Animals...... 15 Selecting planting stock ...... 8 Bluejays and squirrels ...... 15 15 Orchard design ...... 8 Deerdamage ...... Gophers and moles ...... 15 Intercropping with hazelnut trees ...... 8 Meadowmice ...... 16 Arrangement of permanent trees ...... information:9 Moss and lichen ...... 16 Establishing a new orchard ...... 9 Staking out the orchard ...... 9 Harvesting ...... 16 Using a planting board ...... 10 Leaves and trash on the ground ...... 17 Planting the trees ...... 10 Ground preparation for mechanical harvesting...... 17 Pruning at time of planting ...... 10 Time of harvest ...... 17 Protecting against sunburn ...... 10 Ethephon to loosen nuts ...... 17 Mulching ...... 10 Windrowing...... 17 Cleaning equipment on harvesters ...... 18 Managing a hazelnut orchard...... current 10 NontillagePUBLICATION ...... 10 Washing, drying, and storage ...... 18 Cultivation ...... 11 Washing ...... 18 Intercropping ...... 11 Drying ...... 18 Storage ...... 19 Weed competitionmost...... 11 THIS For http://extension.oregonstate.edu/catalog

2 Hazelnuts have been cultivated for The tree may produce a few nuts The Northwest's production is 4 to many centuries. Pliny, in 60 A.D., when 2 or 3 years old, but it is not 6% of world hazelnut production and narrated, "Filberts and hazels... are a considered to be in commercial produc- 2 to 3% of U.S. domestic production kind of nut and were called heretofore tion until it is 6 years old. Mature of all tree nuts (including hazelnuts, Abellinae, of their native place... they orchards produce from less than 1,000 walnuts, almonds, and pecans). Hazel- come out of Pontus into Natolia and pounds of dry nuts per acre to better nut prices are, therefore, influenced by Greece and therefore they may be than a ton or more. A well-managed the world production and supply of called pontic nuts." The hazelnut is a orchard will produce about 1,500 hazelnutsas well as the supply of widely distributed species in Europe pounds of dry nuts per acre as an all other nuts. and into Asia. average. It should remain productive Some authorities believe that the up to 40 years or more. Marketing aids name filbert was originallyfull beard, The Filbert/Hazelnut Marketing referring to the fact that in some Board, created in 1949, administers a varieties the husk entirely covers the Federal Marketing Order. The board is nut. Others believe the name has been composed of five growers, three derived from St. Philibert because processors, and one nonindustry August 22, the date dedicated to him, Economic importance member. The marketing order provides corresponds to the ripening date of the for the marketingDATE. of inshell nuts earliest hazelnuts in England. Al- Crop value according to market demands. Produc- though growers in Oregon usually call The contribution hazelnuts make to tion beyond the demands of the inshell them filberts, most customers know Oregon's economy is considerable. market must be shelled. them as hazelnuts. Between 1979 and 1983, the crop OFThe Filbert Bargaining Association, While there is one species of varied from 7,500 to 18,400 tons, and formed in 1972, bargains for grower hazelnut (Corylus cornuta) native to price and delivery conditions with all Oregon, the cultivated varieties of cash farm receipts ranged from $3 to $17.4 million. The value added by packers of record. In 1980, the hazelnuts (Corylus avellana) were processing is about 43% of the cash association represented about 60% of introduced to the United States from receipts. Therefore, the hazelnutOUT indus- the total tonnage in Oregon. Europe by Felix Gillet, a nursery The Oregon Filbert Commission was manager in Nevada City, California. try contributes between $12.3 and $38.3 million annually to Oregon's established in 1951 for sales promotion Between 1885 and 1905, he intro- economy. IS and production research. Commission duced Barcelona, DuChilly, Daviana, members are growers. Commission Hall's Giant, Montebello, Nottingham, activities are financed by grower and others. Some of these varieties are Geographic distribution assessments. still grown in the Pacific Northwest Hazelnut orchards cover the Wil- In recent years, large nut-marketing today. lamette Valley of Oregon from Eugene organizations from California have The natural growth of the hazelnut to Portland and from the foothills of begun to sell Oregon hazelnuts. (filbert) is a bush or a multitrunked, the Coast Range to the foothills of the shrubby tree. In Turkey and southern Cascade Mountains.information: Hazelnut trees Europe, it has been grown in this grow best on deep river-bottom soils, Production costs manner for centuries. In Oregon, but they also thrive on a wide variety of Production costs usually are classi- however, hazelnuts usually are grown other soils. fied into four major categories: cul- as single-trunk trees that may attain a The dominant feature controlling tural operations, harvesting, drying height of 30 feet under proper manage-the distribution of commercial hazel- and handling, and fixed charges. ment and soil conditions. nut production is the moderate climate Representative costs based on 80 acres While the hazelnut tree itself is quite of the coastal valleys of the Northwest of mature hazelnut trees were esti- hardy, it produces satisfactory crops currentas provided and influenced by the mated at $1,137 per acre in 1982 by only under moderate PUBLICATIONclimatic condi- Pacific Ocean. Oregon State University farm manage- tions. The catkins freeze at 15°F. The In 1980, there were nearly 22,000 ment specialists, county Extension female flowers, which bloom during acres of hazelnuts in Oregon. agents, and selected growers. January and February, will freeze at There is sufficient nursery stock At the time of publication, no more 10°F. most produced to plant about 1,000 acres recent cost analyses were available. Further, the tree cannot tolerate annually. Suitable hazelnut land is Around 30% of these costs were excessiveTHIS dry summer heat, so the available, and the industry has been allocated to cultural operations; 53% production of hazelnuts is limited to increasing by roughly 800 acres per were fixed charges; and 15% repre- the Willamette Valley in Oregon and toyear. sented harvest, drying, and handling. correspondingFor areas in Washington Virtually all of the commercial Total cash costs amounted to and British Columbia. production of hazelnuts in the $344.43 per acre, and the total noncash http://extension.oregonstate.edu/catalogUnited States comes from the costs were $793.27. Assuming a Pacific Northwest. About 97% of the 1,400-pound yield per acre, the cost per U.S. production comes from the pound would be 78.8; with an average Willamette Valley in western Oregon. yield of 1,800 pounds per acre, the cost Washington produces the remain- per pound would be around 63.2; at a ing 3%. yield of 2,200 pounds, costs are 53.5; and at 2,800 pounds, 46.7. Thus, it is important to follow Hazelnut trees draw moisture from Dig holes in March or April and recommended practices for increasing the upper soil layers more rapidly than check to see if they fill with water yields and to include all costs in at lower depths. The top 2 feet of soil overnight. Unless it has rained, water determining the profitability of grow- may be dry by the end of June, while in the holes indicates the presence of a ing hazelnuts. the third and fourth feet may take as high water table. Hazelnut trees can long as August to dry. withstand a fairly high water table in Irrigation might overcome the low March and April, if it drops as the trees moisture problem presented by a soil start to grow in May and if the soil that is too sandy or shallow, but there below 4 feet drains freely. is considerable expense involved. Shal- The small feeder roots affected by Locating the orchard low soils are often poorly drained, so the high water table will die, but when that irrigation would not necessarily drainage occurs, new roots will grow A major factor to consider in improve their suitability for hazelnuts. and use the remaining moisture. locating a hazelnut orchard in western Likewise, irrigation is no remedy for Some soils may require special Oregon seems to be soil; however, do soils that are too heavy. The greatest fertility adjustments before planting. not overlook air drainage. While low benefit of irrigation is in establishing Base any adjustments on an OSU soil temperatures during the blossoming an orchard to obtain large trees more test interpretation by your Extension season have not been known to limit rapidly. agent. DATE. yields, late April frosts in low-lying Tile drainage of wet land has been areas frequently reduce cluster buds attempted with varying degrees of and succulent green shoots. success. On land in need of drainage, No single direction of slope is better the subsoil layer that supports the OF than any other, except as it affects soil water is usually so close to the surface depth and moisture retention. Hazel- that only a very limited depth of Hazelnut varieties nuts do not tolerate wet soils during suitable soil remains above it. their active growing season, but since If the subsoil is so compact and Table 1 outlines the characteristics they are more shallow-rooted than dense that water will not pass through, of the major hazelnut varieties. most fruit trees, they will grow well in tree roots will not penetrateOUT it to Barcelona (figure 1) is the principal locations that may be marginal for provide normal growth. Tiling such variety grown in Oregon. Its popularity crops like cherries or walnuts. soils could increaseIS the area available is based on the inshell market, which Very few plantings have been made for root activity earlier in the year, but favors its round shape and superior on sites above 1,500 feet elevation; it would not provide the best growing flavor. The kernels of Barcelona have a therefore, it is difficult to evaluate conditions. coarse, brown outer coating, or their worth as commercial sites. Plant Where a small area of wet land pellicle, which is very difficult to orchards on sites that you can commit intrudes into larger well-drained tracts remove completely, even after roasting. to long term tree growth. Avoid sites intended for hazelnuts, drainage is However, some processors have found that are likely to be claimed for justified because it allows cultivation ways to do it. subdivisions, freeways, or industrial throughout theinformation: area. The Barcelona tree tends toward an property within the next decade. alternate-year bearing habit. One Determining soil suitability serious weakness of the Barcelona is Suitable soils The soil types of western Oregon that it produces more blanks than many other varieties. A second serious An abundance of suitable land still have been classified and mapped. You can find soil maps in your county weakness is its susceptibility to exists in western Oregon for hazelnut brownstain. culture; consequently, hazelnut orchards Extension and Soil Conservation Serv- The second most common cultivar is should not be located where the soil is ice offices. These maps give the soil current Daviana (figure 1), which is used as a poorly drained, shallow,PUBLICATION too heavy, or series, texture, and (sometimes) the average depth for most potential pollinizer for Barcelona. Daviana has a too light. number of faults. It is susceptible to Trees may grow well on shallow soil orchard sites. for the first 8 to 10 yearsbut then Referring to soil maps is your first big bud mite (Phytocoptelia avellanae), which forms galls in both flower and become poor producers because they step in determining the suitability of a most site for hazelnuts. However, even vegetative buds. The shells are thin, cannot develop deep root systems. A which makes it easy for birds and hazelnut orchard that is relatively though the map gives useful informa- THIS rodents to selectively remove nuts. unproductive because of unsuitable tion on the proposed site, you'll These two factors contribute to low soil can be a liability. probably have to investigate further. For To determine soil depth, dig several yields. Although most of a hazelnuts tree's The Daviana nut is long and does roots are found in the first 2 feet of holes and examine the soil. A post hole not look good mixed with the round soil, soils that are suitable for hazel- digger, soil auger, or shovel will do the Barcelona. When nursery trees are nuts will allow thehttp://extension.oregonstate.edu/catalog trees to develop job. Examine the soil to a depth of 4 to 6 feet in enough spots in the field to available, use Butler instead of Daviana active root systems to depths of 6 to 10 as a pollinizer for Barcelona. feet. Root penetration can be stopped discover any variations in soil depth. Poor drainage is indicated by a A breeding program is currently by rock, hardpans, high water tables, under way to develop varieties that or a lack of aeration in the soil. grayish, yellowish, or reddish mottling of the soil. have heavy annual production, fewer

4 blanks, and more desirable kernel Table 1.Characteristics of hazelnut varieties characteristics. The varieties Butler and Ennis Average Value as (figure 1) were discovered by growers °lo Barcelona Produc- Smoothness in their orchards. Their nut and kernel Size kernel Shape Size pollinizer tivity of kernel characteristics are acceptable to proc- Barcelona 42 Round Med-large None Moderate Smooth essors. Selections of Butler and Ennis Butler 48 Oval Med-large ExcellentModerate Smooth are being increased by both layerage Daviana 52 Oval Medium ExcellentVery light Smooth and graftage. DuChillya 44 LongL Large Good Heavy (al- Shriveled Ennis is not a pollinizer for ternately)c on outside Ennis 47 Round Large None Heavy Some Barcelona. It is a large nut with inshell roughness quality that is slightly better than Hall's Giant 38 Round Medium Good Low Some Barcelona. Ennis is more productive roughness than Barcelona. Montebello 42 Round Med-smallNone Moderately Smooth Butler was introduced as a replace- heavy ment for Daviana. It will pollinize aFallsin husk, not free of it. Barcelona and the early flowers of bCharacteristiccrease on side of shell. Ennis. Butler is more productive than cAlternatelyrefers to crop production every other year. DATE. Daviana. OF

Barcelona OUT Butler IS

Ennis Daviana

Figure 1.Four prominentinformation: Oregon hazelnut varieties.

Nut development currentEgg. Female cell, which (after Fertilization.The union of sperm To help you understandPUBLICATION this section fertilization) develops into the kernel. and egg to start the new generation better, here's a glossary of the most (embryo or kernel). commonly used botanical terms (figure Parts of catkins (male) 2 illustrates some of them): Catkin.Pollen-producing organ. Floral initiation and Pollen.Grains bearing sperm formed development Parts of florets (female) most in anthers on catkins. The life of a hazelnut nut begins with Stigma.THISThe uppermost part of the Pollen germination.The growth of athe formation of flowers more than a female flower at the end of the style, tube out of the pollen grain. This year before harvest. Most of the which receives the pollen. The stigma is occurs when pollen is placed under flowers form in buds at the axils of the red. For suitable conditions such as on the leaves on the current season's growth. Style.Middle portion of female stigmas of flowers. The male catkins begin to form in flower, between the http://extension.oregonstate.edu/catalogstigma and the Pollen tube.A tube bearing the April or May and begin to appear in ovary. sperm. In the process of germination, June, although they do not reach Ovary.Lower part of the female it grows down the style and into the maturity until the following December flower. It consists of a wall of tissue ovary, where it transfers the sperm to or January. (eventually the nut shell) and two the egg. ovules. Pollination.Transfer of pollen from Ovule. Structure within the ovary anther to the stigma of a female that bears the egg. flower. Effective pollination stimulates the bud until they extend to their maxi- ovary to develop from this basal bit of mum length, wither, and fade. This tissue. It grows very slowly the first 4 takes place from late November until months (until about mid-May) and early March in some seasons. then begins to grow rapidly, attaining Because each flower cluster is 90% of its growth in the next 5 to 6 receptive to pollen for such an weeks. extended period, one pollinizer variety By mid-July the shell is full size, and that sheds heavily during the peak shell hardening is well under way. bloom, or even somewhat past the During the middle of this rapid growth peak, will provide adequate pollination. period (mid-June), when the ovaries Daviana and Butler shed most of are 8 to 10mm in diameter, the ovary their pollen in January and February. becomes a mature organ containing Commonly used in orchards as a single egg cells. pollinizer, Daviana is successful in The resting sperm becomes activated, setting a normal crop. Since Ennis secondary pollen tubes begin to grow, blooms late, a late pollinizer for it and fertilization takes place. This 4- or (such as Butler) is important. 5-month lapse between pollination and DATE. fertilization is one of the unusual Pollinizer spacing features of hazelnut floral biology. (In and placement most other plants, fertilization follows pollination by a few hours or a few OFThe standard placement of hazelnut days.) pollinizers has been every third tree in After fertilization, the kernel devel- every third row (3 x 3). This ops rapidly, reaching full size in about arrangement provides for more than 6 weeks (early August). From this time 11 °lo of the trees as pollinizerswhich until harvest, maturation changes is too many trees. occur (an increase in oil OUTcontent, for Since most pollinizer varieties are example). Towards October, the husk less productive than Barcelona, or are Figure 2.Hazelnut flowers: upper left, of less value, or are different enough to female or pistillate; lower right, male surrounding the nutIS dries and spreads open, and the nut falls to the ground. significantly reduce the uniformity of catkins in bloom. the nut mixture, it is desirable to have the smallest number of pollinizers per acre that is necessary to provide adequate pollination. The female clusters begin to form in Each Daviana catkin produces over August and are first seen in late Nov- Pollination one million functional pollen grains, ember or early December. January information:and each tree usually bears several through February is the peak of the pol- Pollinizer requirements thousand catkins. The quantity of lination season, but this varies some- pollen usually is not a factor in what according to weather conditions. Hazelnuts are self-incompatible; determining the number of pollinizer During this time, the female cluster they will not set nuts with their own trees, but their arrangement in the appears as a bright red tuft of feathery pollen. Also, certain combinations of orchard could be. stigmas projecting out of the bud varieties are cross-incompatible (that For convenience of harvesting, some scales. Within the bud scales are the is, pollen of some varieties is ineffec- growers have planted solid rows of lower portion of 4 to 16 individualcurrenttive in setting nuts on certain other Daviana pollinizers in every tenth or flowers. Each flowerPUBLICATION consists of a pair varieties). twelfth row. This provides 10% of the of long styles with surfaces that are Controlled pollinations made on trees as pollinizers, which is unnecessar- mostly stigmatic (receptive to pollen) Barcelona have demonstrated that ily high. There is no evidence available and a tiny bit of tissue (0.25 mm or certain compatible varieties such as to support or discredit this practice, Daviana, Hall's Giant, Butler, and less) at the base. most but solid rows of pollinizers create a The female hazelnut flower is very Lansing set a normal nut crop, and situation where certain lots of nuts unusual.THIS At the time of pollination, that other incompatible varieties such have a very high percentage of instead of having an ovary containing as Montebello, Kruse, Camponica, pollinizers. This has been considered ovules withFor egg cells ready for Ennis, and Barcelona set only a very an inconvenience by nut handlers. fertilization, it has only the rudimen- few nuts or none at all. It is essential to tary bit of tissue mentioned in the last choose a compatible pollinizer variety. paragraph. http://extension.oregonstate.edu/catalogEarlier recommendations to place Within 4 to 7 days after pollination, three pollinizer varieties in an orchard the pollen tube grows to the base of the were based on the extended period of style, where the tip of the tube bearing time during which female flowers the sperm becomes "walled off" and continue to appear. Stigmas are enters a long resting period. receptive from the time they first appear as a tiny red dot at the tip of the Pollen grains can be carried great Factors that contribute to high You can increase your final percent- distances by the wind. The density of percentages of blank nuts are not age of nut set with a single spray of the pollen cloud decreases with the definitely established. Some evidence Solubor (sodium pentaborate), using 2 distance from the source. Thus, suggests that insufficient soil moisture pounds of product per 100 gallons of distance is the most important consider- in midsummer results in a higher water (8 pounds per acre), applied in ation in pollinizer placement. The mostpercentage of blanks. Other indica- late May. Foliar-applied boron has logical placement of pollinizer trees tions are that the pollinizer variety or increased nut cluster set by 33%. would be one in which they are tree nutrition may influence blank The best time to spray depends on dispersed throughout the orchard production. There also appear to be whether the season is early or late. Do rather than in solid rows, to use the varietal differences in blank production. not apply more than 1 pound of actual wind to best advantage. boron per acre (excess boron can be It was found that in 25 x 25 foot Brownstain toxic). plantings, pollinizers every third tree in Brownstain is a disorder that causes every third row, or seven per acre, severe crop loss in some seasons, provided an abundance of pollen. usually about every 8 to 12 years. The Ina2O x 20 foot orchard, cause is not known. Brown stains are pollinizers every sixth tree in every seen on the sides of nuts in early July. third row, staggered (diamond arrange- Affected nut clusters often drop from GrowingDATE. and selecting ment) would provide six pollinizers per the tree in July and August. planting stock acre, which is adequate. Many affected nuts are blanks or The greatest distance to a pollinizer only partially filled. Among the main tree would then be 60 feet. This 6 x 3 commercial varieties, only Barcelona OFMethod of propagating arrangement is also considered ade- quate for spacings closer than 20 x 20 has a serious brownstain problem. Hazelnuts are propagated by simple Abandoned or partially neglected feet. layerage (rooting a plant part while orchards have less brownstain than that part is still attached to the parent well-maintained orchards. plant). The suckers of an orchard tree OUT or the stems in a stool bed are bent in Flower cluster losses an S-shape, so that one bend is under Another yield-limitingIS factor that is ground where roots can form on it. Blanks, brownstain, even more serious than blanks is the The tip end of the stem is left above early dropping of female clusters. In ground to form the new tree (see and developmental the Barcelona variety, this amounts to figure 3). 35 to 50% of the clusters produced on To begin the layerage procedure, dropouts the tree. loosely cultivate the soil around the The majority of flowers in these stool. Next, select a stem from the Blank formation clusters have been pollinated, and previous season's spring growth, about development hasinformation: progressed for a few the time it begins leafing out. Strip the Potential yields of all varieties are months at the normal slow rate before leaves from all but the apical 12 to 18 reduced by varying percentages of inches of the stem. Bend the stem and blank nuts. A blank nut consists of a growth is arrested. Although the individual flowers are larger (1-2 mm slightly twist it over to the side as you shell without a sound kernel. Blanks diameter) at their base than at the time set it in the ground to a depth of a occur when pollination stimulates the of pollination (0.25 mm), the clusters shovel blade. Hold it in place by shell to develop, but the kernel fails to are still so small that their dropping is firming soil on top of the buried develop normally. Either it fails to section. grow at all or it starts to grow and then not conspicuous in the orchard. Part of currentthe flowers in clusters that do hang on Roots form on the underground aborts, especially in the early stages of PUBLICATIONthe tree, because of the normal portion of the stem during the summer. growth. development of at least one nut, are In autumn, after leaf fall, cut the However, in some cases, kernels may layered stems from the stool and dig grow to over half their expected size also subject to arrested growth. A close examination of nut clusters for pruning and grading. and then shrivel. These nuts also are during summer will disclose a few tiny, Trees grown from simple layerage, culled out as blanks althoughmost they do undeveloped flowers embedded among with the roots originating in a short hold THISkernels. the fleshy husks. The potential loss in space (2 to 4 inches) along the stem, Lackofpollination is never the the Barcelona variety due to these will produce fewer suckers after causeofblank nuts because aflower "developmental dropouts" amounts toplanting. The better layered trees do that is not pollinatedFor simply does not 75 to 85% of the total individual not have a crook at their base (see develop beyond its tiny size at figure 4). pollination. When pollen is withheld flowers produced by the tree. from female clustershttp://extension.oregonstate.edu/catalog by covering them with bags, the clusters dry and fall off by late April or early May. Propagating from suckers Nursery trees are dug in early winter, Additional nursery trees can be after leaves have fallen and the plant produced from suckers arising from tissue has hardened. The roots of dug the base of existing orchard trees. trees are "heeled" into moist sawdust When they are 2 to 3 feet long in early or soil so the roots will not dry out or summer, place a wire or bag-closure freeze. Order and plant trees early for twist around the base of the sucker. best results. For another way to increase rooting, apply some indolebutyric-acid-based rooting hormone to the surface of the first few inches of stem. Cover the suckers with moist barkdust, sawdust, or leaf mold to a depth of at least a Orchard design foot. You can hold this mulch in place lntercropping with with a roofing paper collar encircling hazelnut trees the tree trunk outside of the suckers. One way to get profitable returns Most of the suckers will root by the from anDATE. orchard much sooner, while following December. After harvesting, avoiding the usual drawbacks of they should be grown in a nursery with intercropping, is to make a high- irrigation for a year before being OFdensity planting. For example, you planted in the orchard. could plant trees 10 x 18 feet and thin to a 20-foot triangle or an 18 x 20 Grafted trees. A new development inrectangle after 10 years or when the hazelnut growing involves the use of trees begin to crowd. nonsuckering rootstocks and grafted Since the yield per tree in a closely trees. Research aimed at findingOUT spaced orchard is nearly the same as on superior rootstocks for hazelnuts is a widely spaced orchard for the first5 under way. Callusing of hazelnut to 6 years, yield per acre goes up in grafts depends on temperature;IS tempera- proportion to the increased number of tures over 70°F are required for a high trees. level of success. Once the trees begin to crowd, it is Delay grafting in the field, therefore,essential to prune back the temporary until the average daytime high tempera- trees to allow the permanent trees to tures are in that range. Scionwood expand in a fairly normal pattern. An must be cut in midwinter when it is still average yield for 6-year-old hazelnut Figure 3.In propagating hazelnuts by dormant, and information:held in cold storage until trees is about5½pounds. Table 2 simple layerage, the stool produces long then. shows yield per acre for different tree shoots, which are bent down and covered Whip-grafting with two-bud scions populations, assuming a 5½-pound withsoil in the spring. These stems produce has been successful. Tie it with a yield per tree at 6 years. roots and form marketable trees by -inch-wide grafting band, being summer. careful to overlap to exclude air. Paint Table 2.Effect of tree population on the cut tip of the scion with elastic per-acre yield of hazelnuts (sixth year) grafting compound. It may also be currenthelpful to paint the scion white to keep Spacing Trees Yield PUBLICATIONit cooler. arrangement per acre per acre Don't paint the elastic band. Graft- (feet) (pounds) ing in the dormant season can be 10 x 18 rectangle accomplished using rooted layers and a 242 1,331 20 x 20 square 108 594 specially constructed hot-callusing tube. 15 x 15 square 194 1,067 most 18 x 18 triangle 155 853 THIS Selecting planting stock The best quality tree gives the best With the change from cultivation to For performance. Hazelnut nursery stock flailing, a rectangular arrangement of should be at least ½ inch in diameter at trees has become the most popular. a point 6 inches above the soil line. Spacings of 10 x 20 feet (218 trees/ http://extension.oregonstate.edu/catalogAlthough hazelnut trees often are sold acre), or 12 x 18 (201 trees/acre) allow by height, caliper or diameter provides for thinning to a triangle of approxi- a more reliable indication of the stored mately2o, 21, or22 feet. Figure 4.A strong-rooted Barcelona food reserve of a nursery tree. layered tree, just removed from the stool and ready for planting. Although a herbicide-treated strip of The 20 x 20 foot square, with 108 soil down the row reduces the need for trees per acre, is adaptable to a variety cross-flailing, cross-flailing helps to of soils and situations. It will provide eliminate grooves in the soil surface. an easily managed orchard for inexperi- enced growers. It is most attractive to Arrangement of growers who contract harvesting or other operations. Disadvantages are permanent trees lower yield than at closer spacings and Trees on deep, medium-textured a longer period of time to reach bottom land will be larger when maturecommercial production. than trees on soils that are shallow, The 10 x 18 foot rectangle, with 242 sandy, or clayey. Consider these trees per acre, can be thinned to form a factors when you plan final tree triangle 20 x 20.6 feet by removing spacing. every other tree. Early yield is the There are three basic ways to arrangeprinciple advantage of this arrangement. trees in an orchard: square, rectangle, Inability to cross-flail, higher costs and triangle. The square is the least for trees and tree maintenance, and the efficient in terms of numbers of trees cost of tree removal at thinning time Figure 5.LayingDATE. out the orchard by the per acre at a given spacing; the are principal disadvantages. Only those square method. equilateral triangle is the most efficient. growers who are willing to provide Table 3 illustrates this point. intensive management should use this system. OFthe distance apart that you plan to set out the trees. Make the set of two Table 3.How tree arrangements relate to wires, with one end of each wire joined trees per acre together on a small ring. Fasten the free ends to two separate rings. Dimensions Trees After staking off the base line at the (feet) Arrangement per acre Establishing a OUT intervals you've chosen for the trees, 20 x 20 Square 108 start staking the tract. By placing the 18x 22 Rectangle 110 new orchardIS two ring ends of the wire over stake I 20 x 20 Equilateral triangle 125 and stake X, and drawing the common Staking out the orchard center ring away to make the wires The first consideration in laying out taut, you can then place a stake at The 15 x 15 foot square, with 194 an orchard is to establish base lines point M (figure 5). trees per acre, has been a popular two or more lines if you plant your Next move the wires so that you can spacing in the past. It is most suitable trees on the square or rectangle system, place the free rings over stake M and for soils with good water-holding one line if you layinformation: out your orchard on stake 2. Then place a third stake at the capacity but too close for shallow or the triangular system. common center ring at point N. sandy soils. For the square system, select one You can carry on this process The closeness of the trees presents side of the field from which you can layindefinitely, backward and forward several difficulties in management (for off a line parallel to the fence or road. across the field, until you've com- example, very tight turns with equip- Use this side as the base line AB (see pletely staked out the field. ment). Furthermore, standard equip- figure 5). Hold the wires in the same plane ment, especially sweepers, doesn't fit With a tape or other means, lay out each time and draw them up to the this spacing. The 15 x 15 foot squarecurrent60 feet on AB. Then, to lay out line same degree of tautness. Occasionally requires very intensive management. AC, approximate a right angle to base check by sighting or by remeasuring For orchards with goodPUBLICATION soils and line AB, measure off 80 feet, and strike wires to straighten out rows, especially good management, the 18 x 18 foot tri- an arc using A as a pivot point. if the field is uneven. angle with 155 trees per acre is the best From point B, with a line 100 feet Other methods of staking out permanent spacing, and it will accom- long, strike another arc intersecting the orchards include using a transit and modate standard-sized equipment.most previous arc. The point at which the sighting from two sides of the field It is possible to work the orchard in arcs intersect will be D, the point with someone to help set the stakes at three THISdirections. This permits the through which you locate line AD the points desired. Overall, wire is removal of grooves in the soil surface, permanently. AD will be at a right probably the quickest and simplest which may formFor when the orchard is angle to base line AB. method of staking level land. Often a always worked in a single direction. It is generally an advantage to lay offsingle long wire with soldered points The principal disadvantage is that it is another base line at the opposite side ofindicating where stakes are to be set is difficult to design hazelnuthttp://extension.oregonstate.edu/catalog interplants the field from AD and at right angles used alone. within this arrangement. with the base line AB. For laying off by the square, rectangle, or hexagonal systems, ob- tain a set of wires the same length as The triangular or hexagonal system Planting the trees trees are easily sunburned, especially of planting requires only one base line Plant the trees in early winter, as near the surface of the soil or mulch. (figure 6). Measure the base line off soon as possible after you receive them Painting the south side of the trunks from the nursery. Don't let the tree once per season for the first 2 years, roots dry out before planting. The with a 5OWo dilute solution of white earlier a tree is planted, the more exterior latex paint and water, will chance it has to develop a working root provide ample sun protection. ,/o_ system before it leafs out in the spring. Be sure to paint the trunk so that the reflective white surface is at or / \ / Root growth is active in January and / below the mulch level. The mulch / \ February, when soil temperatures are N' W will often settle, leaving an unpainted P 40°F or above. ft section of the bark near the soil // \\ 1/ \ Prune off the ends of broken roots and remove any of the original layered lineand this section will be more / \ 1 wood remaining below the main area susceptible to sunburn. Don't use lead \ of rooting. base paints. 3 2 Dig holes for the trees 18 to 24 inches Tree protectors tied loosely around Figure 6.Laying out the orchard by the wide and 10 to 12 inches deep. Digging the trunks will also provide sufficient hexagonal method. in wet ground with a power auger may protectionDATE. from sunburn. Some translu- cause compaction on the sides of the cent plastic wraps or highly reflective holes. If this happens, break down the white collars may actually increase the into the regular intervals at which you edges of the hole to eliminate the heat injury to trunks. will plant trees and drive stakes at each compacted area and partially fill the OFMulching. A sawdust mulch about 3 point. hole with soil. to 4 inches deep around young trees Using the wire set, place the rings Spread the tree roots out and press both suppresses weed growth and over stakes 1 and 2 (figure 6), draw the them down into the bottom of the hole. preserves soil moisture. In trials, young wires tight, and set a stake at M. Then Plant the trees so the top root is 2 to 3 trees that were mulched but not place the rings over stakes 2 and 3. inches below the soil surface.OUT Tamp the irrigated grew nearly as rapidly as Now place a stake at N, and so on soil firmly around the roots to exclude irrigated trees. Black plastic mulch is throughout the field. air pockets. even more effective but may not be as If you use this method, you will need IS economically practical. Organic mulches to fill out the side of the field. By may reduce the effectiveness of certain placing one free ring over M in the Pruning at time of planting After you plant the trees, head back herbicides; therefore, herbicide applica- second row and 0 in the third row, you tions should precede mulching. can place a stake at Y so the third row the tops, leaving a trunk 30 to 36 inches will be lengthened out to line up with in height. This top reduction should row 1. offset the root damage suffered by the tree during digging and handling. In transplanting, information:a considerable portion Using a planting board of the roots are lost, and the water- A planting board may be of value to absorbing capacity of the plant is Managing a set trees in line after staking out the reduced. field. This board is 3 to 4 feet long with If trees are not topped, their root hazelnut orchard a notch at each end and another notch systems may be unable to provide along one side in the exact center. sufficient moisture to replace that lost Nontillage Before digging the tree hole, place by transpiration. Consequently, the the planting board so that the stake,current In the past, weed control in hazelnut trees will be retarded in growth or may orchards was accomplished exclusively which marks where the tree will be, is PUBLICATIONdie. If trees are branched, cut the by cultivation. Most hazelnut growers cradled in the center notch. Place a laterals back to a few buds, or remove have changed from cultivation to flail stake in the notches at each end of the all laterals and treat the tree as a board and remove the center stake and mowing and use herbicides in the tree headed whip. row. planting board. After pruning each tree, sterilize Flail mowers (figure 7) are con- After you dig the hole,most place the tree pruning tools with rubbing alcohol to structed to mow weeds as close as ¼ in theTHIS hole and replace the planting prevent the spread of filbert blight. inch from the soil surface. Flailing is board in the original position over the started in spring as soon as the ground two end stakes. Line the tree trunk up is dry enough to accommodate a in the centerFor notch to retain the Protecting against sunburn In the first few seasons after tractor with wide, high-flotation tires original staking alignments. The board without making ruts. Usually this must face the same direction for each planting, the trunks of young hazelnut http://extension.oregonstate.edu/catalogoccurs in March before ground vegeta- planting. tion is 6 inches high. After the winter rains subside, winter annual weeds die outbut the more competitive, drought-resistant summer weeds germinate and grow.

10 flailing do not differ appreciably from those under clean cultivation. The soil in the top 3 to 6 inches is usually drier under flailing than under cultivation, but at lower depths there is no difference. The earthworm population increases under flailing if moisture is preserved. Earthworm castings can be a nuisance during harvesting. However, the verti- cal tunnels the worms make greatly Figure 7.A flail mower controls weeds increase water penetration and drainage, mechanically as it moves between the rows so that harvesting can be resumed soon of hazelnut trees. after a heavy rain. Figure 9.Low-pressure herbicide sprayers Under flailing, soil erosion is mainly apply herbicide in a strip down the row. confined to the herbicide-treated strip. With this plan, the orchard doesn't have to Cover crops are rarely planted; These strips should run across rather be designed to allow cross-flailing. usually, volunteer weeds are simply than with the slope. DATE. Before you can begin flailing, your allowed to grow. A few growers, compete with the young trees for however, seed subterranean clover as a orchard floor must be smooth and even. Remove mounds of soil around moisture. The result is poor growth winter cover crop and clip it close in and a relatively high rate of mortality. spring. When clover is planted, go- the tree trunks (you may need a OF phers tend to increase. Control of leveling device). It is easiest to do this Weed competition. Some herbicides gophers is especially important in an leveling before the trees are planted. can be applied several weeks after orchard planted with clover (see It may be best to delay flailing as planting; others carry a precaution "Gophers and moles," page 15). your primary orchard-floor manage- against their use on trees under Early flailing and a combination of ment method until the trees have been 3 years of age. Read the label preemergence residual herbicide and in the ground 1 or 2 years. OUT carefully to determine which herbicides contact herbicide in the tree row will you can safely use during your help reduce weed competition. Always Cultivation IS orchard's first few years. See apply herbicides according to label Although most hazelnut orchards figure 9. A good herbicide program in directions. are currently managed with nontillage, the tree row, with flailing between The nontillage system of soil manage- some operators prefer to cultivate. rows, provides the best protection ment is popular because it eliminates Cultivation is mechanical weed control against weeds. most of the ground preparation work and conserves moisture only as it In wet years, weed growth may necessary for harvest (figure 8). The succeeds in killing weeds or cover crop. become so rank that it will prevent or tillage method of weed control does When cultivating,information: remember that most retard normal harvest operations. If not. Usually four to six flailings per hazelnut roots are in the top foot of you anticipate this, use some late- season give satisfactory weed control. soil, where they are easily pruned off season chemical weed control. Sometimes, even with flailing, it is by implements. Since herbicide registrations change necessary to float the surface before Limit depth of tillage to 4 inches for from year to year, no chemicals are harvest to fill in small depressions. working down the cover crop and listed here. Contact your Extension Studies have shown that soil mois- reduce to 2 inches for the balance of agent for suggestions. ture levels in the trees root zone under the tillage season. currentAs soon as weeds are under control, Cover crops PUBLICATIONprepare tilled soil for nut harvest by For orchards with tillage programs, rolling to smash clods and dragging to annual winter cover crops are smooth the area. This is a dirty, necessary to prevent soil erosion in expensive job (one you can avoid most cultivated orchards. The growing almost entirely if you use flail culture). cover crop slows runoff and aids most penetration of rainfall or irrigation THIS lntercropping water. Cover crops reduce the soil It is a faily common practice to plantcompaction caused by movement of another crop between the rows of trees vehicles in the orchard. For for the first few years after planting. Willamette vetch, hairy vetch, oats, When the crop is irrigated, this can winter wheat, or winter barley make http://extension.oregonstate.edu/catalogactually help the trees grow in the early good cover crops. Sow these immedi- years. Strawberries and beans are com- ately after nut harvest. Managing mon intercrops in irrigated situations. native populations of subclover or Under nonirrigated conditions, any annual bluegrass also provides good intercrop usually is detrimental to cover. Sometimes there are enough growth of the young trees, sometimes volunteer weeds to serve as a cover Figure 8.Nontillage practice allows har- crop, to help prevent erosion and vest without bogging down in mud. extremely so. Both intercrop and weeds reduce soil compaction.

11 Training and pruning The objectives of tree training, in the first and second years after planting, are totally different from those used in pruning mature orchards. The main objective of training is to develop a strong system of major scaffold limbs. Select three to five major limbs in the first 2 to 3 years. Thereafter, very little pruning is required for several years. Heavy pruning of young trees (to promote cultivation close to the trunks) is detrimentalit prolongs the nonbearing period. Pruning also forces sucker growth to develop from wounds; this growth fills in the center of the tree and shades the other limbs. Pruning of mature trees helps to DATE. maintain a high level of production of large nuts and discourages the alternate- bearing habit of the hazelnut. Tree condition is the best indicator of the OF Figure10.Left:Heavy pruning has opened up this hazelnut tree's center and has left a need for pruning. large scaffolding for new fruiting wood.Right:After one growing season, this heavily It is time to prune when: pruned tree shows excellent upright growth. 1. a reasonable fertilizer and soil management program fails to pro- duce an average of 6 inches or more In general, thin the tree OUTso that light of annual terminal growth; rot following pruning. To reduce the penetrates to all remaining parts. Cut danger of wood rot after pruning, 2. numerous dead twigs appear in the limbs flush with the trunk wherever make cuts in smaller wood high in the tree center and lower branches; practical (stubs do ISnot heal over, and tree, and avoid cutting close to the 3. moss and lichen growth develops they provide entry for wood rot trunk. throughout the tree; and organisms). 4. the outside rows show more vigor Mechanical side hedging with gang Sucker control and better foliage color than inner saws has increased in recent years. This tree rows. is a rapid, economical way to remove A sucker is a shoot originating from This may come as early as 12 years large amounts of wood from an low on the trunk or from roots near the after planting in some orchards or as overgrown orchard.information: Yields have in- trunk. late as 20 to 25 years in others (figures creased in some older orchards after All hazelnut varieties and all root- l0aand lob). side hedging. However, production did stocks except the Turkish hazel (Corylus Experiments have shown that yields not increase in test plots with young colurna) will sucker to some degree. If are reduced the first year after heavy trees (apparently, they were in less needyou promptly and carefully remove pruning, but they are substantially of pruning). suckers during your first few years increased in the second and later years. Side hedging would most likely after planting, you'll greatly reduce the It takes considerably less time to cut benefit an older orchard, where the labor you'll need for this operation in 50% of the bearing surface from 20%currenttreetops have grown together, more later years! of the trees than it doesPUBLICATION to remove 5 to than a younger orchard where this The general-purpose herbicide 2,4-D 8% of the bearing surface on all of condition hasn't yet developed. is now registered for control of suckers your trees each year. Regrowth is often so rapid that the in hazelnuts. Spray suckers thoroughly Since yield is slightly reduced the space between trees created by hedging when they are 6 to 9 inches tall. Spray first year after pruningmost and since heavy is filled in after two seasons. when needed, April through August, pruning rejuvenates the tree for several With hedging, all new growth but not more than four times. Read the years,THIS it seems advisable to prune a becomes concentrated along the plane product label carefullyand follow portion of your orchard each year. of cutting. Growth in other parts of thethe instructions. Remove as much of the unthrifty, tree may be reduced unless you do Dinoseb general weed killer with oil moss-coveredFor wood as possible, leav- some followup hand pruning. Mechani- has been used successfully for sucker ing a large scaffolding on which to cal topping reduces yield for at least control. However, it may damage the grow new fruiting http://extension.oregonstate.edu/catalogwood. Trim out the the following two seasons; but after bark of young trees, so don't use it for centers and shorten the low laterals that, yields increase. the first 5 years after planting; after (this also will make it easier to move that, be careful to minimize its contact equipment in the orchard). Remove Wound dressings with the bark. Paraquat has also been suckers that grow up through the used successfully but without the bark canopy from lower limbs, unless you There is no conclusive evidence that damage associated with Dinoseb. can use these suckers to fill an wound dressings help to prevent wood opening in the top of the tree.

12 Nitrogen (N). Apply N only after Lack of pruning Poor soil drainage Orchard nutrition one growing season has passed. Young Winter injury Disease trees should grow 18 to 30 inches Physical injury Insects New orchards annually (table 6). Winter freezes Rodents Soil sampling and testing the fields Poor pollinationShallow soil or you expect to plant to hazelnuts is Deep cultivation limited moisture Table 6.Proper use of nitrogen recommended. Applying and incorpo- Nitrogen (N). Table 7 is a leaf- rating certain nutrient elements into Apply this amount analysis guide for applying N to soil (such as K and Mg) is done best Age (lb N/tree) mature trees with an average crop. before planting. Planting to 1 year None Applying N in early fall could Potassium (K). Broadcast it and 2-5 years ¼'A increase danger of winter freeze plow it under when you prepare the 6-7 years /3 ½ 8-10 years ½-% land for planting (table 4). Table 7.Leaf-analysis guide for N

applicationa Table 4.Proper use of potassium Apply this Mature orchard nutrition Wo leaf N amount of N If OSU soil test Apply this amount in AugustDATE.lb/tree lb/acre for K reads (ppm) (lb/acre)a In fertilizer experiments, hazelnut yields have been increased only by 0-75 300-400 250-330 Under 1.8 (severe 3 300 applying nitrogen, potassium, mag- deficiency) 75-150 200-300 165-250 nesium, and boron. Increased yield has Over 150 None OF1.8-2.2 2 200 not been observed with other elements (deficiency) K2O x 0.83 = K. such as phosphorus or zinc. 2.2-2.5 1 100-150 If other factors aren't seriously limit- (optimal) Over 2.5 (excess) None None Magnesium (Mg). Broadcast and ing, leaf size and color and shoot plow under Mg, too, when you prepare growth reflect the tree's nutritional aln a year of heavy cropping, N levels will be the land for planting. condition. Short shoots andOUT small, pale about 0.2'o higher. If the OSU soil test for Mg is less leaves leaves may indicate a nitrogen than 0.5 mg per 100 g of soil, apply 1.0 deficiency. IS damage and loss of N by leaching or ton/acre of dolomitic limestone. It acts With potassium deficiency, leaves denitrification. For these reasons, N is in a similar manner to ordinary are also small. The husks surrounding usually applied between February 15 the nuts are abnormally short, and limestone in correcting soil acidity. The and March 15. Adjust rates according leaves may start dying at the edges in need for applying Mg is usually greater to results of application in previous severe potash deficiencies. where K and calcium levels in the soil years. are high. For trees that have not yet grown Fertilizer needs together, the best way to use the Lime. If liming is needed before information:fertilizer is to place it in the area planting, it is best to mix it into the soil and application starting halfway between the tree trunk to as great a depth as possible. Leaf analysis indicates which ele- and the drip line. Applying lime to the surface of ments are present in adequate, deficient, established orchards without soil incor-or excessive amounts. Take a sample Phosphorus (P) deficiency has not poration has also been effective. To consisting of 50 leaves, S from each of been found. Hazelnuts use little P and determine if you need liming, take soil 10 trees that are representative of the are able to store P in buds and twigs samples and use your OSU buffer test orchard or of the troubled area. for later use. as shown in table 5. currentPick leaves from the middle of PUBLICATIONnonbearing shoots of average vigor, Potassium (K) deficiency is common located at about breast height around in Oregon hazelnut orchards. Since K Table 5.Proper use of lime the periphery of the tree. applications tend to reduce magnesium If they are very dirty, wash them uptake, don't apply K unless leaf Apply this amount of briefly in cold water with a few drops analysis indicates a deficient or border- If the OSU buffer 100-score lime line level. test for lime reads initiallymost (tons/acre) of detergent, rinse, and spread out to THIS dry. Sampling can be done any time in Table 8 is a leaf-analysis guide for below 6.1 2-3 August. Predictions of fertilizer needs applying K to mature trees with an 6.1-6.4 1-2 for established orchards based on soil average crop. over 6.4For 0 tests alone are usually not reliable. K levels decline in a year of heavy Suspect nutrient deficiency if you cropping. The K content of fertilizer is can't identify the cause of poor tree expressed as the oxide (K20) on Do not apply fertilizershttp://extension.oregonstate.edu/catalog of any kind fertilizer labels. Multiply K2O by 0.83 in the tree hole. Fertilization at performance as one or more of the following: to convert to K. planting time may burn the newly Place K in a concentrated band forming roots, retard growth, and about 6 inches wide on the soil surface, increase tree mortality the first season. about halfway between the trunk and Young nursery trees generally do not the drip line. respond even to "slow release" fertiliz- ers applied at planting time. 13 Table 8.Leaf-analysis guide for K Detailed information on control of application insect pests is available from your Extension agent. Use herbicides and Applythis % leaf K amount ofK20 pesticides safely! in August lb/tree lb/acre Wear protective clothing and safety devices as recommended on the Under 0.4 (severe 10-12 1,000-1,200 deficiency) label. Bathe or shower after each use. 0.4-0.6 6-10 600-1,000 Diseases (deficiency) Read the herbicide labeleven if 0.6-0.8 4- 6400- 600 you've used the herbicide before. (borderline) Orchard sanitation Follow closely the instructions on Over8.0(optimum) None None Health authorities emphasize sanita- the label (and any other directions tion of nut crops. Contamination from you have). animal manure is the principal concern. Apply muriate of potash (KC1) in fall Be cautious when you apply herbi- For this reason, and because you cides and any other pesticides. Know or before mid-February to avoid harvest the crop from the ground, it's chloride toxicity. You can eliminate your legal responsibility as a herbi- not advisable to use animal manure in cide applicator. You may be liable chloride burn by using the sulfate(50°lo nut orchards. DATE. K20) or nitrate (44% K20 and13% for injury or damage resulting from nitrogen) forms of potash. herbicide use. Potassium levels often do not Bacterial blight increase until the year following Commonly known as filbert blight, OF application. A single application is this is the most important disease of usually effective for 2 to5years. Lesserthe hazelnut in Oregon. Its prevalence amounts banded annually in exactly and destructiveness varies with the buds and nut-bearing twigs in the tops the same location may be as effective season. The disease is usually very often are killed, reducing yield. as a single large dose. On some sites, prevalent after heavy fall rains. The The disease is seldom found on the even repeated banding of K fertilizer disease is usually more of aOUT problem nuts or in the roots. You can signifi- has failed to increase leaf K or growth. when it's preceded by a fall season cantly reduce bud and twig infections with heavy rains (see figure 11). caused by bacterial blight, in both Boron (B). One annual spray of The most seriousIS phase of filbert young and old orchards, by sprays or sodium pentaborate (Solubor or Boro blight is trunk girdling and killing of dusts. spray) has increased hazelnut set as trees up to5years of age. Trunks of Sprays include Bordeaux6-3-100or much as33.5'owhere leaf analysis has older trees are seldom infected, but tribasic copper sulfate(6pounds per indicated deficient boron levels. Apply 100 gallons of water) and Kocide 101 (4 about 1 pound of actual boron (4.88 to6pounds per 100 gallons of water). pounds of Solubor) per acre between A compatible wetting and sticking May15and May30.The amount of information:agent will increase effectiveness of water used in commercial orchards has these spray mixtures. varied from30gallons to300gallons In a normal season, one spray per acre with equal effectiveness, application in late August or early provided thorough coverage was September (before the first heavy fall attained. rains) is usually enough to give Repeated annual boron sprays may commercial control of filbert blight. build B up to a toxic level after several In seasons with heavy and prolonged years. When B levels in the leaf reachcurrent rainfall during the fall and winter, a 200 ppm, stop the applicationsPUBLICATION until second application may be necessary the leaf B levels decline below 100 when about three-fourths of the leaves ppm. are off the trees. Wounds from pruning, leaf stripping, tillage equipment, frost damage, and most other causes provide ready entry to THIS blight organisms. Avoid them or treat them promptly. Insects Sterilize pruning tools and exposed For surfaces with a reliable disinfectant like The filbert worm is the most 70% denatured (rubbing) alcohol. important insect pest. Leafrollers, Sponge the exposed surfaces with the aphids, and filbert http://extension.oregonstate.edu/catalogbud mites are also disinfectant. Disinfect pruning tools serious pests. between trees. Normally, the filbert worm is controlled with Sevin or Guthion Figure 11.Bacterial blight kills buds and twigs, substantially reducing bearing area. applications about July 10 to15,with a repeat application in3weeks in heavily infested orchards.

14 Eastern filbert blight Chemical repellants have been par- tially successful in deterring deer. Bags Plant quarantine has kept this of blood and bone meal hung on the fungus disease from western hazelnut trees are the most commonly used orchards for the past 50 years. Now it repellants. has been found in Clark and Cowlitz When replaced every 2 or 3 months, counties of Washington and Columbia they have been relatively successful. County, Oregon. The disease can kill Several chemical repellants on the entire orchards and seems likely to market have been successful in some spread if not identified and contained instances. As the tree grows, the new (figure 12). foliage needs protective treatment. This disease is caused by a fungus, (Keeping dogs in the area will also Anisogramna anomala. Don't confuse Figure 12.These hazelnuts shoots show help.) it with the more common bacterial pustules of eastern filbert blight. blight of hazelnuts. The fungus attacks stems and twigs of the cultivated Gophers and moles European hazelnut grown in the A single gopher may kill a dozen or Pacific Northwest, as well as the wild more trees in one season. Usually, American hazel of the eastern U.S. It gophers areDATE. attracted to the orchard by has not been reported attacking the Animals the succulent roots of the cover crop. wild beaked hazel of the Pacific Coast. When the cover crop is turned under, The fungus attacks the new twigs gophers turn their attention to the first, but later it involves the large Blue jays and squirrels OFtrees. Gopher activity can be recog- limbs. Eventually, most of the tree Blue jays and squirrels often congre- nized by the crescent-shaped mounds above the soil line is killed. The gate in large numbers around hazelnut of earth with either an open or a pollinizer variety Daviana appears to orchards. They consume large quanti- plugged hole. be most susceptible and may be the ties of nuts. Three practical methods of control- first tree in an orchard to show Shooting is a common controlOUT ling pocket gophers are toxic baits, symptoms of the disease. method, but it's costly and time- burning sulfur with a weed burner The fungus infects the bark, which consuming. down the hole, and trapping. Over turns dark in color. Twigs and Trapping with ordinaryIS steel traps large or heavily infested areas, baiting branches become girdled, and the made for rodents has been fairly is the fastest and most economical leaves beyond the infected area may successful. Traps are more effective method of control. wither. At this point, symptoms are when attached to the top of posts Early spring baiting, before the similar to those caused by most (short posts for squirrels, long posts young are born, is the most satisfactory. canker-producing organisms. for blue jays). Prop the posts against Bait only where there is fresh gopher Later, the spore-producing pustules trees along the outer row of the activity. Stragglers that are not poi- of the fungus appear in lines on the orchard. Nuts oninformation: the trees are the only soned will continue to throw up fresh dead bark. Pustules are oval and bait. mounds (trap these individuals). distinctly raised above the surface of One grower uses an electric fence to For the sulfur-burning method, the bark. Each pustule is about'/8inch keep squirrels out. A chicken wire place several tablespoons of sulfur in a wide and ¼ to 'A inch long, appearing fence 20 inches high is topped off with recently made burrow, after you have in almost straight rows lengthwise a slanted cover that exposes a gap removed the plug of soileven better, along the branch. almost large enough for squirrels to do it before the gopher plugs the hole. Spores of the fungus are spread in pass through. The top of this surface Then light a propane weed burner and the orchard by wind and rain. The currententrance is strung with electric wire, train it on the sulfur, burning it and disease apparently spreadsPUBLICATION over greater shocking rodents as they attempt to blowing the fumes down the hole. distances by wind-blown spores. It may climb over the fencing. In recent years, a mechanical device also be carried to new areas on leaves, known as the pocket gopher burrow twigs, or infected wood. Deer damage builder has been developed. Pulled Deer are particularly serious pests of behind a tractor, it builds an artifical Control. The numbermost of new infec- burrow at an adjusted depth and at the tions per tree has been reduced by the young hazelnut trees in orchards next THIS to wooded areas. So far, no satisfac- same time drops grain bait at regulated fall and winter application of copper. intervals. Either Bordeaux 8-8-100 or Kocide 4 tory answer to deer damage has been found. Deer fencing around the entire It's being used very successfully for pounds! 100 may be applied after the control of all pocket gophers that harvest andFor again in January. orchard is the most reliable solution, but it's expensive. Special hunting will accept grain baits. No machine has licenses may be obtained for some yet been produced to use the vegetable http://extension.oregonstate.edu/cataloglocations. bait needed for the large Willamette Valley pocket gopher. Moles don't eat trees, but they make mounds that interfere with mechanical harvesting. Mole mounds are circular with a hole in the center. A mole trap is the only practical way to kill moles.

15 Meadow mice The usual damage caused by meadow mice is girdling of both roots and stems. The mice depend on cover for protection, and damage usually occurs when cover exists (heavy sod, cover crop, litter, or snow). The most effective, most economical, and least hazardous control is poison baits. Wheat coated with a solution of zinc phosphide is the most widely used bait in Oregon. A new bait, Ramik Brown, has been used to a limited extent in the Northwest. Bait location is important. Meadow mice stay close to their established runways, so place the bait directly in the burrow entrances or the runways. DATE. You can make a false cover from box ends or tar paper rolls and place it over Figure 13a.How windrowing works. The sweeper first passes or in the runways. This cover provides down one side of the tree row. the mouse with a protected dining area. OF Keep dogs and cats out of an orchard that has been baited. OUT Moss and lichen IS

These can be a problem in some orchards, especially if you don't prune off the wood they infest. The most serious problem is limb breakage during heavy wet snows or ice storms. Sprays are effective in controlling these information: bark parasites. Apply Bordeaux 12-12-100 or lime- sulfur (10 gallons to 90 gallons of water) in March after blossoming is Figure 1 3b.Then it passes up the other side, to complete the complete, but before leafing out. windrowing of nuts and leaves. Thorough saturation is necessary to kill the moss or lichens. Don't use these sprays during the pollination periodcurrent from mid-DecemberPUBLICATION to late February. Moss and lichens do not harm the tree except to encourage limb breakage. Good pruning programs and good growth of the trees usuallymost eliminates mossTHIS and lichen problems. For Harvestinghttp://extension.oregonstate.edu/catalog Most hazelnut harvesting operations involve two machines, one that sweeps the nuts into windrows and another that picks them up from the ground and separates them from leaves and Figure 1 3c.Now the harvester straddles the windrow. sticks.

16 2. Use a spring-tooth harrow or peg harrow for summer weed control, often with a roller for breaking clods and a float or drag behind. Some growers use a rod weeder, Gent weeder, or Kimble. 3. Level the orchard floor, float it, and roll it in two directions to prepare for harvest. Use sprocket rollers for clod mashing and smooth rollers for firming the soil for pickup operations. Grass and chickweed often grow after the orchard has been rolled and leveled and some nuts have fallen. Don't use herbicides at this timethey would contaminateDATE. the nuts. Figure 13d.Next, the harvester picks up leaves, nuts, and all. Time of harvest Then it separates leaves and trash, blowing them to one side. Rains and windy weather will bring OFthe last hazelnuts down, but they will also create muddy conditions for the pickup operation. The downdraft from a helicopter will help remove the last portion of the crop when 90 to 95 'o of the crop is down, so that harvest can OUT begin before the fall rains create difficult conditions. A little rain before harvest helps to IS reduce the dust and firm up the picking surface. A once-over mechanical har- vest is not possible before October in most years. Frost usually hastens nut drop. information:Ethephon to loosen nuts The hazelnut nut is mature when you can turn it in the husk by hand. This occurs several weeks before the husk Figure 13e.Finally, the harvester deposits nuts (plus some hulls spreads open and releases the nut. You that stick together) into a trailer. can speed up husk aging and opening by applying ethephon. The nuts are usually mature enough current to be sprayed with ethephon during the Leaves and trashPUBLICATIONBlank nuts fall before good nuts. A last week of August or the first week in on the ground final flailing and floating to fill small September. Thorough spray coverage depressions may be desirable after of the tree is essential. The amount of leaves that fall beforeblanks have fallen and just before good Response to ethephon is greater if harvest is a major consideration in nuts begin to drop. high temperatures follow sprayffig. pickup operations. Leafmost fall occurs Under cultivation, much more work Nut fall from ethephon-treated trees earlierTHIS in potassium-deficient orchards.is needed to prepare the soil surface for may be nearly complete by the end of A heavy application of nitrogen can harvest. The usual procedure for September. Be sure to follow label induce a deficiency of K, thus increas- ground preparation in a cultivated instructions. ing leaf fall.For Drought, deep cultivation,orchard is as follows: or mites and aphids may also cause early leaf drop. 1. Disk under the cover crop (or winterWindrowing http://extension.oregonstate.edu/catalogweed growth) with a cover crop Before the pickup operation, nuts Ground preparation disk, field disk, or Rototiller. are windrowed between tree rows into one or two rows, 2 to 4 feet wide for mechanical harvesting (figures 13a to l3e). Sweepers for nuts Under nontillage orchard manage- vary in size and cost. Most growers ment, little or no extra work is required have a leaf blower attached to their to prepare the soil surface for harvest. 17 sweepers to move the nuts away from the trees. Most mechanical sweepers will clean the nuts from the tree row without additional hand work. Sometimes sweepers are mounted on the front end of a regular farm tractor. Cleaning equipment on harvesters Perhaps the greatest problem in mechanical harvesting is getting a clean product. Processors and buyers com- plain about "clean away" or "wash away" and usually charge the grower for additional cleaning done at the packing plant. Probably one of the cheapest places to clean the produce is DATE. in the field. Figure 14.Wet nuts are promptly hulled (if required) and cleaned in equipment like this. Hazelnuts present some difficult cleaning problems. Nuts must be separated from clods, hulls, blank OF nuts, leaves, rocks, and twigs. Clean- ing methods include blowing or sucking, revolving rollers, revolving drum or Washing, drying, Drying "squirrel cage," and revolving tines or and storage Do not store damp or undried brushes. OUT hazelnuts (and this condition is not One of the best places to separate Washing always evident from the appearance of leaves and nuts by blowing is as they the shells) for any length of time fall from the end of a conveyor into a Hazelnuts that comeIS directly from because kernels may become moldy or bin or other cleaning device. Hulling the orchard will be either dusty or off-flavored. cylinders have been developed for muddy and may be mixed with a To avoid loss of weight and spoilage, removing husks. considerable amount of clods, sticks, dry your hazelnuts to a moisture The squirrel cage helps to remove leaves, and rocks (figure 14). Hazel- content of 8 to lOWo. Since nuts are leaves, clods, and small sticks, but it is nuts must be cleaned before buyers will bought and sold on a dry-weight basis, too slow for most operations. The accept them, and cleaning is most one of the most important factors rollers pull leaves and twigs down easily done beforeinformation: drying the nuts. affecting the price you as producer will between them and send the nuts to the Most driers are equipped with a receive is the amount of moisture in the rear. They work better when either processing line that includes a derocker crop you deliver. The best drying completely dry or kept moist by to remove rocks and dirt clods; a temperatures are 90 to 100°F. Forced applying water. squirrel cage washer to remove mud, air circulation is as important as All of this cleaning equipment must sticks, and leaves; and a fresh water temperature in proper drying. operate rapidly enough to keep ahead rinse to finish the washing operation. Many inexpensive, fairly efficient of the pickup section, or the whole Sanitizing equipment, using chlorine dryers have been made by remodeling operation is slowed down and the nutscurrentto kill harmful bacteria, is the latest old buildings on the farm. Place the are not thoroughly PUBLICATIONcleaned. addition to the washing line. This heating unit so that it will provide an Problems encountered in the clean- treatment is necessary because there is equalizing chamber under the drying ing process include: not enough heat in the drying process bins and thus ensure even amounts of to sterilize the nuts to the recom- warmed air passing up through all 1. hardclods or stones the same size as mended standard. the nuts, parts of the nut-drying area. most The drying floor can be made of wire 2. mud-clogged conveyors, THIS cloth or expanded metal laid on strips 1 3. wet leaves that will not blow, x 2 inches or 2 x 3 inches. At least 4. sticks and trash that jam equipment, 8OWo of the floor space should be open, and For allowing air to pass upward. Provide 5. an overall process that is too slow. outlets in the roof of sufficient size to allow free upward movement of If harvest conditionshttp://extension.oregonstate.edu/catalog are too difficult, moisture-ladened air. Ducting to allow clean the nuts partially in the field and recirculation of the air through the clean them more thoroughly later in a stationary cleaner outside the orchard.

18 dryer can reduce fuel requirements. Few growers maintain drying tempera- tures continuously for 24 hours a day. There has been a recent trend toward onfarm dryers using grain-drying structures (figure 15). Although they may be more costly to purchase than modified buildings, their greater capac- ity may make their use economically justifiable. You can dry small lots of hazelnuts by spreading them out a few layers deep on the floor in a dry room. Stir the nuts frequently. With hazelnuts, the kernel is firm at the start and becomes spongy during the drying process; as it approaches dryness, it becomes firm again. Start- ing at the outside of the kernel, the DATE. color gradually changes from white to a creamy color. When the color change reaches the center of the kernel, the nut is dry. OF Careful checking of both firmness Figure 15 .After cleaning, the nuts are and color will help determine when the dried. This is one of the new types of nuts have dried enough. onfarm driers that have recently come into Sulfur vapor is often used to sanitize use. inshell nuts. OUT Storage The full flavor of hazelnutsIS is Storage is usually not the producer's brought out only by roasting. Place the concern, since you normally sell the shelled kernels in an oven at 275°F for hazelnuts undried as you harvest them 20 to 30 minutes or until the skins from the orchard or immediately after crack. After cooling, the kernels drying. should be fairly crunchy, not rubbery. For common storage, dry nuts at Roasted hazelnuts will go rancid at 100°F or less to a total moisture room temperature very quickly, but content of 7 to 8% for inshell nuts, 3½ you can hold theminformation: in a freezer for a to 4½% for shelled nuts. Use properly long time. sealed plastic liners in boxes, bags, or bulk bins and store at 70°F or below. Nuts will keep satisfactorily for up to a full year. For refrigerated storage, after drying, store nuts at 32-35°F for as long as 2 years if packaged in sealed plastic or current burlap bags when relativePUBLICATION humidity is maintained at 60 to 65 Wo. Store nuts away from odor-producing substances. After storage, allow nuts to warm in unopened bags (in a well-ventilatedmost area if you don't use plastic bags). For THISfreezer storage, you can store dried nuts at 27°F or lower for 2 years, with or withoutFor plastic containers. After storage, allow nuts to warm as in refrigerated storage.http://extension.oregonstate.edu/catalog

19 DATE. 6 OF OUT The Oregon State University Extension Service provides education and information based on timely research to help Oregonians solve problems and develop skills related to youth, family, community, farm, forest, energy, andIS marine resources. Extension's agriculture program provides education, training, and technical assistance to people with agriculturally related needs and interests. Major program emphases include food and fiber production, business management, marketing and processing, and resource use and conservation.

This publication was prepared at Oregon State University by Lloyd C. Baron, Extension agent emeritus, Washington County; Craiginformation: Riggert, Extension agent, Washington County; Robert L. Stebbins, Extension horticulture specialist; and Susan Bell, former research assistant, Department of Horticulture. The authors express appreciation to these colleagues at Oregon State University: Maxine Thompson, professor of horticulture; Harry B. Lagerstedt, research leader, USDA National Clonal Germplasm Repository; H. Ronald Cameron, professor of botany and plant pathology; lain C. MacSwan, Extension plant pathologist; and E. Hugh Gardner, Extension soil science specialist. This publication revises and relaces Extension Bulletin 628, Growing Filberts in Oregon. Earlier editions currentwere prepared by C. E. Schuster and John H. Painter, USDA PUBLICATIONhorticulturists stationed at Oregon State University. Trade names are used in this publication as illustrations only. This does not mean that the OSU Extension Service either endorses these products or intends any discrimination against products not mentioned.

mostExtension Service, Oregon State University, Corvallis, 0. E. Smith, director. This publication was produced and distributed in furtherance of the Acts of Congress of May 8 THIS and June 30, 1914. Extension work is a cooperative program of Oregon State University, the U.S. Department of Agriculture, and Oregon counties. For Oregon State University Extension Service offers educational programs, activities, and materials without regard to race, color, national origin, sex, or disability as required by Title VI of the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, http://extension.oregonstate.edu/catalogand Section 504 of the Rehabilitation Act of 1973. Oregon State University Extension Service is an Equal Opportunity Employer.