sionnantes, mais ne s'appliquent pas vraiment au probleme wicklung dienenden ,,tree bank" wird ausführlich erörtert. debattu. Les partisans de toutes les metlhodes desirent la Die Griünde für Irrtümer und Mißverständnisse wie auch meme chose: le maximum d'amelioration dans le minimum die Diskussion von Stärken und Schwächen werden vor- de temps. gebracht. (3) Grünlde für die Entscheidung zugunsten der Klonsa- Zusammenfassung menplantagen im „N. C. State-Industry Cooperative Tree Titel der Arbeit: Samenplantagen für die Erzeugung ge- Lmprovement Program" werden in Kürze diskutiert unter netisch verbesserten Saatguts. Bezugnahme auf den anderen Weg, die Sämlings-Samen- (1) Samenplantagen sind notwendig, um genetisch ver- plantagen. bessertes Saatgut in Mengen zu erhalten. Dieser Aufsatz (4) Durch den ganzen Aufsatz zieht sich die Aufforderung soll den theoretischen Hintergrunld des Wegs erklären, den an die Vertreter verschiedener Metholden, ihren Fall unter man hinsichtlich der Samenplantagen im „N. C. State-In- Hinweis auf Vorteile und Stärken positiv darzustellen, und dustry Cooperative Tree Improvement Program" (Gemein- nicht die Schwächen anderer Verfahrensweiser. anzupran- sames Programm von Staat und Industrie in North Caro- gern oder ihre Ideen in eindrucksvollen Formeln wieder- lina) beschreitet. zugeben, die mit dem diskutierten Problem wahrhaftig (2) Das Gedankengebäude der Kombination zwischen der nichts zu tun haben. Die Befürworter aller Methoden wol- kurzfristig der Saatguterzeu~gungdienenden Samenplan- len das Eine - ein Höchstmaß an Züchtungsfortschritt in tage und der langfristigen, der Verfolgunig der Weiterent- einem Mindestmaß an Zeit.

Clonal or Seedling Seed Orchards?

By JOIINC. BARBER and KEITH W. DORMAN

Southeastern Forest Experiment Sta:.ion Forest Service, U. S. Department of Agriculture

Introduction When considering seed orchard methods it shou!d be The production of seed In sufficient volume for field kept in mind that a seed orchard is very specific and real. planting is a logical extension ~f a successful applied tree An orchard consists of one species or variety; its genetic breeding program. A planted area of geneticslly improved characteristics and the local environment are getermining trees managed for seed production is one of the more in- factors. Seed orchards cost money and local financial tensive methods proposed for producing such seed; in budgeting and work scheduling apply. They are generally other words, a forest tree seed orchard. production jobs, not research, and production rnethods ap- The purpose of a seed orchard is to supply seed of im- ply. Also, all details have to be worked out for the specific proved genetic quality for the generation of forest stands. orchard from start to finish; generalities can't be applied. The orchard stands as an entity and the genetic quality One weakness in theory in the whole chain of events may of the seed produced is deter-mined by the parent trees result in failure of the whole prnject. These are very im- used in its establishment. Roguing may change the aver- portant factors but they haven't always been recognized by age genetic quality of the seed produced, but the orchard some writers when presenting the theory of seed orchards has a ceiling determined by the best materiai used in its started with seedlings. establishment. Although orchards may be used for a num- ber of purposes, they should not be considered primarily as Selection of Parents breeding areas or as steps "leading" to future gains. Regardless of which type of orchard is chosen. a selection Inasmuch as we are still in the early stages of applied program must be startod to locate the parents used in forest tree breeding, the considerable interest in methods establishlment. Selection criteria will be determined by in- of seed orchard establishment and management is only dividual needs and a certain minimum number c,f selections natural. Various authors have dealt with the subject at must be made, depending on the orchard requ'rcme~ts.In length (ZOBELet al. 1958; ZAR 1956; LAR~EN1956; KI.AERN this phase, neither the seedling or clonal method has any 1960; DRIVER and CECH 1960; MARQUARDT1956). a~dvantage,,but fewer selections may be safcly used in a Recently there have been discussions of a refined method clonal orchard without creating undesirable ~ffects. of seed production based on a combination cf breeding method, progeny testing, and seed production with stands Seed Orchard Establishment started from seedlings (SCIIREINER1962; WRIGIIT 1959 a, As soon as selections are made. the clonal orchard can br 1959 b, 1960; GODDARDand BRO~N1961). started. Grafts can be made imrnediately if suitable root- We would like to discuss and compare some of the stocks are available and at most, a delay of one year to various features of orchards started with seedlings and grow rootstocks would be encountered for the southern with clonal material. To make the discussion more rnean- pines. If a small orchard, say 10 acres, were being establish- ingful, we will restrict it largely to slash pine (Pinus el- ed, it is conceivable that the establishment phase of s liottii ENGELM.),an important species in the tree breeding clonal orchard would be completed in 2 years. In contrast, programs of the southern and southeastern United States. pollinations for a seedling orchard, as proposed by GODDARD We ifeel that only by considering specific species with thcir and BROWN(1961), would require a delay in control pollina- inherent traits and problems can we advancc a discussion tion until all selections were made so that pollen could be beyond the theoretical considerations publishe:! heretofore. bulked for the crosses.