Graduate Thesis Or Dissertation

 

Influencing flower initiation and flower cluster set in the 'Barcelona' filbert with growth regulators Public Deposited

Contenu téléchargeable

Télécharger le fichier PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/9s161925q

Descriptions

Attribute NameValues
Creator
Abstract
  • The alternate bearing cycle in the 'Barcelona' cultivar poses a major problem to the filbert industry. This study was conducted to alleviate this problem in one of two ways: by (1) increased floral initiation in the "on" year, and (2) increased cluster set in the "off" year. Growth regulators were selected on the basis of their effectiveness when applied to other alternate bearing crops. These growth regulators were then applied to 'Barcelona' trees at the times corresponding to floral initiation and cluster set in this cultivar. During April and May, trees were treated with two concentrations (15 and 50ppm) of GA₃ to influence cluster set. The GA₃ applications caused a large number of clusters to abscise in the season applied, however, female flower production was quadrupled for the following season. These results suggest that when applied to filbert trees in the spring, GA₃ may have a hormonal effect on cluster abscission. The first GA₃ application (April 20) significantly increased catkin production, indicating that the initiation of the catkins was in progress during this month. Gibberellic acid's influence on vegetative growth was minimal, with no substantial increase in shoot length or node number observed. Increased floral initiation is suggested to be the outcome of hormonal and carbohydrate level changes rather than through any dramatic change in vegetative growth. In the year following treatment, yield increases were due to the greater number of flowers initiated rather than an increase in percent cluster set. Gibberellic acid (50ppm), TIBA (25ppm), and ethephon (500ppm) were also applied to 'Barcelona1 filbert trees during the floral initiation process (July-August). Hand-thinning of nut clusters was also done during the initiation process. All of these treatments, except GA₃, resulted in increased female flower clusters the following spring. Gibberellic acid did not affect female flower initiation, however, catkin drop was accelerated. The average number of nuts per cluster, percent set, and yield were not affected by TIBA, ethephon, or GA₃ sprays in the year applied. Increased yield in the following year was attributed to the increased floral initiation brought about by the TIBA, ethephon, and hand-thinning treatments. Yield was also increased by GA₃ through greater percent set, and it is suggested the latter may be linked to the catkin abscission. The carbohydrates that would have been utilized in catkin production may have been made available to the developing nut clusters and vegetative structures, and may account for the resulting increase in yield.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Déclaration de droits
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec inPDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Des relations

Parents:

This work has no parents.

Dans Collection:

Articles