首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Nut-yield Variations and Yield–diameter Relationships in Open-canopy Black Walnut Trees in Southern USA
Authors:David Brauer  Adrian Ares  William Reid  Andrew Thomas  John P Slusher
Institution:(1) US Department of Agriculture, Dale Bumpers Small Farms Research Center, Agriculture Research Service, 6883 South State Highway 23, Booneville, AR 72927-9214, USA;(2) Weyerhaeuser Company, 2730 Pacific Boulevard Southeast, Albany, OR 97322, USA;(3) Pecan Experiment Field, Kansas State University, Chetopa, KS 67336-0247, USA;(4) Southwest Center, University of Missouri-Columbia, 14548 Highway H, Mt. Vernon, MO 65712-9523, USA;(5) Department of Forestry, University of Missouri-Columbia, Columbia, MO
Abstract:Many landowners in the United States have little knowledge of the potential economic returns from agroforestry practices. Economic simulators for temperate agroforestry practices have been generated; yet, there are few data sets on yields of timber and other products to validate and refine such models. The objectives of this study were to characterize variations in nut yields among open canopy eastern black walnut (Juglans nigra L.) trees and apply this information to the development of predictive equations between tree diameter at breast height (DBH) and nut yields. Three data sets were analyzed that included results from Tennessee; Chetopa, Kansas; and Mt Vernon, Missouri. Tree-to-tree variation in nut yields was high within each data set, with coefficients of variation for nut yields typically exceeding 50%. Averaging nut yields over several consecutive years reduced coefficients of variation. Nearly half of the high nut producing trees exhibited an alternate, biennial nut bearing pattern. Trees with low average nut yields had either sporadic or irregular patterns of nut bearing. The regression coefficients for equations relating stem diameter and nut yields varied considerably. Averaging nut yields over consecutive years, and averaging stem diameter and nut yields over a number of trees increased regression coefficients of such equations. These results indicate that predicting nut yields of a tree stand over a several year-period will be easier than predicting yields for a specific tree in a specific year. Deceased 2002
Keywords:Juglans nigra  Nut bearing patterns  Tree growth  Tree stand
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号