Relationships between Leaflet Nitrogen: Potassium Ratio and Yield of Pecan

This study examines the relationship between foliar nitrogen:potassium (N:K) ratio and in-shell yield of pecan [Carya illinoinensis (Wangenh.) K.Koch]. Regression analysis of linear and curvilinear relationships between leaflet N:K ratio and in-shell yield identified associations relevant to orchard nutrition management. Analysis revealed that ON (heavy crop) year N:K ratio correlates with ON year yield (r2 = –0.69), OFF (light crop) year yield (r2 = +0.34), 2-year average yield (r2 = −0.52), and difference between ON and OFF year yields (r2 = –0.69) below the optimum yield level (less than 1800 kg·ha−1) for southeastern U.S. pecan orchards. Pecan yield therefore appears to be associated with N:K ratio. This study suggests that a decline in pecan yield is associated with high N:K ratios in the ON year, thus meriting further investigation into the relationships of N and K to yield. It is suggested that pecan orchards be managed such that foliage contains a N concentration of 2.5% to 2.9% and a K concentration of 1.3% to 1.5% while maintaining the N:K ratio at ≈2:1 for maximization of pecan yields in the southeastern United States over the long term.

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Homophily and Social Capital in a Network of Religious Congregations

Religions ◽

10.3390/rel12080653 ◽

2021 ◽

Vol 12 (8) ◽

pp. 653

Author(s):

Jennifer M. McClure

Keyword(s):

United States ◽

Social Capital ◽

Social Network ◽

Network Analysis ◽

Southeastern United States ◽

Sociology Of Religion ◽

Religious Congregations ◽

Major Metropolitan Area ◽

Curvilinear Relationships ◽

The Relationship

This article investigates the relationship between homophily, the tendency for relationships to be more common among similar actors, and social capital in a social network of religious congregations from eight counties encompassing and surrounding a major metropolitan area in the southeastern United States. This network is inter-congregational, consisting of congregations and the relationships between them. Two types of social capital are investigated: the first involves the extent to which congregations bridge across structural holes, or bridge together otherwise disconnected congregations within the network; secondly, network closure involves the extent to which congregations are embedded in tight-knit clusters. Analyses use two types of homophily (religious and racial) to predict both outcomes, and they test linear and curvilinear relationships between both forms of homophily and the outcomes. Results indicate that congregations with moderate levels of religious homophily are more likely to bridge between otherwise disconnected congregations; however, congregations with low or high religious homophily as well as congregations with high racial homophily are more likely to be embedded in tight-knit relational clusters. This article contributes additional social network research on congregations and evidence of curvilinear relationships between homophily and social capital to the fields of social network analysis and sociology of religion.

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Mechanical Hedge Pruning of Pecan in a Relatively Low-light Environment

HortScience ◽

10.21273/hortsci.44.1.68 ◽

2009 ◽

Vol 44 (1) ◽

pp. 68-72 ◽

Cited By ~ 3

Author(s):

Bruce W. Wood

Keyword(s):

United States ◽

Southeastern United States ◽

Carya Illinoinensis ◽

Alternate Bearing ◽

Low Light ◽

Tree Canopies ◽

Interior Zone ◽

Dormant Season ◽

Annual Summer

Long-term productivity of commercial pecan [Carya illinoinensis (Wangenh.) K. Koch] enterprises in relatively low-light environments such as the southeastern United States are limited by excessive tree crowding as orchards age. An effective horticultural strategy for countering this problem in relatively high-light environments is mechanical hedge-type pruning; however, uncertainty persists regarding the best strategies in low-light environments. This report describes the results of a 4-year study regarding the response of ≈25-year-old ‘Desirable’ pecan trees to different mechanical hedgerow-type, moderate canopy width (i.e., 2.43-m cuts from tree axis) pruning strategies. Canopy treatments were nonpruned control (NPC), annual dormant season side-hedge pruning on two faces, annual summer season side-hedge pruning on two faces, and alternating annual dormant season side-hedge pruning on a single alternating face. Relative to the NPC treatment, all three pruning strategies: 1) reduced in-shell nut yields by roughly 19% to 38%; 2) reduced marketable nut-meat yield by ≈19% to 36%; 3) failed to stimulate shoot development or fruiting within the central interior zone of tree canopies; 4) increased kernel percentage of nuts; 5) increased nut-meat grade; 6) substantially reduced alternate bearing intensity (I = 0.51 to ≈0.20); and 7) reduced orchard crowding. Pruning-associated reductions in nut yield appear sufficient to limit the commercial usefulness of annual or biennial mechanical hedgerow-type pruning of ‘Desirable’ pecan orchards at moderate canopy widths in relatively low-light environments such as the southeastern United States.

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Control of Mistletoe in Pecan Trees

HortScience ◽

10.21273/hortsci.39.1.110 ◽

2004 ◽

Vol 39 (1) ◽

pp. 110-114 ◽

Cited By ~ 3

Author(s):

B.W. Wood ◽

C.C. Reilly

Keyword(s):

United States ◽

Growth Regulators ◽

Phosphonic Acid ◽

Southeastern United States ◽

Control Agent ◽

Carya Illinoinensis ◽

Effective Control ◽

Host Trees ◽

Dormant Season

Semi-parasitic evergreen mistletoe (Phoradendron flavescens Nutt.) is an increasingly serious weed causing loss of nut yield and tree vigor in pecan [Carya illinoinensis (Wangenh.) K. Koch] orchards of the southeastern United States. Several herbicides and growth regulators were evaluated for efficacy against mistletoe. The dimethylamine salt of 2,4-D proved to be an effective control agent. Ethephon, glyphosate, paraquat dichloride, and polyborate exhibited little or no long-term efficacy. The dimethylamine salt of dicamba also killed mistletoe, but exhibited potential for harming host trees. Dormant season treatment of mistletoe clusters with 2,4-D reduced photosynthesis by about one-third soon after treatment, and by ≈90% from 6 to 16 weeks posttreatment, but clusters did not die until ≈4 months posttreatment. Host limbs, less than ≈3 cm in diameter at the site of mistletoe attachment, usually died within 12 months of 2,4-D treatment of the associated mistletoe cluster. Treatment of entire host trees with 2,4-D did not harm trees if applied prior to ≈1 week of budbreak. Spot treatment of mistletoe clusters, with 2,4-D at 1.2 to 2.4 g·L-1 a.i. (plus 2% crop oil), ≈2 to 3 weeks before budbreak, gave effective long-term control of mistletoe. The inclusion of a crop-oil in the 2,4-D spray greatly increased efficacy. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon).

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Long-term measurements of the transport of African mineral dust to the southeastern United States: Implications for regional air quality

Journal of Geophysical Research Atmospheres ◽

10.1029/1999jd900072 ◽

1999 ◽

Vol 104 (D13) ◽

pp. 15917-15927 ◽

Cited By ~ 399

Author(s):

Joseph M. Prospero

Keyword(s):

United States ◽

Air Quality ◽

Mineral Dust ◽

Southeastern United States ◽

Regional Air Quality

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Long-Term Timber Contracts in the Southeastern United States: Updating the Primer Valuation Framework

Forest Science ◽

10.1093/forsci/fxaa020 ◽

2020 ◽

Vol 66 (6) ◽

pp. 653-665

Author(s):

Hector I Restrepo ◽

Bin Mei ◽

Bronson P Bullock

Keyword(s):

United States ◽

Interest Rates ◽

Southeastern United States ◽

Price Volatility ◽

Forest Products ◽

The United States ◽

Raw Material ◽

Conditional Volatility ◽

Material Supply

Abstract Timberland ownership has drastically changed in the United States since the 1980s, driven by the divestitures of vertically integrated forest products companies. Having sold their timberland, forest products companies have exposed themselves more to the risk of raw material supply. To hedge against this risk, forest products companies usually use long-term timber contracts (LTTC). The objective of this article is to update the valuation framework for LTTCs proposed by Shaffer (1984) by including alternative option price models and refining the estimates of some key economic variables. In particular, conditional volatility from the generalized autoregressive conditional heteroscedasticity model and quasi-conditional volatility from rolling estimation windows, in addition to simple standard deviation, are used for the volatility estimates in the option pricing models. Contrary to the previous result by Shaffer (1984), our analysis suggests that LTTCs that were once profitable for forest products companies in the 1980s are no longer so under current market conditions. This is primarily because both timber price volatility and the risk-free interest rates have declined significantly. Thus, to be better off, forest products companies need to either lower the administration and management costs of those LTTCs or rely more on the open market for timber procurement. Study Implications: Forest products companies have traditionally relied on long-term timber contracts (LTTC) negotiated with forest landowners to mitigate the risk of raw material supply. The value of these LTTCs highly depends on the economic context. This research provides some insights into the valuation of LTTCs in the southeastern United States. Forest products companies can use this updated framework to aid their decisionmaking in timber procurement.

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Histological Evidence that Microsclerotia Play a Significant Role in Disease Cycle of the Boxwood Blight Pathogen in Southeastern United States and Implications for Disease Mitigation

Plant Health Progress ◽

10.1094/php-2012-0403-01-br ◽

2012 ◽

Vol 13 (1) ◽

pp. 45 ◽

Cited By ~ 8

Author(s):

Sarah M. Weeda ◽

Norman L. Dart

Keyword(s):

United States ◽

Significant Role ◽

Potential Role ◽

Histological Study ◽

Southeastern United States ◽

Host Tissue ◽

Term Survival ◽

Long Term Survival ◽

Histological Evidence

Cylindrocladium pseudonaviculatum, the causal agent of box blight, has been shown to survive in soil for at least 5 years. The occurrence of microsclerotia in host tissue remains undocumented, making the mechanism for long term survival of this pathogen unclear. If the boxwood blight pathogen has indeed lost or never evolved the ability to produce microslerotia in tissues, one could infer that the pathogen is either less equipped for long term survival in soil than other Cylindrocladium species or the pathogen has evolved another mechanism to enable it to persist in soil. Based on these assumptions, we conducted a histological study to determine the potential role, if any, of microsclerotia in the lifecycle of C. pseudonaviculatum. Accepted for publication 17 February 2012. Published 3 April 2012.

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Establishment size and employment stability in logging and sawmilling: a comparative analysis

Canadian Journal of Forest Research ◽

10.1139/x01-146 ◽

2002 ◽

Vol 32 (1) ◽

pp. 67-80 ◽

Cited By ~ 2

Author(s):

Robert G Lee ◽

Penelope Jennings Eckert

Keyword(s):

United States ◽

Comparative Analysis ◽

The United States ◽

Wood Products ◽

Manufacturing Industries ◽

Employment Stability ◽

Establishment Size ◽

The Relationship ◽

Competitive Nature

Wood products employment stability (defined as year-to-year variation) was examined as a function of establishment size (grouped by number of employees). Small- and medium-sized establishments were consistently found to be more stable than large establishments. Comparison of Washington, Oregon, the United States, and Japan showed that the relationship between establishment size and employment stability was maintained regardless of long-term growth or decline in wood-products employment. Moreover, the smaller wood-products establishments in the United States were found to be more stable than the smaller establishments in other manufacturing industries. Structural stability in employment has been associated with the highly competitive nature of smaller wood-products establishments. Employment stability can best be promoted by policies that support the continued viability of smaller establishments.

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