WEED CONTROL IN A NEWLY ESTABLISHED ORGANIC VINEYARD By CALLIE S. BOLTON A ...

133 Pages·2011·12.92 MB·English

by  Callie Bolton

WEED CONTROL IN A NEWLY ESTABLISHED
ORGANIC VINEYARD

By

CALLIE S. BOLTON

A thesis submitted in partial fulfillment of
the requirements for the degree of

MASTER OF SCIENCE IN CROP SCIENCE

WASHINGTON STATE UNIVERSITY
Department of Crop and Soil Sciences

May 2011
To the Faculty of Washington State University:

The members of the Committee appointed to the thesis of CALLIE SPENCER BOLTON find it
satisfactory and recommend that it be accepted.

Chair, Timothy Miller, Ph.D.

Co-chair, Carol A. Miles, Ph.D.

Mercy A. Olmstead, Ph.D.

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ACKNOWLEDGMENTS

I am grateful for the funding provided by the Washington State University Center for
Sustainable Agriculture and Natural Resources and the Graduate Research Assistantship in the
Department of Crop and Soil Sciences. I am especially grateful to my committee for their guidance
and support: Dr. Tim Miller, Dr. Carol Miles, and Dr. Mercy Olmstead. This project was also assisted
by the technical support and guidance provided by Jacky King, Gary Moulton, and Jonathan Roozen.

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WEED CONTROL IN A NEWLY ESTABLISHED
ORGANIC VINEYARD

Abstract

By Callie S. Bolton, M.S.
Washington State University
May 2011

Chair: Richard T. Koenig

Environmental concerns regarding the impact of agriculture have created ever-growing pressure for
growers to incorporate increasingly sustainable practices. Consumer demand for organic grape
products, the major organic horticultural fruit crop worldwide, has led to growers seeking more
information on organic grape production. Within organic grape production, weed management is the
most critical issue with a newly established vineyard. In 2009, an organic vineyard was established
to analyze the effectiveness of cover crops compared to tillage for weed control. Five treatments
were applied to ‘Pinot noir précoce’ (PNP) and ‘Madeleine angevine’ (MA) grapes during the first two
years of establishment. Weed control treatments were standard cultivation between-row and hand-
weeding in-row (ST), in-row tillage with Wonder Weeder® and grass ((Lolium perenne L. and Festuca
rubra L. ssp. arenaria ‘Osbeck’ F. Aresch.) cover crop seeded between-row (WW), winter wheat
(Triticum aestivum L. cv. ‘Otis’) cover crop and in-row string-trimming (W), Austrian winter pea (Pisum
arvense L.) cover crop and in-row string-trimming (P), and wheat and pea cover crop mix and in-row
string-trimming (W/P). Weed biomass in September 2009 was greater in the P treatment than under
ST and W. Weed biomass in July 2010 was greater in W, P, and W/P than in ST or WW. By
September, however, weed biomass was not different among treatments. Plot maintenance in ST
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required more time than WW or the annual cover crop treatments. MA produced more shoot growth
than PNP in September 2010. Grapevines under ST measured significantly longer than vines under
any other treatment. Weed biomass was reduced by the wheat and pea cover crops, and the vine
growth was also negatively affected by these cover crops. Wheat and pea did not differ in their level
of competition with the weeds or the grapevines. Cultivation and hand weeding reduced weed
biomass, but hand weeding required the greatest maintenance. In a newly established organic
vineyard, the most effective and efficient management regime includes a vegetative-free zone in-row
maintained using a specialty cultivator to minimize the need for hand weeding and a perennial cover
crop in the alleyway to reduce weed biomass.
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TABLE OF CONTENTS

PAGE
ACKNOWLEDGEMENTS..................................................................................iii
ABSTRACT....................................................................................................iv
LIST OF TABLES............................................................................................ x
LIST OF FIGURES.........................................................................................xii
CHAPTER 1 LITERATURE REVIEW ...................................................................1
1.1 Wine grape industry...................................................................................................1
1.1.1 Organic wine grape production practices..............................................................2
1.1.2 Economics of organic grape production................................................................4
1.1.3 Pacific Northwest wine grape industry...................................................................4
1.1.3.1 Grapevine selection.......................................................................................5
1.1.3.1.1 Rootstock.............................................................................................6
1.1.3.1.2 Sources ................................................................................................7
1.2 Organic vineyard establishment and maintenance........................................8
1.2.1 Climate.....................................................................................................................9
1.2.2 Light..........................................................................................................................9
1.2.3 Topography.............................................................................................................10
1.2.4 Soil tests.................................................................................................................10
1.2.5 Trellising.................................................................................................................11
1.2.6 Training and pruning.............................................................................................11
1.2.7 Plant nutrition........................................................................................................12
1.2.8 Irrigation.................................................................................................................13
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1.2.9 Weed control..........................................................................................................14
1.2.9.1 Cultivation....................................................................................................15
1.2.9.1.1 In-row cultivation................................................................................15
1.2.9.1.2 Between-row cultivation....................................................................17
1.2.9.2 Cover cropping.............................................................................................17
1.2.9.2.1 Legume cover crops..........................................................................18
1.2.9.2.2 Grass cover crops..............................................................................20
1.2.9.2.3 Combinations.....................................................................................21
1.2.9.3 Mowing and string-trimming.......................................................................22
1.3 Conclusions.................................................................................................................23
1.4 References ..................................................................................................................25
1.5 Tables............................................................................................................................39
CHAPTER 2 ESTABLISHING AN ORGANIC VINEYARD IN
WASHINGTON STATE ................................................................ 40
2.1 Introduction.................................................................................................................40
2.2 Vineyard establishment..........................................................................................42
2.2.1 Start up expenses..................................................................................................42
2.2.2 Vineyard site selection..........................................................................................44
2.2.2.1 American Viticultural Areas (AVAs).............................................................44
2.2.2.2 Topography..................................................................................................44
2.2.2.3 Climate.........................................................................................................45
2.2.2.4 Light..............................................................................................................46
2.2.2.5 Rainfall.........................................................................................................47
2.2.2.6 Soil................................................................................................................48
2.2.3 Choosing grapevines.............................................................................................50
2.2.3.1 Cultivars........................................................................................................51
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2.2.3.2 Rootstocks....................................................................................................51
2.3 Vineyard site preparation and maintenance ..................................................54
2.3.1 Trellis system.........................................................................................................54
2.3.2 Fertilizer...........................................................................................................................................57
2.3.3 Irrigation.................................................................................................................60
2.3.4 Planting the grapevines........................................................................................61
2.3.5 Weed control..........................................................................................................62
2.3.5.1 In-row............................................................................................................63
2.3.5.2 Between-row................................................................................................64
2.3.5.3 Cover crops..................................................................................................65
2.3.6 Disease and insect pest control...........................................................................66
2.3.7 Pruning and training..............................................................................................68
2.4 Conclusions.................................................................................................................70
2.5 References ..................................................................................................................72
2.6 Tables............................................................................................................................77
2.7 Figures ..........................................................................................................................79
CHAPTER 3 : WEED CONTROL IN A NEWLY ESTABLISHED ORGANIC
VINEYARD................................................................................ 81
3.1 Abstract ........................................................................................................................81
3.2 Introduction.................................................................................................................82
3.3 Materials and methods...........................................................................................84
3.3.1 Vineyard establishment.........................................................................................84
3.3.2 Climate...................................................................................................................86
3.3.3 Grapevines.............................................................................................................86
3.3.3.1 Irrigation.......................................................................................................87
3.3.3.2 Fertilizer........................................................................................................87
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3.3.3.3 Cover crop treatments.................................................................................88
3.3.4 Vineyard maintenance..........................................................................................89
3.3.5 Measurements.......................................................................................................89
3.3.5.1 Shoot length.................................................................................................90
3.3.5.2 Shoot diameter............................................................................................90
3.3.5.3 Weed biomass.............................................................................................90
3.3.5.4 Weed management.....................................................................................91
3.3.6 Statistical analysis.................................................................................................91
3.4 Results..........................................................................................................................91
3.4.1 Soil testing and amendments...............................................................................91
3.4.2 Treatment effects on weed biomass distribution and composition in 2009....92
3.4.3 Treatment effects on weed biomass distribution and composition in 2010....93
3.4.4 Treatment effects on grapevine shoot growth in 2009......................................94
3.4.5 Treatment effects on grapevine shoot growth in 2010......................................94
3.4.6 Maintenance requirements..................................................................................95
3.5 Discussion ...................................................................................................................95
3.5.1 Weed control..........................................................................................................95
3.5.2 Grapevine growth...................................................................................................97
3.5.3 Maintenance..........................................................................................................98
3.6 Conclusions.................................................................................................................99
3.7 References ................................................................................................................101
3.8 Tables..........................................................................................................................108
3.9 Figures ........................................................................................................................117
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LIST OF TABLES
PAGE
Table 1.1 Common legumes used as cover crops and their average
N fixation rates ............................................................................ 39
Table 2.1 Line post options and features for organic vineyard establishment.............. 77
Table 2.2 Specialized cultivators commonly used in vineyards................................ 78
Table 3.1 Soil analysis of organic vineyard prior to plant establishment at WSU Mount
Vernon NWREC (2008)................................................................. 108
Table 3.2 Mean dry-weight biomass in organic weed control treatments between or within
grapevines rows in 2009............................................................... 109
Table 3.3 Mean dry-weight biomass of weeds between or within grapevine rows under five
organic weed control treatments in 2010.......................................... 110
Table 3.4 Mean dry weight biomass of white clover and other weeds within five organic
weed control treatments in 2010.................................................... 111
Table 3.5 Mean grapevine shoot length for five organic weed control treatments and two
grapevine cultivars in 2009 ........................................................... 112
Table 3.6 Mean grapevine shoot length for five organic weed control treatments and two
grapevine cultivars in 2010 ........................................................... 113
Table 3.7 Mean hours (h!p-1!ha-1) required for mowing, disking, Wonder Weeding (WW),
hand weeding (HW), string-trimming (STR) and all season-long maintenance
tasks (Total) for five organic weed control treatments and two grapevine
cultivars in 2009......................................................................... 114
Table 3.8 Mean hours (h!p-1!ha-1) required for mowing, disking, Wonder Weeding (WW),
hand weeding (HW), string-trimming (STR) and all season-long maintenance
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