Polyethylene and biodegradable plastic mulches improve growth, yield, and weed management in

floricane red raspberry

Huan Zhang, PhD student

Advisor: Lisa DeVetter; Co-advisor: Carol Miles

Washington State University Northwestern Research and Extension Center

1

Lisa DeVetter

2

Processed Red Raspberry~ 78 Million Pounds in Washington State

Whatcom County: over 97% of State Production

WRRC, 2018

Tissue CultureNumber of Plants

Aseptic Techniques

Establishment Difficulty

Weak Competitor with Weeds

http://kryptokoryne.aquaticscape.com/

3

Biodegradable Plastic Mulch (BDM)

• Manufactured with different feedstocks and additives compared to

polyethylene (PE) mulches

• Engineered to biodegrade in soils by microbial activities (ASTM

D5988)

• Potential to reduce plastic waste generation

4

Lisa DeVetter

ASTM, 2018

Why Consider a BDM?

Gerbrant, 2015; Król-Dyrek and Siwek, 2015; Tecco et al., 2016; https://www.mlive.com/

• Few studies, but promising results

• May reduce labor and costs associated with PE mulch

removal and disposal

• May promote on-farm efficiencies

5

Root Lesion NematodeMajor Plant Parasite

Activity

No Previous Studies

Zasada et al., 2014; Rudolph and DeVetter, 2015; Gerbrandt, 2015; https://communities.grdc.com.au/field-crop-diseases/root-lesion-nematode/

6

Spring-Planted Trial Established May 2017

7

Treatments

Treatment Code Thickness Extruder/converter

BASF 0.5 A 0.5 mil PolyExpert Inc.; Laval, Quebec, Canada

BASF 0.6 B 0.6 mil PolyExpert Inc.; Laval, Quebec, Canada

Novamont 0.5 C 0.5 mil Dubois Agrinovation; Saint Remi, Quebec, Canada

Novamont 0.6 D 0.6 mil Dubois Agrinovation; Saint Remi, Quebec, Canada

Polyethylene E 1.0 mil FilmTech, LLC., Stanley, WI

Bare Ground

(BG; control)

F -- --

BDMs

8

Spring Trial

9

Experimental Design

Size 2 acres

Design Randomized Complete

Block

Treatments 6

Replications 5

Plot Length 120 ft

Block Across Row

Fumigation Broadcast; Sept. 2016

Cultivar WakeTMField

Plot Map Design Details

Objectives

1. Plant growth

2. Fruit yield

3. Weed incidence

4. Root lesion nematode populations

5. Soil temperature and moisture

6. Mulch surface and in-soil degradation

10

Weixin Gan

11

▪ Primocane height, number, and

emergence

▪ Yield

▪ Percent soil exposure (PSE)

▪ In-soil degradation

▪ Apr. 2018 to Oct. 2019

Mulch

▪ Soil temperature

▪ Soil moisture

▪ Soil nutrient status Soils

Data Collection

▪ Weed number

▪ Weed shoot fresh and dry weight

▪ RLN root and soil densities Pests

Plant

Lisa DeVetter

Weixin Gan

July 2017

12

Sept. 29, 2017

Weixin Gan

13

0

10

20

30

40

50

60

70

80

90

100

25

-Ma

y

30

-Ju

n

28

-Ju

l

30

-Au

g

29

-Se

p

27

-Oc

t

Prim

oca

ne

heig

ht

(in.)

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE Bare Ground

2017 Primocane Height

NS **

***

***

*** ***

NS: nonsignificant

*** : P ≤ 0.01

*** : P ≤ 0.000114

14 in.

difference

0

2

4

6

8

10

12

14

16

18

20

28

-Ju

l

30

-Au

g

29

-Se

p

27

-Oc

t

Prim

ocane n

um

ber

/ hill

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE Bare Ground

2017 Primocane Number

NS

***

***

***

NS:

nonsignificant

*** : P ≤ 0.000115

5 canes (71%) difference

January 2018

16

April 2018

17

Plant Growth Comparison (2018 April)

Mulched Non-mulched

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE BG

18

19Nadia Bostan

Treatment Primocane emergence/30 ft

July

Primocanes/plant

Sept.

Primocane height (in.)

Sept.

BASF 0.5 35 abz 5 125

BASF 0.6 37 ab 6 125

Novamont 0.5 30 b 6 128

Novamont 0.6 41 ab 6 125

PE 23 b 5 129

BG 45 a 6 124

P - value 0.05 0.28 0.71

2018 Plant Growth

zMeans followed by the same letter are not significantly different at P < 0.05, using a means comparison with a Tukey’s Honestly Significant Difference test except total yield, which was analyzed with LSD Student’s t

test.

20

Harvest 2018

0.0

2.0

4.0

6.0

8.0

10.0

12.0

1 h

arv

es

t

2 h

arv

es

t

3 h

arv

es

t

4 h

arv

es

t

5 h

arv

es

t

6 h

arv

es

t

7 h

arv

es

t

8 h

arv

es

t

9 h

arv

es

t

10

ha

rve

st

11

ha

rve

st

12

ha

rve

st

13

ha

rve

st

Yie

ld (

lbs/3

0ft

)

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE BG

Peaks

6/29 7/4 7/7 7/11 7/14 7/17 7/20 7/23 7/26 8/1 8/4 8/8 8/10

21

Treatment Early

6/29-7/10

Middle

7/11-7/25

Late

7/26-8/10

Total Yield

BASF 0.5 7.0 33.4 abz 16.7 a57.1 a

BASF 0.6 6.8 39.7 a 20.0 a66.5 a

Novamont 0.5 7.0 38.1 a 17.9 a63.0 a

Novamont 0.6 7.8 36.6 a 17.5 a61.8 a

PE 9.0 39.9 a 15.0 ab 64.0 a

BG 5.5 25.0 b 12.8 b 43.4 b

P - value 0.08 0.004 0.002 0.04

zAverages followed by the same letter are not significantly different at P < 0.05, using a means comparison with a Tukey’s Honestly

Significant Difference test except total yield, which was analyzed with LSD Student’s t test.

Average Fruit Yield (lbs/30 ft)lbs/acre

8976

lbs/acre

6233

lbs/acre 22

Total Yield

8198

9555

9052

8882

9191

6233

2743

lbs/acre

23

▪ Primocane height, number, and

emergence

▪ Yield

▪ Percent soil exposure (PSE)

▪ In-soil degradation

▪ Apr. 2018 to Oct. 2019

Mulch

▪ Soil temperature

▪ Soil moisture

▪ Soil nutrient status Soils

Data Collection

▪ Weed number

▪ Weed shoot fresh and dry weight

▪ RLN root and soil densities Pests

Plant

Lisa DeVetter

Weixin Gan

Lisa DeVetter

0

5

10

15

20

25

30

30

-Ju

n

28

-Ju

l

30

-Au

g

29

-Se

p

27

-Oc

t

Weeds c

oun

t (n

um

ber/

11 ft2

)

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE BG

2017 Cumulative Weed Number

*

**

*

*

NS: nonsignificant

*** : P ≤ 0.0524

Hand weeded BG plots 3 times

during growing season

Root Lesion Nematode Densities(Sampled Oct. 11, 2017)

25

Rachel Rudolph

Root Lesion Nematode (RLN)

Lisa DeVetter

May 2017z October 2017 May 2018 September 2018

Treatment

RLN/

100g soil

RLN/

100g soil

RLN/

g root

RLN/

100g soil

RLN/

g root

RLN/

100 g soil

RLN/

g root

BASF 0.5 0 51 aby 105 ab 52 a 1538 258 ab 1352 ab

BASF 0.6 1 49 ab 134 ab 50 ab 937 225 ab 430 b

Novamont 0.5 0 66 ab 165 a 40 ab 1471 116 b 1620 ab

Novamont 0.6 0 100 a 164 ab 38 ab 1109 209 ab 1445 ab

PE 1 72 a 45 b 40 ab 995 350 a 2605 a

BG 0 5 b 44 b 10 b 997 212 ab 692 b

P - value 0.40 0.03 0.02 0.04 0.20 0.01 0.01zPre-plant densities.yAverages followed by the same letter are not significantly different at P < 0.05, using a means comparison with a Tukey’s Honestly Significant Difference

test for the May 2017 data and a non-parametric multiple comparisons Wilcoxon test for the October 2017, and May and September 2018 data.

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▪ Primocane height, number, and

emergence

▪ Yield

▪ Percent soil exposure (PSE)

▪ In-soil degradation

▪ Apr. 2018 to Oct. 2019

Mulch

▪ Soil temperature

▪ Soil moisture

▪ Soil nutrient status Soils

Data Collection

▪ Weed number

▪ Weed shoot fresh and dry weight

▪ RLN root and soil densities Pests

Plant

Lisa DeVetter

Weixin Gan

0

10

20

30

40

50

60

70

80

90

1005

/26

/17

6/1

5/1

7

6/3

0/1

7

7/1

4/1

7

7/2

7/1

7

8/1

5/1

7

8/3

0/1

7

9/1

5/1

7

9/3

0/1

7

10

/16

/17

10

/27

/17

11

/15

/17

11

/30

/17

12

/13

/18

1/7

/18

1/1

6/1

8

1/3

1/1

8

2/1

6/1

8

3/2

/18

3/1

9/1

8

3/3

0/1

8

4/1

6/1

8

PS

E (

%)

BASF 0.5 BASF 0.6 Novamont 0.5 Novamont 0.6 PE

Percent Soil Exposure (PSE; %)

NS *

* **

*

NS NS * **

*

*

7 wind events with a speed

over 10 mph in Oct. and Nov.

– WSU AgWeatherNet

BDM PE

Before cane tying: PE: 2.6%; BDMs: 67 to 81%

After cane tying: PE: removed; BDMs: 90 to 95%

NS: nonsignificant

*** : P ≤ 0.05

Raspberry cane tying

**

**

* *

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Conclusions to Date

• Plants grown with BDMs and PE mulch exhibited greater primocane

height and number relative to the BG control

• Yield was higher in all mulched treatments than the BG control

• There is no difference in average berry weight

• Mulched treatments successfully controlled weeds so no hand weeding

was needed

• RLN soil and root populations were greater when soil and plants treated

with PE mulch

• Soil temperature was higher with mulched treatments

• PE removal activity could remove 1010 pounds soil per acre

• Overall, BDMs and PE mulch are viable tools to use in commercial red

raspberry production with plants established as TC transplants

28

Team

29

Lisa

DeVetter

Carol

Miles

Chris

Benedict

Me

Inga

Zasada

Shuresh

Ghimire

Left to right, top to bottom: Ed Scheenstra, Matt Arrington, Clara TeVelde, Naida Bostan, Qianwen Lu,

Weixin Gan, Sean Watkinson, and Washington raspberry growers.

Additional Team Members and Thanks

Funding and Material Support

31

Literature Cited

• American Society for Testing and Materials (ASTM). 2018. Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in Soil. ASTM D 5988-18. ASTM International, West Conshohocken, PA. Accessed at www.astm.org on 29 June 2018

• Biodegradable mulch website: https://ag.tennessee.edu/biodegradablemulch/Pages/default.aspx.

• Gerbrandt, E. 2015. New techniques for getting raspberries and strawberries off to a better start. 2015 Lower Mainland Horticulture Improvement Association Horticulture Growers’ Short Course. Accessed on 19 Sept. 2017 at <http://www.agricultureshow.net/horticulture-growers-short-course>

• Król-Dyrek, K. and P. Siwek. 2015. The influence of biodegradable mulches on the yielding of autumn raspberry (Rubus idaeus L.). Folia Horticulturae 27(1):15-20.

• Rudolph, R. and L.W. DeVetter. 2015. Management strategies for Phytophthora rubi and Pratylenchuspenetrans in floricane red raspberry (Rubus idaeus L.). J. Am. Pom. Soc. 69(3):118-136.

• Tecco, N., C. Baudino, V. Girgenti, and C. Peano. 2016. Innovation strategies in a fruit growers association impacts assessment by using combined LCA and s-LCA methodologies. Sci. Total Environ. 568:253-262.

• Washington State Red Raspberry Commission (WRRC). 2017. PNW Red Raspberry Production Statistics. Accessed on 2 June 2018 at https://www.red-raspberry.org/statistics.

• Washington State University Small Fruit Horticulture website: https://smallfruits.wsu.edu/.

32

Thank You!

33

Huan Zhang

Email: huan.zhang@wsu.edu

Phone: 360-333-8527

Washington State University Small Fruit Horticulture website:

https://smallfruits.wsu.edu/