Volume 6 Issue 9
Huan Zhang1, Lisa DeVetter1, Carol Miles1, Shuresh Ghimire1, Chris Benedict1, Inga Zasada2
1Washington State University; 2United States Department of Agriculture, Agricultural Research Service
Background
• Tissue culture (TC) plugs are hard to establish and are weak competitors with weeds.
• Plastic biodegradable mulches (BDMs) can be comparable to polyethylene mulch (PE) for weed management, increasing soil temperature and moisture, promoting crop growth, and enhancing crop yield.
• Plastic BDMs are used in annual vegetable production systems.
• Few studies have tested plastic BDMs in perennial crop production systems, like red raspberry. There is potential that plastic BDMs promote raspberry establishment when planted as TC plugs.
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan1-e1505835595131.jpg)
Figure 1. Spring-planted raspberry TC trial, 18 May 2017.
Objectives
- Evaluate weed incidence with BDMs and PE mulch in comparison to bare ground (control treatment) in establishing TC red raspberry in both spring and fall planted systems in northwestern Washington.
- Monitor surface and in-soil degradation of BDMs in spring and fall planted raspberry systems.
- Evaluate growth, establishment, plant nutrient and moisture status, and yield of raspberry grown with BDMs and PE mulch in comparison to bare ground.
- Monitor soil temperature and moisture across BDM, PE, and bare ground treatments.
- Assess populations of root lesion nematodes (Pratylenchus penetrans; RLN) in the soils and roots of raspberry before and after using BDMs and PE mulch; populations will be compared to the bare ground treatment.
Treatments
- Organix 0.5 mil (BDM)
- Organix 0.6 mil (BDM)
- Bio 360 0.5 mil (BDM)
- Bio 360 0.6 mil (BDM)
- PE 1.0 mil (non-BDM)
- Bare Ground Control
Cultivars are ‘WakeField’ and ‘WakeHaven’ for the spring- and fall-planted trials, respectively.
Preliminary Results (only spring-planted trial results)
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan2.jpg)
Figure 2. Plant height (in) on 30 August 2017.
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/Huan3Combo-e1505844669353.png)
Figure 3. Comparison of plant height on 15 August 2017; bare ground (A) and BDM treated (B, Organix 0.5mil).
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan4.jpg)
Figure 4. Primocane number/hill on 30 August 2017.
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan5.jpg)
Figure 5. Average daily soil temperature (values averaged over 24-hours period at a 4 inch depth; 15-27 July 2017).
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan6.jpg)
Figure 6. Downloading soil moisture and temperature data.
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan7.jpg)
Figure 7. Average daily soil moisture (values averaged over 24-hours period at a 4 inch depth; 15-27 July 2017).
Data Collection
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan8-e1505837154331.jpg)
Figure 8. Measuring plant height.
• Weed number and weight (monthly)
• Soil and root samples for RLN population assessment
• Machine harvestable yield (in 2018)
• Mulch degradation (PSE)
• Plant height and primocane number (once per month, May-Oct)
• Soil temperature and moisture (logged every 15 minutes with a Decagon logger)
• Photosynthesis rate (once a year, between mid-July to mid-August)
• Leaf water potential (once a year, between mid-July to mid-August)
• Plant and soil nutrient content
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/huan9-e1505837233930.jpg)
Figure 9. Counting primocane number.
Acknowledgements
• Technical assistance from Sean Watkinson, Edward Scheenstra, Clara Tevelde and Matt Arrington, WSU NWREC.
• Funding from Washington Red Raspberry Commission and Washington State Commission on Pesticide Registration.
• Special thanks to grower cooperators.
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/WRRC_Logo.jpg)
![](http://s3.wp.wsu.edu/uploads/sites/2091/2017/09/WASCPR.png)
Resources:
WSU Small Fruit Horticulture Program: http://smallfruits.wsu.edu/
Biodegradable Mulch: http://www.biodegradablemulch.org
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