Effects of landscape fabrics on pest control in a raised-bed trough system for strawberry production without fumigation

Authors: CABRERA, ALFONSO - University Of California; Wang, Dong; Gerik, James; GAN, JAY - University Of California

Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 9/19/2011
Publication Date: 10/21/2011
Citation: Cabrera, A., Wang, D., Gerik, J.S., Gan, J. 2011. Effects of landscape fabrics on pest control in a raised-bed trough system for strawberry production without fumigation. International Conference on Methyl Bromide Alternatives and Emissions Reductions, San Diego, California, October 31-November 2, 2011. p. 5.

Interpretive Summary: Pre-plant soil fumigation with methyl bromide and other alternative fumigant chemicals used for the control of soilborne pathogens and nematodes is highly restricted in California. Therefore, there is an increasing interest in finding alternative methods to avoid or reduce the use of fumigants. Greenhouse and field experiments were conducted to evaluate landscape fabrics for controlling soil nematodes and fungal pathogens in a raised-bed trough system for strawberry production. The greenhouse experiment was carried out using soil pots inoculated with root-knot nematode juveniles and Phytophthora and Verticillium pathogens. One strawberry transplant was planted in each pot in a clean peat-perlite medium set on top of the inoculated soil and separated with different types of landscape fabrics. The field experiment was conducted using actual soil beds, also inoculated with the same nematodes and pathogens as in the greenhouse experiment. Strawberry transplants were planted in troughs filled with clean peat-perlite and separated from the inoculated soil below using the fabrics. All fabrics were able to retain roots inside the substrate and only very limited penetration by few large roots was observed. All fabrics prevented nematode penetration in strawberry roots and no pathogen could be found in strawberry plants. The study showed that the landscape fabrics could be used in the substrate trough system without relying on pre-plant soil fumigation for controlling soilborne pests.

Technical Abstract: Landscape fabrics are geotextiles that have been used to control weeds. The objective of this study was to determine the performance of landscape fabrics for the control of nematodes and fungal pathogens for strawberry fruit production. Four different commercially available landscape fabrics were used and greenhouse and field experiments were carried out with cultures of root knot-nematodes (Meloidogyne incognita), Phytophthora cactorum, and Verticillium dahliae. In the greenhouse experiment, soil in pots was inoculated with nematodes (5000 freshly hatched J2 root-knot nematodes) and pathogens (50 g of soil containing 10890 P. cactorum cfu/g soil and 485 V. dahliae cfu/g soil). One of the four different fabrics was placed over the infested soil. Above the fabric, 1000 cm3 of soilless substrate (60% peat; 40% perlite) was added. A strawberry transplant (cv. Camarosa) was planted per pot. In the field experiment, soil beds were constructed with a specially built bed shaper and covered with plastic mulch. Nine beds were randomly assigned to one of three different landscape fabrics and filled with peat-perlite substrate. Strawberry transplants (cv. Albion) were planted in each bed which was infected with nematodes and pathogens. After 18 weeks of nematode and pathogen inoculation, the number of roots that penetrated the fabrics was determined. Nematodes and pathogens were evaluated in roots and substrate. In general, all fabrics exhibited strong capacity to contain the roots and preventing M. incognita from entering plant roots. No P. cactorum infection was found in strawberry roots and very little incidence in the soilless substrate. There was a V. dahliae infection found in one petiole sample of the greenhouse experiment in one fabric. However, no V. dahliae incidence was found in roots or substrate in any other fabrics tested. This investigation demonstrated the potential of landscape fabrics to reduce the infection of nematodes and soilborne pathogens for strawberry fruit production. The landscape fabric trough system could be an alternative to manage soilborne pests in areas where pre-plant soil fumigation is restricted.