Integrating rowcovers, compost and rhizobacteria to manage nutrients and key pests in organic cucurbit production

Open Access
- Author:
- Hernandez Heredia, Ermita
- Graduate Program:
- Horticulture
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 02, 2013
- Committee Members:
- Elsa Selina Sanchez, Dissertation Advisor/Co-Advisor
Elsa Selina Sanchez, Committee Chair/Co-Chair
Shelby Jay Fleischer, Committee Member
William James Lamont Jr., Committee Member
Richard P Marini, Committee Member
Beth Krueger Gugino, Committee Member - Keywords:
- IPM
nutrient management
cucurbits
muskmelon
winter squash
compost
PGPR
rowcover - Abstract:
- A three-year field experiment was conducted to examine the combined effect of rowcover (removed at different times), compost (applied using different mineralization rates) and PGPR (plant growth promoting rhizobacteria) seed treatment on muskmelon and squash pests, yield and soil fertility in an organic system. Three rowcover treatments (removal at anthesis, removal 10 days after anthesis and no rowcover), three nutrient treatments (applied using 10 or 30% mineralization rates, and organic bagged fertilizer) and two PGPR treatments (with or without seed treatment) were assigned to plots in a split plot factorial design. An extra rowcover treatment (removal at harvest with bumblebee hives placed under the rowcovers) was used in squash. Data were collected for ambient air and soil temperatures, striped cucumber beetle densities, bacterial wilt severity, squash bug density, soil properties, leaf tissue nutrient concentrations, open flower counts, bee visitation, seed counts, fruit quality, earliness and yield. Rowcovers modified the crop microclimate by increasing air and soil temperatures. In muskmelon, removing rowcovers 10 days after anthesis significantly reduced cucumber beetle density and bacterial wilt disease severity, enhanced earliness and increased yield. In 2009, the use of rowcovers increased plant nutrient concentrations. In squash removing rowcovers at anthesis prevented squash bugs from laying their eggs on plants and significantly increased yield. Soil proprieties were variable between years for different nutrient treatments in muskmelon and squash. However, applying compost using a 30% mineralization rate (low amount) was the best nutrient treatment for reducing bacterial wilt and squash bug egg masses and increasing soil fertility and organic matter without impacting yield compared to the organic bagged fertilizer for muskmelon and squash. Interaction terms were found between PGPR and nutrient treatments on the severity of bacterial wilt during the three years of the study in muskmelon but no significant effect was found on squash. Results of this study provide immediate management options for organic cucurbit growers to adopt and increase farm sustainability and yield in the eastern part of the U.S.