Bioactive Natural Products: A feasible method of organic disease management in float bed production systems

Project Overview

LS03-147
Project Type: Research and Education
Funds awarded in 2003: $19,883.00
Projected End Date: 12/31/2004
Region: Southern
State: Tennessee
Principal Investigator:
Kimberly Gwinn
University of Tennessee

Annual Reports

Commodities

  • Vegetables: tomatoes

Practices

  • Pest Management: allelopathy, botanical pesticides, chemical control, mulches - killed
  • Soil Management: organic matter

    Abstract:

    Greenhouse production is an excellent means of augmenting income for farms, as it can provide spring and fall cash crops that are not weather dependent. A careful system of exclusion, sanitation, and environment management has allowed us to eliminate the use of pesticides in our modified hydroponics greenhouses. Many diseases can be controlled through cultural practices; however, species of water-borne pathogens, specifically Pythium and Phytophthora, remain potential threats in a hydroponic greenhouse production system. The objective of the research funded by this planning grant was to investigate the impact of three types of alternative biorationals on production of tomatoes in a modified hydroponic system. Botanical alternatives (bioactive herbage), and two types of microbial alternatives (endophytic Beauveria and PGPR) were applied alone and in combination to tomatoes grown in hydroponic culture. Tomatoes were grown under standard conditions for modified substrate culture. Herbage and PGPR treatments were applied directly to the substrate at transplant; Beauveria was applied as a seed treatments. Tomatoes were harvested April 27, 2004 through June 15, 2004. At harvest, tomatoes were weighed and graded. Protocols for exclusion, sanitation and environment management were sufficient to eliminate the need for commercial pesticide applications. For fresh market tomatoes, tomato yield was significantly impacted by interaction of Monarda herbage and herbage rate. There was a significant interaction between Pythium and herbage at the high rate for yield of fresh market tomatoes. There were no significant differences in Processing Tomato or Total Marketable Tomato yields due to Pythium and herbage. Treatment with Roman chamomile herbage resulted in reduced weight of Fresh Market Tomatoes. Treatment with Roman chamomile did not affect weight of Processing Tomatoes or Total Marketable Tomatoes. There was no effect of the interaction among Beauveria, Pythium and PGPR on Fresh Market Tomatoes or Total Marketable Tomatoes when all cultivars were considered but there was a significant decrease in the weight of Processing Tomatoes in treatments with Beauveria in some cultivars. Within all data sets, effects of Pythium treatments were rarely significant, but when they were, plants treated with Pythium produced more fruit. Based on these data, we have identified biorational combinations that not only have the potential to control Pythium disease in hydroponic tomatoes but also to increase yield. A proposal based on the data collected in this research was submitted to Southern SARE in response to the 2005 Call for Proposals for Research and Education grants.

    Project objectives:

    Originally, the objective of this planning grant was to investigate the use of Monarda bioactive herbage on disease control in tomato transplant production in float beds. The market research study that was conducted in the initial stages of this project found that, due to grower belief that float bed production systems produce tomato transplants of markedly inferior quality, there is unlikely to be a market for this product. At that point, research goals were redirected in order to provide data that would most benefit growers, consumers, and other stakeholders.

    The objective of this research was to investigate the impact of three types of alternative biorationals on production of tomatoes in a modified hydroponic system. Botanical alternatives (bioactive herbage), and two types of microbial alternatives (endophytic Beauveria and PGPR) were applied alone and in combination to tomatoes grown in hydroponic culture.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.