2011 Annual Report for GS10-097
Enhancing nitrogen and water use efficiency in tomato production by using grafting technique
Summary
In addition to disease management, grafting technology has been suggested as an innovative approach to improving nutrient and water use efficiency in vegetable production through appropriate selection of rootstocks. Yet, systematic research is needed to provide growers with updated information to better integrate this technology into sustainable farming systems. This study was conducted to evaluate the response of grafted tomato (Solanum lycopersicum) plants to different nitrogen (N) application rates (56, 75, 148, 224, 298, and 372 kg/ha) and irrigation regimes (50% and 100% of recommended water supply). A popular tomato cultivar 'Florida-47' was used as scion to graft onto two selected rootstocks with vigorous root systems and high resistance to soilborne pathogens. Grafted and non-grafted control plants were grown in plastic-mulched raised beds with drip irrigation in sandy soils in North Florida. Crop growth and development parameters, fruit yield, N and water use efficiency, and fruit quality were compared between grafted and non-grafted plants.
This annual report covers both 2010 and 2011 as the grant funding did not arrive until September 2010.
Objectives/Performance Targets
Assess the yield, nitrogen fertilizer use efficiency, and irrigation water use efficiency of grafted tomato under different combinations of irrigation regimes and nitrogen fertilization rates in field production.
Accomplishments/Milestones
The experiment was conducted during the spring season of 2011 at the North Florida Research and Education Center-Suwannee Valley in Live Oak, FL. A split-plot design with four replications was used. The whole plot treatments, i.e., 12 combinations of two irrigation regimes and six N fertilization rates, were arranged in a randomized complete block. The subplot treatments included 'Florida-47' grafted onto two interspecific rootstocks 'Multifort' and 'Beaufort' and the non-grafted 'Florida-47' as control, all randomized within each whole plot unit. There were 12 plants in each treatment combination per replication. Mature green tomato fruit were harvested and graded. The grafted plants showed significantly higher marketable fruit yields as compared to non-grafted plants. As a result of enhanced fruit yields, the grafted plants showed significantly greater nitrogen use efficiency and irrigation water use efficiency as compared to the non-grafted plants.
Impacts and Contributions/Outcomes
Given that grafted plants showed improved fruit yields and differential response to nitrogen supply levels as compared with non-grafted tomato plants, it is likely that nitrogen fertilizer inputs may be adjusted in grafted tomato production in contrast to the recommended application rate for non-grafted plants. Findings from this project will help provide recommendations for developing nitrogen fertilization management of grafted tomato in field production especially in sandy soils in Florida.