1a.Objectives (from AD-416)
The objective of this cooperative research project is to determine the effects of ethylene on growth, water use efficiency and yield of corn grown under different levels of irrigation and water deficit.
1b.Approach (from AD-416)
The availability of water for irrigated agriculture is decreasing as population growth continues in the western U.S. and water is being diverted from farms to urban communities. The Water Management Research Unit of USDA-ARS is beginning a multi-year research project on the effects of limiting irrigation on growth and yield of corn, sunflower, dry beans and wheat. One component that may limit yield in these crops is the response of plants to endogenous ethylene that is produced by a plant under water stress. If the plant’s perception to ethylene is reduced at critical times in the growth cycle, it possible that yield could be protected under water stress conditions. 1-methyl-cyclopropene (1-MCP) is a chemical that can lower a plant’s response to endogenous levels of ethylene by competitively binding at the ethylene receptor sites. Many fruits are currently treated with 1-MCP to reduce the perception of ethylene and thereby prolong their quality during storage. The approach in the proposed research is to treat corn plants grown under different levels of irrigation with 1-MCP at a vegetative and early reproduction stage to determine if lowering the plant’s response to ethylene will result in increased yield with limited water. Plants will be treated with 1-MCP at the V5 to V12 and VT to R2 growth stage and measurements taken on plant growth, transpiration, senescence, and yield. In addition, research will be conducted in the greenhouse to determine the physiological response of corn and other crops to 1-MCP and exogenously applied ethylene. The results from this research will help us determine the role of ethylene in corn’s response to water stress and could provide a tool for farmers to protect yield under limited water conditions.
A study on the effects of 1-MCP, a plant growth regulator that interferes with a plant’s response to ethylene, on corn grown under three different levels of irrigation continued with a new cooperative agreement between USDA-ARS and Agro fresh. In 2011, we concentrated on measuring multiple physiological parameters along with photosynthesis, transpiration and chlorophyll fluorescence. Greenhouse studies begun in June, 2011 on the interactions between water stress and 1-MCP application in corn and sunflower showed that plants treated with 1-MCP recover more quickly from short term water stress compared to untreated plants. It appears that the leaves of corn treated with 1-MCP do not respond to drought stress as rapidly as untreated plants. The effects of 1-MCP on water use, yield and yield components will be determined. Site visits by cooperators from Agro-Fresh were conducted in 2011 and the results of the 2010 experiments were presented at a workshop on 1-MCP in February, 2011.