Description
Alfalfa autotoxicity causes yield reductions in alfalfa production by inhibiting plant establishment and decreasing plant productivity. Accurate predictions regarding autotoxic potential of the soil in a given field at a given time are an essential tool for alfalfa growers to make appropriate planting decisions. To address this issue, we are developing a soil bioassay that can be conducted as a mail-in soil test for alfalfa growers through plant diagnostic service laboratories. We hypothesize that we will detect differences in seed germination, emergence, root length, and root morphology between control and autotoxic soils. A preliminary trial testing alfalfa field soils and fallow field soils against a potting soil control found significant response of percent abnormal roots (P < 0.001) and average root length (P < 0.05) to soil variety. There were significantly lower percentages of abnormal roots in the control and fallow soils than in alfalfa soils (P < 0.05) and significantly longer roots in the control soil than in alfalfa soils (P < 0.05). An ongoing field trial encompassing multiple alfalfa varieties and termination dates will be used to validate the bioassay methodology for detecting autotoxicity. Implementing this bioassay could inform alfalfa establishment decisions, reduce yield losses from autotoxicity, and allow collection of data that can be used to further understand alfalfa autotoxicity.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Developing a Simple Bioassay for Detection of Alfalfa Autotoxicity in Field Soils
Alfalfa autotoxicity causes yield reductions in alfalfa production by inhibiting plant establishment and decreasing plant productivity. Accurate predictions regarding autotoxic potential of the soil in a given field at a given time are an essential tool for alfalfa growers to make appropriate planting decisions. To address this issue, we are developing a soil bioassay that can be conducted as a mail-in soil test for alfalfa growers through plant diagnostic service laboratories. We hypothesize that we will detect differences in seed germination, emergence, root length, and root morphology between control and autotoxic soils. A preliminary trial testing alfalfa field soils and fallow field soils against a potting soil control found significant response of percent abnormal roots (P < 0.001) and average root length (P < 0.05) to soil variety. There were significantly lower percentages of abnormal roots in the control and fallow soils than in alfalfa soils (P < 0.05) and significantly longer roots in the control soil than in alfalfa soils (P < 0.05). An ongoing field trial encompassing multiple alfalfa varieties and termination dates will be used to validate the bioassay methodology for detecting autotoxicity. Implementing this bioassay could inform alfalfa establishment decisions, reduce yield losses from autotoxicity, and allow collection of data that can be used to further understand alfalfa autotoxicity.
