<html><head></head><body><div class="yahoo-style-wrap" style="font-family:courier new, courier, monaco, monospace, sans-serif;font-size:16px;"><div dir="ltr" data-setdir="false">I am in the process of studying the effects of horticultural vinegar on Japanese Stiltgrass <span><span style="color: rgb(77, 81, 86); font-family: Roboto, "helvetica neue", helvetica, arial, sans-serif;">(<i>Microstegium vimineum</i>). </span><span style="color: rgb(77, 81, 86);">I used a 2 liter Futone pressure sprayer like one I would use to spray issues in our small yard with 30% and 15% vinegar (acetic acid) on two small sections of a remote trail we use which have dense <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass. The experiment is only 9 days old. The stems were 2" to 3" tall.</span></span></span></span></div><div dir="ltr" data-setdir="false"><span><span style="color: rgb(77, 81, 86);"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><br></span></span></span></span></div><div dir="ltr" data-setdir="false"><span>What I am seeing so far is that the 30% acetic acid was more effective than the 15%. The photos show about 50% "browning" of foliage. The issue appears that like in many foliar applications the key to success in killing the Japanese Stiltgrass with either concentration is the amount of the foliage the spray wetted. I am thinking that a day where the grass is wetted with heavy dew or fog is the best time to spray as it will spread the acetic acid better on the foliage and stems than dry days.</span></div><div dir="ltr" data-setdir="false"><span><span style="color: rgb(77, 81, 86);"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><br></span></span></span></span></span></span></div><div dir="ltr" data-setdir="false">I do not have the ability to do a water control or try standard household vinegar at 4.5% acetic acid due to equipment limitations. My negative control is the untreated stretches of trail with <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass.</span></span></div><div dir="ltr" data-setdir="false"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><br></span></span></div><div dir="ltr" data-setdir="false"><span>With better equipment such as a backpack sprayer, which is on order, I a certain the preliminary results would have been better. I intend to redo this experiment as soon as the backpack sprayer arrives.</span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><span>This will be an ongoing experiment borne of necessity if we expect to use some of the local trails.*</span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><span>*The main issue we have with <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass in this situation is that the taller the <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass grows the harder it is to see footing, especially on rocky trails like this one. If we expect to use this trail safely we need a clear path through the <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass. Last year I used a weed whip with some success when the <span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Japanese Stiltgrass was mid-calf high.</span></span></span></span></span></span></span></span></span></div><div dir="ltr" data-setdir="false"><span><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><br></span></span></span></span></span></span></span></span></span></div><div dir="ltr" data-setdir="false"><span><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;">Another issue I have is that our dog is often on leash which means I have to watch my footing, look for other dog hikers and handle a 15" (homemade) leash. Even though this is a remote and lightly used trail we have encountered dog hikers several times.</span></span></span></span></span></span></span></span></span></div><div dir="ltr" data-setdir="false"><span><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: "courier new", courier, monaco, monospace, sans-serif; font-size: 16px;"><br></span></span></span></span></span></span></span></span></span></div><div dir="ltr" data-setdir="false"><span><span>We use this trail mainly to avoid other more heavily used trails where we have less control in the number of people (and dogs) we encounter. In this age of COVID and living in a bleeding red section of Pennsylvania where few are vaccinated the fewer people we encounter the better.</span></span></div><div dir="ltr" data-setdir="false"><span><span><br></span></span></div><div dir="ltr" data-setdir="false"><span><span>Even though we are vaccinated we are still being very cautious in our encounters with other people. The fewer people we come in contact with, especially people we are uncertain of their vaccination status, the better.</span></span></div><div dir="ltr" data-setdir="false"><span><span><br></span></span></div><div dir="ltr" data-setdir="false"><span><span> Richard Gardner</span></span></div></div></body></html>