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As a Result of the Weather...

In our July 2020 post, we talked about the activity we would be doing moving forward into 2020, placing an emphasis on applying day-to-day real-world application of IWM principles to further develop realistic options for producers. For a full re-cap of our planned courses of action, see the “2020 Plans Preview” section of our July 2020 post “Year II Kick-Off.”

Like anything in agriculture, weather plays a commanding role. When we shared the post during the first week of July, our area was doing well weather-wise, with adequate moisture and reasonable temperatures. But that quickly changed. Beginning the middle of July, we experienced hot, dry conditions that continued into the last week of August. Temperatures were well above average and the moisture pretty much shut off. Even though the US Drought Monitor now shows our area as being only “abnormally dry” with moderate drought in regions very close to us, the plants did what Mother Nature designed them to do and quickly slowed in growth. Applying herbicide soon became impractical since the plants would not have taken in much chemical. Planting grass seed would have been a lost cause particularly because of the risk of new plants sprouting only to dry up.  
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Consequently, we were not able to start any new chemical test plots, nor were we able to test the effectiveness of using cattle to work grass seeds into the ground. We did try to spray some areas prior to the weather bringing everything to a halt and chemically treated the variable-height mowed plots that had been grazed by cattle and some areas within a goat pasture. But this was towards the end of July and the hot, dry weather had already begun to affect how the plants were growing. The chemically-treated chicory did not produce as many flowers as the plants that were not sprayed, but all the plants continued to grow. As of September 2nd, there doesn’t seem to be much difference between the chicory that was sprayed and other plants that were not treated. 

​We were particularly disappointed in the variable-height test plots. Even after these plots were mowed at the end of the 2019 growing season, then grazed with cattle in 2020, and then chemically treated, the chicory in these plots was able to grow significantly. Again, we did not note many flowers so we will have to evaluate the success or failure of our actions when growing conditions improve.

The true indication of whether the chemical weed control measures were successful or not probably won’t be obvious until next spring when new plants, if any, begin to grow. That is an instance affirming that weed control, even with IWM principles, is not a one-time job. It is a non-stop commitment. That is also a clear example of the IWM rule stressing the importance of using the plant’s physiological characteristics—when the plant is most susceptible to being affected by a control method—to your advantage. We knew the plants’ maturity was getting advanced and being affected by the weather, diminishing the chances for optimum results to happen. But with everything else going on around the farm, things didn’t always work according to a neat schedule. We pushed the time and weather limits. The results, good or bad, will be good information to know.

One of the primary goals of this project has always been to find an effective, sustainable means of controlling the invasive spread of chicory in fields and pastures, retain a sustainable production of the field or pasture, and not remove the desirable legumes such as alfalfa and clover in the process. Even though all of the IWM principles (mechanical, biological, cultural, chemical) have some value and should be used together, as no one technique should be depended upon alone, our research has continually come back to chemical treatment as the most effective, long-term measure to deal with the invasive nature of chicory. As mentioned in earlier posts, some of the SDSU herbicide trials have produced some promising results to control chicory but not eliminate the alfalfa. We are still very much interested in expanding those trials by trying some additional real-world applications to verify the initial results. If successful, we will have accomplished the most significant goal of this research. But those trials simply cannot be completed this year, and we will need to wait for more favorable conditions, perhaps next spring, to continue further.
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Initially, we had hoped to conclude our research during the two-year period of this project and be able to provide producers with proven options they could use on their farm or ranch. As our final report (coming in October) will reflect, we can make conclusions about certain aspects of mechanical, biological, and preventative IWM practices. However, as we mentioned and as is typical in chemical and certain features of cultural trials, weather plays a huge role. Beyond heat and moisture, patience is essential to assure recommendations are safe, effective, and valid. All in all, two years simply is not enough time to adequately test and evaluate certain solutions. Even so, we feel confident that we’ll have some promising results to build upon next year. Regarding chemical trials in particular, the first year served to identify which chemicals were quickly effective to control or eliminate the chicory and to evaluate the immediate impact on desirable plants, particularly legumes. This second year provided insight into whether the chicory would be able to rebound and grow back. It also substantiated whether desirable forages impacted the first year could recover during the second growing season or whether they were weakened to the point that they could not regrow. Next year will hopefully solidify those results further. 

​Chemical IWM Run-Down

This October, when the growing season is complete and we can be more certain of the outcomes, a complete list and the associated results of the fifteen chemicals tested will be published. At this point, we feel safe in reporting that one chemical (Plateau) was found to be completely ineffective for use on chicory, as it had no adverse impacts on the plant. The good news is Plateau had no adverse effect on the alfalfa or clover either. The remaining fourteen chemicals were found to be effective in controlling and/or actually eliminating chicory. However, of those fourteen, eleven impacted the desirable forages to the point that we would not recommend them to control chicory in hay fields or pastures unless there was no concern to also eliminate legumes such as alfalfa and clover.
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The final three chemicals produced results that merit further research. These chemicals (Clarity, applied at a rate of 1.5 pints per acre; Garlon 4, applied at 1.5 pints per acre; and Cimarron Plus, applied at 0.5 ounces dry weight per acre) all eliminated the chicory. While they did not leave the red clover unscathed, the alfalfa appeared to recover to an acceptable degree. Clarity and Cimarron Plus appeared to have more of an impact on the alfalfa than Garlon 4. But, the results in the Garlon 4 plots definitely show great promise to remove chicory from hay fields without causing an unacceptable loss of alfalfa. These three chemicals will be the subject of further testing next year.

​It MUST be emphasized that the alfalfa in the test plots is “old,” at least 20 years old. It is uncertain what effect any of the chemicals would have on newly planted (within 5 years or less) alfalfa. Therefore, the results we are mentioning for the purpose of this project must be cautiously applied to newer stands of alfalfa. 

Other 2020 Happenings

On a couple of other notes we reported in July, we had been conducting other routine IWM practices on our farm as part of our normal operation and have identified a potential problem with Deptford Pink (scientific name, Dianthus Armeria). South Dakota State University Weed Science Department (the same people conducting the chicory trials) was able to begin research on July 15th of this year on controlling the Deptford Pink in one field that suddenly became heavily infested with the plant. Fourteen chemicals are being tested in a total of 60 plots.
 
Little seems to be known about this potentially invasive plant so we are starting with limited information. We have been able to determine so far that Deptford Pink is a biennial that reproduces from seed only. A plant develops the first year without a flowering stalk. Then, during the second year, it bolts to form the flowering stem. Our research has failed to prove conclusively what a first-year plant looks like. We believe it is a small rosette type of plant but we are not certain. This information is determined from the fact that Deptford Pink is a member of the dianthus family and other dianthus plants form rosettes at the beginning. The overwhelming majority of the plant photos on the internet show the second-year plant only.
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What has became apparent is that Deptford Pink appears to mature in hot, dry weather. The plots were chemically treated on July 15th and within 15 days, all of the plants turned brown. However, this was not necessarily the result of the chemicals, as all the plants, treated and untreated, within the test plots and outside of the testing area all look the same. 

​So, unfortunately, any observations of obvious impact on the standing plants from the chemical treatments is completely unreliable. Using the presumption that the first-year plant begins as a rosette, we examined the ground level of the test plots to determine if the chemical treatment had any effect on the young, first-year rosettes. Small rosettes were found and we noted some of the chemicals had a definite impact on the rosettes and some did not.

We are also conducting germination tests on seeds collected from the test plots to determine if the chemical treatments had any effect on the viability of the seeds. There are no results to report as of the date of this post.

Again, observations made next spring will likely be a key indicator as to whether any chemical treatments were effective or not and whether chemicals are at all useful in controlling Deptford Pink. This plant could potentially create a major problem. Stay tuned for more developments on this project.
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Finally, a note of caution to anyone who uses goats to graze pastures. It is common knowledge that goats are browsers and prefer to eat woody plants. We have owned goats for ten years. We know that they eat pine needles and small branches on trees. What we didn’t realize is that they will also eat the bark and chew through the bark to the inner fiber layers of the trees. If the goats are able to completely girdle a tree, they can potentially kill it, even a large pine tree. We have had to resort to covering the trees in one pasture with plastic snow fence to keep the goats from destroying the pine trees. Goats may not actually eat everything, but sometimes they eat enough to be a problem. Just a word to the wise.

Stay tuned for our final report in October. Until then, if you haven’t already signed up for our newsletter on our website or Facebook page, we invite you to do so by following this link. See you next month!