Some areas of Kansas currently have substantial second- and third-generation corn earworm populations maturing in whorl and boot stage sorghum. These will not create economic losses, but when adult moths emerge, they pose a risk to maturing seed heads. One or two larvae of corn earworm or fall armyworm per head can cause 5- to 10-percent yield losses.
Both of these pests are migratory, and thus the extent of their damage is quite unpredictable from year to year. If action is taken to preserve yield, it is essential to detect larvae when they are still small (most less than one inch long). Larger larvae are much harder to kill and there is little point in spraying them because they will soon stop feeding. On the other hand, there is much to be gained from treating small larvae, as almost 60 percent of food is consumed in the final instar.
Milo heads are susceptible up to the milk stage. Sample a sorghum field by picking a series of five to 10 heads and beating them against the sides of a plastic bucket or white ice cream container. Count the larvae falling into the bucket and repeat this procedure in at least five different places in the field.
The threshold for treatment is an average of one or two larvae per head, depending on projected yield and price of the crop.
A number of materials are registered for use against "worms" in sorghum heads. Refer to the latest version of the Sorghum Insect Management Guide for suitable materials and application information: http://www.oznet.ksu.edu/library/entml2/MF742.PDF. This publication also is available at the Finney County Extension Office.
Propagating plants from cuttings
Within the next six to eight weeks we will be facing our first fall frost, signaling the end of many beautiful summer plants, including Artemesia, Buddleia (butterfly bush), Caryopteris (blue mist spirea), Coleus, geraniums, Lamium, lavender and many others. Several terrific reference books or the Internet will provide additional lists of plants that can be fall propagated.
With that in mind, now is a great time to begin taking cuttings from your existing plants to generate plants for next summer's garden. It's easy to create plants for new locations in next year's landscape or to share with friends. Plus, you avoid the expense of buying new plants and get an early start on next spring's growing season.
Begin the process of propagation by choosing a good rooting media and buying a rooting hormone. Sand, perlite, peat moss or vermiculite all are components of a good rooting media, especially when mixed up in a 50/50 combination mixture: sand-perlite; perlite-peat moss; sand-peat moss; or sand-vermicullite. The rooting media should be porous, well-drained and heavy enough to firmly hold the cuttings upright.
Rooting hormones can be purchased either as a liquid or a powder. Several common brands are available through nurseries and garden centers. Also choose a rooting container, or pot, for the cuttings with drainage holes and small enough for a gallon-sized bag to fit over the top.
To begin, take cuttings about six inches in length from the growing tips of plants in late summer before the first killing frost. Remove all leaves from the lower half of the cutting and remove any flowers or flower buds. Dip the cut end in rooting hormone and then push the bare stem of the cutting into the rooting media. Don't allow any remaining leaves to lay on top of the soil or they will quickly begin to rot.
When placing the cuttings in the container, place them far enough apart so their leaves do not touch or overlap since leaves that touch usually rot.
Once all the cuttings have been put into the rooting media, water the container to thoroughly moisten the soil and put the plastic bag over the top of the container. This will create a high level of humidity inside the bag, keeping the cuttings from wilting while new roots are being formed.
Place the container in a warm location that receives bright but indirect sun. Avoid excessive heat or humidity build-up within the bag; if water droplets form on the inside of the bag, remove the bag and allow it to dry out for several hours before replacing it.
Check the rooting medium for moisture every week. It usually stays fairly moist for several weeks before additional water is needed. Plant the cuttings into small individual containers filled with a coarse, well-drained soil mix, when new roots are one-half to one inch long; this usually will take three to four weeks. Pot the cuttings at the same depth in the new container as they were in the rooting medium. Gradually move the plants into more direct light, watering and fertilizing them as needed throughout the remainder of the winter.