The week leading up to June 26 produced the largest weekly growth this year as the plants leaped to 84 inches in height blessed by 1.6 inches of rain one day that week, and 23% more growing degree days than average. At that point, there was no evidence of tassels or ears on the stalks I observed.
The long-awaited ears have appeared! Even though cooler weather resulted in 16% fewer growing degree days than is typical, the plants have continued to mature normally and reached 106 inches height to the tips of their tassels. An additional few tenths of an inch of rain helped insure against drought stress. Typically, the ear and its kernels is the primary feature of interest in corn plants, but since a portion of this year's crop will probably be harvested for silage like it was last year, the volume of stalk harvested is probably also important. We will continue to monitor both stalk growth and ear development as the season progresses so all our readers won't miss any exciting details!
"The Japanese beetle is probably the most devastating pest of urban landscape plants in the eastern United States." Those words from two entomologists at the University of Kentucky aptly describe the impact of these pests that unfortunately have invaded our yard again this year.
About four years ago I described our initial battles with Japanese beetles, and showed a picture of the Spectracide bag system that we employed. After being emptied several times, and being subjected to the winds common in our yard, that bag ripped beyond repair and forced me into a different alternative. I was pleased with the success of the lure and trap idea, but modified the concept as shown below.
The lure is still the Spectracide Bag-A-Bug Japanese Beetle Trap2 Lure which you can see suspended by a 12 gauge insulated wire above the red funnel. The bag has been replaced by a 5-gallon bucket which contains about a gallon of soapy water. This allows me to avoid the steps of dumping the bag into a bucket of water and waiting for the bugs to suffocate. Every day or so I empty the bucket and refill it with soapy water and wait for more beetles to enter and die. Hundreds of beetles accept my invitation each day and enter the bucket to take a swim.
The bucket lid has a 3.5" diameter hole cut in the top and the funnel is simply caulked in place. The funnel end was trimmed back so the smallest portion of the funnel is about 1" in diameter to allow the beetles to more easily enter the bucket. After four years of use I replaced the lid this year as the original Menards lid became brittle and unusable after many hours of exposure to the sun. The bucket itself also cracked at the mounting hole of the handle, but I was able to relocate the handle to a different location so I hope to get more seasons of use from this bucket.
The big question is: does this type of trap attract more beetles than it kills? A quick search around the internet (and reading the article from the Kentucky entomologists quoted above) will show that there are plenty of folks that think these traps are a waste of money and worse for your plants than if you didn't have a trap at all. Spectracide recommends placing your trap 30 feet downwind from the plant of interest, but because our wind comes from lots of different directions, and we have four different plants that attract the beetles, a perfect location on our property would be hard to identify. The image above shows the trap location that has served us well for the last four years. As you can see, none of our plants is less than 30 feet from the lure, and most don't even have a line of sight to the lure. Whether that makes the trap more or less effective, I can't say.
What I can say: the damage due to Japanese beetles on our property is severely reduced by the presence of our trap. Does the lure attract beetles from neighboring properties? Maybe, but if our plants have less damage, I don't really care whose beetles I'm killing. Are there more beetles attacking our plants because I have a lure in my yard? Judging by the damage to the plants, I would conclude that fewer beetles attack our plants since we have less damage when the trap is active.
Tips for best success with a beetle trap
1. Set the trap out early in the season. By the middle of June here in Central Illinois the beetles' damage can be visible from a distance. In my experience, luring the beetles before they can cause extensive damage will reduce the total amount of damage done.
2. Pick beetles off of plants by hand. If you find beetles on your plants, you can easily remove them by grabbing them and tossing them into a bucket of soapy water. I carry my lure bucket to the raspberry plants and hops and have it close by when I physically remove as many bugs as I can. This is easiest to do in the morning or evening as the beetle are much more lethargic and typically don't try to fly away when you grab them. If you find grabbing them unpleasant, you can position your soapy water beneath the branch and shake them into the container. With taller plants like our cherry tree, I simply try to shake the branches to cause the beetles to fly away or drop to the ground. Either way, they're likely to smell the lure and be more attracted to my trap than the tree. The maple tree is too tall, so I make no attempt to remove the beetles from that tree.
3. Remove as many beetles as possible. Several sources indicate these beetles can smell a plant that is being eaten by another beetle, so it's common to see beetles swarm a plant and ignore its neighbor. I have found that if I can remove all the beetles from a plant the beetles are much less likely to come back to that plant. Repeating the process over several days can leave a plant beetle-free for the rest of the summer even though it had been a favorite days before.
I don't have scientific test results that prove our trap is beneficial, rather only my observations. I've seen the damage that beetles can do when left unchecked, and I remember wondering if our cherry tree was going to survive their attack. Since employing our lure bucket, the only time we've had noticeable damage was when I was late setting the trap out and the beetles got a head start on me. I don't have experience dealing with the beetles in the larva stage (other than killing the ones I find when digging in the yard), but I do know the adult beetles can be controlled significantly with a lure trap like mine.
The week before June 5th was warmer each day than the historical average, accumulating 34% more heating degree days than normal. The plants cooperated by leaping up to 24 inches tall on average, which is about average for this time of year, and consistent with 2010 when the planting date was about the same as this year.
You may have heard the phrase, "knee-high by the Fourth of July" when referring to corn growth. In our backyard, the knee-high phase is typically passed by the Fourth of June, as was the case this year. Here's photographic proof.
The week prior to June 12 saw five of the seven days average warmer temperatures than the historical average, but rainfall only managed a trace. Heating degree days totaled 23% more than average and the corn plants continued to match historical norms by reaching 40 inches tall.
I wouldn't say the corn plants looked bad on June 19, but continued hot weather with minimal rain showed its effect on the grass in my yard, and the corn around it. You'll notice the leaves have a slightly spiky appearance that is the result of dry, hot weather as the plant attempts to conserve moisture. All seven days of the week were warmer than average, resulting in 31% more growing degree days than normal, while the plants continued to grow at a normal pace, reaching 57 inches tall.
The other item worthy of note is the fact that the farm across the highway is barely visible now, and the vehicles on the highway are fully hidden from view.
Is there any object in your house that makes you smile every time you look at it? Several years ago, Karen found this tree and we gathered photos, made copies in appropriate sizes, and populated the frames as you see in these two photos. Even though I've been looking at these photos almost every day for years now, I still find joy in the beauty and memories captured in this project.
Karen's side includes a darling picture of her as a preschooler at the top, and images of her parents immediately below revealing her mother as a huggable toddler, and her father sporting an impish grin that was probably well known to his parents. Karen's grandparents are on the next row down, both shown in their wedding photos. At the bottom, Karen's father's maternal grandparents are pictured in their engagement photo on the left while Karen's mother's paternal grandparents are shown in a semi-candid shot later in their marriage.
My side of the tree includes a shot of me as a preschooler at the top, and photos of my parents as teenagers just below mine. We included my mother's parents' engagement picture on the next row, along with the wedding picture of my father's parents. The bottom row has two candid shots, showing my mother's maternal grandparents on the left and my father's paternal grandparents on the right (an image that has graced this other post on this blog).
It's probably good that the tree doesn't have four frames on the bottom branches as I'm not aware of any photos of the great-grandparents that are missing from the tree now. I only have recollection of one of my great-grandparents, and since Karen and I both lost at least one grandparent before we were born there are plenty of people on this tree we've never met. Nonetheless, my heart is warmed by this reminder of the people that have made us who we are.
The week leading up to May 22 was quite a bit colder than normal, and recorded a bit more than half the historical average for growing degree days. Consequently, the plants only grew a couple inches that week. Special thanks to my trusty assistant, Lily, for taking photos for me while I was out of town on the 22nd.
The next week turned warmer and provided decent rain such that the plants sprouted up to 15 inches tall while enjoying 49% more growing degree days than average. Like most years, it appears that the plants won't have any trouble reaching knee high by the fourth of June.