No Two Years Are Alike: Unusual Spring Leads to Unusual Summer Pests
One thing we all know about farming and working with nature: no two years are alike, especially with weather.
I have always been of the mind that Spring sets the table for Summer. If the spring is dryer and warmish, crops get planted on time, mature on time, and, consequently, are harvested on time. On years when the spring weather is unsettled - too cool or too wet – it’s almost a roll of the dice when harvest rolls around as to yield and harvest dates. This has been one of those years.
This has also been the year of powdery mildew and army worms. We usually don’t see a need to start pest treatments until early August, but nature’s weather patterns have blessed us with an abundance of these two pests this year. As a result, we’ve been treating for weeks now.
We are seeing early infestations of powdery mildew (PM) this year. PM is a disease caused by fungi. A tell tale symptom of an affected plant is powdery white spots appearing on leaf surfaces. We can control PM with repeated applications of wettable sulfur (a natural fungicide), and in some cases Kaligreen (a contact-type fungicide with potassium bicarbonate as the active ingredient). We don’t spray until we see symptoms in our fields. Similarly, we don’t treat for pests until we spot them during our regular field scouting.
Army worms can be very destructive if left untreated. We have seen army worms in our asparagus, winter squash, watermelons, tomatoes, peppers, and various flowers this season in large numbers (in short: they’re everywhere). Fortunately, organic growers have two products that are quite effective: Bacillus Thuringiensis (BT) and Spinosad, both of which are bacterium.
BT is quite effective on Lepidoptera (moths and butterflies), but only when applied at a larval stage. Application of BT results in death for the worm/larvae by upsetting their digestive tract. Spinosad works by simply attacking the insects’ nervous system which causes death by hyper-excitation. While BT is toxic only to larval stages of Lepidoptera, Spinosad is effective against a number of pests including caterpillars, true bugs (an order of insects, Hemiptera, that are defined by having piercing, sucking mouthparts), and small flying insects that feed upon plants.
Although we typically don’t find a need for treatments until August, we know that no two years are alike, so we can’t rely on a schedule to help us address pest and disease issues. Regular scouting of the fields is essential to pest management on organic farms, as application coverage and timing are critical to the effectiveness of our various treatments. All the pest management tools we use are benign to beneficial insects, mammals, and birds. Which means that even with our spraying, the beneficial insects, mammals, and birds can continue their life cycle in our fields, undisrupted.
So far, it has been a year of unusual and untimely findings. Hopefully these Summer treatments will continue to prove effective, as some already are, and the late summer will hold no more unusual surprises leftover from our unusual Spring.