PHOTO PROVIDED Penn State Extension is taking a look back at the 2023 growing season.

Farming is a stressful profession. Farmers’ resilience, perseverance and ability to cope with all the challenges that mother nature, commodity prices, markets and laws and regulations bring to the table every year are things to admire. According to the latest National Agricultural Statistics Service in Pennsylvania, about 95% of the soybean acres have been harvested, 80% of the corn and more than 80% of the winter crops (barley and wheat) have emerged. Now that harvest is wrapping up, I would like to share some events that will make the 2023 growing season one to remember and another reason to thank our farmers for what they do. We will just talk about events that occurred in the field.

January and February were characterized by unusually high temperatures that allowed small grains to break their dormancy, followed by rain and freezing temperatures. These thawing and freezing periods damaged crops in certain areas, with barley being most impacted.

In the spring, cash crop planting season started at the end of April, followed by a long dry spell. Zero to negligible rain occurred during May and the first two weeks of June. The lack of rain led to delayed planting, slowed seed germination and caused crops that had germinated to suffer from water deficits. Farmers questioned whether it would be necessary to replant, switch to shorter maturity crops, or, depending on the crop, not planting at all. Thankfully, the rain came right at the time when some of these decisions were made.

For small grains, the dry weather kept the risk of Fusarium Head Blight low, which was good news to farmers until the question became whether there would be enough water for a complete grain fill. Temperature is the primary driving force for plant development in crops like corn and wheat. Luckily, the dry spell was also when we experienced cooler-than-average temperatures that may have hampered the pace at which wheat moves through growth stages and could have played a key role in maintaining average yields. Right before wheat harvest, a black mold started to spread among wheat fields, covering the spikes and raising concerns about losses in quality and yield. The problem was caused by “sooty mold.” Fortunately, the fungi involved are not pathogenic and cannot produce mycotoxins, a common concern for wheat growers.

Another highlight from the 2023 growing season was the smoke from the wildfires in Canada. In Pennsylvania, smoke from the wildfire arrived in early June, at the end of June, and in the middle of July, and many questions were raised about the potential effect these could have on crop yields. Previous studies on the impact of smoke on crops have reported both yield increases and yield losses. We know crop yield is determined by the plant’s ability to capture sunlight and efficiently transform it into resources allocated to seed or other plant parts. It is logical to think that if solar radiation is blocked, crop yields could be affected. However, the effect of smoke is more complex than that. The problem with smoke is the particle pollution (particulate matter, PM). How the PM interacts with solar radiation will depend on the altitude, particle size distribution and composition of the aerosol (1), and the effect on crops will depend on the stage of development and other meteorological events, like seasonal cloud cover. Solar radiation reaching the plant’s surface can be direct or diffuse (i.e. scattered by airborne particles or objects). Crop yield increases have been attributed to an increase in radiation scattering that allows for greater carbon uptake; however, the crop response to the scattered fraction varies according to the properties of the canopy and their effect on light distribution (2). Furthermore, when the density of the smoke plume increases (3) the increase in PM can offset the positive effect that more diffuse light may have in yield.

Other significant challenges farmers faced included the widespread distribution and severity of white mold of soybean (Sclerotinia sclerotiorum), increases in Cercospora leaf blight (Cercospora kikuchii), and the arrival of tar spot of corn (Phyllachora maydis) to central PA. Farmers also had to keep their guard up since many males of western bean cutworm, an important pest of corn, were trapped in Central Pa during the critical period of corn silking.

Finally, the corn harvest was extended because the corn dried down slower than usual. Factors that influence the drydown rate are corn hybrid characteristics and environmental conditions, most importantly, temperature. As mentioned earlier in the article, given that the start of the growing season and early summer was colder than average, corn may have fallen behind in development, slowing corn maturity and drying at the end of the season.

If you have any questions about the content of this article, please feel free to contact Adriana Murillo-Williams via email, axm1119@psu.edu or by phone at 814-355-4897.