A cool week ending with several warm days with consistent winds provided favorable first cutting hay-making weather. June 4th brought widespread precipitation across almost all of NE Illinois. Below average temperatures slowed crop growth, most apparent on no-till soy fields. Recent changes in weather patterns and welcome precipitation should accelerate growth. The regional soy crop ranges from emerging to V3. The majority of corn is V4 to V7. Yellowish corn that has yet to receive intended sidedress nitrogen is apparent. Why is nitrogen deficient corn yellow? The short answer is that nitrogen, including many other important processes, is required to produce chlorophyll used in photosynthesis; its chlorophyll that gives the corn its green color. The general consensus is to sidedress nitrogen before the corn reaches the period of rapid nitrogen uptake (V7-8 through pollination). The Nitrogen Management for Corn document authored by Dr. Emerson Nafziger shared that applying N as late as tasseling in severely N-deficient fields may increase yields, but the later the application, the more yield will be lost. Post corn herbicide applications have started when weather (including wind) has allowed. Producers are encouraged to evaluate both pre and post herbicide applications.