Although some areas of Ohio have received small but timely amounts of rainfall, the general lack of it across the state to this point in the season has become a concern, especially where dryland, non-irrigated crops are stake. As one example, according to one weather station at the OSU campus in Wooster, rainfall for the period May 15, 2023 – June 10, 2023 was the lowest on record for the same period since 1999 and roughly half the amount received during the same period in the previous driest year. Not surprisingly, stand establishment in a non-irrigated potato planting made on May 15 at the research station in Wooster has been much lower and slower than normal.
On the other hand, overall conditions for many irrigated crops have been acceptable, minus the damaging early season frosts and windstorms. Temperatures have been moderate for the most part, so damage due to the lack of rain has not been significantly compounded by problems associated with high temperatures. Also, a lack of rain can maximize the amount of time available to complete other work — although many would gladly trade some time for rain.
Indeed, dry conditions to date have interfered with crop establishment and development and other aspects of production, particularly where irrigation is not being applied. So, we welcome forecasts including a high probability of meaningful rainfall.
This article references six items to consider if rainfall begins to “even out” in terms of timing and amount.
1. Continued crop thirst. Irrigation tends to be beneficial in all but the wettest years. Even short periods of low water stress can damage crops. Therefore, those who have been irrigating or begin to irrigate may need to continue the practice until harvest, in accordance with rainfall amounts and other factors, per usual.
2. Nutrient availability. Dry fertilizers applied before, at, and/or soon after planting may begin to solubilize more completely, boosting nutrient availability. In-season applications may need to be adjusted to account for this increased availability, although later than planned. Consider in-season soil, tissue, and/or sap testing to assist in the process.
3. Weed control, particularly as affected by herbicide activity. Dr. Lynn Sosnoskie of Cornell University summarized this issue well in the June 7 edition of the Cornell Cooperative Extension VegEdge Newsletter. Contact Dr. Sosnoskie (lms438@cornell.edu), the Cornell Vegetable Program (cce-cvp@cornell.edu), or me (Matt Kleinhenz; kleinhenz.1@osu.edu) for a copy of the article, which summarizes factors to consider for weed control during extended dry periods and should rains resume.
4. Crop protection, especially disease. Soil moisture, nutrient availability, and weed growth may increase if rains begin and so may disease pressure. Crop protectants, application schedules, and other tactics may need to be adjusted to account for increases in leaf wetness periods, relative humidity, and, perhaps, disease inoculum levels.
5. Soil erosion. Ideally, this dry period will be broken by grower-friendly light rains capable of providing the most benefit with the least trouble. However, soil erosion is possible if rains are brief and heavy and fall on uncovered, unprotected soils. If possible, use the dry period to check, improve, and explore drainage systems and soil management tactics.
6. Crop growth and harvest readiness. The best-laid plans set before the season call for seeding and transplanting to occur on farm-specific schedules, partly to meet harvest timing and market goals. Following through on those plans is difficult under dry conditions since they slow growth and alter maturation schedules. For example, for fruiting vegetable crops, a rule of thumb has been that drought before flowering speeds maturation while drought after flowering can slow it. Regardless, early-season dry conditions followed by more normal rainfall patterns can complicate maturation timelines across plantings (early, mid, late) and variety maturities. So, monitoring and flexibility remain important.