Weather: What’s left of May is forecast to be a repeat of the past several days of sunshine and mild to warm weather, which is expected to continue through May. The forecast for June is for more “normal” precipitation. At the Michigan State University Enviroweather station at Applewood Orchards in Deerfield, the growing degree day (heat units) for 2023 are 466 GDD, slightly behind last year (490 GDD) and the six-year average of 468.5 GDD. Precipitation as of April 1 has been 4.12 inches, compared to 4.87 inches last year and a six-year average of 5.91 inches.

Corn in the early season can be green, purple or yellow depending on the varietal characteristics, air and soil temperature, compaction, herbicide injury or nitrogen deficiency. Unless there is an identified problem, corn will grow out of discoloration to a healthy, dark green color in a few days or weeks.

Monroe County, based on historical soil test results, has sufficient phosphorus, so this may not be the cause of purple corn. Dry soils accumulate more nitrate nitrogen, so this may not be the cause of yellow corn. Nighttime temperatures are not forecast to be cool enough to be a problem, so warm days and plenty of sunshine should allow young plants to grow quickly and of a nice, dark green color. Some wilting may occur with no rain in the forecast, but this is another matter.

Corn planting has mostly finished, with dry soil conditions persisting.  Early season dry weather is expected to continue through May, which will allow plants to root deeper to find moisture. At this time, the Weather Prediction Center is calling for more normal rainfall to return into June.  Black cutworms and armyworms are two insect pests of corn to scout, although armyworms will prefer wheat and other vegetation unless or until it matures and plants dry out. Corn produces DIMBOA (benzoxazinoids), a natural defense against European corn borers and pathogens, including fungi and bacteria. Higher concentrations of DIMBOA are found in very early plant growth stages, diminishing as plants grow.

Wheat will be flowering very soon now that most fields are rapidly moving from the “boot” stage (Feekes stage 9) and heading out at Feekes growth stage 10.5. Flowering begins at Feekes 10.5.1 stage and is considered the optimum time to apply fungicides to suppress Fusarium head blight (scab). However the forecast for generally warm and dry weather means that the pathogen may not be present sufficient to justify spraying. Varietal characteristics, such as disease resistance, is very important, and one reason to not throw away the company literature which describes variety traits.

The Penn State Fusarium head blight (scab) infection computer model will give disease forecasting projections and is a very useful guide to predict the incidence of scab this year for our area. Dry weather does not favor disease development at this time. Armyworms are an insect pest that need to be scouted, as they can almost literally “march” across wheat fields, eating and clipping heads.

Watering the garden (and lawns) can be simple, complicated, a science and an art. In simple terms, a garden, planted in the soil, needs about one inch of water per week. However, smaller plants need less, while bigger plants use more, and the air temperature, amount of sunlight, transpiration and evapotranspiration all affect water use and efficiency. Although plants need about 1 inch of water per week, it likely is not best to only water once per week. Plants do best when watered about three times per week, factoring in rain and heat. Seedlings, with small root systems, may do best when watered even twice a day until they become established. The worst time to water is evenings which may then keep the foliage wet for 12-18 hours, factoring in dew, which can allow diseases to become established. A drip system, or otherwise watering earlier in the day so the foliage remains or can become dry, is better.

If you don’t have a rain gauge in the garden, use a small can, such as a tuna or cat food can, to measure when one inch of rain or water has been collected. One inch of water per one square foot equals 0.62 gallon. For scale, an inch of water in 1 acre equals 27,154 gallons of water. To save money on the water bill, use mulch, untreated grass clippings, or black-and-white newspaper to help keep weeds suppressed and retain soil moisture.

Ned Birkey is an MSU Extension educator emeritus and a regular contributor to The Monroe News.

This article originally appeared on The Monroe News: Monroe County Agriculture: Plan 1 inch of water each week for plants