All this wet weather is creating havoc on area gardens. Plants aren't growing or are barely hanging on and the disease situation is escalating. Many people I've spoken to have complained about their tomato plants, and how they're dying from the bottom up. This is caused by two fungal diseases: early blight and Septoria leaf blight. Driving rain splashes the soil (and disease organism) onto the lower leaves. The disease multiplies and the next rain splashes it to the next set of leaves. Keeping rain from splashing soil is the chief means of reducing these diseases. The use of mulches (newspapers with straw or grass clippings spread on top) helps a great deal. Make sure to mulch the whole garden because the organism can survive for a couple of years in the soil and rain can splash soils for long distances. Fungicides can help keep the disease in check.
Other plants can also be adversely affected by disease. Since it rains 3-5 times per week, disease pressure is high. Keeping a diligent spray schedule is not easy, but under these conditions, expect heavy pressure. The rule of thumb is that one inch of rainfall washes off any applied pesticides.
Crops suffer several ways due to the excess water. Saturated soils have no oxygen, which means that after a couple of days of saturated conditions, roots begin to die off. No functioning root system means no fertility uptake. Young crops suffer more than established crops do.
Yellowing of foliage is probably the first symptom of nitrogen deficiency, which is an indicator of no or low nitrogen in the plant. This may or may not be due to low N levels in the soil. As stated earlier, root systems are not very effective under saturated soil conditions. The classic example is on corn, where the lower leaves will turn yellow at the leaf margins, starting at the leaf tip. Applying nitrogen under these conditions will not help. Wait until the soils dry and the crop is growing before making the determination to provide supplemental nitrogen.
We really haven't seen much sun in the past 3 plus weeks, but crops seem to be maturing rapidly (in those soils where good drainage removes water quickly).
Weed control issues are and will develop. You really can't control weeds when you can't even walk in the garden. And the constant rains allow the weed seeds to germinate rather easily. Pulling them does little good when it rains the next day as they re-root. One solution is to physically remove any weeds and place them in a compost pile. I'm thinking some gardens might need a lawn mower to reduce the weed size before pulling them or hoeing them out.
Strawberry patches need to be renovated as soon as soil conditions allow. Space doesn't allow me to fully explain this task, so I'll refer you to a web site that details that information. http://ipm.illinois.edu/ifvn/contents.php?id=63
Reminder of a couple of educational programs coming up:
Tuesday, July 7, 1-3pm, Use of Drones in Agriculture and other businesses. JWCC, Quincy. Register at web.extension.illinois.edu/abhps
Friday, July 10, 2nd Annual Adams County Beef Tour. http://web.extension.illinois.edu/units/event.cfm?UnitID=629&EventID=69464