How to Control Powdery and Downy Mildew in the Vegetable Garden
The Cucurbit Family
Some of our favorite vegetable garden crops are in the cucurbit family which includes squash, cucumbers, winter squash, and summer squash. However, these cucurbit crops are the most susceptible to powdery mildew and downy mildew which are very harsh diseases in the vegetable garden. When temperatures start to rise up and we experience high humidity or moisture in the air that's when the powdery mildew begins to really affect the plants.
What is Powdery Mildew?
A severe fungal disease that can really affect a wide variety of plants is powdery mildew. This powdery mildew is most commonly known to affect plants in the cucurbit, nightshade, and legume families. Once the fungus begins to take over control of one of your plants it will fill the plant with a layer of mildew made up of many spores along the top of the leaves. Those spores will then carry to other plants by the wind. If you've experienced powdery mildew in the past, new outbreaks come from dormat spores in old vegetative material or weeds nearby in the garden. Powdery mildew affects your plants by slowing down growth, reduce fruit yield, and the overall quality of fruits. Unlike other fungal diseases, powdery mildew thrives in warmer temperatures and dry/humid temperatures. In order to identify powdery mildew in your garden, it usually starts out as circular white spots on the top of plants but may grow on the undersides as well. Since young foliage is most susceptible you should ensure you have an effective pest control schedule early on in the vegetable garden to avoid any severe issues.
How to Treat Powdery/Downy Mildew
If are experiencing this powdery and downy mildew disease on your plants, we highly recommend treating it with Bi-Carb Fungicide. This fungicide will disrupt the cell in the powdery mildew and will cure it. Another way to avoid powdery mildew in the garden is to plant cucurbit varieties that have disease resistance. Some of the older plant leaves are experiencing some downy mildew which starts out with yellow spots on the leaves. As the yellow spots get bigger they start to degrade the leaves and eventually create large brown rough spots on the leaves. To ensure our new growth does not experience the same issue we spray our new foliage with Complete Disease Control and Liquid Copper Fungicide in order to protect that new plant foliage. These fungicides are organic pesticides that can be used as a foliar spray which will effectively take care of the plant disease by spraying the top of the leaves. The most important way to ensure you have better success with controlling these diseases is to identify which disease is affecting your plants and begin to understand how you can control them in the vegetable garden. Once you identify these diseases you will be able to effectively kill off and overall control many diseases in your garden.
Growing Blue Bayou Pumpkins
Along with his cucurbit varieties, Greg is growing some hybrid Blue Bayou Pumpkins that provide heirloom beauty with a strong disease package such as resistance to powdery and downy mildew. This pumpkin variety produces trailing vines that supply large 15-20 lb pumpkins. Their unique color profile consists of a light blue exterior with deep ribbing along the outer coating. Since Blue Bayou has a resistance to powdery and downy mildew it performs great in humid areas like the South where disease pressures are typically higher in the vegetable garden. Another way to avoid powdery and downy mildew we recommend using drip irrigation to ensure all winter squash and pumpkins are getting feed effectively and reduce any plant moisture that they may experience in the garden.