With all that blessed rain comes new problems for veggie gardeners-mainly fungal diseases are on the rise.
WOW! This has been a great monsoon season this year. Last year we had 2 tiny monsoon storms and then they disappeared and we went into an extreme drought. This year, we have gotten more rain than I can remember in many years. Every week we get a significant amount of rain and 2 weeks ago we got 2.5 inches of rain in 1.5 hours. It was torrential. Those of us on the southeast side of Santa Fe have gotten most of the rain while those on the west side of town haven’t gotten much.
TOMATOES-EARLY BLIGHT: I already trimmed the tomato plants so no leaves touch the ground, put straw around each plant so no dirt is showing, but I still have started to see Early Blight (EB) on a few of the tomato plants. Early Blight fungal spores live in the ground and when rain splashes the dirt up on the lower leaves, the fungal spores start to colonize on the lower underside of the leaves. They become blotchy with the lower leaves getting big yellow splotchy areas. This is Early Blight. Without doing anything, it will spread upwards and go up through the plant and eventually kill it. But we can control it. I use to use Serenade, a biological fungicide that has other micro-organisms that colonize on those leaves and crowds out the EB spores. But now we can’t get Serenade anymore. I don’t know why but can’t find it anywhere. So I’ve turned to 2 other products. One is called Cease, which has the same ingredients as Serenade but is way more expensive and the other is Copper Fungicide which has copper in it which helps suppress the EB disease but you shouldn’t spray the soil as it can affect the earthworms-keep it on the foliage.
The way to control it is: trim off all lower branches that show signs of EB. Be sure to dip your cutters in a solution of 10% bleach to water. I just put a little in a small container of water and dip the shears and your hand into it BEFORE moving to the next plant. EB is contagious between plants so disinfecting your cutters between plants will make sure you don’t spread it.
SQUASH-POWDERY MILDEW: Another fungal disease on squash and pumpkin plants is Powdery Mildew. If your leaves start to die and get a powder on them, you should spray them on top and underside of leaves with a fungicide. Again copper fungicide, Neem, Baking soda/water mix, GreenCure. My favorite IS Green Cure as it works pretty fast. Spray any of the affected plants at 2-3 times with any o the above to get rid of it.
TOMATO-BLOSSOM END ROT: There are other problems arising from too much rain (is that possible out here in the southwest?!) Tomato blossom rot is from too much water, or uneven watering or not enough calcium in the soil (leached out because of too much rain). It is not a fungal disease but rather a deficiency of calcium in the tomato. It appears on the bottom of the tomato and is a sunken brown lesion. You can cut it out and eat the rest of the tomato if the whole fruit is not impacted.
Keeping the soil evenly moist helps. If we get a big rain, turn off your drip system for a day or two. You can also do a foliar spray on the plants with a kelp (seaweed) solution. But usually it will correct itself thru time. Adding calcium in the form of bone meal, oyster shell powder or gypsum — to the soil when you plant usually helps prevent this problem from developing.