One of my favorite parts of summer is having access to delicious tomatoes that are not available during the rest of the year. As a kid I never appreciated grandma’s tomato sandwiches, but now as an adult that is what I ask for when I see her on the weekends. There are many different pests, pathogens, or environmental issues that can leave us with a tomato crop failure and leaves us with having to rely on friendly neighbors who have a surplus. One of these issues is know as Blossom-End Rot.
Blossom-End Rot is not caused by a pest or pathogen, rather environmental issues. Ultimately this condition is caused by lack of calcium in the fruit, although a lack of calcium in the soil is not necessarily the issue. The issue is found in the plant’s ability to take in calcium from the soil, and this can be caused by a few different factors. In other words, you could have sufficient calcium levels in your soil, but the plant is not able to absorb sufficient levels of calcium, therefore leading to calcium deficiency in the plant.
If a soil analysis is done and calcium levels are adequate, the most typical causes of Blossom-End Rot are due to drought conditions, irregular watering schedule, root damage caused by improper cultivation, or acidic soil. Drought conditions and mechanical damage can weaken the tomato plant’s root structure and does not allow for sufficient water to be absorbed, therefore decreasing calcium level uptake. Too much water can also be the culprit, as drowned roots cannot function properly.
Here are some tips on Blossom-End Rot mitigation.
· Perform a soil analysis to determine soil pH. Make a Lime application if soil pH is lower than 6.0.
· Make fertilizer applications per the exact amount prescribed by the label. Too much fertilizer can also cause Blossom-End Rot.
· Mulch your tomato plants with straw or newspaper to conserve moisture.
· In drought conditions, water your plants adequately. Tomatoes need 1.5 inches of water per week during fruiting.
· If you do see evidence of onset Blossom-End Rot. Drench the soil around the roots with a calcium solution containing 4 tablespoons per gallon of water. Make sure to drench the soil and roots, not the foliage or fruits.
· Select tomato varieties that are less susceptible to Blossom-End Rot. Heirloom varieties tend to be more susceptible than improved varieties.
Note that these management tips are also effective for other plants that are susceptible to Blossom-End Rot on their fruit such as peppers, eggplant, cucumber, and watermelon.
