Blossom drop in tomatoes

Blossom drop is a disorder found in tomatoes, but may also affect peppers, beans and other vegetables. The condition is not a disease or insect problem: blossom drop is caused by a combination of stresses which lead to improper pollination. Other stresses that lead to nutrient deficiency also plays a role.

Symptoms:

The plant blooms but it drops its flowers. In blossom drop, the stems of the flowers (called the pedicle) turn yellow before the blooms fall off. Depending on the severity of the underlying stresses, some or all of the blooms fall off.

The primary causes of blossom drop is a combination of stresses:

• extreme hot/cold temperature fluctuations; or temperatures over 40ºC for more than 4 hours interferes with pollination and can cause flowers to abort
• humidity that is either too high or too low can interfere with the release of pollen and its ability to stick to the stigma

Other causes of blossom drop are:

• lack of pollination due to a lack of wind or insect pollinators like bees
• too much or too little nitrogen
• drought conditions which interfere with the uptake of nitrogen and other nutrients
• a plant may abort excess flowers if there is heavy fruit set

Keep your plants well watered – do not let them dry out. It helps to mulch around the plants to conserve moisture. Fertilize regularly with a balanced fertilizer - 20-20-20, according to the instructions on the label. Fortunately, tomatoes will continue to flower, so there is a chance that the plants will produce more flowers - and hopefully some fruit.

Source:

Ozores-Hampton, M., Kiran, F., MacAvoy, G. (n.d.). Blossom drop and reduced fruit set in tomatoes. Retrieved March 24, 2021, from https://swfrec.ifas.ufl.edu/docs/pdf/veg-hort/tomato-institute/presentations/ti2011/ozores.pdf