Pepper plant signals and what do they mean?

DR. MOHYUDDIN MIRZA

Greenhouse peppers are one of the most difficult crops to grow because firstly it takes almost 120 days from seeding to first harvest. Then, making it vegetative or generative becomes a challenge because of the day and night temperatures, 24 hours average temperature and the way fruit load is managed. It is worth mentioning that pollination with bumble bees or honey bees reduces the days from fruit set to harvest, increases the percentage of extra large and larger fruit.

Here are a few pictures of flowers and fruits to understand plant signals. All pictures are courtesy of Schriemer Family Farm, Manitoba.

Flowers bent away from the stems are a signal of good balanced vegetative and generative growth. They are a signal to bees to perform pollination. Such flowers also indicate a very good climate, especially the Vapour Pressure Deficit (VPD) in the range of between 3 and 7 grams/m3 of air.

If flowers are large, over vigorous and tending to grow upright, the plant is vegetative and requires higher 24 hours average temperature. This can be accomplished by increasing the temperature during the peak light period from 11:00 to 14:00 hours. Remove any deformed “bottom fruit.”

These flowers are well spaced. If they are located too close to the head, then try to steer plants towards generative direction. Flowers which have been pollinated will show petals losing their lustre and fruit can be seen inside.

A good internodal length indicates good balance. Very short internodes and a compact plant indicate very strong vegetative direction.

Dr. Mohyuddin Mirza is a greenhouse industry consultant based in Edmonton, Alberta.