Temperature Effects on Flowering and Yield

At high temperatures plants do not produce sufficient IAA for cell division. This is very important during the time of flower formation. If the flower buds do not have sufficient IAA for cell division, they will become dormant. Bud dormancy, flower production and flower fertility are affected by high temperatures because plants do not produce sufficient IAA for cell division.

Since canola is a member of the brassica family, they have more problems producing sufficient IAA as the temperature increases.

Two simple principles:

  1. Seed treatment with Stimulate on canola gives a good yield response even though the rate per acre or hectare is very low.
  2. During periods where temperatures exceed 86°F/27°C, it would be beneficial to foliar spray canola or rapeseed with a solution of Stimulate plus calcium boron. The Stimulate will add auxin to the plant, the calcium will cause auxin movement, and the boron will cause an increase in the auxins half-life.

When treating with Stimulate and calcium boron, the suggested application is:
3 oz. per acre or 200 ml per hectare of Stimulate + 1 liter per acre or 2 liters per hectare of CaB, applied as a foliar spray every 10 days during the period preceding flowering. This application should be continued on 10 day intervals throughout the flowering period.only if the temperatures exceed 86°F/27°C.

It is becoming evident you need to have Stimulate, calcium and boron sprays, which are to be used only during periods of high temperatures. If the temperatures are not high, farmers will complain about adequate response to the expenditure of the treatments. If temperatures are high, farmers will get a tremendous return on their investment.

It has been known the use of boron on canola and rapeseed has been a profitable practice. Now experts know the reason why is because it increases the half-life of what little IAA the plant produces during hotter temperatures. Now everyone needs to understand and correct the insufficiency of IAA in canola, brassica, and all other types of crops.

ALL FLOWERING CROPS ARE SENSITIVE TO HIGH TEMPERATURES BECAUSE CROPS DO NOT PRODUCE ADEQUATE IAA FOR THE NUMBER OF FLOWERS AND FERTILITY OF FLOWERS.