To get even flower set and to reduce blossom end rot it is important to get good calcium levels in the fruit but throwing large volumes of calcium at the crop is an ineffective way to achieve this.
Calcium absorption in plant cells is linked to ‘polar auxin transport’ therefore parts of plants high in auxin absorb calcium easily (if available) and parts of plants low in auxin absorb calcium sparingly (no matter how much is supplied).
In common with most crops, peppers struggle to get good calcium levels in the fruit. This is due to the fruit being a low auxin tissue and therefore a poor sink for calcium. When the fruit is young and small (<2mm) it is in the cell division stage where the new cells that will become the fruit are being created and at this point auxin levels are good, however as the fruit starts to increase in size cell division is no longer occurring the cells are instead expanding and auxin levels are lower. This means as fruit increase in size the ability to absorb calcium decreases.
To get even flower set (vital for getting the crop even at harvest), and to reduce blossom end rot it is important to apply calcium between flowering and 2-3 mm fruit size. This is when new cells that form the fruit are formed, and applications are more effective in this window.
For best results crops will benefit from use of products containing LoCal technology such as Levity’s Albina. LoCal improves calcium absorption in low auxin parts of plants and can be used to get calcium into fruit where the natural ability to absorb is low.
To improve fruit calcium levels and give even fruit set use Albina at 1 litre per hectare at flowering. Repeat at two weeks intervals from commencement of flowering until harvest finishes. This will be more effective than higher volume and more frequent applications of standard formulations.