View Single Post
Old March 6, 2019   #66
SQWIBB
Tomatovillian™
 
Join Date: Jan 2018
Location: Philly 7A
Posts: 739
Default

by Dr. Curtis E. Swift, Colorado State Area Extension Agent

The use of a foliar spray is a common recommendation for the prevention of blossom end rot. A one percent (1%) calcium chloride (8 lbs. of calcium chloride per 100 gallons of water) has been thought to be beneficial. However, Drs. Hodges and Steinegger, Extension Specialists with the University of Nebraska, Lincoln, report calcium does not move from leaves to the fruits.


Thus, foliar sprays of calcium won't correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) through which calcium can be absorbed. Contrary to past belief the direct application of calcium as a spray, based on information from Hodges and Steinegger, is ineffective.

The addition of limestone, gypsum or crushed eggshells to the soil well before transplanting is recommended in some states to overcome the soil calcium deficiency. The use of calcium sulfate (gypsum) at the rate of two pounds per 100 square feet of soil area is recommended in some areas.


Research by Taylor, Locascio and Alligood found the form of calcium applied to the soil does make a difference on Ca uptake. The addition of calcium sulfate (CaSO4) resulted in higher soil Ca concentrations than when calcium nitrate [Ca(NO3)2], calcium chloride (CaCl2), or calcium thiosulfate were applied to the soil (listed in descending order of benefit). They also found the addition of potassium (K) reduced the uptake of calcium resulting in more problems with blossom-end rot.


In high K soils as are found in much of Colorado, using a complete fertilizer containing K will contribute to problems with BER.
Liming is recommended in areas with low pH (acid) soils. The application of up to two cups of lime per plant is recommended in North Carolina. When used lime needs to be worked into the soil 12-inches deep. The addition of lime or gypsum is not, however, recommended in Western Colorado. For a more in-depth discussion on Western Colorado soils, refer to the Web Pages on this topic.

Maintaining the proper balance of potassium, phosphorus and other soil nutrients and avoiding excessive growth due to over-fertilization with nitrogen is recommended.


Excess levels of ammonium (NH4--N), magnesium, potassium and sodium have been reported to reduce the availability of calcium. English et al., report the use of nitrate nitrogen (NO3- - N) stimulates Ca uptake while ammonium nitrate (NH4- - N) reduces the uptake of CA. A soil test should be conducted to help determine what needs to be added and what should not be added to your garden soil.
SQWIBB is offline   Reply With Quote