SOME RESPONSES OF TOMATOES TO THE CONCENTRATION OF POTASSIUM IN RECIRCULATING NUTRIENT SOLUTIONS

The effects of a wide range of potassium levels on the yield and quality of tomatoes were studied using recirculating nutrient solutions (MFT). Two crops were grown at six concentrations of potassium (10, 20, 50, 150, 400 and 800 mg e^-1) that were maintained continuously, and fruit were harvested for 27 and 14 weeks respectively.

Symptoms of potassium deficiency developed on plants grown at 10 mg K e^-1 in both crops.
In the first crop, the early yield was depressed by the lowest (10 mg e^-1) and the highest (800 mg e^-1) levels of potassium (P < 0.01); the latter response was due to delayed harvesting.
Although the final yields were not affected significantly, the number of fruit per plant tended to increase with the level of potassium whilst the proportion of unevenly ripened fruit declined.
The dry matter content of the fruit and the titratable acidity, potassium content and electrical conductivity of the expressed juices increased with the concentration of potassium supplied, as did the rate of potassium uptake and the potassium content of the leaves.

Symposium on Nutrition, Growing Techniques and Plant Substrates

P. Adams, M.M. Grimmett

https://doi.org/10.17660/ActaHortic.1986.178.2