OPTIONS FOR SUPPLYING POTASSIUM TO KIWIFRUIT VINES

In supplying the 250 kg of potassium required by a productive hectare of kiwifruit, there are several options available in the form and timing of fertiliser applications.
In this paper, soil and leaf analysis are emphasised in interpreting field trials using different means of supplying potassium.
The preliminary results of trials in which fertigation followed early season potassium applications suggest that fertigation can be used to supply K. To date, the different treatments have not brought about any significant differences in plant responses.

Results of soil analysis also helped in interpreting the effects of chloride supplied in potassium chloride to kiwifruit vines.
Most chloride was still within the root zone several months after fertiliser was applied.
Leaf levels of potassium tended to be lower when potassium sulphate was used compared to potassium chloride.
The use of potassium chloride as the sole source of potassium has, however, caused foliage problems in the past.
Until this effect is fully understood a mixed fertiliser strategy using equal amounts of potassium chloride and potassium sulphate is regarded as being the most appropriate approach.

II International Symposium on Kiwifruit

K.B. Marsh, R.W. Tillman, B.M. Stowell

fertiliser, chloride, sulphate, soil analysis, leaf analysis, fertigation

https://doi.org/10.17660/ActaHortic.1992.297.45