Control of Grape Chlorosis Through Nutrient Applications on Leaves

Abstract

Chlorosis affects grape-vines, but also peach and morello cherry trees in the districts of Rheinhessen and Vorderpfalz. It especially attacks grape-vines growing on heavy calcareous soils if wet and cold weather periods occur in the blossom time.

The control of this disease used to be effected by adding burned coke and styrene foam to the soil when planting a new vineyard. ‘Sequestrene 138’ then won significance after the discovery of Fe chelates and that it was possible to combine the chelate and the pesticide and apply them together.

From our experiments we then found out that from the regular use of a 1% complete leaf fertilizer (12-4-6) the grape-vine could apparently store so many reserve substances that no chlorosis infection started or that infection was only mild. Similar results could be obtained by using hydrolyzed proteins, such as ‘Siaptone’ (Messrs. Christoffel) or ‘Ergostin No 9’. These compounds, however, are not succesful against severe cases.

Adding Fe sulphate to these hydrolyzed proteins can cure chlorosis.

Today, chelates with multiple bounded Fe are important. The compounds successfully used by us were: ‘Folicin DP’ (Messrs. Metalldünger Jost), ‘Fetrilon 13’ (BASF), furthermore an FE suspension with phosphate bound Fe which unfortunately did not go into production (i.e. ‘Product No. 635’ of Schering), and last year the experimental ‘Product SD 1219’ (Schering).