During three successive seasons, fertilizing Crimson Seedless vines with
N+K was studied. The vines were five years old, grown in a sandy soil. The vines
were fertilized with three levels of nitrogen 10. 20 and 40 Kglfeddan each level was
accompanied by three levels of K20; 50, 100 and 150 Kglfeddan. The control
received 60 Kg N/feddan + 120 Kg K20lfeddan which was the common fertilization
applied in the farm. Nitrogen and potassium peaked 15 days before bloom then
decreased at bloom, fruit set and veraison. Increasing N+K up to 40 Kg N/feddan +
100 Kg K20lfeddan significantly increased number of clusters/vine, yield/vine and
cluster and berry weight. This treatment was found to be the best one in this respect.
TSS was significantly increased than the other treatments due to the application of
40 Kg Nlfeddan + 100 or 150 Kg K20lfeddan. The treatments did not affect acidity in
any season of the study. TSS/acid ratio followed similar trend of TSS. Chlorophyll
increased as N+K were increased. High values were recorded for 40 Kg N/feddan +
150 Kg K20lfeddan and 60 Kg N/feddan + 120 Kg K20/feddan (control). Anthocyanin
increased in the treatments of 20 Kg N/feddan + 150 Kg K20lfeddan and 40 Kg
N/feddan + 50, 100 and 150 Kg K20lfeddan. N% increased as N+K were increased
whereas increasing K fertilization increased K%. Fertilizing Crimson Seedless vines
with 40 Kg N/feddan + 100 Kg K20lfeddan could be recommended.