THE EFFECT OF THE RASTIM-30-DKV ON SUGAR- BEET AND ITS QUANTITY AND QUALITY

In the field experiments established during 1988 to 1992 at the Experi mental Station of the Department of Plant Production of the University of Agriculture in Prague the influence of the Rastim 30 DKV on the yi eld quantity and quality was compared in the control untreated stands to treated ones. The first spraying was done at the stage of 6 to 14 l eaves at the beginning of row formation in field stands, i.e. 26 to 38 phase at the scale DC of the growth and development. The dose was 300 ml.ha-1. Second treatment done at the phase 46 with a dose of 180 ml. ha-1 was probably 4 to 6 weeks before harvest time. Rastim 30 DKV is a new growing regulator with a wide spectrum of the activity, it was te sted on some field and garden plants; 3-(benzyloxykarbonylmetyl)-benzo thiazolinon-2-on is an active matter of the preparation. In commercial ized preparation of the active matter 300 g.l-1 of the solution is con tained. Active matter is dispersed in water solution. The results are presented in the Tabs I and II and Figs 1 to 3. On average of three-ye ar trials performed during 1988 to 1992 two treatments with Rastim 30 DKV increased the yield of the root (increases of 5 %). That was 2 t.h a-1 of the root yield increase in the case of mean yield, e.i. 43.73 t .ha-1. Leave productivity (in their quantity) was not influenced. Dry matter of the roots decreased, but it was compensated by higher stand productivity per 1 ha (3.54 %, i.e. sugar yield 11.01 t.ha-1). Sugar c ontent was not influenced, as 16.92 % in control and 16.81 % on treate d stands of sugar was obtained. Digestible sugar higher by about 4.11 %, white sugar higher by about 3.64 %. White sugar yield was 5.66 t.ha -1 after treatment, and 5.42 t.ha-1 in control, untreated stands. Ther e were 240 kg.ha-1 sugar yield increases observed, after applying Rast im 30 DKV in spray for the growth and development control.