RESPONSE OF BLACK CURRANT (RIBES NIGRUM L.) CV. 'TITANIA' TO MICROIRRIGATION UNDER LOOSE SANDY SOIL CONDITIONS

Abstract

The field experiments were carried out in the years 1992-1995 at Kruszyn Krajenski near Bydgoszcz. This area has the lowest precipitation rate in Poland, the annual rainfall does not exceed 500 mm and from April to September is 324 mm. This region of Poland has the highest irrigation requirement for cultivated plants. The main purpose of the study was to recognize the influence of drip and micro-sprinkler methods of irrigation on the growth and yield of black currant grown in the very light soil during the initial harvesting seasons. Experiments were established as one-factorial trial, in randomized block design in four replications. The examined factor was irrigation. Three variants of irrigation have been examined: I - control (without irrigation), II - drip irrigation, III - micro-sprinkler irrigation at a soil moisture tension of up to - 0.03 MPa. Experimental periods should be recognized as dry, because the average rainfall amount for the growing season (April-September) was 64 mm lower than the mean long-term precipitation (324 mm) of the period. Average seasonal water rates amounted 197 mm in case of micro-sprinkler irrigation and 116 mm in case of drip irrigation. The experiment was located on a soil classified to Typic Hapludolls. The clay content was 7 % in the top soil and from 3 to 5 % in the sub-soil. The average organic matter content was 1.19 %. The water reserve to 1 m depth of soil at field capacity was 88 mm and the available water 68 mm. Black currants were planted in autumn 1991. The cultivar used was ‘Titania’. The plot area was 25 m2 (2.5 x 10 m) and included 10 bushes. The results indicated the decisive role of water on the outcome of yield and quality of black currant cultivated on a soil of limited water holding capability. The experiment proved that black currant production in such climatic-soil conditions was only possible with the use of irrigation. The irrigation factor significantly increased the growth, the fruit weight and yields of berries. Vitamin A and C content was differentiated more strongly by micro-sprinkler irrigation than by drip irrigation. In most cases under irrigation, the content of both vitamins in fruits decreased.