EFFECT OF PHOTOPERIOD ON GROWTH, FLOWERING AND OFFSET PRODUCTION OF THREE VARIETIES OF DENDRANTHEMA GRANDIFLORJJM

Abstract

The research was conducted during 2001/2002 and 2002/2003 seasons as a factorial experiment according to the RCBD design with five replications. The study included two treatments of day length (short day- 8 hours light and long day-14 hours light, in which the plants were covered with a black polyethylene sheet since the first of August and forwards for three months from 6pm until Sam), The vegetative growth and flowering characters of three types of chrysanthemum were studied, these types were included Pompon (Cameo), Decorative (Evelyn Bush) and Single (Rex).The results indicated that long day (14 hours light) increased the plant height, branches/plant and leaves/plant at both seasons. Plants height were 34.96, 25.38 cm; 4.73, 4.30 branches/plant; 78.04, 57.63 leaves/plant for both seasons, respectively and increased stem diameter, flower buds/plant and inflorescence diameter at the first season only. The stem diameter was 0.51 cm; flower buds/plant were 7.38 while inflorescence was 4,78 cm. Short day (8 hours light) significantly reduced the time to the appearance of flower buds that was 104.62 days and flowering (time to flower) at the first season which was 117.00 days and increased the No. of offsets/plant (8.87) height and stem diameter of offsets (90.52, 0.35 cm) at the second season.