Stimulation of Growth and Development of Celosia argentea L. by Crude Extracts of Senna alata (L.) Roxb

The effects of different concentrations of Senna alata crude water extracts on the germination, growth and flowering of Celosia argentea were studied. All concentrations of this extract induced a consistent decrease in absolute percentage and rate of germination, and inhibited radical elongation in Celosia argentea. Earliness in flowering and overall increase in height was obtained from seedlings sprayed with 75 /0 C and 100 % C crude water extracts. @JASEM Celosia argentea L is an annual herbaceous vegetable of the family Amaranthaceae. Six species of the genus Celosia in Nigeria had earlier been describe by Hutchinson and Dalziel (1954). Other useful descriptions, economic importance and mineral composition of Celosia argentea have been recorded (Omueti, 1980; 11TA 1972; Grubben, 1976). Senna alata L is a leguminous plant of the family Caesalpiniaceae. The medicinal potentialities of this plant have been documented (Ayensu, 1978; Nwalozie, 1984). The effects of several medicinal plant extracts on other plants have been investigated at different times mainly at the cytological level (Palmer et al., 1960; Hussein and Hakeem 1961; Cardinali, 1961; Tarkowska, 1971; Cornors, 1971; Shehab 1979, 1980; Nwalozie, 1984; Okoli and Russom 1986). For instance, increased depressive effect on the mitotic index, loss of tugor after six hours, and stimulation of an increase in the percentage of cells at prophase with corresponding decrease of cells in other phases were all cytological effects of high concentrations and long duration of treatment of Allium cepa roots with crude extracts of Pulicaria crispa (Shehab, 1979). It is noteworthy that the cytological effects of these extracts will always manifest in different physiological results. Thus, Onofeghara (1981) using water extracts of Senna alata was able to achieve earliness in the flowering of Arachis hypogea and Vigna unguiculata reducing their flowering periods from 42 to 105 days and 64 to 150 days respectively. This particular study looks at the physiological effects of Senna alata water extracts on the germination, growth and flowering of Celosia argentea. MATERIALS AND METHODS Preparation Of Extract: Seeds of Celosia argentea and leaves of Senna alata were used for this study. 300g of the fresh leaves of S. alata were weighed out on a top loading meters balance (model PB163) and blended with a homogenizer in 1 Litre of distilled water. The green paste so obtained was filtered under suction (850 air compressor, 54750FBF). The wine coloured filtrate was stored in the refrigerator at 4C until required. This was regarded as 100% crude water extract (C). From this stock concentration lower concentrations of 75% C, 50% C, 40% C, 30%C, 25% C, 12% C, 10% C, and 5% C were prepared. Germination Studies: Petri-dishes lined with 9cm Whatman filter paper moistened with distilled water, were used as germinators. 3 replicates each containing 50 seeds was used for each concentration. A control experiment was also set up for each treatment. To each petri dish, 10ml of the particular concentration (i.e. 5%C , 10% C, 12.5% C, 25% C, 30% C, 40% C, 50% C, 75%C and 100% C) was added and left at room temperature. Measurements were taken at intervals of 24hours and the emergence of radicle (Agboola, 1998) was taken as indicative of germination. Growth Studies: Four plastic buckets were filled with top soil from the garden and seeds of Celosia argentea were sown in them. Nine other sets each having four buckets were treated similarly. Twentyone days after sowing (i.e. at 4 –5 leaf stage) the various concentrations of crude water extract were sprayed on the stems and on the surfaces of the foliage using a spraying pump. One set of four buckets, which was sprayed with distilled water served as the control. The height and leaf area of the plants were measured at weekly interval, so also were the dry weight, relative growth rate (RGR), and net assimilation rate (NAR). The time of flowering was noted. The seedlings were watered twice daily (morning and evening) except the evening the plants were treated. *Corresponding author