Abstract: The experiment was conducted to find out morphological and reproductive variability in response to different sowing time and fertilizer treatments with two varieties of French bean under the agroclimatic conditions of Mymensingh, Bangladesh. Fertilizer treatments had significantly different effects on plant height, leaf number, leaf length and breath, days required for maximum flowering, number of flowers per plant and number of pods per plant. The interaction of sowing dates and varieties, had significant effects on the above characters except plant height. The best morphological and reproductive attributes performance were observed in January sowing and highest fertilizer treatments combination.
INTRODUCTION
Phaseolus vulgaris L. is a member of the family Leguminosae and sub-family Papoilionacae. It is an annual harbaceous plant with errect stem and trifoliate leaves. The plant has terminal raceme and subtending axillary bisexual flowers. It's corolla are white, pink or yellow in colour. It has ten stamens, with small globuse anthers. The gynoecium is single with multi-ovuled ovary. The flowers are normally self fertilized developing into straight or slightly curved fruits (the pods). Nutrient requirements for different cultivars usually similar except on poor soils (Adams, M.W. 1984). Nitrogen, phosphorus and potassium are applied before planting followed by top dressing of potash or nitrogen to stimulate early growth. Chandra et al. (1987) stated that plant growth and yield increase with increasing nitrogen and phosphorus fetilizer treatments. Fertilizer placement at 10-25 cm depth has promoted growth and development of root or shoot of French bean (Chaib, et al., 1984). In case of application of various fertilizer doses, there were significant differences in pod number per plant in French bean (Sa et al., 1982). Increased pod yield was reported with NPK fertilization (Srinivas and Naik, 1988). Seed yield also increased with increasing fertilizer doses (Perez, 1979; Hara et al., 1985; Gonzalez et al.,1983). Abdalla and Fischbeck (1978) has stated that the pod set of French bean was poor at day/night temperature of 30/25°C. On average, duration of flowering in French bean was doubled when the day/night temperature was increased from 15/12°C to 18/15°C (Apel, 1988).The seed yield varied with different sowing dates (Chages et al., 1982; Iglesias et al., 1984; Vyas et al., 1994). Dwarf cultivars of French bean is generally sown in 60x20 cm spacing. Spacing had little effect on yield except during the wet season when yields were significantly higher at wider spacing with no fertilizers (Lima et al., 1983).French bean is grown in Sylhet and Chittagong in winter. Its young pods and mature seeds are used as cooked vegetable. Beans are also pickled and cooked beans are served cold in salads, canned and home prepared red kidney beans are used in salads and meat and fish dishes. The young leaves are also used particularly in East Africa. French bean is used as fodder crop. French bean is very rich in protein as vegetables. In a country like Bangladesh where animal protein for human nutrition are becoming scarce day by day, French bean may be an alternative source of protein. Because beans and pulses are the best available source of vegetable proteins. Cultivars of French bean is not known to us like other beans and it is now being grown only in some parts of the country. While there is a lot of research information on other beans, there is little or no documented research reports on French bean are available in Bangladesh. So, this piece of research work was undertaken with the view to study morphological and reproductive attributes in French bean in response to sowing dates and fertilizer treatments on French bean.
MATERIALS AND METHODS
The present investigation was carried out in the field laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during the period from December 2001 to April 2002. The experimental plots belonged to the Brahmaputra alluvial soil tract. The soil was sandy loam. The plot had been used for rice cultivation for over a decade. Seeds of Phaseolus vulgaris L.(vars. yellow and red) were collected from Mitali seed store, Mymensingh. The experimental area was under sub-tropical climate. The land was ploughed with power tiller and the soil was exposed to sun for three days before the final preparation was made for planting. The experiment was laid out in Randomized Block Design using four replications each having two different varieties and three fertilizer treatments. The total experimental area was 43.8x33m equaled to 0.357 acre. The size of an individual experimental unit or plot was 4x2.4 m. A drain of 1 meter width was made between two plots. Seeds were sown in rows. The row to row distance was 100cm or 1 meter and plant to plant distance was 60cm. Urea, triple super phosphate, muriate of potash and well rotten cow dung were applied at the rate of 47.23 quintal per hectare before final preparation of the land. The total quantity of cow dung and muriate of potash and 1/3rd of the quantity of urea and half of the quantity of triple superphosphate were applied at the time of final preparation of the land was mixed thoroughly with the soil in the plots. Seeds were sown after seven days of application of manure and fertilizers. The rest quantity of urea and triple superphosphate were later on used as side dressing in two instalments. One when the plants were about 4-5 inches in height and the other just before flower initiation. Germination test was performed in the laboratory before sowing the seeds in the field by using, number of seeds germinated divided by number of seeds sown x 100 of this formula. Seeds were sown at three different times-December' 2001, January' 2002 and February' 2002. Due to non-availability of land and delayed rainy season an early sowing was not possible. In each plot seeds were sown in rows and there were five rows in each pot. In the row plant to plant distance was 60 cm and row to row distance was 100 cm. Two seeds were sown in each hill at a depth of about 1 and 2 inches soil. Surrounding the experimental plot rows to bean plants were sown as broader crops to protect experimental plants from grazing by animals. Seedlings were transplanted to fill-up the gap where seeds failed to germinate. Seedlings of about 6 inches in height were transplanted from boarder rows with roots plunged 2 inches below the soil in hills preferably in the evening and then watering was to protect the seedlings from wilting. All gaps were filled up within two weeks after germination of seeds. Irrigation was done whenever necessary. Necessary precautions were also maintained against pest and diseases. As the seeds were sown in the field at three different times the crops were harvested at three different times. Immature green pods, suitable for use as vegetable, were harvested after 66 days of seed sowing and they were weighed to estimate fresh pod yield. These pods were smooth and soft. Again, the pods were harvested at mature stage when the plants and pods became yellow and dry. The seeds were collected from the pods and sun dried. Seeds were weighed to know the seed yield. The representative plants were selected at random from each unit plot and data pertaining to the characters of pod length, number of seeds/pod, weight of fresh pods/plant, weight of dry seeds/pod, moisture content of pod (percentage) and yield of pod and seed qha–1 were recorded. Finally, collected data were analyzed by Duncan's Multiple Range Test (DMRT).
RESULTS AND DISCUSSION
In case of fertilizer treatments, T2 produced the tallest plants (21.76 cm) and T0 the shortest one (15.10 cm) (Table 1). Among varieties, the variation was insignificant (Table 2). Among sowing dates, S1 produced the tallest plants (22.30 cm), followed by S2 (21.87 cm) and shortest in S3 (12.80 cm) (Table 3). Interactions among sowing dates and varieties S1V1 produced the tallest plants (25.20 cm) and S1V2, S 2V2 varied insignificantly between themselves (Table 4). The shortest plants were produced by S3V2 but S3V1 and S3V2 varied insignificantly between themselves. Interaction among sowing dates and fertilizer treatments S2T2 produced the tallest plant (26.04 cm) followed by S1T2 (25.65 cm) and S3T0, S3T1 varied insignificantly between themselves but produced the shortest plants (12.20 cm and 12.62 cm, respectively) (Table 5). The present observation is in full agreement with that of Chaib et al. (1984) who reported increased plant height with increasing fertilizer treatment in Phaseolus vulgaris L. Similar trend in height increment with nitrogen and phosphorus treatments were also observed by Srinivas and Naik (1988). The plant height might have varied due to the effect of low temperature prevailing in during the sowing time. Considering leaves, T2 produced the highest number of leaves (23.87), T1 (22.20), T0 (14.20). Among the sowing dates, S1 and S2 varied insignificantly between themselves while S3 produced the lowest number of leaves per plant (16.68).
| Table 1: | Morphological and reproductive attributes of French bean as influenced by d fertilizer treatments |
| Table 2: | Morphological and reproductive attributes of French bean as influenced by variety |
| Table 3: | Morphological and reproductive attributes of French bean as influenced by sowing dates |
| Table 4: | Morphological and reproductive attributes of French bean as influenced by sowing dates and variety |
| Table 5: | Morphological and reproductive attributes of French bean as influenced by sowing dates and fertilizer treatments |
| Similar letters in a column do not differ significantly at 1 % level of probability | |
Both the varieties, V1 and V2 did not produce any significant number of leaves per plant. Interactions, between sowing dates and varieties, they did not produce any significant variation in producing the number of leaves per plant. Interactions between sowing dates and fertilizer treatments, S1T2 and S2T2 varied insignificantly between themselves but produced the highest number of leaves (26.95) followed by S1T1 (24.48). The least number of leaves were produced by both the S1T0 and S3T0 treatments. The present observation is in full agreement with that of Meyer (1964) who reported growth in a tissue that requires a constant supply of carbohydrate and nitrogenous food materials. This has been demonstrated in this study that the number of leaves was increased only with increasing supply of nutrient. In case of leaf length and breath, both the T2 and T1 fertilizer treatments produced the maximum leaf length (7.84, 7.52) and leaf breath (4.98, 4.93), respectively, while T0 produced the minimum leaf length (5.72) and leaf breadth (4.02). Both the varieties V1 and V2 did not produce any significant variation in leaf length and leaf breadth. Larger leaf length were attained by both the S1 and S2 treatments (7.15) and (7.09), respectively followed by S3 (6.84). S1 also produced larger leaf breadth followed by S2 (4.63) while S3 gave the lowest leaf breadth (4.47). As regards interactions among sowing dates and fertilizer treatments, S1T2 produced the highest leaf length (8.12), S2T2, S1T1 and S2T2 produced the second highest leaf length and they did not produce significant variations among themselves. Minimum leaf length were found in S3T0, S2T0 and S1T0. Highest leaf breadth were obtained by S1T1, S1T2 and S2T2 followed by S2T1 and S3T2. Least leaf breadth were attained by S1T0 and S3T0. From the Table (Table 1 and column 6) it was found that the treatment T0 and T1 produced maximum number of flowers (47.23) and (47.00), respectively, while the T2 produced the least. Varieties V1 and V2 were found insignificant. Among sowing dates, S2 and S1 gave maximum flower at 13.55 and 12.85 days after sowing, while S3 failed to anthesis any bud. Interaction between varieties and sowing dates, produced no significant variation in days required for maximum flowering. Interactions between sowing date and fertilizer treatments varied insignificantly but anthesized maximum flower at 47.98 and 47.72 DAS. S3T0, S3T1, S3T2 failed to anthesize any flower. The present observation was in full agreement with that of Graham (1979) who reported the French bean plants did not flower at 35-25°C but flowered at day-night temperature of 25-15°C. The variation of flowering might be due to variations in temperature due to aspect of sowing dates. The S1 (December) and S2 (January) shown plants flowered at 25-28°C and S3 (February) sown plants flowered was anthesized.
Among the fertilizer treatments, T1 produced the maximum number of flowers per plant (15.50) followed by T1 (13.73) and T0 (10.36). Variety V1 and V2 did not vary significantly. The highest number of flowers per plant (13.55) showed the S2 sowing date followed by S1 (12.85) per plant. S3 failed to anthesis any flower. Interactions between the sowing dates and varieties were statistically insignificant. However both the varieties failed to flower at S3 sowing dates. The interactions between sowing dates and fertilizer treatments, S2T2 and S1T2 varied insignificantly between themselves but produced the maximum number of flowers 15.73 and 15.28 flowers per plant, respectively. The S2T1 and S1T1 produced the second highest number of flowers per plant while the S3T0, S3T1, S3T2 produced no flower. Graham (1979) reported that French bean did not flower at day/night temperature of 35/25°C but flowered at 25/15°C. For this observation it could be noted that temperature was an important factor for flowering. S3 (February) sown plants were grown at 15-29°C. At flowering stage (March), the temperature was 19-33°C. Therefore, a few flower was initiated but no flower was anthesized. The flowers were withered and dried. So, February sown plants had no record of the number of flowers per plant. Among the fertilizer treatments, T2 produced the maximum number of pods per plant (14.89) followed by T1 and T0. Both the varieties did not produced the any significant variation with respect to pots per plant. S2 sowing date produced the maximum number of pods per plant (13.04) followed by S1(12.12). Among the varieties and sowing dates interactions, they were found to be statistically insignificant. Among the sowing dates and fertilizer treatments interactions, S2T2 produced the maximum number of pods per plant followed by S1T2, S2T1 and S2T0. There had been no difference with the interaction S3T0, S3T1 and S3T2.The present observation was in full agreement with that of Sa et al. (1982) and edge et al. (1975) who reported significant differences in pod number per plant with fertilizer treatment. Abdalla and Fischbeak (1978) stated that the pod set of French bean was poor at day/night temperature of 30/25°C. From the above observation it was obvious that due to high temperature S3 (February) sown plants failed to produce any pod.