Cauliflower (Brassica oleracea var. botrytis L.) is a popular cool season vegetable in Bangladesh. The crop is very Sensitive to Soil and climatic requirements (Nath et al., 1987). Varieties also differ in temperature requirement for curd initiation. A good number of Cultivars are found to be grown in the recent years in Bangladesh. Among them there are some local cultivars which can be regarded as Indian cauliflower (Swarmp and Chatterjee, 1972). Some exotic cultivars of tropical type (Wiebe, 1975) are also found to produce curd in winter season. But quality and yield performance are not always satisfactory and problems like buttoning and riceyness make it difficult for the farmers to grow cauliflower (Rashid, 1976). Farmers are oftenly misguided in selecting proper cultivar to achieve the expected output due to the lack of information regarding performance under different agro-climatic conditions. Therefore, the present investigation was undertaken to identify varieties / lines suitable for the eastern region (Chittagong) of Bangladesh
MATERIALS AND METHODS
The study was conducted at the Regional Agricultural Research Station, Hathazari, Chittagong during the period from September, 1995 to January, 1996. The cauliflower cultivars both from local and exotic origin were included in this study (Table 1). Seeds were sown on 17 October, 1995 providing 60 x 60 cm spacing. The unit plot size was 3.60 x 3.60 m and the experiment was laid out in a randomized complete block design with three replications. The crop was fertilized at the rate of cowdung 15 t ha1, N, P2 O5 and K2O @ 110, 85 and 132 kg ha1, respectively.
|Table 1:||Name of the cultivars of 10 cauliflower Genotypes with their origin
The entire quantity of cowdung, TSP and half of urea and MP were applied during final land preparation. The remaining half of urea and MP were applied in three equal installments as top dressing. Irrigation along with other intercultural operations were done as and when needed. Days required for curd initiation was recorded by visual observation of each plant every day. Data on different morphological and yield parameters were taken from ten randomly selected plants in each plot. The date were analysed statistically and the means were separated by DMRT for interpretation of results.
RESULTS AND DISCUSSION
The ten different cultivars of cauliflower were varied significantly in respect of all the characters under study (Table 2, 3 and 4). Whole plant weight ranged from 720.00 to 1916. 67 g in the case of Tropical - 45 days and shiroyama - 65 respectively. Among the cultivars, Boiltali and Rakhushi late produced the plants with statistically at par whole plant weights. The height of plants varied from 46.13 to 68.00 cm but statistically similar heights of plants were attained by Rakhushi late and Shiroyama-65.
|Table 2:||Morphological characters of 10 cauliflower cultivars
|Table 3:||Variation in earliness of 10 cauliflower cultivars
|Table 4:||Yield and yield components of 10 cauliflower cultivars
|In a column, means followed by common letters do not differ significantly from each other at 1% level of probability|
The number of leaves per plant is often an important character that influences the yield. The cultivars included in this study produced an average of 21.50 to 28.93 leaves plant1. Early maturing cultivars produced lower number of leaves with exception as in case of cv. Japani and cv. Shiroyama 65 which matured late but produced relatively lower number of leaves compared to the other late maturing cultivars such as Boiltoli and Rakhushi late (Table 3). Production of lower number of leaves in some late maturing cultivars was probably due to slow rate in leaf initiation which could be an inherent character of the cultivar. This is in agreement with previous investigations in which some of these cultivars were included (Aditya et al., 1989). In determining the photosynthetic efficiency of the leaves, the surface area of the leaves is an important factor. In this trial, the length and breadth of the leaves in each cultivar were recorded and found significant differences. The ranges of the length and breadth of the leaves were 40.30 to 56.03 cm and 16.40 to 22.17 cm respectively.
In respect of earliness of curd initiation and harvesting (Table 3), the cultivars under study were found to vary significantly. The average number of days from sowing to curd initiation varied from 79 to 95. The cultivar Patnai was the earliest and Shiryama- 65, the latest in respect of curd initiation. The average period from curd initiation to the optimum time of harvesting varied from 11 to 18 days among the cultivars. Earliness is a desirable character from the commercial point of view as well as from the consideration of fitting the crop in cropping system in a particular area. It was observed that most of the local cultivars were early maturing type compared to the exotic ones. However, the exotic cultivar, Tropical 45 days and local cultivar kartika were found to be the earliest in curd maturity which took 95 days from sowing. Cultivar Shiroyama - 65 was the latest in maturity among the cultivars studied which took 110 days. The earliest and the latest cultivars differed by 15 days in maturity.
This showed that the cultivars represent a good range of genetic diversity in respect of earliness. The smallest curd was produced by Poushali (230.33 g). The biggest curd (Shiroyama-65) resulted from the highest curd length and diameter (8.70 and 19.22 cm) and the smallest curd was produced in Poushali where curd length and breadth were 7.69 and 14.88 cm, respectively.
The total yield (t ha1) of the cultivars varied from 6. 40 to 18. 38. The lowest and the highest yields were produced by Poushali and Shiroyama-65, respectively. Considerably good yielding cultivars were Patnai (11.01 t ha1), Boiltali (11.64 t ha1) and Rakhushi late (11.03 t ha1). Bose and Som (1986) reported similar yield potential of cauliflower cultivars under the Indian sub- continent situation.
In review of the experiment, the cultivar Shiroyama-65 appeared to be potentially high yielder under Chittagong situation but it is late whereas, Patnai, though a comparatively poor yielder, produced marketable curd 13 days earlier than Shiroyama-65.