Influence of micronutrient (boron) for the growth and yield of cauliflower

A field experiment was conducted at the Horticultural farm, Sher-e-Bangla Agricultural University, Dhaka-1207 during the period from October 2015 to February 2016 with micronutrient Boron applied to cauliflower cultivar, ‘F1 hybrid’. Four treatments viz., B0: Control, B1: 1kg ha-1, B2: 1.5kg ha-1, B3: 2kg ha-1 was utilized in this experiment which was arranged in Randomized Complete Block Design with three replications. Maximum Plant height (41.66 cm), Leaf number (19.35), Leaf area (182.51 cm2), 50% curd initiation (47.23 days), pure curd weight (698.20 g), curd weight with leaves (1.56 kg), curd yield plot-1 (1.53 kg) and curd yield ha-1 (15.30 t) at harvest was found at B3 treatment while lowest was (14.28 cm, 6.33 leaves, 121.85 cm2, 48.44 days, 418.60 g, 1.07 kg, 1.05 kg, 10.49 ton ha-1 respectively) was recorded from control. Therefore, result indicates that application of micronutrient (Boron) in supplement with recommended fertilizer at 2 kg ha-1 will successfully increase growth and yield of cauliflower.


I. Introduction
Cauliflower (Brassica oleracea, Brassicaceae) is an economically important winter vegetable crop grown in Bangladesh (Akter et al., 2011). It is nutritionally rich which contains good amount of vitamins like riboflavin, thiamine, nicotinic acid and high quality of proteins and minerals like calcium and magnesium. 100 g of edible part of cauliflower (known as Curd) contains 89% moisture, 2.3 g protein, 50 mg vitamin C. In Bangladesh cauliflower covered in an area of 40970 hectares with a total production of 2, 11,585 metric tons (BBS, 2015). It can be grown in all types of soil with good soil fertility (Islam, 2008). Because of over mining of the soil nutrient by plants most of the micronutrients run short in supply to the crops and some disorder appears resulting in low yields (Joshi, 1997). Boron deficiency has been commonly reported in soils which are highly leached and/or developed from calcareous and alluvial deposits (Borkakati and Takkar, 2000). Several soil factors and conditions Published with open access at journalbinet.com EISSN: 2312-7945, © 2018 The Authors, Research paper render soils deficient in boron. For example, low soil organic matter content, coarse/sandy texture, high pH, liming, drought, intensive cultivation and more nutrient uptake than application, and the use of fertilizers which are poor in micronutrients are considered to be the major factors associated with the occurrence of boron deficiency (Niaz et al., 2007). Therefore, productivity of cauliflower is not satisfactory due to poor soil fertility and imbalanced fertilization. Micronutrients deficiency is more prevalent in acidic soils.
In Bangladesh fertilizer application rate has increased than earlier in crop production but application of micronutrients has largely been neglected. Therefore, rational and optimum use of micronutrient coupled with recommended fertilizers would be beneficial for increasing curd yield per unit area. Boron is also an essential micronutrient for the growth of plant new cells. However, in case of cole crops such as cauliflower, broccoli and cabbage, boron requirement is very high. Boron normally becomes less available to plants with increasing soil pH. When calcium (Ca) availability is high, there is a greater requirement of boron for plant growth and yield (Tisdale et al., 1995). Yield and yield components of crops were affected positively and negatively by boron depending upon soil status, type of crop and the doses used. Khanam et al. (2000) found that the application of boron is essential for improving yield potentiality of chickpea and lentil at BAU farm soil in Bangladesh. Application of different levels of boron influenced the growth and yield in different crops also reported by Efkar et al. (1995) in potato; Ali et al. (2001) in papaya and Sohel et al. (2006) in broccoli. Alam (2006) showed that application of boron at 2kg ha -1 with NPKS increased cabbage head yield by 119% (on average) than NPKS alone. In fact information regarding B fertilizer requirements for vegetable should be meager in Bangladeshi soil. Therefore, an attempt was made to study the effect of boron levels on growth and yield components of cauliflower.

II. Materials and Methods
The single factor experiment was executed at Horticultural farm in Sher-e-Bangla Agricultural University, Dhaka, during the period of October 2015 to February 2016. The research work was carried out to evaluate the effect of boron on growth and yield of cauliflower with four treatments: B0: Control, B1: 1kg ha -1 , B2: 1.5kg ha -1 , B3: 2kg ha -1 in Randomized Complete Block Design (RCBD) with three replications. Planting material was collected from Bangladesh Agricultural Research Institute (BARI). Twenty five days old seedlings (F1 hybrid) were transplanted into the main field (plot size 3m × 1m) maintaining a required spacing of 60cm ×30cm. Manure and fertilizer was applied according to BARI recommended dose. Plants in each plot were selected randomly and tagged. The tagged plants were used for data recording according to the following characters: Plant height, Number of leaves plant -1 , Leaf area, Days to curd initiation, Days to 50% curd initiation, Days from curd initiation to harvest, Curd diameter, Curd weight, Curd weight with leaf at harvest, Curd yield plot -1 , and Curd yield ha -1 . The recorded data for different characters were analyzed statistically using "MSTAT-C" to find out the significance of variation among the treatments. Difference between treatments was evaluated by Duncan's Multiple Range Test (DMRT) test at 5% level of probability (Gomez and Gomez, 1984).   (Table 01) that there was observable variation in case of leaf area due to different doses of micronutrient boron. B3 treatment (Boron @2kg boron ha -1 ) produced the maximum (182.51cm 2 ) leaf area whereas control (B0 treatment) represented minimum leaf area (121.85cm 2 ). This result was supported by Balyan et al. (2004).

Days to 50% curd initiation
Micronutrient boron application resulted significant variation in days to 50% curd initiation. Therefore, maximum days (48.44) were required in case of B0 (control) treatment while minimum days (47.23) was in B3 treatment (2 kg boron ha -1 ) which is alike to Moklikar et al. (2018) (Table 01).

Days required for curd initiation to harvest
Maximum (11.81) days (Table 01) required for curd initiation to harvest was recorded from that of control (B0) and minimum days (9.79) was recorded from B3 treatment (2kg boron ha -1 ). The result was in support with that of Mukhopadhayay et al. (2002).

Curd diameter
Curd diameter followed spectacular variation on Boron application (Table 01). Maximum curd diameter (13.67 cm) was found in B3 treatment (2 kg boron ha -1 ) and minimum (12.55 cm) was recorded from control (B0) treatment. Pure Curd weight (g) Curd weight differs significantly in case of different doses of boron. Highest (698.20 g) curd weight per plant was obtained from B3 @2 kg boron ha -1 whereas lowest (418.60 g) was recorded from control (B0) treatment (Table 02).

Curd weight with leaf at harvest (kg)
Curd weight with leaf varied significantly due to the application of different doses of micronutrient treatments. Boron @2 kg ha -1 represents maximum (1.56 kg) curd weight (B3). On the other hand, control treatment (B0) showed minimum (1.07 kg) curd weight with leaf at harvest (Table 02).
Curd yield plot -1 (kg) Data represented in (Table 02) showed variation of curd yield plot -1 by the application of boron at different doses. Maximum (1.53 kg) curd yield per plot was obtained from B3 (2 kg boron ha -1 ) and minimum (1.05 kg) was recorded from control (B0) treatment.

IV. Conclusion
Insufficient quantity of micronutrient in the crop field might be considered as one of reason behind lower yield of cauliflower in Bangladesh and as a micronutrient boron had significant effect on curd yield of cauliflower. In this regard, application of boron (2 kg ha -1 ) as micronutrient supplemented with recommended fertilizer could be an effective measure for cauliflower production in Bangladesh.