Effect of molybdenum and its application on seed production of cauliflower

Transcription

1 Bull. Inst. Trop. Agr., Kyushu Univ. 41: 67-72, Effect of molybdenum and its application on seed production of cauliflower M. F. Hossain 1), M. R. Uddin 2), M. R. Humauan 3) and J. Hossain 4) Abstract The experiment was conducted at Regional Agricultural Research Station, Ishwardi, Pabna during rabi season of to find out the appropriate dose of Molybdenum for seed production of cauliflower (var. BARI Phulcopi-1). Five Mo doses (0 kg/ha, 0.5 kg/ha, 1.0 kg/ha, 1.5 kg/ha and 2.0 kg/ha) and three application method (100% basal, 50% basal + 50% foliar spray and 100% foliar spray) were used as treatment variables. Maximum number (16.33) of leaves/plant was found in 2 kg Mo/ha as basal application which was statistically similar to 1.5 kg Mo/ha (16.00) as basal application and minimum number (13.33) of leaves/plant was recorded from control. The highest seed yield ( kg/ha) was obtained from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray and the lower seed yield ( kg/ha) was obtained from control. The highest gross return (Tk ), gross margin (Tk ) and benefit-cost ratio (12.31) wererecorded from the same treatment. Keywords: Boron, cauliflower and seed yield, molybdenum Introduction Cauliflower (Brassica oleracea var. botrytis L.) is a biannual and herbaceous vegetable crop belonging to the family Cruciferae. It is one of the popular winter vegetables in Bangladesh. Seed yield and quality in crop plants greatly influenced by both macro and micronutrients. Micronutrients have an important role in the physiology of crop and are required for plant activities such as aspiration, meristematic developments, chlorophyll formation, photosynthesis, tannin and phenolic compound development (Anonymous, 2007). Molybdenum (Mo) is an essential micronutrient for plants, bacteria and animals. It is directly related to metabolic function of nitrogen in the plant through nitrate reductase enzyme that reduces the nitrate to nitrite and this is the first step of the incorporation of nitrogen to proteins (Bambara and Ndakidemi, 2010). Molybdenum deficiency causes whiptail in cauliflower. Whiptail results in a deformed growing point, causing no head to develop, as well as leaf blades consisting mostly of midribs (Sharma, 2002). Curds with hollow stem disorder are a major problem in cauliflower production and is associated with Mo deficiency (Weir, 1984). So, Mo application is a crucial factor for yield and quality as well as to control curds with hollow stem disorder (Noor et al, 1996). Many horticultural, cereal and legume crops growing at deficient molybdenum levels in the presence of nitrate fertilizers will develop 1) Senior Scientific Officer 2) Princilap Scientific Officer 3) Senior Scientific officer 4) Regional agricultural research station, Ishwardi, Pabna *Corresponding author: farukgolap@gmail.com

2 68 M. F. Hossain et al. pale green leaves and, simultaneously forming necrotic regions at leaf margins with accompanied decreases in overall plant growth (Chatterjee and Nautiyal, 2001). Molybdenum is needed by plants for chemical changes associated with nitrogen nutrition. In non-legumes (such as cauliflower, tomatoes, lettuce, sunflower and maize), molybdenum enables the plant to take up the nitrates from the soil. Where the plant has insufficient molybdenum the nitrates accumulate in the leaves and the plant cannot use them to make proteins. In molybdenum deficiency, plants were stunted with symptom similar to those of nitrogen deficiency. Chahal and Chahal (1991) claimed that foliar applications of molybdenum stimulated nodulation and biological nitrogen fixation, thus improving the plant growth. Again Mo has toxic effect to plants when concentration is high. Plants grown on high concentrations of molybdenum will have leaves to accumulate anthocyanins and to turn purple (Bergmann, 1992; Gupta, 1997b). However, necessary information regarding the optimum dose of micronutrients particularly Mo are scanty for seed yield of cauliflower under Bangladesh condition. In this context, the present investigation is to observe the role of Mo on the seed production of cauliflower and to find out the optimum dose for maximizing the seed yield of cauliflower under Bangladesh agro-climatic condition. Materials and Methods The experiment was carried out at Regional Agricultural Research Station, Ishwardi, Pabna during rabi season of Five Mo doses (0 kg/ha, 0.5 kg/ha, 1.0 kg/ha, 1.5 kg/ha and 2.0 kg/ha) and three application method (100% basal, 50% basal + 50% foliar spray and 100% foliar spray) were used as treatment variables. Foliar spray was done at curd initiation stage. The treatments were factorial combination of the two factors and the experiment was conducted using a randomized complete block design with three replications. The unit plot size was 6 m 3 m. Seeds of variety BARI Phulcopi-1 were sown in the nursery beds on 5 October Beds were immediately irrigated with the help of watering cane. Thirty days old seedlings were transplanted in the evening time in the experimental plot. Healthy seedlings of uniform size were selected for planting. The land was fertilized with well decomposed cowdung at 15 t/ha and 120, 55, 100, , and 2 kg/ha N, P, K, S, B, and Zn as a source of Urea, TSP, MoP, Gypsum, Boric acid, and Zinc sulphate, respectively. Total amount of cow dung, TSP, gypsum, zinc sulphate, boric acid and sodium molybdate were applied in the plot during final land preparation. Urea and MoP were applied in four equal installments at 20, 40, 60 and 90 days after planting. After transplantation, the experimental plot was irrigated by watering can and second irrigation (flood irrigation) was done 3 days after transplantation. Other intercultural operations were done as and when required. In the early stage of transplantation damping off disease was occurred and it was controlled by spraying Bavistin at 2 g per liter water. Scooping (removing centre portion of curd) was done when it is fully formed to help the easy emergence of the flower stalks. The flower stalks were supported with bamboo stakes to avoid lodging. Ten plants were selected randomly for data collection. Harvesting was conducted on 16 to 30 March in 2014 when the pods were brown in colour. The collected data were analyzed statistically and the mean values were separated by LSD using R software.

3 Effect of molybdenum and application on cauliflower 69 Results and Discussion Effect of molybdenum on plant growth characters of cauliflower Number of leaves/plant at flowering stages was significant among the treatments. Maximum number (16.33) of leaves/plant was found in 2 kg Mo/ha as basal application which was statistically similar to 1.5 kg Mo/ha (16.00) as basal application and minimum number (13.33) of leaves/plant was in control. The promotional effect on plant development of cauliflower plants may be due to the regulatory effects of molybdenum on plant development through largely functions in the enzyme systems of nitrogen fixation and nitrate reduction. The results were in harmony with the previous researchers Elkhatib (2009) and Gupta (1997) on common bean soybean. Molybdenum had no significant effect on leaf length but had significant effect on leaf breadth. Comparatively, the longest leaf (44.66 cm) was found in basal application of kg Mo/ha and the shortest leaf (37.33 cm) was found in basal application of kg Mo/ha. The highest leaf breadth (24.00 cm) was obtained from basal application of 2 kg Mo/ha and the lowest leaf breadth (19.33 cm) was obtained from control treatment. The earliest 50% flowering (114 days) occurred in basal application of 0.5 kg Mo/ha whereas, delayed flowering (120 days) in basal application of 2.0 kg Mo/ha. Maximum plant height (100 cm) was measured from 2 kg Mo/ha as basal application and the minimum plant height (90 cm) was measured from control (Table 1). Table 1. Plant growth and flowering of cauliflower Treatment Number of leaves/ plant Length of leaf Breadth of leaf Days to 50 % Plant height at pod at 50 % flowering (cm) (cm) flowering harvest (cm) T 1 M T 1 M T 1 M T 2 M T 2 M T 2 M T 3 M T 3 M T 3 M T 4 M T 4 M T 4 M Control LSD (0.05) CV (%) T 1 = 0.5 kg Mo/ha, T 2 = 1.0 kg Mo/ha, T 3 = 1.5 kg Mo/ha, T 4 = 2.0 kg Mo/ha, M 1 = 100% basal, M 2 = 50% basal + 50% foliar spray and M 3 = 100% foliar spray Effect of molybdenum on seed yield and seed yield contributing characters of cauliflower The number of flower branches/plant was significantly affected by Mo application (Table 2). The range of number of branches/plant was The highest number of branches per plant was recorded from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray which was statistically similar to 1.5 kg Mo/ha used as basal application and the lowest number (10.02) was recorded from control. Sharma (2002) reported that more number of branches per plant was obtained when combined B and Mo was

4 70 M. F. Hossain et al. applied. Number of pods per plant is an important yield contributing factor for seed production of cauliflower. Maximum number (1490) of pods/plant was produced from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray which was statistically similar to 2.0 kg Mo/ha-used as 50% basal + 50% foliar spray and minimum (839) was produced from control. The results were in agreement with Jana and Mukhopadhaya (2002) who reported that combined application of boron, molybdenum and zinc significantly increase the number of pods per plant. The highest number of seeds/pod (16.22) was recorded from 2.0 kg Mo/ha as basal application which was statistically similar to 1.5 kg Mo/ha as 50% basal + 50% foliar spray while the lowest number of seeds/pod (111.73) was recorded from control. Number of seeds per pod was influenced by Mo application probably because of involving in the nitrate reduction system of nitrogen metabolism. Application of Mo had positive effect in 1000-seed weight. All the treatment produced higher 1000-seed weight than control. However, the highest 1000-seed weight (2.80g) was recorded from 1.5 kg Mo/ha as 50% basal + 50% foliar spray which was statistically similar to 1.5 kg Mo/ha used as 100% basal and the lowest 1000-seed weight (1.93 g) was from control. Sharma (2002) observed that 1.5 kg Mo/ha with 2.0 kg B/ha increased significantly the highest thousand seed weight. The highest seed yield ( kg/ha) was obtained from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray possibly due to higher number of pods/plant, seed/pod and 1000-seed weight. Significantly the lower seed yield ( kg/ha) was obtained from control. The results are in agreement with Jana and Mukhopadhaya (2002) who reported that combined effect of B, Mo and Zn showed significant increase in seed yield. Similar observation was also made by Sharma (2002) who described that maximum seed yield was obtained by applying the combination with 2 kg of B and 1.5 kg of Mo per hectare. Table 2. Seed yield and seed yield contributing characters of cauliflower Treatment Number of flower Number of Number of 1000 seed Number of branches /plant pods /plant seeds /pod weight (g) plants /plot Yield (kg/ha) T 1 M T 1 M T 1 M T 2 M T 2 M T 2 M T 3 M T 3 M T 3 M T 4 M T 4 M T 4 M Control LSD (0.05) CV (%) T 1 = 0.5 kg Mo/ha, T 2 = 1.0 kg Mo/ha, T 3 = 1.5 kg Mo/ha, T 4 = 2.0 kg Mo/ha, M 1 = 100% basal, M 2 = 50% basal + 50% foliar spray and M 3 = 100% foliar spray Economic performance The economic performances of sowing date and plant spacing on seed production of cauliflower are presented in Table 3. The highest gross return (Tk /ha) and gross margin (Tk /ha) was

5 Effect of molybdenum and application on cauliflower 71 obtained from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray. Maximum benefit cost ratio (13.36) was also obtained from the same treatment. Hence, 1.5 kg Mo/ha as split application ie.50% basal + 50% foliar spray would be economically profitable for cauliflower seed production. Table 3. Benefit-cost analysis of cauliflower seed production under different treatments Treatments Seed yield (kg/ha) Gross return (Tk/ha) Total cost (Tk/ha) Gross margin (Tk/ha) BCR T 1 M T 1 M T 1 M T 2 M T 2 M T 2 M T 3 M T 3 M T 3 M T 4 M T 4 M T 4 M Control (0 kg Mo) Marked price: Seed = Tk 10,000 /kg (OP variety), Sodium molybdate = Tk /kg Conclusion The study revealed that the seed yield of cauliflower was significantly affected by Mo application. The highest seed yield ( kg/ha) was obtained from 1.5 kg Mo/ha used as 50% basal + 50% foliar spray and the lowest seed yield ( kg/ha) was obtained from control. The recommendation derived from the present study is that 1.5 kg Mo/ha as 50% basal + 50% foliar spray is the suitable for maximizing seed yield of cauliflower. References Anonymous The year book of Agricultural Statistics of Bangladesh. Bangladesh Bur. Stat., Minis. Plan., Govt. People s Repub, Bangladesh. Bambara S and PANdakidemi The potential roles of lime and molybdenum on the growth, nitrogen fixation and assimilation of metabolites in nodulated legume: A special reference to Phaseolus vulgaris. African J. Biotech., 8: Bergmann W Nutritional disorders of plants. Visual and analytical diagnosis. Jena: Gustav Fischer Verlag. Chahal, VPS and PPK Chahal, Interaction studies between Rhizobium leguminosarum and Meloidogyne incognita on pea (Pisumsativum L.) growth under different concentrations of molybdenum. Plant Soil Sci., 45: Chatterjee C, Nautiyal N Molybdenum stress affects viability and vigour of wheat seeds. Journal of Plant Nutrition24: Elkhatib, H A Growth and yield of common bean (Phaseolus vulgaris L.) in response to Rhizobium Inoculation, nitrogen and molybdenium fertilization. Alex. Sci. Exchange J., 30: Gupta UC Symptoms of molybdenum deficiency and toxicity in crops. In: Gupta UC, ed. Molybdenum in agriculture. Cambridge: Cambridge University Press, UK. Jana J C and T P Mukhopadhaya Yield and quality of cauliflower seeds as influenced by added boron, molybdenymabd zinc in West Bengal. Bangladesh J. Agril. Res., 27 (1): 1-4.

6 72 M. F. Hossain et al. Noor S, M. Rahman, N C Shill, S K Nandy and M N Anwar Effect of zinc and molybdenum on the yield and yield components of cauliflower. Bangladesh Hort., 14 (1&2): Sharma S K Effect of boron and molybdenum on seed production of cauliflower. Indian J. Hort., 59 (2): Weir R G Molybdenum dificiency in plant. Ag act AC. 4, 2 nd edition.