Effect of Different Sources of Organic Manures on Growth and Yield of Broccoli

Trichoderma Indiscriminate use of chemical fertilizers is a common practice which is hazardous both for soil health and the environment. It has been more than three decades that the global agriculture has been depicted towards organic agriculture owing to sustainability and reduced environmental effects. An experiment was conducted in Randomized Complete Block Design (RCBD) with three replications to study the effect of different sources of organic nutrients on growth and yield of broccoli. The experiment consisted of five different sources of manures; control (no manure), cowdung (25 t/ha), Trichoderma compost (10 t/ha), vermicompost (12 t/ha) and poultry litter (14 t/ha) along with two cultivars of broccoli; ‘Imperial’ and ‘Premium Crop’. Different sources of manures and cultivars had significant influence on plant


INTRODUCTION
Broccoli (Brassica oleracea L.var.italica) belongs to the family Brassicaceae.It is a fast-growing crop and requires high nitrogen input.It is one of the most important crops as it is highly nutritious vegetable with abundant vitamins and minerals such as vitamin A and C, carotenoids, fiber, calcium, and folic acid (Paradis, et.al., 1995;Michaud et al., 2002).Broccoli and other brassica vegetables have high content of glucosinolates which has cancer-fighting properties.Broccoli buds are rich source of minerals especially K, S, P, Mg and micro-elements (Zhao et al., 2007).The sustainability of conventional agriculture in Bangladesh is under threat from the continuous degradation of land and water resources, as well as declining yield due to indiscriminate use of agro-chemicals.Excessive use of chemical fertilizers causes unforeseen environmental impacts and sensitivity to pests and diseases through the oversupply of nitrogen (Chen, 2006).Environmental impacts of excessive applications of chemical fertilizers in Bangladesh have been reported (Muhibbullah et al., 2005).Application of chemical fertilizers alone can supply only one or two nutrient elements to the crop.On the other hand, supplying only organic inputs can improve soil physical and biological environment, waterholding capacity, high cation exchange capacity and low bulk density and foster diverse population of beneficial soil microorganisms (Bulluck et al., 2002).Organic fertilizers contain macro and micro-nutrients, vitamins, growth-promoting factors indole 3-acetic acid (IAA), gibberellic acid (GA), and beneficial microorganisms (Natarajan et al., 2007) and they increase production in ways similar to inorganic fertilizers (Tonfacks et al., 2009).
However, in the modern days, when agriculture is motivated not only for production, but also accounts for the sustainability of all the resources including soil for the generations to come.The use of chemical fertilizers has been many-a-times reported for degrading soil and water resources.Moreover, organic farming is both a philosophy and a system of agriculture (Chowdhury, 2004), which avoids or largely excludes the use of synthetically produced fertilizers, pesticides and to the maximum extent possible relies upon crop rotations, crop residues, animal manures, legumes, green manures, off farm organic wastes, mineral bearing rocks and bio-fertilizers to maintain soil productivity and to supply plant nutrients and biological means to control insects, weeds and other pests.Thus, this experiment was carried out in order to study the effect of various sources of plant nutrients on growth, development and yield of broccoli and to compare the nutrient value of various sources of organic manure used in production of broccoli.

MATERIALS AND METHODS
The study was conducted under field conditions in the experimental field of the Department of Horticulture, Patuakhali Science and Technology University (PSTU) during winter season from October 2022 to March 2023 on broccoli cv.Imperial (V1) and Premium Crop (V2) obtained from local seed market with five treatments viz.Control (M0); (No organic manure), Cowdung (M1); (25 t/ha), Trichoderma compost (M2); (10 t/ha), Vermicompost (M3); (12 t/ha), Poultry litter (M4); (14 t/ha).The following doses of manures and fertilizers i.e. cowdung: N:P:K-15000:115:30:100 (kg/ha) were recommended for broccoli production by Rashid (1993).The above doses of manures and fertilizers were converted into manures as per treatment of the experiment so that almost same amount of N is supplied by each type of manure.After conversion the dose of each manure and their % nutrient content used in the experiment was as follows, Cowdung (N:P:K:S-1:1.6:0.2:0.3),Trichoderma compost (N:P:K:S-1.2:0.61:0.77:0.24),Poultry litter (N:P:K:S-1.6:1.5:0.85:0.4) and Vermicompost (N:P:K:S-2.16:1.44:2.55:0.8)(Source: Fertilizer Recommendation Guide, BARC, 1997).The experiment was laid out in randomized complete block design (RCBD) and the treatments were replicated three times.The broccoli seeds were sown in nursery bed and raised the seedlings.After one month, the seedlings were transplanted in the main field at a spacing of 60 cm (row) by 40 cm (plant) on beds.Planting was done in the afternoon to avoid transplanting shock.Seedlings were watered after transplanting.Banana leaves were used around seedlings as mulch.Weeding, irrigation, crop management and harvesting were done manually.The curds were harvested in compact condition before the flower buds opened (Thompson and Kelly, 1988).Five plants were randomly selected for data collection from each plot and labelled and the following data were recorded: plant height, leaf number per plant.All broccoli curds of each plot were harvested at marketable stage and the following variables were measured: weight of primary curd and secondary curd, no. of secondary curd, fresh weight and dry weight of curd, yield (g/plant) and yield (t/ha).The data obtained from the characters were statistically analyzed to find out the variation resulting from experimental treatments following F variance test.The differences between treatments were adjusted by Duncan"s Multiple Range Test (DMRT) (Gomez and Gomez, 1984).Cost and return analysis were done following the procedure of Alam et al. (1989).

RESULTS AND DISCUSSION
The soil analysis before the planting and after the harvesting of broccoli indicated the soil organic matter content was 1.15% and 1.26%, respectively.During planting, the soil pH was 6.64 and the electrical conductivity (EC) was 1.58 (dS/m).The results revealed that variance in different nutrient doses had significant influence on plant height in different growth stages of two cultivars of broccoli.In combined effect, the highest plant height (50.3, 62.8 and 65.3 cm at 45, 60 and 75 DAT, respectively) was found in 'Premium Crop' cultivar with vermicompost while the lowest plant height (37.8, 53.1 and 53.6 cm at 45, 60 and 75 DAT, respectively) was recorded from the cultivar 'Imperial' with no organic manure (Table 1).Similar results also found by Singh et al. (2000).Thompson and Kelly (1988) reported that the rate of release of nitrogen from the manure is higher in vermicompost than other sources of manures which ultimately were reflected in higher plant growth.Height up to curd from ground level was highest (31.5 cm) in M3V2 treatment combination followed by M4V2 (31.4 cm) and M2V2 (31.3 cm) treatment combinations respectively and the lowest (26.6 cm) was found from M0V1 treatment combination.
The combined effect of different sources of manures and cultivars were significantly influenced on the number of leaves per plant, length of leaf, breadth of leaf, plant canopy, curd diameter and length of stem.The highest number of leaves (20.6) was recorded from the cultivar Premium Crop with vermicompost treatment which was followed by the same variety treated with Trichoderma (19.8) while the lowest number of leaves per plant (16.2) was found from the Imperial cultivar with no organic nutrient source (Table 2).The longest leaf (52.5 cm) was found from the plants in treatment combination M3V2.On the other hand, the shortest leaf (37.6 cm) was obtained from M0V1 treatment.It was observed that the breadth of leaf was the highest (22.1 cm) in the plant having a treatment combination of M3V2 and the lowest (17.8 cm) leaf breadth was recorded from the treatment combination M0V1.In this study, organic manure increased the activity of microorganisms which ultimately made more availability and absorption of essential plant nutrients resulting increased leaf and plant morphology.The maximum canopy (87.8 cm) was obtained from the treatment combination M3V2 which was statistically identical to the combination M4V2 (87.2 cm) whereas the lowest canopy (59.4 cm) was obtained from the combination M0V1.The maximum length of stem (5.3 cm) was obtained from the treatment combination M3V2 followed by M2V2 (4.8 cm) and M4V2 (4.8 cm).However, the lowest length of stem (3 cm) was obtained from the treatment combination M0V1.The maximum diameter of curd (17.8 cm) was obtained from the treatment combination M3V2 and it was statistically identical to the combination M2V2 (17.2 cm).However, the lowest diameter of curd (12.1 cm) was obtained from the treatment combination M0V1 (Table 2).Steffen et al. (1994) observed the effect of organic matter (spent mushroom compost at 64 t/ha + rotten cattle manure at 57 t/ha) on the growth and yield of broccoli.They concluded that broccoli yield and curd diameter were greater in the amended treatment.In yield attributes of Broccoli, significant variations were found for different organic nutrients and two cultivars.The highest number of secondary curd (7.5) was found from vermicompost in Premium crop cultivar (M3V2) where the minimum number of secondary card (5.2) was recorded from no manure in Imperial cultivar (M0V1).The maximum weight of primary curd (246.7 g) per plant was recorded from M3V2 whereas the lowest primary curd weight (133.7 g) was measured from M0V1 treatment combination.The interaction effect of different sources of manures and cultivars were highly significant for secondary curd weight.The highest secondary curd weight (205.8 g) was recorded from the Premium Crop cultivar with vermicompost (M3V2) which was followed by the same cultivar with Trichoderma (193.7 g).The lowest secondary curd weight (84.2 g) was measured from Imperial cultivar with no manure application (M0V1) (Table 3).
The highest yield per plant (441.1 g) was recorded from vermicompost applied plot plant with Premium Crop variety (M3V2) followed by poultry litter manure (420.2 g) whereas the lowest (218.2 g) yield per plant was recorded from Imperial cultivar (M4V2) with no manure application (M0V1).The highest yield per plot (8.1 kg) and yield per hectare (17.32 tonnes) were obtained from the Premium Crop along with vermicompost treatment (M3V2) followed by poultry litter manure (7.74 kg and 15.68 t/ha).The lowest yield (4.1 kg/plot and 6.62 t/ha) were recorded from the cultivar Imperial with no organic manure application (M0V1) (Table 3).It was possible that organic manures provided good soil condition for growth as well as supplied sufficient plant nutrients that helped the production of highest yield per plant.Sharma et al. (2000) a field experiment was conducted to evaluate the effects of N (60, 120, 180 and 240 kg/ha) and P (60, 120 and 18 kg/ha) on the growth and seed yield of Broccoli cv. Green Curd and observed.In general, all parameters significantly improved with increasing concentrations of N and P.

No. of secondary curd
Weight of primary curd (g)  Positive response of vermicompost in different growth parameters of broccoli is due to fact that it increases the microbial population and also provides the source of energy to sustain them and remain active (Ghimire et al., 2013).It increases the plant growth and yield by providing nutrients in the available form as compared to other organic manures and conventional inorganic fertilizers.Vermicompost retains nutrients for long time while the conventional compost fails to deliver the required amount of macro and micronutrient including the vital NPK to plants in shorter time.Euras (2009) reported that the vermicompost is proving to be highly nutritive organic fertilizer and more powerful growth promoter over the conventional composts.The Vermicomposting accelerates the rate of decomposition of the organic matter, alters the physical and chemical properties of the material, and lowers the C: N ratio, leading to a rapid humification process in which the unstable organic matter is fully oxidized.Application of vermin-compost to soils increased their microbial biomass and dehydrogenase activity (Albanell et al., 1988).This increase in microbial mass and dehydrogenase activity helps in nitrogen fixation and increase the availability to the crop and boost up the growth and development.Rosen & Bierman (2005) reported it improves soil structure or tilt and increases its water holding capacity.

Cost and Return Analysis
The cost and return analysis were done on the basis of total yield, gross income and total expenditure as well as count benefit cost ratio (BCR).Materials, non-materials and overhead cost were recorded for all the treatments of unit plot and calculated on per hectare basis.The total cost of production ranged between Tk. 97352.5 to Tk. 128645.8 per hectare among the different treatment combinations.The variation was due to different cost of broccoli cultivar and different sources of organic nutrients.The highest cost of production Tk.128645.8 per hectare was recorded in the treatment combinations of vermicompost with "Premium Crop" or "Imperial" cultivar; while the lowest cost of production TK.97352.5 per hectare was recorded in the combination of no manure with "Premium Crop" or "Imperial" cultivar.The gross return from the different treatment combinations ranged between Tk. 35047.5 and Tk.234098.1 per hectare.The sale of harvested broccoli was @ Tk. 20,000 per ton.Among the different combinations, vermicompost with "Premium Crop" cultivar gave the highest net return (Tk.234098.1 per hectare) while the lowest net return (Tk.35047.5 per hectare) was obtained from the cultivar "Imperial" with no manure.
The benefit cost ratio (BCR) was found the highest (3.08) in the treatment combination M3V2 (Vermicompost with "Premium Crop" cultivar) while the second highest was recorded from M4V2 (2.91) combination where poultry litter with "Premium Crop" cultivar were used.On the other hand, the lowest BCR (1.36) was recorded from M0V1 (no manure with "Imperial") cultivar.

CONCLUSION
The experiment showed that the use of vermicompost was better for broccoli growth and development as compared to other organic manures used in the experiment.The use of high cost-chemical fertilizer can be readily substituted by farm-produced organic sources of plant nutrients and thus aid in sustainable and efficient resource use.However, it is important to note the better results of vermicompost as the source of organic manure in broccoli.

Table 1 .
Combined effect of different sources of manures and cultivars on height of broccoli at different days after transplanting (DAT) M0 = No manure; M1 = Cowdung; M2 = Trichoderma compost; M3= Vermicompost; M4 =Poultry litter; V1= Imperial and V2= Premium Crop; Mean in the column followed by different letters differed significantly by DMRT at 5% level of significance

Table 2 .
Combined effect of different sources of manures and cultivars on growth parameters of Broccoli

Table 4 .
Cost and return of broccoli due to use of different sources of nutrients and varieties