Md. Shipon Miah
Department of Horticulture, Bangladesh Agricultural University, Mymensingh, Bangladesh
Rafia Hasan Taheri
Department of Horticulture, Bangladesh Agricultural University, Mymensingh, Bangladesh
Md. Golam Rabbani
Department of Horticulture, Bangladesh Agricultural University, Mymensingh, Bangladesh
Md. Rezaul Karim
Department of Horticulture, Bangladesh Agricultural University, Mymensingh, Bangladesh
Application method, Boron, Micronutrient, Onion, Zinc.
Horticulture Field Laboratory in Bangladesh Agricultural University.
Crop-Soil-Water Management
Fertilizer, Onion
The experiment was studied during the rabi season (October 2015 to March 2016) at the Horticulture Field Laboratory in Bangladesh Agricultural University. The geographical situation is 18m above sea level (Khan, 1997) and belongs to the sub-tropical climate. The soil containing 6.5 pH belonging Old Brahmaputra Flood Plain (UNDP, 1988). Planting materials, treatments, and design A cultivar of onion ‘BARI Peaz-1’ was used for the experiment. The seeds were collected from Spices Research Centre, Bogura. Total of nine treatments were arranged to conduct the study with RCBD (randomized complete block design) trial. The treatments were control (T0), soil application of zinc (T1), soil application of boron (T2), foliar application of zinc (T3), foliar application of boron (T4), soil application of zinc and boron (T5), soil application of zinc and foliar application of boron (T6), foliar application of zinc and boron (T7), soil application of boron and foliar application of zinc (T8). The source of zinc and boron for the soil application were zinc sulfate and borax, respectively. And, the foliar applications were done with 1% solution of chelated zinc and solubor, respectively. All the nutrients were applied following the fertilizer recommendation guide (BARC, 2012). Land preparation The seedbed was raised about 20cm height with 3m × 1m in size for raising seedlings. The light textured and well-drained soil of the land was opened and left for drying for 10 days. Finally, by removing all the weeds, stubbles, and mixing well with decomposed cow-dung the soil was made loose, friable, and brought to fine tilth. The main field was prepared with a power tiller. The preparation was done one month before transplanting the seedlings. Final land preparation was done by removing weeds, stubbles and breaking all the clods with desired tilth by ploughing, cross ploughing and laddering. Each plot was raised about 15cm high from the soil surface with draining facilities. Manure and fertilizer Manures and fertilizers were applied with the prescribed doses of nutrients (BARC, 2012). All the treatments were treated with prescribed doses of NPKS. All the manures and fertilizers with 1/3 portion of urea were applied on the day of final land preparation. The remaining urea was applied in two equal installments. The first installments were 30 days after transplanting (DAT) and the second installments were done at 50 DAT. The foliar applications of micronutrients were done 3 times at 15 days interval from 40 DAT. Raising seedlings, transplanting and intercultural operations After sowing the sprouted seeds at a depth of 0.5 cm, the raised seedbed was then covered with light soil and compacted carefully. Weeding, irrigation, and protective measures were taken as per the requirement of the seedlings. Following 15cm × 10cm spacing some healthy, disease-free and homozygous onion seedlings were transplanted. Thus, each plot contained 100 seedlings. The seedlings were collected followed by watering to keep minimum injury during uprooting. Immediate light irrigation was done just after the transplantation. This provide a better environment for seedlings to be established. The supplements of light irrigation were continued up to seven days. Border plants were kept to fill the gap. The moisture level was monitored regularly for irrigation to maintain the steady moisture level of the site. Weeding was followed by urea top dressing and also as per the requirement of the site to keep better soil aeration. The seedlings were invaded by cutworm (Agrotisipsilon R.) and field cricket (Brachytrypes portentosus L.) both in the seedbed and main field, were controlled mechanically. While, the purple blotch disease (Alternaria porii) was controlled by spraying of Supravit at 7 days' interval. Harvesting and data collection The maturity index was confirmed with the sign of drying leaves and true shape of the onion bulbs. Onions were harvested in the presence of 80% of mature crops (Bhonde et al., 1983). To record the qualitative and quantitative characters of different stages of growth, ten sample plants were taken from every plot and tagged properly. The border plants were avoided to select sample plants. The data were collected from the sample plants for the parameters of plant height and leaves number at 15 days interval from 30 DAT. And, during harvesting data collected for the parameters of leaves length, bulb height, bulb diameter, pseudostem height, pseudostem weight, pseudostem diameter, bulb weight, and plant weight. The plant weight was sampled without the bulb portion and the bulb was sampled keeping 2-2.5cm of pseudostem. The weight of all the plants and bulb weight from plots were collected and converted as t ha-1 to construct the value of total plant weight and yield, respectively. Percent dry matter in bulb After harvesting, the sample bubs were chopped with a sharp knife and sun-dried. To attain constant weight the sun-dried sample was then kept at 70°C in an oven. The constant weight was then recorded in gram (g). The obtained data were statistically analyzed to understand the significance of different treatment combinations. The analysis was done by MSTAT program. The deviations among different treatments were evaluated through the least significant differences (LSD) at 5% level (Gomez and Gomez, 1984).
International Journal of Biosciences; ISSN: 2220-6655 (Print), 2222-5234 (Online); Vol. 17, No. 4, p. 126-133, 2020
Journal