Geographical Location of the Experiment The present piece of research work was conducted at the experimental plot of the Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during the Rabi seasons, which geographically situated at 25o 41’ North latitude and 88o 39’ East latitude with an elevation of 37m from sea level.
Soil and Climatic Condition The experimental land was medium high land. The soil belongs to the old Himalayan Piedmont Plain agroeconomic zone (AEZ-1), textured by sandy loam with pH of around 6.2 during the growing period of the crop total rainfall and mean temperature for the month were recorded.
Experimental Material In this work, maize inbred lines were used. There are thirty genotypes and each of the genotype was produced in the 2012-2013 cropping seasons, and purity and genotype percentage were around 98% and above 98%, respectively the source of all the genotypes was collected from Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
Layout of the Experiment The experiment was laid out in the randomized complete block design (RCBD) with three replications. The layout of the experiment was prepared for distributing the genotypes into every line of each block. There were total of 90 lines, and 30 genotypes were assigned at random into 30 lines of each replication and each of block measuring 20m x 3.5m. The distance maintained between two lines was 0.60m and block was 0.83m. The total area of the experiment was (20 x 18) square meter.
Preparation of the Main Field The plot selected for the experiment was opened at the second week of November 2016 with power tiller and was the exposed to the sun for a week, after one week the land was harrowed, ploughed and crossed-ploughed several times followed by laddering to obtain a good tilth. Weed and stable were removed and finally obtained a desired tilth of soil for planting of maize seed. The experiment plot was partitioned into the unit plots in accordance with experiment design mentioned in earlier. The recommended doses of well rotten cow dung as manure and chemical fertilizers as indicated in next were mixed with the soil of each unit plot.
Application of Manure and Fertilizer Green manure and decomposed organic matter were used at the rate of 6.0 ton/ hector before final land preparation. The chemical fertilizer such as Urea, MOP, Gypsum, boric acid and zinc sulphate were applied in the plot at the rate of 50, 195, 100, 10 and 10kg/ha respectively as basal doze. The rest 1120 kg urea was applied in three equal splits (i.e. 40 kg/splits) a 25, 45 and 60 days after planting as side dressing, 3-5 cm away from the plat and the furrow of the fertilizer are hilled up immediately, At the same time third dressing of Urea, rest 35 kg of MOP was used.
Planting of seed in the field, their care and harvesting The maize seed were planted in lines, plant to plant distance 0.25 m and row to row distance 0.6 m and socked seed was planted in the well-prepared plot on 24 Nov 2016. When the seedling started to emerge in beds it was kept under careful observation. After the emergence of seedling, various inter-culture operations were accomplished for better growth and development of the maize seedling. Irrigation was provided knee stage, pre-flowering stage and milking stage at 35, 65 and 80 days after planting (DAP) for three times of proper growth and development of the plant. The seeding was first thinned from all of the line at 10 days after germination and 2nd thinning was carried out for maintaining proper spacing the experimental plot. Weeding and mulching were done to keep the plots free from weeds, easy aeration of soil and to conserve soil moisture, which ultimately endured better growth and development. The newly emerged weeds were uprooted carefully after complete emergence of maize seedlings as and when necessary. Breaking of crust of soil, when needed was done through mulching. After 50 days of planting, first spray of chloropyriphose was done against sucking pest such as jessid and aphid. The crops were harvested when the husk cover was completely dried and yellowish color was formed in the grain. The cobs of ten randomly selected plants of each genotype were separately harvested.
Data Collection (Quantitative Trait) Observation on quantitatively inherited traits viz. cob height (cm), plant height (cm), cob length (cm), cob diameter (cm), number of kernel rows per cob, number of kernels per row, number of kernels per cob, thousand kernel weight (g), yield per plant (g) pith weight (g) was recorded on ten competitive randomly selected plants. the average was taken as the mean of treatment.