M. Shahinul
Department of Agricultural Extension (DAE), Ministry of Agriculture, Bangladesh.
M. Rahman
Department of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh.
M. M. R. Salim
Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Bangladesh.
B. Ahmed
Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Bangladesh.
M. H. Rashid
Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Bangladesh.
Dry matter; Fiber content; Lettuce; Seeding; Transplanting.
Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur Bangladesh.
Crop-Soil-Water Management
The experiment was conducted at the research farm of the BSMRAU, Salna, Gazipur, Bangladesh from October 2012 to May 2013. The field plot was previously under foreland and recently developed for the research work. The location of the site is 24.09ºN latitude and 90.26ºE longitudes with an elevation of 8.2 meters from sea level. The climate of the experimental site is subtropical, which is characterized by heavy rainfall during months from April to September and scantly rainfall for the rest of the year, which is reflected in weather data collected from October to May. As we expected May (191.6 mm) and September (572.4 mm) had a huge rainfall whereas from November to April had no or scanty rainfall. The relative humidity of the experimental site was consistently higher in the morning compared to the afternoon throughout the crop growing period along with an average maximum and minimum temperature of 30.11ºC (May) and 18.11ºC (January), respectively. BSMRAU lettuce-1 was used throughout the study. Two factorial experiments were conducted: factor (A) 3 planting method viz. transplanted seedling produced on nursery bed (M1), transplanted seedling produced in polybags (M2), and direct seeding (M3); factor (B) 5 sowing time viz. 16 October (T1), 1 November (T2), 16 November (T3), 1 December (T4), and 16 December (T5). Treatment combinations were M1T1 (transplanting seedlings from nursery bed on 16 October), M2T1 (transplanting seedlings from polybag on 16 October), M3T1 (direct seeding on 16 October), M1T2 (transplanting seedlings from nursery bed on 1 November), M2T2 (transplanting seedlings form polybag on 1 November), M3T2 (direct seeding on 1 November), M1T3 (transplanting seedlings from nursery bed on 16 November), M2T3 (transplanting seedlings form polybags on 16 November), M3T3 (direct seeding on 16 November), M1T4 (transplanting seedlings from nursery bed on 1 December), M2T4 (transplanting seedlings form polybag on 1 December), M3T4 (direct seeding 1 December), M1T5 (transplanting seedlings from nursery bed on 16 December), M2T5 (transplanting seedlings form polybag on 16 December) and M3T5 (direct seeding on 16 December). The experiment was laid out in randomized complete block design with 3 replications. Fifteen treatment combinations were randomly assigned in each plot. The dimension of each plot was 1.6 m x 1.5 m accommodating 24 lettuce plants at the final stage. Plant to plant distance was maintained at 25 cm and row to row distance was 40 cm in each plot. The plots to plot and block to block distance were 0.5 m and 1.0 m, respectively. Thirty days old seedlings (both seedbed and polybags) were transplanted in the experimental plots in the afternoon and light irrigation was given around each seedling for their establishment. Necessary intercultural operations were done during the growing period for proper growth and development of the crops. Weeding and irrigation were done when necessary. Irrigation was given at an interval of 8-10 days depending on the soil moisture content. Topdressing of urea fertilizer was done at 12- and 24-days after transplanting of seedling and it was followed by irrigation on the same day. Two weddings were done at 10- and 20-days after transplanting. Plant protection measures were not required at the vegetative stage. Other cultural operations including mulching of the pit soil were done as and when needed. From each plot at 40 days after transplanting (DAT) 50% of plants i.e. 12 plants were uprooted for leaf yield and the rest of the 50% i.e. 12 plants were allowed for further growth. Forty DAT was followed for harvesting leaf as described by Rahman et al. Seed stocks were cut off when 80% of seed clusters display feathering followed by the sun-dried for further processing. The seeds were threshed, dried, and preserved at 4ºC until further use. Data were recorded for the following parameters; plant height (cm), number of leaves per plant, canopy diameter (cm), leaf size (cm2), leaf yield per plant (g), leaf yield per hectare (t/ha), fiber content (%), dry matter content (%), organoleptic test, days to 50% flowering, days to seed maturity, seed yield per plant (g), and seed yield (t/ha). The recorded data for different characters were analyzed statistically using the MSTAT-C program to find out the variation among different treatments, treatment combinations, and their interactions. Treatment means were also compared by the Duncan’s Multiple Range Test (DMRT) as described by Gomez and Gomez.
Asian Journal of Agricultural and Horticultural Research - 4(4): 1-12, 2019
Journal