Experiment 1: The experiment was conducted at the research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) under natural conditions. The soil of the experimental site was silty clay loam in texture belonging to Salna series having a pH of 5.5, 0.054% total nitrogen and 1.38% organic matter. The small type bitter gourd ‘Uchjha’ (Momordica charantia L.) of BG5 genotype was used in current investigation. The experiment was laid out in a randomized complete block design with three replications. The following treatments were used in the experiment: T1 - control (no fertilizer applied), T2 - N0 P45 K60, T3-N60 P45 K60, T4-N90 P45 K60, T5-N120 P45 K60, T6-N90 P0 K60,T7-N90 P30 K60, T8-N90 P60 K60, T9-N90 P45K0 and T10-N90 P45 K80.
The land was opened with a tractor; ploughed and cross-ploughed with a power tiller followed by laddering to bring leveled good tilth for sowing. Four days before transplanting, necessary irrigation channels were made around the plots. The N, P and K were applied as urea, Triple Super Phosphate (TSP) and Muriate of Potash (MOP), respectively. The whole amount of TSP, MOP, Gypsum and Zinc Sulphate were applied at the final land preparation. While urea was applied in three equal splits at 15, 30 and 60 Days after Transplanting (DAT). Seeds were germinated and raised in cow dung filled polyethylene bags under nursery shade conditions, six uncontaminated and homogeneous one month old "Uchjha" seedlings with hard five leaves were transplanted at the spacing of 1x1 m.
Experiment 2: The experiment was conducted at the experimental farm of the Crop Botany Department of BSMRAU, Gazipur, Bangladesh on the same soil with the same plant material and the same methodology of land preparation, fertilizer application, designing and seedling transplanting. However, the whole experimental area was divided into three equal blocks, each representing one replication. Each block was sub-divided into 10 plots, thus the total number of unit plots was 30 and the unit plot size was 4x2.5 m with an inter block and inter plot spacing of 1 and 1 m, respectively. Ten treatments imposed for the experiment were: T1: GA3 20 ppm, T2: GA3 40 ppm, T3: GA3 60 ppm, T4: NAA 50 ppm, T5: NAA 75 ppm, T6: NAA 100 ppm, T7: Ethophon 100 ppm, T8: Ethophon 150 ppm, T9: Ethophon 200 ppm, T10: control. These growth regulator combinations were applied exogenously at 21, 35 and 50 DAT, respectively with the help of hand sprayer.
Mature fruits were harvested at 3 days interval up to ageing of plants and data on yield and yield attributes were recoded encompassing the border effect. The plants were terminally harvested at 120 DAT and shoot dry matter was taken by drying the sample in an electric oven at 71°C for three days and statistical analyses were performed by Least Significant Difference (LSD) test among the treatment means after Gomez and Gomez by using MSTATC computer package.