A study on the effect of ethephon doses on vegetative characters, sex expression and yield of cucumber (Cucumis sativus cv. Bhaktapur Local) was conducted in Gulmi, Nepal during 21st April to 24th August 2017.  The experiment was laid in single factor Randomized complete Block Design (RCBD) with 4 replication and 5 treatments. Four different doses of ethephon 100, 200, 300 & 400 ppm with control were applied. Two sprays of ethephon was made one at two true leaf stage and other at four true leaf stage. Ethephon was found to reduce the plant height compared to control, minimum (238.8 cm) with 400 ppm and maximum (310.4 cm) with the control. The number of nodes and branches per plant were found to be highest with 300 ppm. Ethephon was found to shift first male flowers and female flowers towards upper and lower nodes respectively. The plot treated with 300 ppm ethephon, bearing 20.31 female flowers per plant was found superior to other doses for increasing total female flowers. Maximum and minimum number of male flowers per plant was recorded with control(107 per plant) and 400 ppm (46.90 per plant) respectively. Similarly, 300 ppm of ethephon was found superior for reducing (male: female) sex ratio. Maximum yield 27.51 t/ha was recorded with 300 ppm and minimum yield of 17.48 t/ha with the control. 57% increment in the yield was observed with 300 ppm ethephon as compared to the control. Thus, proper use of ethephon is found to be beneficial to farmers. Int. J. Appl. Sci. Biotechnol. Vol 7(3): 370-377

The field experiment was carried out to study the effect of different doses of nitrogen on production of spring maize (Arun-2) in Ishma rural municipality, Chaurashi, Gulmi from February to June 2018. The experiment was laid out in single factor Randomized complete Block Design (RCBD) comprising of five levels of nitrogen (0, 30, 60, 90 and 120 kg/ha) as treatment with four replications. The results showed that the different levels of nitrogen significantly affected the biometrical, phenological, yield attributes and yield of maize. The biometrical observations (plant height and leaves number) increased with increased level of nitrogen and found the highest at 120 kg N/ha which were stasticially similar with 90 kg N/ha. The phenological observations (tasseling, silking, physiological maturity, seed fill duration) showed significant relationship with doses of nitrogen but days of emergence and anthesis-silking interval were non-significant with nitrogen dose. The longest days to tasseling and silking were found with control (0 kg/ha) whereas, days to physiological maturity and seed fill duration were the highest at 120 kg/ha dose of nitrogen. Similarly, increasing soil nitrogen favored both plant growth, and the survival of stem-borers. Hence, the highest maize borer infestation was found with 120 kg N/ha followed by the lower doses. Likewise, yield attributing characteristics (cob length, cob diameter, number of kernel/rows, number of kernel row, test weight) were the highest at 120 kg/ha but was similar with 90 kg/ha. Treatment 120 kg/ha produced the highest yield (2.481 t/ha) which was similar with 90 kg/ha (2.394 t/ha). The increment in yield over control was maximum with 120 kg N/ha (44 %) followed by 90 kg N/ha (39 %), 60 kg N/ha (25%), 30 kg N/ha (15 %). Thus, this research showed that the treatment with 90 kg N/ha was the most appropriate for the production of spring maize Arun-2.