The aim of this research is to study some physical and mechanical properties of cucumber fruits for seed production, to help the design of handling machines. The physical and mechanical properties are incorporated in the development of the seedextraction machine as a case study.The main results in this study can be summarized as follows: Physical properties of cucumber fruits: diameter = 52.15 -229.5 mm, length = 52.15 -68.87 mm, mass = 273.8 -470.4 g, volume = 380 -860 cm 3 , projected area = 250 -500 cm 2 , real density = 0.94 -1.10 g/cm 3 , bulk density = 0.41 g/cm 3 , sphericity = 3.13 -3.77.Mechanical properties: cucumber-fruit firmness = 64 -100.9 N/cm 2 , the axial cutting-force = 30 -70 N.The physical and mechanical properties are incorporated in the design of seedextraction machine is given also in the paper as a case study.

This experiment was conducted to determine the rate of blended fertilizers and urea for potato production under rainfed condition in Jeldu, West Showa, Ethiopia. Different fertilizer treatments viz., 150 kg ha-1 NPSB+80 kg ha-1 urea, 250 kg ha-1 NPSB+80 kg ha-1 urea, 350 kg ha-1 NPSB+80 kg ha-1 urea, 150 kg ha-1 NPSB+140 kg ha-1 urea, 250 kg ha-1 NPSB+140 kg ha-1 urea, 350 kg ha-1 NPSB+140 kg ha-1 urea, 150 kg ha-1 NPSB +200 kg ha-1 urea, 250 kg ha-1 NPSB +200 kg ha-1 urea and 350 kg ha-1 N+200 kg ha-1 urea was used for the production of Belete and Gudenie potato varieties (cv. Jeldu Wereda) during 2018-2019 using RCBD factorial arrangement in three replication. This study revealed that there was a highly significant difference between the yield and yield components of potato due to the main effect of fertilizer rates. The interaction did not significantly affect any parameter of potato during the study. The highest total and marketable yields (22.95 t ha-1 and 20.06 t ha-1), respectively were harvested from 350 kg ha-1 NPSB+200 kg ha-1 urea though not significantly different from total and marketable yield of 250 kg ha-1 NPSB+200 kg ha-1 urea (22.08 and 19.14 t ha-1) and 350 kg ha-1 + 140 kg ha-1 urea (21.65 and 18.84 t ha-1), respectively. The partial budget analysis indicated that the highest benefit (64,916.00ETB) was fetched from 350 kg ha-1 NPSB+200 kg ha-1 urea followed by 250 kg ha-1 NPSB+200 kg ha-1 urea (63,004.00ETB) while the highest marginal rate of return (19,430.00%) was recorded from 250 kg ha-1 NPSB+200 kg ha-1 followed by 150 kg ha-1 NPSB+200 kg ha-1 urea (17,000.00%). From this, it can be concluded that the NPSB+ urea rates highly significantly affected the yield and yield component of potato. Thus, 250 kg ha-1 urea+200 kg ha-1 urea can be used for high yield and high economic return of potato in Jeldu district.

Potato is an important food and cash crop in Ethiopia, especially in the high and mid-altitude areas. Lack of scientific recommendation of fertilizer rate to popular varieties limited crop yield, especially under irrigation potential. The research was conducted in Holetta Agricultural Research Center, under irrigation during 2019-2020 off-season to find and recommend the NPSB blended fertilizer and urea rates for potato using rates of blended NPSB + urea (0, 150

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