Application of organic and inorganic fertilizers is essential for sustainable production of crops including potato. This study was therefore initiated to identify the optimum rate of farmyard manure (FYM) and blended compound NPS fertilizer for profitable production of potato in Koga Irrigation Scheme, Northwestern highlands of Ethiopia. Four rates of FYM (0, 4.5, 9, and 13.5 t ha −1) and NPS fertilizer (0, 81.7, 163.4, and 245.1 kg ha −1) were laid down in Randomized Complete Block Design with three replications. The results revealed that FYM and blended NPS fertilizer as well as their combination influenced most of the tested growth and yield parameters of potato including plant height, main stem number, and tuber weight. Application of 245.1 kg ha −1 NPS combined with 13.5 t ha −1 FYM recorded the highest marketable and total tuber yields of 43.52 and 47.04 t ha −1 , respectively. Although, the highest marginal rate of return was obtained from plants supplied with the combination of 4.5 t ha −1 FYM and 163.4 kg ha −1 NPS fertilizer, combined application of 245.1 kg ha −1 NPS and 13.5 t ha −1 FYM is recommended for economical production of potato in the study area as it recorded the highest net benefit with acceptable marginal rate of return.

The longevity of cut flowers including cut roses can be however prolonged using different pulsing preservatives where researches in this regard are lacking in the country. Keeping these bottlenecks of the sector in mind, this study was therefore initiated with objective to evaluate the effectiveness of different pulsing preservatives in prolonging vase life of cut rose varieties. The experiment was conducted at Tana Flora PLC in Bahir Dar, Ethiopia. As pulsing preservatives Al2(SO4)3)(250 mg-1), Ca(ClO)2 (66.7 mg-1), STS [Ag (S2O3)2] (0.5 ml-1), Sugar (20 g-1) and distilled water were used. The three rose varieties namely: Upper class, Athena and Moon walk were used. Healthy flower buds having uniform length and harvested early in the morning were put immediately in containers filled with the respective concentration of pulsing preservatives. Flasks with six rose flowers each were placed in pre-cooling room (8-10 OC) for about 2 hours. Finally, treated cuttings were transferred into experimental room with temperature of 22-250C and 75% relative humidity and arranged in Complete Randomized Design (CRD) with three replications. At this time, pulsing preservatives were replaced by distilled water. The analysis of variance revealed that most of parameters were highly significantly influenced by the main as well as interaction effects of pulsing preservative and varieties (P<0.0). Maximum water uptake (7.73 g/flower/day), transpiration loss (7.08 g/flower/day), flower fresh weight (21.77 g/flowers), flower head diameter (7.6 cm), and maximum flower vase life (23 days) were recorded in Athena variety pulsed with STS. Contribution/Originality: This study is one of very few studies which have investigated to improve the shelf life and quality of rose flowers particularly in our country. Therefore, the present finding will contribute to flower growers through identifying appropriate pulsing preservatives for rose cut flower. 1. INTRODUCTION Rose (Rosa hybrid L.) belongs to the family Rosaceae, under which more than 150 species and 1400 cultivars are consisted. Rose is one of the most popular cut flowers since the dawn of civilization (Elgimabi, 2011). Rose enjoys superiority over all other flowers being extensively used for decorative purposes and is prized for its delicate nature, beauty, charm and aroma. Rose plants produce an exquisite floral display consisting of many vibrant colors, shapes, sizes and perfumes. Throughout the history of civilization, no other flower has been so immortalized and integrated into daily life of the people as the rose. Thus, it is rightly called as the queen of flowers (Gault and Synge, 1971; Elgimabi, 2011).