No abstract

Appropriate spacing enables the farmers to keep appropriate plant population in the field. Hence, it can avoid over or less population in a given plot of land which has negative effect on yield and quality of onion. Spacing of 40 × 20 × 10 cm between furrow, row and plants, respectively has been used for onion production in Ethiopia. But producers complain 10 cm intra row spacing produces large bulb size which is not preferred by consumer for home consumption. To optimize onion productivity, full package of information is required. To fill this gap field experiment was conducted to study the effect of inter and intra row spacing on the bulb yield and yield components of onion at Ribb in Fogera, Woramit in Bahir Dar and Koga in Mecha districts in 2014. The interaction of the lowest inter and intra row spacing mature earlier by 15 days compared to highest inter and intra row spacing. Forty nine percent of medium sized bulbs were produced with the interaction of 15 and 6 cm inter and intra row spacing while only 32% of medium sized bulbs were produced by the interaction of 25 and 8 cm inter and intra row spacing. Small sized bulb distribution decreased as intra row spacing increased while large bulb sized distribution increased when intra row spacing increased. The highest bulb weight (102 g) was produced by the interaction of highest inter and intra row spacing while the lowest bulb weight (45 g) was produced by the lowest inter and intra row spacing. Interaction of inter and intra row spacing of 15 and 4 cm respectively, scored the 1 st highest marketable bulb yield (39 ton ha-1) and interaction of 15 and 6 cm inter and intra row spacing scored the 2 st highest marketable bulb yield (36 ton ha-1). The result revealed that the earlier recommendation (20 and 10 cm inter and intra row spacing) produced more number of medium and large sized bulbs with a yield penalty of 8.0 and 10 ton per ha-1 compared to interaction of inter row spacing of 15 cm with intra row spacing of 6 and 4 cm, respectively. Therefore, the interaction of inter and intra row spacing of 15 with 6 cm is recommended as a first option for producers who wishes to produce maximum bulb yield with maximum medium sized bulbs. It is also confirmed that earlier recommendation is better as a second option for producers who wishes to produce for export market which requires medium and large sized bulbs of onion.

This study has investigated the effects of different irrigation frequency and depth on yield and water productivity of snap bean at Koga and Ribb irrigation scheme, NW Amhara, Ethiopia. It was done in a factorial experiment laid out in split-plot design with three replications of two irrigation intervals and five variable irrigation depths. Irrigation depth had shown a significant effect on marketable pod yield, and irrigation water productivity whereas irrigation frequency hadn't shown a significant effect. The interaction effect hadn't shown a significant effect on marketable pod yield and response for irrigation water productivity of snap bean at Koga. At Koga, the application of 75% ETc gave an optimum marketable yield of 10.66 t ha −1 and irrigation water productivity of 2.89 kg m −3 . At Ribb, marketable pod yield and irrigation water productivity had no significant effect on irrigation frequency while marketable pod yield and irrigation water productivity had shown a significant effect on irrigation depth and the interaction effect. At Ribb, the

Determining the optimum crop water requirements is considered one of the most important factors affecting plant productions. Excessive application of water can damage watermelon and face fruit quality with problems, leading to a reduction of the melon fruit yield, lower fruit quality characteristics, and plant disease. Therefore, the main objective of this study was to determine the crop water requirement of watermelon in a field experiment using the CROPWAT model at Koga and Rib irrigation schemes. The experiment was conducted from 2016 to 2018 irrigation seasons for two years in the Amhara region, Ethiopia. The experiment was arranged in a randomized complete block design having 12 treatments; three irrigation intervals (14, 21, and 28 days) and the model generated depth of 50 %, 75 %, 100 %, and 125 %. The results indicated that 75 % depth of water applied within 14 days interval at Koga irrigation scheme gave a total of 40.2 t ha −1 yield with water productivity of 0.29 kg m −3. In the case of Rib, 75 % of irrigation depth showed that better yield production within 21 days irrigation interval and produced 67.9 t ha −1 fruit yield with water productivity 0.94 kg m −3. In both locations, the fruit diameter and fruit length were not statistically significant among treatments. Generally, this research showed that an appropriate regime of irrigation had significantly increased crop water use and yield production.

Development of irrigation technologies and agricultural water management systems holds significant potential to improve productivity and reduce vulnerability to climate change. Our study dealt with the behavior of irrigation water productivity, partial nutrient balance and grain yield of wheat under the application of different irrigation water management technologies in the Koga irrigation scheme in Ethiopia. For our analysis, we considered three nutrient fluxes entering and leaving farmers’ fields. Our experimental design had three irrigation blocks with three different irrigation water management practices (wetting front detector, Chameleon soil moisture sensor and farmers’ practice as control) on three farm plots replicated in each block. To calculate irrigation water productivity and grain yield of wheat, the amount of irrigation water applied and the agronomic attributes of wheat yield were recorded during the irrigation period. Further, three input and output variables were considered to determine the partial nutrient balances of nitrogen (N), phosphorus (P) and potassium (K). The results showed that the amount of irrigation water used was 33% and 22% less with a wetting front detector and Chameleon sensors, respectively, compared to the farmers’ practice. The wetting front detector (WFD) and Chameleon sensor (CHS) treatments gave a 20% and 15.8% grain yield increment, respectively, compared to the farmers’ practice plot. The partial nutrient balances of N and K were negative for the wetting front detector and chameleon sensor practices while it was positive for P in the control (farmers’ practice) treatment. We conclude that irrigation water management with appropriate technologies can improve yield, water productivity and the nutrient utilization. However, further research needs to be conducted on the suitability of irrigation management technologies to achieve full nutrient balance.