Low soil fertility is one of the critical factors limiting the productivity of potatoes (Solanum tuberosum L.) in western Ethiopia. The field experiment was conducted in the 2015 and 2016 cropping seasons to elucidate the response of potato yield, yield components, tuber quality to nitrogen and phosphorus fertilizer, and their economic benefit. The treatment comprised five levels of nitrogen (0, 50, 100, 150, and 200 kg N ha −1 ) and five levels of phosphorus (0, 50, 100, 150, and 200 kg P 2 O 5 ha −1 ). The experiment was laid out as a randomized complete block design in a factorial (5 × 5) arrangement and we replicated the treatments three times. The results revealed that the interaction of nitrogen and phosphorus did not affect growth, yield, and quality parameters of potato. However, nitrogen alone affected plant height, tuber number per plant, number of stems per hill, and marketable and total tuber yield, but not tuber quality parameters. The optimum yields of both marketable (25.5 Mg ha −1 ) and total (28.4 Mg ha −1 ) tuber yields were observed in the application of 150 kg N ha −1 . Phosphorus treatments had no response for most of the yield, yield components, or tuber quality parameters. Applications of 150 kg N ha −1 provided a maximum gross margin ($5138.68 or 141,773.55 Ethiopian Birr [ETB] ha −1 ) with a 79.4% gross profit margin and the highest benefit-cost ratio (4.86).

Applications of nutrients are determined by the plant’s nutritional requirements and the soil’s available nutrients; however, the precise nutrient application is difficult. At Assosa, a field experiment was conducted to determine how soil chemical characteristics and accumulation of phosphorus and potassium in potato tissue responded to phosphorus and potassium fertilizers application. The treatments included four potassium levels (0, 100, 200, and 300 kg·K2O ha−1) and six phosphorus levels (0, 46, 92, 138, 184, and 230 kg·P2O5 ha−1). The experiment was set up as a factorial randomized complete block design (RCBD) and was repeated three times. According to the preplanting soil analysis, the cropping area’s soil has a medium CEC, low accessible phosphorus, and very low exchangeable potassium. The application of phosphorus had a highly significant influence on accessible phosphorus, exchangeable potassium, and CEC, the concentration of phosphorus in the leaf and tuber tissue of the potato plant. While potassium had a significant effect on exchangeable potassium, CEC, phosphorus concentration in potato plant tuber tissue, and potassium level in both the leaf and the tuber, the interaction effect of phosphorus and potassium on all of the above-mentioned soil chemical properties, as well as the amount of P and K in potato plant tissues, was observed. The critical potassium level in the leaf blade for optimum crop yield tissue content was determined to be 100 kg·K2O ha−1, while the critical level of phosphorus was determined to be 184 kg·P2O5 ha−1.

Poor germination of peach seeds is the major limiting factor for rootstock production under the Holetta condition because of the seed dormancy problem. Stratification plays an important role in shortening the dormancy and increasing the germination of peach seeds. The study aimed to find easy stratification techniques for the germination of peach seeds using shade and different bed types. The experiment was carried out at the Holetta Agricultural Research Center in two successive years of 2017 and 2018. We got seeds used for this study from peach trees, which were well adapted for the Holetta area. It was arranged in a completely randomized design with five treatments of under tree shade on a flatbed, under tree shade in sunken bed, out of tree shade on a flatbed, out of tree shade in sunken bed and refrigerator as a standard check. They put all treatments except the refrigerator under the grass shade constructed 1 m3 wide. The treatments replicated four times, and each replication contained 200 seeds. The results showed that temperature is the most important factor affecting the germination percentage of the peach seeds. Seeds sown under the temperature close to 8 0C which is in the refrigerator found to have better germination percentage (47.1%) followed by the seeds sown in the grass shade under the tree shade both on sunken (35.8%) and flatbeds (34.9%). Peach seeds stratified in the refrigerator had good germination percentage whereas survival of the seedling was better at out of tree shade in sunken bed and out of tree shade on the flatbed. Even though the germination percentage was lower and the germination speed index was higher than the refrigerator. Seeds stratified at a temperature of above 17 OC experienced a poor germination percentage.

How to cite this paper: Habtam Setu.

Potato is one of the most important food security and cash crops in Ethiopia. It is constrained by poor soil fertility. A field experiment was conducted at Assosa Agricultural Research Centre to investigate the effect of phosphorus and potassium fertilizers on growth performance and yield of potato. The experiment was laid out as a randomized complete block design (RCBD) in 4×6 factorial arrangement of potassium (0, 100, 200 and 300 kg K 2 O ha-1) and phosphorus (0, 46, 92, 138, 184 and 230 kg P 2 O 5 ha-1) in three replicates. A potato variety, Gudanie (CIP-386423-13) was used. Analysis of the data revealed that the interaction effect of both phosphorus and potassium did not influence the phenotypic, growth parameters and tuber yields of potato, but their main effect is significant influence on days to 50% flowering, physiological maturity, plant height, marketable and total tuber yields, leaf area, above and underground dry biomasses. Optimum above and underground dry biomass (232.11 and 494.74 Mg* ha-1), marketable (23.94 kg K 2 O ha-1) and total tuber (29.56 kg K 2 O ha-1) yields were attained at 200 kg K 2 O ha-1 ; for phosphorus, optimum marketable tuber (23.30 Mg ha-1), total tuber (28.83 Mg ha-1), and yield of above ground and underground dry matter (218.48 and 479.60 Mg ha-1) were attained at 138 kg P 2 O 5 ha-1. The lowest yield obtained from above ground and underground dry matter, marketable and total tuber in both fertilizers were recorded at zero level.