EFFECTS OF STEM CUTTING NODE NUMBER AND ROOTING MEDIA ON GROWTH, SEED TUBER YIELD AND YIELD-RELATED TRAITS OF POTATO (Solanum tuberosum L.) AT HARAMAYA, EASTERN ETHIOPIA

Abstract

Potato (Solanum tuberosum L.) is an important crop in Ethiopia for nutritional security and poverty alleviation. Shortage of disease-free and quality planting material led to a lower production of potatoes. In this regard, soil and tuber borne diseases free planting materials can be produced by stem cutting and it will be used an alternative seed multiplication method. However, this practice is not common and recommendations are lacking for stem-cutting node number and rooting media using stem-cutting techniques for potato seed production in Ethiopia. Therefore, this study was conducted to determine the effect of stem cutting node number and rooting media on rooting performance, seedling growth, seed tuber yield, and yield-related traits at Haramaya, eastern Ethiopia, during the main cropping season of 2023. Three levels of cutting node number (one node, two nodes, and three nodes), and five types of rooting media [coco peat, sand (2 mm grain size), forest soil, coco peat + sand (1:1), and sand + forest soil (1:1)] in factorial combinations and laid in a completely randomized design (CRD), evaluated under a lath house. In a separate condition experiment, the rooted stem cuttings were transplanted in the field and studied for growth, tuber yield, and yield-related traits in a randomized complete block design (RCBD) with three replications. The rooting media significantly influenced all the parameters except root fresh weight and leaf width. The best root quality was obtained from cuttings rooted in a cocopeat+sand 1:1, and the highest survival rate (83%) was observed in cocopeat media. The best seedling growth was obtained from the cutting with three nodes, which recorded maximum number of leaves (509.5 per plant), number of branches (11.6 per plant), and plant height (86.2 cm). The cuttings rooted in forest soil produced the highest values in most of the growth and yield parameters. Using forest soil as rooting media produced the maximum leaf number per plant (549.2), number of branches per plant (12.3), plant height (91.3 cm), average tuber mass per plant (0.41kg), total tuber yield (33.4t ha-1), total seed tuber yield (32.5t ha-1), large tuber size number (50.9%) and yield (26.4 t ha-1). Thus, considering the overall performances, it is recommended to use the forest soil medium as rooting media of Bubu potato variety propagated from stem cutting to produce planting materials free from soil and tuber borne diseases in the study area. However, as this study was conducted in a single location and in a single season, it would be better to conduct an in-depth investigation under various macroclimatic and rooting media