EFFECT OF SEED SOURCE AND RATES ON SEED QUALITY, YIELD AND YIELD RELATED TRAITS OF BREAD WHEAT (Triticum aestivum L.) VARIETIES AT KULUMSA, ARSI, ETHIOPIA

Abstract

Arsi zone is one of the major wheat production areas in Ethiopia, however, the yield of the crop is not to the level of the area's potential due to the limited supply of quality seed of improved varieties and seed rate used for production. This research was conducted to assess the seed quality of different seed sources, the effect of seed sources and seed rates on yield and yield related traits and estimate the association of seed quality, yield, and yield related traits of bread wheat varieties. The seeds of quality of Abay and Shaki varieties obtained from Oromia Seed Enterprise (OSE), Kulumsa Agricultural Research Center (KARC), and Ethiopia Agricultural Business Corporation (EABC) were evaluated in a completely randomized design with four replications. The seed samples at four seed rates (100, 125,150, and 175 kg ha-1) in factorial combination were evaluated for yield and related traits in a randomized complete block design with three replications. The interaction effect of Variety and seed sources had a significant influence on most of the seed quality. The interaction of variety and seed sources had a significant influence on the percentage of pure seeds, inert matter, seed germination, abnormal seedling and dead seeds, seedlings length, root length, vigor index I, and percentage of seed infection by Penicillium spp., Alternaria triticicum, Aspergillus flavus, and Rhizopus spp. The Shaki variety had a higher thousand seed weight (49.25g) and moisture content of seeds (13.08%). Seeds of the Shaki variety obtained from EABC and KARC, and seeds of the Abay variety obtained from OSE had a higher percentage of pure seeds (99.52 and 99.51%) whereas seeds of the Abay variety obtained from KARC had the highest percentage of seed germination (96.5%) and seedling vigor index I (2208.6). The phenology, growth traits, yield components and yield of the crop were significantly influenced by one, two, or three of the main factors. Days to 50% heading, many tillers, productive tillers, plant height, and spike length are significantly influenced by the interaction of variety, seed source, and seed rate and all possible two factors interaction except days to heading and spike length (cm) were not significantly influenced by the two factors interaction. number of kernels per spike was significant variation was observed due to the interaction of variety and seed rate and source and seed rate. Abay and Shaki varieties from seeds obtained from KARC at a seed rate of 150 kg ha-1 produced higher grain yields of 6.52 and 6.49 t ha-1, respectively. However, it had a nonsignificant difference in grain yield (6.32 t ha-1) produced by the two varieties from seeds collected from EABC and OSE at a seed rate of 175 kg ha-1, and grain yield of the Shaki variety from seeds obtained from KARC and OSE at a seed rate of 125 and 150 kg ha ha-1, respectively, and Abay variety from seeds obtained from all sources at a seed rate of 100 kg ha-1. The moisture content of seeds, speed of germination, seedling root length, dry weight, and vigor index II had positive and significant correlations with grain yield whereas the percentage of pure seeds, seedling shoot length, and vigor index I showed negative and significant correlations with grain yield. Based on the findings the combination of reliable seed sources (KARC) with a 150 kg ha-1 seeding rate improves the quality and productivity of bread wheat production at Arsi and similar Agro- ecologies.