Browsing by Author "Emmanuel Odama"

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Effect of P-Dipping on Growth of NERICA 4 Rice in Different Soil Types at Initial Growth Stages
(Sustainability, 2023-10-28) Emmanuel Odama; Yasuhiro Tsujimoto; Shin Yabuta; Isao Akagi; Rael Chepkoech; Ibrahim Soe; Jun-Ichi Sakagami
Phosphorus (P) deficiency resulting from P fixation is a major constraint limiting sustainable rice cultivation in sub-Saharan Africa. Soil texture also affects P availability and use efficiency. In a factorial experiment, we evaluated the combined effect of soil texture (sand, clay loam, and clay) and P treatments P-dipping (Pdip) and two other broadcasted P fertilizer levels (Brod1 and Brod2) on the growth of NERICA 4 rice in the initial growth stages. Across all soil textures and P treatments, total plant biomass ranged from 1.06 to 4.63 g pot−1. The Pdip treatment significantly increased shoot and root biomass relative to control from 1.27 to 1.98 and 0.23 to 0.38 g pot−1, respectively. Mean photosynthetic rate values under Pdip (20.1 μmol m−2 s−1), Brod2 (19.5 μmol m−2 s−1), and Brod1 (19.3 μmol m−2 s−1) treatments showed significant 42%, 37%, and 36% increases over control, regardless of soil texture. In a striking contrast, P-dipping significantly promoted growth of root length under clay soil, but without a commensurate increase in shoot P uptake. Contrary to our hypothesis, the interactive effect of soil texture and P-dipping influenced NERICA 4 shoot and root physiological and morphological characteristics under clay loam soil texture as opposed to clay.
Effect of Phosphorus-Based Fertilizer on Groundnut Yield and Incidence of Groundnut Rosette Disease in West Nile Region of Uganda
(National Agricultural Research Organisation, 2023-09-01) Alex Abaca; Emmanuel Odama; Alfred Komakech; Sadik Kassim; John K. Walakira
The objective of this study was to establish the effects of Di-ammonium phosphate (DAP) fertilizer micro-dosing on yields and the incidence of groundnut rosette disease (GRD) on five groundnut varieties in West Nile region of Uganda. The field experimental design used in this study was 5x2 factorial laid in a randomized complete block design (RCBD) with three replicates per location across 6 locations. The results indicated that there were significant (p = 0.05) differences in groundnuts yields across locations and varieties (0.554 – 1.742 tons per hectare) with or without micro-dosing with DAP fertilizer. The effects of DAP fertilizer micro-dosing in groundnut production were twofold: increase in yields across locations from 427.27kg/acre with no micro-dosing to 525.73kg/acre with micro-dosing (23.04% increment) and varieties from 420.46kg/acre with no micro-dosing to 529.71kg/acre with micro-dosing (13.77% increment); and a reduction of groundnut rosette virus disease incidence across locations from 15.13% with no micro-dosing to 11.20 with micro-dosing (27.76% reduction) and on varieties from 15.08% with no micro-dosing to 11.82% with micro-dosing (34.62% reduction). This is the first report of a prospective DAP fertilizer micro-dosing alongside other improved agronomic practices which can be integrated fully into groundnut production in West Nile region of Uganda. To manage yields and GRD incidences, micro-dosing of crops should be taken as a climate smart technology as identified by Food and Agricultural Organization.
Primed Seeds of NERICA 4 Stored for Long Periods under High Temperature and Humidity Conditions Maintain Germination Rates
(Applied Sciences, 2023-02-23) Emmanuel Kiprono Bore; Eri Ishikawa; Julie Ann Mher Alcances Libron; Keita Goto; Emmanuel Odama; Yoshihiro Nakao; Shin Yabuta; Jun-Ichi Sakagami
Agriculture depends on the ability of seeds to survive until the next planting season under ambient conditions that may be averse to seed quality even when the seed is in a quiescent state. Seed priming invigorates seeds, but the impact on the longevity of seeds has limited its adoption. This study investigated the effect of the storage of primed rice seed on seed viability, vigor, and longevity. Three seed priming methods were employed on the rice cultivar New Rice for Africa (NERICA 4) seeds. Subsequently, the seeds were stored for 120 days at 25 ◦C and 65% relative humidity, simulating the ambient seed storage conditions of the tropics and sub-tropics. The primed seed recorded increased vigor compared to the non-primed seed until 90 days of storage. However, seed storage for 120 days reduced seed vigor and viability for all the seeds. The results indicated a significant reduction in seed vigor, increased solute leakage, generation of hydrogen peroxide, and accumulation of malondialdehyde after storage. Priming enhances cell membrane integrity and maintains seed vigor in storage at near ambient conditions long enough before reversal of its performance by the storage conditions. This assures that primed seed can either be stored until the following planting season or remain viable in the soil during delayed germination.