Browsing by Author "Ouma, Josephine Pamela"

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Leaf Gas Exchange and Root Nodulation Respond to Planting Density in Soybean [Glycine Max (L) Merrill]
(Hindawi, 2020-01) Mwamlima, Louis Hortensius; Ouma, Josephine Pamela; Cheruiyot, Erick Kimutai
Planting density influences structural characteristics and affects mineral nutrient acquisition, irradiance and photosynthesis amongst plants. An experiment was conducted to determine the effect of planting density on leaf gas exchange and nodulation of soybean (Glycine max (L) Merrill). e experiment was conducted as a randomized complete block design (RCBD) in a 5 by 2 factorial treatment arrangement and was replicated three times. Planting density (10, 12, 20, 40, and 80 plants m−2) and soybean varieties (EAI 3600 and DPSB 19) were first and second factors, respectively. Collected data were subjected to analysis of variance in GENSTAT. Significantly different treatment means were separated using Tukey’s honestly significant difference test at 0.05 significance level. Higher planting density significantly increased ( < 0.001) interception of photosynthetically active radiation. Increasing number of plants per unit area significantly ( < 0.001) reduced root nodulation, stomata conductance, sub-stomatal CO2 concentration, photosynthetic and transpiration rates. Total chlorophyll content was not responsive to planting density though concentration of chlorophyll “a” content was significantly ( < 0.005) higher at lower plant density than at higher plant density. Soil moisture status increased with reduction in plant density. Indeterminate variety DPSB 19 had higher rates of stomata conductance, photosynthesis and sub-stomatal CO2 concentration compared to determinate variety EAI 3600.
Physiological Response of Soybean [Glycine Max (L) Merrill] to Soil Moisture Stress
(African Journal of Agricultural Research, 2019-04) Mwamlima, Louis Hortensius; Ouma, Josephine Pamela; Cheruiyot, Erick Kimutai
This study was done to determine the effects of varying soil moisture regimes on CO2 assimilation of soybean [Glycine max (L.) Merrill] in pots under greenhouse conditions during 2017 and 2018 cropping seasons. The experiment was conducted as a Randomized Complete Block Design (RCBD) in a 4 x 6 factorial treatment arrangement and replicated 3 times. Soil moisture regimes (80, 60, 40 and 20% of field capacity) and cultivars (Gazelle, Nyala, EAI 3600, DPSB 8, Hill and DPSB 19) were first and second factors, respectively. Collected data were subjected to Analysis of Variance (ANOVA) using Linear Mixed Model in GENSTAT. Significantly different treatment means were separated using Tukey’s test at 0.05 significance level. Leaf relative water content, stomata conductance, photosynthesis rate and substomatal CO2 concentrations significantly (P < 0.001) declined with increasing soil moisture stress. Total leaf chlorophyll content increased (P < 0.001) with increased soil moisture stress. Cultivars DPSB 19 and DPSB 8 had relatively higher leaf relative water content and stomata conductance at reduced soil moisture regime at 20% moisture from field capacity indicating moisture stress tolerance potential of the cultivars. Key words: Flowering stage, podding stage, seasons, soil moisture regimes, soybean cultivars.