SEEDLING EMERGENCE AND GROWTH RESPONSE OF SPINACH TO SOIL AMENDED WITH DIFFERENT SPENT OYSTER MUSHROOM SUBSTRATES

Soil health is one of the most important factors that influence plant productivity. Incorporation of soil into plant residues that are high in organic matter has been reported to improve soil’s physical and chemical properties which enhance plant growth and development. Therefore, the objective of this study was to investigate the effect of soils amended with different spent oyster mushroom substrates on seedling emergence and growth of spinach (Spinacia oleracea). The respective soil samples were amended with different Spent Mushroom Substrates (SMS) at ratio 60:40 (soil/substrate). Treatments were: T1= U. panicoides + soil, T2= Z. mays + soil, T3= D. stramonium + soil, T4= Substrate mix [60% soil: U. panicoides (13.33%), Z. mays (13.33%) and D. stramonium (13.33%)] and T5= un-amended soil (100%). The respective treatments were filled into 25cm diameter pots and arranged in a Complete Randomized Design (CRD) in a temperature-controlled glasshouse. In each respective pot, three S. oleracea seeds were planted at a depth of 2cm and watered 3 times a week. S. oleracea growth response was determined by assessing the following variables: emergence rate, plant height, number of leaves/plant and chlorophyll content over a period of 12 weeks. Total dry biomass was assessed at harvest by oven drying the plants at 60ºC for 72 hrs. On the first assessment, seedlings raised in Z. mays SMS had significantly higher emergence percentage than seedlings raised in D. stramonium, Substrate mix, U. panicoides SMS (p<0.05). Seedlings raised in Z. mays SMS attained 100% emergence 7 days after planting (DAP), and un-amended soils had 91.75% 9 DAP. Seedlings raised in Z. mays and D. stramonium SMS had significantly higher plant height than seedlings raised in U. panicoides SMS and un-amended soils (p<0.05). Seedlings raised in Z. mays SMS attained 26.27cm height compared to U. panicoides SMS and un-amended soils which attained 12.67cm and 14cm height, respectively. Findings of this study revealed that Z. mays and D. stramonium SMS amended soils have inherent properties that positively influenced the seedling emergence, establishment, and growth of S. oleracea. This would, therefore, have influence on the leaves which are the main agronomic yield of the crop

SEEDLING EMERGENCE AND GROWTH RESPONSE OF SPINACH TO SOIL AMENDED WITH DIFFERENT SPENT OYSTER MUSHROOM SUBSTRATES

Soil health is one of the most important factors that influence plant productivity. Incorporation of soil into plant residues that are high in organic matter has been reported to improve soil’s physical and chemical properties which enhance plant growth and development. Therefore, the objective of this study was to investigate the effect of soils amended with different spent oyster mushroom substrates on seedling emergence and growth of spinach (Spinacia oleracea). The respective soil samples were amended with different Spent Mushroom Substrates (SMS) at ratio 60:40 (soil/substrate). Treatments were: T1= U. panicoides + soil, T2= Z. mays + soil, T3= D. stramonium + soil, T4= Substrate mix [60% soil: U. panicoides (13.33%), Z. mays (13.33%) and D. stramonium (13.33%)] and T5= un-amended soil (100%). The respective treatments were filled into 25cm diameter pots and arranged in a Complete Randomized Design (CRD) in a temperature-controlled glasshouse. In each respective pot, three S. oleracea seeds were planted at a depth of 2cm and watered 3 times a week. S. oleracea growth response was determined by assessing the following variables: emergence rate, plant height, number of leaves/plant and chlorophyll content over a period of 12 weeks. Total dry biomass was assessed at harvest by oven drying the plants at 60ºC for 72 hrs. On the first assessment, seedlings raised in Z. mays SMS had significantly higher emergence percentage than seedlings raised in D. stramonium, Substrate mix, U. panicoides SMS (p<0.05). Seedlings raised in Z. mays SMS attained 100% emergence 7 days after planting (DAP), and un-amended soils had 91.75% 9 DAP. Seedlings raised in Z. mays and D. stramonium SMS had significantly higher plant height than seedlings raised in U. panicoides SMS and un-amended soils (p<0.05). Seedlings raised in Z. mays SMS attained 26.27cm height compared to U. panicoides SMS and un-amended soils which attained 12.67cm and 14cm height, respectively. Findings of this study revealed that Z. mays and D. stramonium SMS amended soils have inherent properties that positively influenced the seedling emergence, establishment, and growth of S. oleracea. This would, therefore, have influence on the leaves which are the main agronomic yield of the crop

Effect of ectomycorrhizal fungi in the protection of Uapaca kirkiana seedlings against root pathogens in Zimbabwe

Investigations carried out on the use of ectomycorhhizal fungi in the management of Uapaca kirkiana root diseases caused by three pathogens (Rhizoctonia solani, Phytophthora parasitica and Pseudomonas solani) revealed that different mycorrhizal fungi vary in their ability to protect roots against these respective pathogens. Difference in the disease severity in various treatments was noted to have been due to the combined effect of the intrinsic biological differences of the pathogens resulting in them having different pathogenicity and the biological differences of mycorrhizal fungi. The study also highlighted that ability of mycorrhizal fungi to protect roots against these pathogens was dependent on the colonisation efficiency, which is influenced by factors such as spore germination and hyphal growth through the soil. Certain macro- and microelements were shown to inhibit growth of pathogenic fungi such as R. solani and P. parasitica. In vitro studies indicated both Zn and Cu to be significantly effective against R. solani. These elements suppressed growth of R. solani probably through their antifungal properties. Copper was also significantly effective against P. parasitica. Effect of Ca was, on the other hand, not significantly different from the control (state) on both R. solani and P. parasitica. Findings of this work may be used to explain differences in the ability of different ectomycorrhizal fungi to protect roots against different root pathogens, particularly if the mycorrhizal fungi species differ in their nutrient sequestration.Keywords: ectomycorrhizae; fungi; inoculum; pathogens; Uapaca kirkianaSouthern Forests 2010, 72(1): 37–4