Pretorius, J. C.Engelbrecht, G. M.Mashamba, Nwagu Rodney2018-01-242018-01-242006http://hdl.handle.net/11660/7697English: The challenge for science is to address the need for adequate food provision and a sustainable future for agriculture. The solution for increasing food production can probably only be obtained through expansion of arable land, by increasing irrigation practices or by increasing harvestable yields on available land through the improvement of agricultural technology. With regard to the latter approach, field experiments were conducted at the experimental farm of the University of the Free State, Bloemfontein, during the 2003 and 2004 growing seasons, to determine the effect of Maxiflo and Trykoside (liquid formulations of Azospirillium and Trichoderma based products, respectively) on vegetative growth and yield of two leafy vegetable crops (cabbage and lettuce), a cereal crop (wheat), a fruit crop (tomato), a tuber crop (potato) and a legume crop (peas). A randomized complete block design with six treatments (Control, Maxiflo, Trykoside, Maxiflo + Trykoside, ComCat® and Ke/pak®) was applied in all cases. Maxiflo and Trykoside were applied either separately or together. Two commercially available natural bio stimulants, ComCat® and Ke/pal<®, served as positive controls. Different growth and yield parameters were used to quantify the effect of the test products in the above six economically important crops. In cabbage and lettuce vegetative growth (plant height, plant diameter and stem thickness) were not affected but a significant increase in head mass was observed. Peas were most responsive to treatment with the bio-products in terms of the increase in yield obtained. Treatment with Maxiflo and Trykoside in combination increased the medium/large and large size fruit yield in tomatoes while exactly the same was observed for tuber size in potatoes. However, in both crops the total yield was not significantly affected. In wheat root growth was stimulated significantly by treatment with Trykoside but no significant yield increase was observed at the 5% probability level (P<0.05).Afrikaans: Die uitdaging vir die wetenskap is om die behoefte aan verhoogde voedselproduksie aan te spreek en 'n volhoubare toekoms vir landbou te verseker. Die oplossing kan langs die weg van vermeerdering in landbougrond, verhoogde besproeiing of verhoogde produksie op beskikbare grand gevind word. Ten opsigte van laasgenoemde benadering is veldproewe uitgevoer op die proefplaas van die Universiteit van die Vrystaat, Bloemfontein, gedurende die 2003 en 2004 groeiseisoene om die effek van Maxiflo en Trykoside (vloeibare formulasies van respektiewelik Azospirillium en Trichoderma gebaseerde produkte) op die vegetatiewe groei en oesopbrengs van twee blaargroentes (kool en slaai), 'n graangewas (koring) 'n vruggewas (tamatie), 'n knolgewas (aartappel) en 'n peulgewas (erte) te ondersoek. Volledige blok ontwerpe is in alle gevalle gebruik en ses behandelings (Kontrole, Maxiflo, Trykoside, Maxiflo + Trykoside, ComCat® en Kelpak®) toegepas. Maxiflo en Trykoside is apart of saam aangewend. Twee kommersiele bio-stimulante, ComCat® en Ke/pal<®, het as positiewe kontroles gedien. Groei en oesopbrengs parameters is gebruik om die effek van die toetsprodukte te kwantifiseer in bogenoemde ses ekonomies belangrike gewasse. In kool en slaai is vegetatiewe groei (planthoogte, plant deursnee en stamdikte) nie be·invloed nie maar kopmassa betekenisvol verhoog. Erte het die beste op behandeling met die bio-produkte gereageer in terme van die verkree oesopbrengsverhoging. Behandeling met Maxiflo en Trykoside in kombinasie het tot vermeerdering in die medium/groat en groat tamatievrugte aanleiding gegee terwyl dieselfde tendens met aartappelknolle waargeneem is. Maar, in nie een van hierdie twee gewasse is die totale oesopbrengs betekenisvol verhoog nie. In koring is wortelontwikkeling betekenisvol verbeter deur veral behandeling met Trykoside maar weereens is geen betekenisvolle oesopbrengsverhoging waargeneem by die 5% waarskynlikheidsvlak (P<0.05) nie.enCabbageLettucePeasWheatTomatoPotatoEffectMaxifloTrykosideComCat®Kelpak®Vegetative growthYield componentsPlant growth-promoting rhizobacteriaCrop yieldsCrops -- GrowthDissertation (M.Sc.Agric. (Soil, Crop and Climate Sciences))--University of the Free State, 2006DissertationUniversity of the Free State