Transgenic mitigation through linking the transgene to genes that confer a selective disadvantage such as a dwarfing mitigatorgene, or other mechanisms like cleistogamy in rice, total sterility in tubers and bulb-propagated crops, synthetic auxotrophy etc. could contain gene flow.Low-cost technologies for the production of biopharmaceuticals using plant systems should be used in cases of unprecedented public health crisis such as that caused by COVID-19. Since the production processes and systems of production or sophisticated expression platforms for vaccines and therapeutics are already established, it is possible to rapidly generate the vaccines with higher yield under cGMP practices. N. benthamiana plants can be transiently transformed with target vaccine gene and the leaf biomass harvested and processed to purify the antigen or vaccine. In addition to transient expression systems, plantbiomass propagation with plant cell suspension cultures should be refined.

The Canada-based biopharmaceutical company Medicago Inc. is into transient expression of SARS-CoV-2 virus S protein, using a virus-like particle grown in Nicotiana benthamiana to develop a potential vaccine against the coronavirus disease that has now reached a global pandemic level. Universities and Institutes from several countries including the US, Germany, UK, South Africa,South Korea, Mexico and Thailand are working in the molecular farming field, investing efforts and establishing partnerships and collaborations for treatment or vaccine for COVID-19. Transient transformation approaches are rapid while regeneration of stably transformed plant takes up to 3 months, which is not suitable for addressing a fatal, exponentially-growing pandemic such as COVID-19.Though concept and methodology are concise, there are only limited number of edible vaccines which are approved,tested and commercialised. The COVID-19 pandemic outbreak warrantsa deep investigation and introspection into the technology status, application and progress to address the problem. Transient expression in plant cell suspension cultures seem to be a feasible strategy to produce plant-based vaccine for deadly pandemic outbreak of COVID-19.

Crop production practices within peasant farm holdings in sub-Saharan Africa often progress at the expense of sustainable land use as farmers are primarily concerned about crop and animal production, for the forthcoming season.Hence, long-term processes that adversely affect sustainability,such as decrease and eventual depletion ofsoil nutrient stocks, are less visible and receive a lower priority. Most often, these soils are progressively beingmined of their nutrients whereas there is need to secure present productivity and ensure the sustainability of these farming systems. These farmers have to manage the fertility of their soils by manipulating the flows of nutrients into, out of and within the farm. Indeed, decisions concerning soil productivity are determined by household objectives,available resources and the socio-economic environment.Soil fertility in sub-Saharan Africa is today regarded as a major survival issue, especially in peasant perennial crop-based systems in the humid forests of Cameroon.

This project was initially undertaken to ensure a better understanding and improvement of soil fertility in these cropping systems, to determine the possible role of integrated nutrient management in reversing present trends of nutrient depletion at each farm-level, and to integrate quantitative and qualitative assessment approaches in managing soil fertility.The complexity of peasant farms does not always allow for quantification of all flows and stocks. Nutrient monitoring is a multi-scale modelling approach that was conceived to assess stocks and flows of certain nutrients in a well defined geographical unit following a strict monitoring of all farm inputs and outputs. The NUTMON-Toolbox was developed with three modules to quantify nutrient flows, nutrient stocks and economic performance indicators for farms. It provides guidelines for data gathering in the field, data entry, calculation of flows and balances and data interpretation. Application of the tools from the toolbox results in a thorough analysis providing insight into nutrient flows between the various activities within the farm as well as between the farm and its surroundings.

The specific objectives of this study were therefore to evaluate variations of soil nutrient stocks at farm level,measure and estimate the major nutrient flows at farm level as a means to describe current farm nutrient management,to identify the key factors influencing land management in perennial crop-based farms in the humid forests of South West Cameroon in a bid to discover some ofthe underlying causes of soil fertility depletion. This was particularly supposed to be done using the Nutrient Monitoring Programme or software, a tool that was developed to assess nutrient balances,biomass flow and economic performance at farm level .NUTMON has been suggested as a decision-support model to monitor the effects of changing land use and suggest interventions that improve the nutrient balance .As input and output determinants cannot all be quantified equally well, the model recognizes primary data, estimates and assumptions.