Allometric functions for apple banana leaf area and above ground biomass

The article describes how allomentric functions can be used to estimate apple banana leaf area and above ground biomass

Contribution of biofertiliser (Frateuria auranta) in an integrated potassium management package on growth of apple banana

Bananas demand high amounts of potassium for optimal growth and productivity, yet deficiencies are widespread amid the low input production strategy of smallholder farmers in Uganda. Of the potassium pool in the soil, 90% - 98% is unavailable for plant uptake. Judicious application of fertilisers is required to alleviate soil fertility problems complemented with manures and biofertilisers in an integrated nutrient management (INM) package. Biofertilisers such as potassium solubilising bacteria (KSB) have potential to solubilise unavailable forms of K in soil to forms that are readily absorbed by the plants. However, the added value of each component in this integrated K management package in apple bananas is not known. Therefore, an experiment was set up to quantify the relative contribution of mineral K, manure and KSB on the growth of apple bananas. Potted tissue culture plantlets of apple banana (cv. Sukali ndiizi) were used. The treatments comprised of a full factorial combination of mineral fertiliser (Muriate of potash, 60% K2O), animal manure and KSB (Frateuria auranta). The manure and muriate of potash were applied to supply a total of 150 kg⋅K⋅ha−. Soil microbiological assays were run to evaluate the contribution of indigenous microbial K solubilising activity in the soil to the experimental INM package. Data on pseudostem height, girth at collar and 30-cm height, leaf length and width at the widest point were collected once a week for 24 weeks. Bacillus, Pseudomonas and Frateuria were present as indigenous KSBs in the soil. The biofertiliser applied as F. auranta solubilised 7.4 mg⋅K⋅l−1 (6.2 mg⋅K⋅kg−1) from soil minerals. The integrated K management package significantly (p < 0.001) increased the above ground biomass and leaf area of potted apple bananas by up to 57.5% compared to no input. The Study recommends an economic analysis study to determine the integrated K management package that would suit the resource constrained smallholder farmers

Effect of integrated potassium nutrition on Fusarium wilt tolerance in apple bananas

This study describes the effects of potassium on tolerance to Fusarium wilt in apple bananas using chlorophyll content, stomatal conductance and severity of Fusarium wilt symptoms as indicators

Xanthomonas Wilt of banana drives changes in land-use and ecosystem services across Infected landscapes

Changes in land-use have been observed in banana-based systems in the African Great Lakes region affected by Xanthomonas wilt disease (XW) of banana. Through focus group discussions (FGDs) and the 4-cell method (to map the area under production and the number of households involved), changes in land-use were assessed in 13 XW-affected landscapes/villages along a 230 km transect from Masisi (where XW arrived in 2001) to Bukavu (XW arrived around 2014) in the Eastern Democratic Republic of Congo. Farmers’ perceptions on the sustainability of new land uses were also documented. Soil nutrient content and erosion levels were measured for five major land-use options/trajectories on 147 fields across 55 farms in three landscapes along the transect. From banana being ranked the most important crop (92% of landscapes) before XW outbreaks, its importance had declined, with it grown on smaller farms by most households in 36% of the landscapes, while in 64% of cases by few households on smaller plots. Farmers uprooted entire banana mats or fields, expanding land under other crops. Species richness did not change at landscape level, although 21 crops were introduced at farm level. Banana is, however, still perceived as more sustainable due to its multi-functional roles. Soils under banana had better chemical attributes, while high erosion levels (Mg ha−1 year−1) occurred under cassava (1.7–148.9) compared with banana (0.3–10.7) and trees (0.3–5.9). The shifts from banana could thus affect supply of key services and sustainability of the farming systems. This study offers a good basis for interventions in XW-affected landscapes

Multidisciplinary messages on Matooke

On 28-30 September, NARO, IITA, the Alliance of Bioversity International and CIAT and the Plant Productions Systems chair group of Wageningen University and Research organised the ‘Matooke symposium. The aim was to discuss and share our understanding of the sustainability and productivity of banana-based systems in West and South-West Uganda. This report contains a detailed description of the presentations, discussions and key lessons of the symposium. As scientists, we welcome a healthy and critical debate about research findings and their implications. Some topics were indeed critically debated, and as report authors, we tried to do justice to the presentations and discussions. Given the diversity of scientific disciplines and organizations involved in the symposium, the messages in this report do not necessarily reflect the views of the associated organizations

Assessment of sustainable land use: linking land management practices to sustainable land use indicators

Open Access Article; Published online: 22 May 2021Land degradation threatens food production especially in smallholder farming systems predominant in sub-Saharan Africa. Monitoring the effects of agricultural land uses is critical to guide sustainable intensification (SI). There are various indicators of sustainable land use (SLU), but conventional methods to quantify their metrics are complex and difficult to deploy for rapid and large-scale assessments. Considering that SLU indicators are dependent on agricultural practices, which can be rapidly identified and quantified, we propose a framework for SLU assessment that includes indirect quantifications of prioritized indicators (crop productivity, soil organic carbon (SOC), acidification, erosion, nutrient balance) using agricultural practices; and a SLU index derived from the integration of these indicators. The application of the framework to a case study, consisting of 1319 farm plots in Tanzania, reveals that SOC and N balance were the main contributors to the SLU gap. Only 2.2% of the plots qualified as being used sustainably. The framework proved to be sensitive to practices commonly used by farmers, thus providing an opportunity to identify practices needed to revert land degradation. Further application of the framework as a decision-support tool can enhance the efficiency of SI investments, by targeting practices which effectively enhance food production and preserve land

A multi-objective model exploration of banana-canopy management and nutrient input scenarios for optimal banana-legume intercrop performance

This study used the multi-objective optimization FarmDESIGN model to exlpore for optimal banana-canopy management and nutrient input scenarios for a banana-bush bean intensification system. Severe leaf pruning was confirmed to negatively impact on farm profitability, while the more profitable un-pruned crop options were unsustainable without external nutrient inputs. Thus, investments in external inputs are crucial for a sustainable banana-intercrop system. The FarmDESIGN model made the trade-offs and synergies in this complex intercrop system explicit, thus was also helpful for field-level decision making

Agronomic gain: definition, approach, and application

Open Access Article; Published online: 18 Jun 2021Meeting future global staple crop demand requires continual productivity improvement. Many performance indicators have been proposed to track and measure the increase in productivity while minimizing environmental degradation. However, their use has lagged behind theory, and has not been uniform across crops in different geographies. The consequence is an uneven understanding of opportunities for sustainable intensification. Simple but robust key performance indicators (KPIs) are needed to standardize knowledge across crops and geographies. This paper defines a new term ‘agronomic gain’ based on an improvement in KPIs, including productivity, resource use efficiencies, and soil health that a specific single or combination of agronomic practices delivers under certain environmental conditions. We apply the concept of agronomic gain to the different stages of science-based agronomic innovations and provide a description of different approaches used to assess agronomic gain including yield gap assessment, meta-data analysis, on-station and on-farm studies, impact assessment, panel studies, and use of subnational and national statistics for assessing KPIs at different stages. We mainly focus on studies on rice in sub-Saharan Africa, where large yield gaps exist. Rice is one of the most important staple food crops and plays an essential role in food security in this region. Our analysis identifies major challenges in the assessment of agronomic gain, including differentiating agronomic gain from genetic gain, unreliable in-person interviews, and assessment of some KPIs at a larger scale. To overcome these challenges, we suggest to (i) conduct multi-environment trials for assessing variety × agronomic practice × environment interaction on KPIs, and (ii) develop novel approaches for assessing KPIs, through development of indirect methods using remote-sensing technology, mobile devices for systematized site characterization, and establishment of empirical relationships among KPIs or between agronomic practices and KPIs

Small farms and development in sub‑Saharan Africa: farming for food, for income or for lack of better options?

Open Access Article; Published online: 15 Oct 2021Most food in sub-Saharan Africa is produced on small farms. Using large datasets from household surveys conducted across many countries, we find that the majority of farms are less than 1 ha, much smaller than previous estimates. Farms are larger in farming systems in drier climates. Through a detailed analysis of food self-sufficiency, food and nutrition security, and income among households from divergent farming systems in Ethiopia, Ghana, Mali, Malawi, Tanzania and Uganda, we reveal marked contrasts in food security and household incomes. In the south of Mali, where cotton is an important cash crop, almost all households are food secure, and almost half earn a living income. Yet, in a similar agroecological environment in northern Ghana, only 10% of households are food secure and none earn a living income. Surprisingly, the extent of food insecurity and poverty is almost as great in densely-populated locations in the Ethiopian and Tanzanian highlands that are characterised by much better soils and two cropping seasons a year. Where populations are less dense, such as in South-west Uganda, a larger proportion of the households are food self-sufficient and poverty is less prevalent. In densely-populated Central Malawi, a combination of a single cropping season a year and small farms results in a strong incidence of food insecurity and poverty. These examples reveal a strong interplay between population density, farm size, market access, and agroecological potential on food security and household incomes. Within each location, farm size is a major determinant of food self-sufficiency and a household’s ability to rise above the living income threshold. Closing yield gaps strongly increases the proportion of households that are food self-sufficient. Yet in four of the locations (Ethiopia, Tanzania, Ghana and Malawi), land is so constraining that only 42–53% of households achieve food self-sufficiency, and even when yield gaps are closed only a small proportion of households can achieve a living income. While farming remains of central importance to household food security and income, our results help to explain why off-farm employment is a must for many. We discuss these results in relation to sub-Saharan Africa’s increasing population, likely agricultural expansion, and agriculture’s role in future economic development