Orchard management

Despite tremendous efforts made in agricultural sectors in Sub-Saharan Africa in the last two decades, fruits production and consumption to reduce malnutrition and chronic diseases remain low and have received less attention. Moreover, our knowledge of the current production situation and options for improvement are still limited. In this study, we investigated citrus farming systems and production bottlenecks to identify leverage points for intensification of smallholder citrus farming systems in Benin. We provided a typology of citrus orchards based on 17 quantitative and qualitative variables using Factor Analysis of Mixed Data combined with Hierarchical Cluster Analysis. The typology revealed four categories of citrus farms based on biophysical resources, socio-economic resources and system management practices. Categories 1 and 2 included farms characterised by less diversified cropping systems with nonrecommended management practices. Orchard categories 3 and 4 included farms with high varietal diversity and improved management practices. However, farmers of category 4 neglected staking and digging practices. The inadequate farming practices explained some of the production bottlenecks, which were orchard-type dependent. We discussed the implications of our findings and suggested a number of policy and strategic decisions as well as research and development actions for improving citrus production in Benin.

The market for agricultural machinery is characterized by products with a high degree of maturity in the product life cycle. Consequently, current improvements in new machinery are predominantly incremental and new projects basically use solutions that are already consolidated. This makes this domain appropriate for benchmarking existing systems and envisioning new value propositions. The present paper deals primarily with the former and uses the value curves as a means to structure the comparison among different families of technical systems; in particular, harvesting machines for shell fruits from the ground surface, e.g., chestnuts, walnuts, and hazelnuts, were investigated here. The process of building value curves requires the identification of currently fulfilled requirements. Despite the attention paid by engineering design research to requirements, a structured process is lacking to extract relevant information and create value curves or other representations useful for benchmarking. The present paper approaches this problem and presents how the authors have individuated relevant knowledge for characterizing different categories of harvesting machines. Namely, after an extensive search of the scientific literature and patents, a critical review of existing machines, aimed at individuating their functioning principles, architecture, and attitude in fulfilling specific design requirements, was performed. Then, existing machines were classified in 8 main categories, and their strengths and weaknesses were identified with reference to 11 competing factors. The consequent construction of value curves enabled the identification of possible points of intervention by hypothesizing possible future evolutions of such machinery, both in a structural and in a value-based perspective. Limitations about the repeatability of the followed approach and possible repercussions on design research are discussed.

Glyphosate is an important component of herbicide programs in orchard crops in California. It can be applied alone or in tank-mix combinations under the crop rows or to the entire field and often is used multiple times each year. There has been speculation about the potential impacts of repeated use of glyphosate in perennial crop systems, because of uptake from shallow root systems or indirectly because of effects on nutrient availability in soil. To address these concerns, research was conducted from 2013 to 2020 on key orchard crops to evaluate tree response to glyphosate regimens. Almond, cherry, and prune were evaluated in separate experiments. In each crop, the experimental design was a factorial arrangement of two soil types, four glyph-osate rates (0, 1.1, 2.2, and 4.4 kg ae ha −1 , applied three times annually), and two post-glyphosate application irrigation treatments. In the first 2 yr of the study, there was no clear impact of the glyphosate regimens on shikimate accumulation or leaf chlorophyll content, which suggested no direct effect on the crop. In the seventh year of the study, after six consecutive years of glyph-osate application to the orchard floors, there were no negative impacts of glyphosate application on leaf nutrient concentration or on cumulative trunk growth in any of the three orchard crops. Lack of a negative growth impact even at the highest treatment rate, which included 18 applications of glyphosate totaling nearly 80 kg ae ha −1 glyphosate over the course of the experiment suggest there is not likely a significant risk to tree health of judicious use of the herbicide in these production systems. Given the economic importance of orchard crops in California, and grower and industry concerns about pesticides generally and specifically about glyphosate, these findings are timely contributions to weed management concerns in perennial specialty crops.

As a tropical tree, mango (Mangifera indica L.) cultivated in Mediterranean climate needs protection against low temperatures. The aim of this work is to study the effect of traditional individual protective canopy protection systems in comparison with innovative typologies designed for this experiment on the physiological response of young mango trees during the cold season. We selected 25 four-year-old mango trees cv 'Glenn'. Trees were divided into five different groups: not covered trees (NC); trees with windbreak protection using a shading net (SN); trees with windbreak protection using non-woven sheets (WB); fully covered trees using non-woven sheets (FC); fully covered trees with non-woven sheets and the addition of a 'heat exchanger' device (FC+). Their canopies were fully covered (FC) and (FC+) or enclosed by a handmade individual windbreaks (SN and WB). We studied the evolution of temperature inside the canopy and evaluated the threshold of damage on leaves and shoots. We also monitored soil temperature under the trees. Precision self-made data loggers were assembled. A "heat exchanger" was realized for this experiment to try to recover heat from the ground and place it under the canopy of the plants. It was made with a 50 cm U-shaped aluminum pipeline using recycled materials; this was placed horizontally, 50 cm deep in the soil with one of two extremities above the soil and the other within the canopy. NC trees were damaged by cold temperature. More particular, the young shoot was injured by necrosis followed by fungal disease. The same behavior was observed in SN and WB when the canopy was only enclosed by the protection whereas FC tree shoots were intact. Non-woven sheets preserved intact the shoots only in the FC trees, as the canopies were completely covered by a closed space because the leaves and shoots were isolated from the outside. The 'heat exchanger' device increased, however minimally, the temperature in the closed space containing the canopy. The use of non-woven sheets, covering completely the canopy, allowed to preserve the shoots for future tree development.