Sustainable agriculture should tend to reduce or stop the use of pesticides. However, this absence of chemical control may affect harvest quality by leading to an increase of fungal toxins, named mycotoxins, due to the development of pathogenic fungi in maize, for instance. Agronomists Reboud et al. studied mycotoxin levels in 29 maize fields over 4 years in France. They found mycotoxins levels twice higher in untreated fields, of cumulated 3.7 mg/Kg on average, versus pesticide-treated fields, of 1.9 mg/Kg. However, mycotoxins levels in untreated fields were still about 50% lower than the acceptable legal level for edible maize but with reduced safety margin.
Farmland is increasingly being polluted by pesticides and also by vehicles, notably near urban areas. Since pollution is concentrated at low atmospheric levels, cultivating crops on rooftops may produce high-quality food. Agronomists Liu et al. cultivated leafy greens in Guangzhou, China and found that rooftop grown vegetables were competitive in cost and quality compared to high-end market vegetables.
Coffee planters use diverse strategies to enhance coffee production, such as pruning, fertilising, removing weeds, applying lime to adjust the soil pH, irrigating coffee trees to trigger timely flowering, and removing shade trees that shade coffee plants. Agronomists Boreux et al. studied the factors of coffee production in the agroforestry system of Kodagu, India.
Damage on fruit production depends on the nature and movement of insects. However little is known on the year-round movements of insect predators in fruit crops and surrounding non-crop vegetation such as cover crops and edge plants. Agronomists Sorribas et al. showed that insect biodiversity was highest in organic managed farms. Nonetheless, insect abundance was highest in integrated pest managed systems. Numerous insect species moved from the crop toward edge shelterbelts to overwinter, because shelterbelts were largely preferred over cover crops. As a consequence, control strategies should focus on enhancing flying predators in shelterbelts.
Arbuscular mycorrhizal fungi are root symbionts that play a key role in plant growth. Agronomists Van Geel et al. show that a broad range of crops highly benefit from the inoculation with arbuscular mycorrhizal fungi. They also found that there is no ‘one-size-fits-all’ arbuscular mycorrhizal fungus for all plants. On the contrary, the fungus species should be adapted to the plant partner. Also they observed that the plant should be coupled with only one fungus species, not with a mixture of several fungal partners.
Biosecurity in agricuture and food is a major issue but there is few knowledge on the behaviour and actions of farmers on biosecurity. Mankad reviewed attitudes concerning biosecurity risk, the influence of social incentives and social norms on individual behaviour, and consideration of emotional and cognitive biases in assessing risk. He found that human adoption of and adherence to biosecurity practices is influenced by psychosocial factors.
Rapeseed is the second most important oilseed crop worldwide. Intensive cultivation of rapeseed induces leaching of fertilizers in waters, less efficient fertilization and pollution. There is therefore a need for rapeseed varieties that are more efficient in the use of fertilizer nitrogen. Agronomists Bouchet et al. review new knowledge on rapeseed nitrogen physiology and relevant traits that could be used for plant breeding.
A mycotoxin is a toxic metabolite produced some fungi, commonly known as molds. Mycotoxins contaminate maize and food, and thus pose a serious health risk. The factors favoring mycotoxin contamination are poorly known. A study by Liu et al. show that the main factors for contamination include less strict receiving and inspection criteria, inappropriate storage conditions and poor processing practices. The critical control points for mycotoxin management in the supply chain of maize and maize-based feed, are feed mill receiving, storage and feed processing.
Potato late blight, caused by Phytophthora infestans, is one of the main diseases in potato production, causing major losses in yield. Potato late blight is presently controlled by toxic fungicides. There is therefore a need for safer strategies. Agronomists Pacilly et al. used fuzzy cognitive mapping, a modeling technique, to understand the biological, physical and social factors influencing late blight development, and, in turn, to propose the best management scenario.
The olive moth is a major pest of olive trees, causing up to 40% fruit fall. A potential solution is to use the common green lacewing because its larvae is a voracious predator of the eggs of the olive moth. But how to favour the abundance of green lacewings? Scientists González et al. found that flowering plants such as pignut, wild fennel, honeysuckle and wild asparagus are food resources that increase the longevity and fecondity of green lacewings.