Crop management is a complex task because crop yields depend on hardly predictable factors such as climate change and pest occurrence. A solution is to develop apps that help farmers and agronomists to take the best decision for farming practices. Damos reviews decision tools based upon pest and climate data.
The fall armyworm Spodoptera frugiperda is the larval life stage of a moth. This worm is a pest that can wreak havoc with crops if left to multiply. Biocontrol methods are currently developped to avoid the use of toxic pesticides. Agronomists Figueiredo et al. show that the yield of organic maize can be increased by 19% using the wasp Trichogramma pretiosum and a pheromone sex trap.
The overuse of pesticides leads to contamination of water and food. Therefore there is a need for tools to reduce pesticide applications. Agronomists Nansen et al. present SnapCard, a free computer app that allow farmers to optimise spray coverage, reduce spray drift, and minimize the risk of resistance development in target pest populations.
The toxic alkaloid nicotine, a natural component of tobacco, has been detected in many food crops, medicinal plants and plant food such as spices and teas, thus threatening food security. So far the origin of such nicotine contamination was unknown. Plant scientists Selmar et al. studied the possible contamination of peppermint by soils enriched in nicotine from cigarette residues. They also checked whether peppermint could take up nicotine from cigarette smoke. They found that peppermint take up nicotine from soil and from smoke. The tobacco industry and users are therefore responsible, at least partly, by the wide contamination of many crops and food by nicotine. Selmar et al. also explain that the passive incorporation and metabolisation of nicotine by peppermint is surprising and unprecedented with respect to current knowledge in allelopathy.
Conventional crop protection with toxic pesticides has often led to issues such as pollution, faunal imbalance, and resistance of pests after adaptation to the pesticides. Deguine et al. review safer, agroecological techniques to control Cucurbitaceae flies, a worldwide pest. Results show that farmers from the Reunion Island have reduced insecticide use with substantial cost savings using agroecological techniques. Such agroecological techniques are currently being extended to other countries of the Indian Ocean.
The burrowing nematode, a worm, is damaging banana plantations worldwide. Actual control methods use toxic nematicides to kill the worm. Alternative control methods are therefore needed due to the high demand for safer and organic food. Agronomists Jesus et al. found that an extract of sisal, a plant species growing in desert areas, is effective to contol nematodes. This method is cheap because the sisal extract is a byproduct of fiber and fabric production from the sisal plant.
Global warming is changing the geographical distribution of pests with, for instance, new insect pests appearing in previously uncontaminated areas. Scientists Lamichhane et al. propose seven recommendations to improve plant protection under a changing climate.
Agrochemicals such as pesticides are used to protect crops and ensure food production. However, conventional formulations of agrochemicals contaminate the environment due to a lack of efficiency. Alternatively, polymers such as polysaccharides can be used to coat the active substance, thus decreasing its toxicity and delaying its release over several days. Moreover, when added to the soil, polysaccharides form hydrogels that improve soil structure, and store water and plant nutrients. The use of polysaccharides are reviewed by Campos et al.
Sisal is a major economic crop in the Bahia state of Brazil. Sisal production is decreased by the infection of the red rot disease caused by Aspergillus niger (picture). Current control methods are not effective, and there is a need to invent sustainable treatments as alternatives to toxic pesticides. Gama et al. tested homeopathic drugs to control red rot. Homeopathic drugs are substances used at very low levels, similar to human disease treatments. Results show that homeopathic drugs reduced disease severity.
Food contamination is due to toxic pesticides that are used to control pests and diseases. Therefore safer treatments are need for better food security. Scientists Luvisi et al. show that soil steaming with addition of potassium hydroxide or calcium oxide decreased the infectivity of the Tobacco mosaic virus below 3.0 %.
