Eighty percent of human survival relies on plants. As the human population grows, and environmental degradation intensifies, the pressure on providing healthy, nutritious food (amongst other plant-based products) to the world is mounting. Yet, plant production faces challenges as plants are stressed by biological and/or non-biological factors, which hampers production. Scientists are working tirelessly to bring knowledge to the world that will help farmers to overcome the stresses that plants face, and increase plant productivity, while it is required from farmers to action this knowledge. Currently, though, the call for sustainable intensification, which requires greater plant productivity using resources sustainably, is becoming stronger – yet the practical implementation of intensification is more easily said than done. Still, I believe that a change of mind, towards pro-actively supporting plant health, is a reliable first step that farmers can take toward more sustainable and resilient plant production systems.
Plants, before their intended use as food, feed, fibre, medicine, cosmetics, perfume, or furniture need to be healthy and thrive to deliver optimal plant productivity. The highest plant productivity, in turn, gives returns to society and the economy, not only as food but also as a source of income and by creating jobs. However, what are healthy plants and how do we know when plants are healthy? When a plant is healthy it has no abnormalities in its form or function. It can grow optimally and has access to enough water and nutrients to meet its metabolic needs. Healthy plants also have efficient exposure to light, which the plant will use to manufacture carbohydrates (our main food source) and releases oxygen (also critical to human survival). Moreover, when crops and plants are healthy, they do not suffer as badly from injuries, biotic or abiotic stresses– they are less prone to become sick – just like humans, and more likely to reach their genetic potential.
So, how can the decisions the agricultural producer makes contribute to crop health, and the resilience of the crop production system? There are three considerations that I discuss here, which will shift the production system towards a “healthier” system and will make the requirements for crop protection less intensive. These considerations can also contribute to sustainable yields over years. However, it is important to understand that growing healthier crops starts in the planning of the operations. Crop health should be a goal that is aspired to, and not an incidental benefit from a well-managed agricultural system. Long-term strategic choices and management practices should be put in place to benefit crop health. The following three practices come to mind:
The genetic quality of the plant material
Inherent genetic tolerance or resistance to pests and diseases
Some plants will have a genetic tolerance or resistance to pests and diseases. Mostly, in commercial crop cultivars (cultivated varieties), these traits have been bred into the cultivar by many years of dedicated research and efforts by plant breeders. Infield crops, like wheat, plants may be resistant to some of the rust diseases (caused by Puccinia spp.) or insects like the Russian Wheat Aphid (Diuraphis noxia). In tree crops, like citrus or apple trees, the choice of rootstock may have an influence on the level of attack which will be experienced by plant-parasitic nematodes. This also holds for certain types of nut trees as well as for grapevines.
Inherent genetic ability to tolerate abiotic stress
Other than the inherent resistance to biological stressors, recent advances in biotechnological techniques, including genetic modification and speed or selective breeding allows for the development of cultivars with specific abiotic stress tolerance. For wheat, barley, millet, maize, and rice, for instance, drought-tolerant varieties have been developed. Commercial availability of these cultivars globally is still sparse, but it is becoming available and will probably become more commonplace in years to come. Similarly, heat-resistant varieties of crops are being bred again, including wheat, rice, and millet, but interestingly also cotton, tomato, potato, lentil, beans, and brassicas.
High quality planting material
In field crops, the seeds planted needs to be healthy seed of pure genetic origin. If fungicide or insecticide seed treatments are recommended, it should be used. Simple decisions such as planting time and planting depth can make a significant contribution to the success with which plants emerge, and their vigour in first weeks after emergence impacts on the general wellbeing of the crop later in the growing season.The full article is for subscribed members only. To view the full article please subscribe. It’s FREE!Log In Register