Protection efficiency

The loss factor characterizes the amount of biomass that is lost by external causes, independent from drought or light. In this category, we talk about plant pathogens and insect damage and further separate the plant protection into preventive (passive) and combative (active).

Active plant protection deals with the direct combat of pathogens, pests and unwanted growth of weeds by directly targeting them. Mechanical plucking, chemical agents and the direct handling of infected plants are necessary to protect the whole greenhouse. Based on the intensity of the detected danger this ranges from the plucking of weeds or the application of poison to the removal of entire plants. Combative measures are effective but come with a price. Due to their nature they can only be used when the threat has already shown itself, when the plants are already infected. Early detection systems like sensors in the greenhouse can help, but they cannot prevent it.

Preventive measures are used to prevent an infection in the first place, but need to be carefully considered. Like all preventive actions they cost money and time, without showing a direct positive effect. It is impossible to tell if a greenhouse was not infected by a pathogen due to the preventive measures or just by random chance. Was the application of preventive actions the cause for healthy plants or an unneeded expense? In models this is the area for risk calculations, statistical models that draw data from environmental conditions, other growers experiences and analytical data of the cultivar to determine the risk of an infection. If these risk calculations, whether done by a AI or the growers experience signal a large potential risk for the crop preventive measures are advised. For more details see this article on risk management [Wikipedia].

Further details can be found in the IPM (Integrated Pest Management) section of this handbook.