Yield Losses Due to Pests

Since the beginning of what we consider today to be agriculture which was around 10,000 years ago, farmers have had to compete with harmful organisms to insure food security – pests. As with abiotic causes of crop losses, especially the lack or excess of water in the growing season, extreme temperatures, high or low irradiance, nutrient supply – biotic stressors have the potential to reduce crop production substantially.

In agricultural ecosystems, thousands or even millions of individuals of a single crop species are planted in a monoculture. To maximize the growth of the desired crop, we try to eliminate organisms that we consider pests. Pests are organisms that might compete with or damage crop species. They reduce plant density, cause plant stunted growth and their death, cause lower production capacity, damage berries, and in many other ways reduce the yield or quality of agricultural products.

Agricultural pests are plants, animals, and fungi that reduce crop yields. Pest management may be controlled by applying physical (cultivation, mechanical weeding, etc.), biological (cultivar choice, crop rotation, antagonists, predators, etc.), and chemical measures (pesticides/insecticides).

Crop Protection as a Means to Preventing Yield Loss

Crop protection is the science and practice of managing pests, plant diseases, and other pest organisms that damage agricultural crops. Pesticides help farmers to reduce crop damage from pests and increase food production. They’re very important as they improve the quality and yield of agricultural produce. Crop protection has been developed for the prevention and control of crop yield losses due to pests in the field. Pests reduce crop productivity in various ways, classified by their impacts;

• Stand reducers; damping-off pathogens
• Photosynthetic rate reducers; fungi, bacteria, viruses
• Leaf senescence accelerators; pathogens
• Light stealers; weeds, some pathogens
• Assimilate sappers; nematodes, pathogens, sucking arthropods
• Tissue consumers; chewing animals, necrotrophic pathogens

Abiotic and biotic factors causing crop losses

Yield Losses Without Preventive Protection

Without preventive protection with pesticides, natural enemies, host plant resistance, and other nonchemical controls, 70% of crops could have been lost to pests. Weeds produced the highest incidence or loss (30%), with animal pests, pathogens, and plant diseases being less important (losses of 23 and 17%). The efficacy of control of pathogens, plant disease management, and animal pests only reaches 32 and 39 %, respectively, compared to almost 74 % for weed control. Beside losses caused by pests, about 15% of losses are caused by economic damage and a further 15% because of harmful biological diversity and climate change.

Efficacy of pest control worldwide in reducing loss caused by pathogens, viruses, animal pests, and weeds.

Crop Loss Assessment: Where to Start in Order to Reduce Yield Loss

The path to crop health starts in the field, which means that every intervention in the field to a greater or lesser extent will be reflected in the quality of the crop. Protection makes only 5-8% of the total cost during production in one vegetation.

On the other hand, plant health and damages resulting from the absence of proper care or poor performance can be huge. If all other interventions (fertilizing, weeding, tillage …) are not performed properly, there will be a loss in the quality and quantity of farm yield. If protection is omitted or done superficially and inadequately, losses will be even higher.

The Most Beneficial Time for Crop Protection

Once the pest occurs on the plant, it’s very difficult to manage it completely and making yield losses inevitable. Hence, farmers must implement crop protection measures in order to minimize losses to an acceptable level.

Control measures can be applied before the pest attack at the time of favorable conditions. Control measures can also be applied immediately after the pest attack or at the economic threshold. This is the time when the pest population on the crop can cause significant economic damage.

The recommended farm practice is to take preventative measures instead of curative. Preventative measures make up half the work needed in order to provide for healthy and quality crops.

Activities that maintain crops in terms of growth potential and also help us in the fight against pests are:

• Fertilization
• Pruning
• Weeding
• Loosening the soil
• Irrigation
• Removal of crop residues from fields
• Crop rotation
• Tillage

These principles control a number of animal pests and diseases, some of which are certainly the most dangerous: downy mildew, powdery mildew, leaf rust, blight, thrips.

Pest Management: Best Practices

Good agricultural practices which unite the full range of preventive measures are extremely important. When planting permanent crops, you should choose the best location, which should be sunny and airy, where dew/humidity does not retain for long. Sow/plant varieties resistant to most diseases, regularly suppress weeds, keep an eye on conditions favorable to the development of diseases and pests.

Although some pests are not extremely harmful to plants, they all cause at least some, thus reducing the crop quality and total yield. Therefore, accurate and proper pest protection is crucial for yield preservation. It’s assumed by many that crop protection is the most efficient practice in cash crops (53–68%), while in food crops it prevents 43–50% of potential yield loss.

Crop protection was developed in order to prevent and control crop losses due to pests in the field (pre-harvest losses) and during storage (post-harvest losses). Along with production types, a few protection methods are known to be effective, such as:

• Natural; natural pest predators (ladybug, praying mantis)
• Cultural; tracking of weather, monitoring fields, and crops
• Physical; disinfection of the soil, seed, and seedlings
• Mechanical; pruning and removing diseased plants from the field/orchard
• Biological; various beneficial fungi, bacteria, and parasitic wasps used as pest predators
• Chemical; chemical-based fungicides, insecticides, and herbicides

As the part preventative measures used, physical, cultural, and biological measures are used mostly in organic and integrated crop production, where they serve as the foundation of crop protection along with sustainability.

The occurrence of most pests is caused by certain weather conditions; high humidity, low or high temperatures, rain, drought. Weather and temperature data are particularly helpful in following a pest’s life cycle or in predicting how long it takes a certain pest to develop. Using software tools that can help you fight pests and diseases is also a must.

Pest Management Through Smart Farm Management Software

AGRIVI Farm Management Sofware uses cutting-edge agricultural research and real-time data which when with integrated pest management systems recognizes the possible occurrence of pests in your fields and alarms you 7 days in advance. Using AGRIVI, farmers and agriculture supply-chain providers are able to maintain the highest levels of agricultural production and perform on-time pest protection and reduce the risk of lower yield due to pests and diseases.