Pest and disease identification

Pest and Disease Identification

Understanding Pests

  • Pests in the horticulture industry are organisms that cause damage to cultivated plants and crops.

  • Pests can include a wide range of species including insects, mites, nematodes, slugs, snails, rodents, birds and larger mammals.

  • Key identifiers for insect pests can include damage patterns such as chewed leaves, wilting plants, holes or tunnels in plant tissue, or presence of a sticky substance known as honeydew.

Common Types of Pests

  • Aphids are common pests which are small in size and come in shades of green, black, brown and pink. They tend to cluster on the undersides of leaves or on stems.

  • Slugs and snails can also cause significant damage, identifiable by a slimy trail and large, irregular holes they eat into leaves and stems.

  • Caterpillars are another common pest. These are more noticeable due to their size and characteristic feeding patterns, often leaving holes or notches in leaves, and can be a particular problem for fruit-bearing plants.

Understanding Diseases

  • Plant diseases are usually caused by pathogens or by environmental stresses.

  • Pathogens include viruses, bacteria, and fungi, all of which can spread disease among plants.

  • Signs of plant diseases include discolouration, spots on leaves, galls on roots or stems, wilting, rotting, and stunted growth.

Common Types of Diseases

  • Powdery Mildew is a common fungal disease where plants display white powdery spots on leaves, stems and buds.

  • Rust is another fungal disease, identifiable by orange or brown pustules on undersides of leaves.

  • Fire blight, a bacterial disease, causes wilting of branches that look as if burnt by fire. It can also produce a sticky, white liquid.

Importance of Accurate Identification

  • Proper pest and disease identification is crucial as it forms the basis for implementing an effective Integrated Pest and Disease Management programme (IPDM).

  • Correct identification allows for appropriate treatment selection, which can reduce the risk of unnecessary use of pesticides or the spread of disease.

  • Identifying the problem early can prevent wide-scale damage and crop loss.

Knowledge of pests and diseases is key within horticulture. An understanding of types of pests, their traits, and the signs of diseases ensures that measures can be put in place to effectively manage and mitigate the risk they pose to plant health and productivity.