DOWN TO EARTH: PESTS AND DISEASES

SOL MORGAN, GROWISE CONSULTANCY

While processing the abundance that our gardens provide, questioning which crops performed well and which didn’t offers us an opportunity to review and learn.

As a rule, the more fertile and biologically active our soil is, the more likely our crops and other garden plants will be healthy. Plant pests (and diseases) attack crops that show weakness. Unhappy plants don’t photosynthesise to their optimum, creating simple sugars instead of complex carbohydrates. These simple sugars are what attracts the pests to your crops. The ideal is to have optimised plant operations, maintained by good soil health and plant care. Climatic conditions can put stress on plant health, making some crops susceptible to pest and disease attack.

This summer season was quite wet, which proliferated fungal diseases like brown rot in peaches, leaf spot on celery, and mildew on zucchinis. Good cultural practices, especially maintaining soil health, helps prevent disease spread. Practices like maintaining adequate airflow by keeping weeds down, and adequate plant spacing. Ensuring good sunshine action on the garden by keeping the shelter trimmed. Practice crop rotation to lessen the presence of the same crop families in the same ground (which helps maintain various disease populations in the soil). Remove weed species in the same crop family too. Avoid watering in evenings, where moisture and cooler night-time temperatures can encourage disease. Don’t use overhead sprinklers on crops with sensitive leaves like zucchini and tomatoes, which are prone to getting fungal spores splashed up on them. Burn diseased residues or make sure they are hot composted.

Some pests were a nuisance, like green vegetable bugs that tap into the seed in crops like beans and tomatoes. Regular collecting of these in a large Agee jar is effective. Slugs and snails were more prevalent, with more water about. Keeping weeds down deters slugs, and mulched soil supports the crops. Carrot rust fly is minimised with regular application of used pungent coffee grounds around carrots and parsnip.

In the orchard, codling moth damage in pip fruit can be limited using pheromone traps, and Madex 2 (bio-control virus) early in the season. Then trunk paste and cardboard traps during summer, which are removed and burnt in autumn. With greater knowledge of pests, disease life cycles, and what conditions encourage them, there are loads of practices and treatments that can be employed to minimise major outbreaks without using toxic chemicals, to grow a decent crop.