• Botrytis: Ten must-knows

  March 26, 2025

  withstand the cold like no other and is even active at very low temperatures (up to 0°C). The fungus survives on plant parts, bulbs, or in the ground. The spores [...] movement in the crop, and disposing of affected parts in a plastic bag. Focusing on plant resilience has a lot of benefits and reduces the chances of the fungus [...] important to know the following ‘ Botrytis facts’. Botrytis is also called ‘grey mould’. This name indicates exactly what the fungus looks like: grey powder on

• Rainy Woes – Conquering Downy Mildew and Botrytis Naturally

  November 3, 2023

  1: The disease triangle The nexus of the three elements (Susceptible host, Conducive environment, and the Pathogen) leads to the occurrence of the disease [...] can be identified from the violet and brown patches on the leaves. The leaves later turn yellow and fall off. On the underside of the leaves, you often see [...] also called ‘grey mould’. This name indicates exactly what the fungus looks like grey powder on leaves, flowers, fruit, or the stem. The fungus penetrates

• Black sigatoka disease

  month old. The symptoms run parallel to the veins. Within a few days, the spots become a few centimetres in size and turn brown with light grey centres. [...] them, so the spores cannot be discharged from the lower leaves in the stack Use under-canopy (drip) irrigation to reduce splash dispersal Lower the humidity [...] enlarge further and the tissue around the lesions turns yellow and dies. Lesions merge and the whole leaf turns brown and ultimately dies. In cases of severe

• Green peach aphid

  from the plant and disturb the balance of growth hormones. As a result, the plant’s growth is retarded giving rise to deformed leaves or, if the infestation [...] occurs early enough in the season, the death of young plants. Retarded growth and defoliation reduce yield, Plant sap is rich in sugars, but has a low [...] quantities of sap to get sufficient protein. The excess sugar is secreted in the form of honeydew, making the crop and its fruit sticky. Black fungal moulds

• Impatiens thrips

  causing the surrounding tissue to die. The resulting silver-grey patches on leaves and the black dots of their excreta indicate their presence in the crop [...] americanus is often found low in the crop. In sweet pepper the damage can be seen as discolouration of older leaves at the bottom of the plant. [...] egg to adult on the plant, specifically on the leaves. Eggs are deposited in the leaf tissue, while subsequent stages are found on the upper- and undersides

• Onion thrips

  develops in six stages: egg, two larval instars, prepupa, pupa, and finally the adult insect. The eggs of the onion thrips (Thrips tabaci) are laid in leaves [...] head and bright red eyes. The colour of the adult depends on the food source. Onion thrips (Thrips tabaci) usually pupate in the ground, although pupae can [...] by piercing the cells of the surface tissues and sucking out their contents, causing the surrounding tissue to die. The resulting silver-grey patches on

• Downy mildew of rose

  extruding from the stomata. In lettuce, the foot is infected first and this causes the plant to fall over. In cabbage the stem is also infected in severe epidemics [...] brown. On the underside of the leaf fluffy growth appears which is first white and later turns grey-brown. This is, in fact, the sporulation of the pathogens [...] 15 °C. The closer the temperature is to these 15 °C , the shorter the leaf wetness period that is required for germination. Inside the plant, the pathogens

• Cotton bollworm

  long. The first instars are the most mobile, and move like loopers. The caterpillars are often aggressive and cannibalistic. Pupation occurs in the soil [...] 19 mm in length and have a wingspan of about 40 mm. The grey-green males are smaller. The forewings are edged with a line of black spots, and the hindwings [...] General The cotton bollworm ( Helicoverpa armigera ) occurs in the tropics and sub-tropics of all continents except for North America. Larvae of the cotton

• Phytophthora blight

  fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur, usually circling the stem. On potato [...] wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens via water, since the zoospores can readily [...] optimal for crop growth. Phytophthora overwinters in roots, infected tubers and bulbs or in the soil in different stages: as oospores (sexual overwintering

• Cotton leafworm

  caterpillars crawl to the ground and settle in the surface layers. The pupa is 15 to 20 mm long and reddish brown in colour. The forewings of the adult cotton leafworm [...] originates in Egypt, and is currently found in Africa, the Canary Islands, the Middle East and parts of Mediterranean Europe including the Balearic Islands [...] yellow. They are laid in clusters of 20 to 500 pieces on lower leaf surfaces, often on the lower parts of the plant. The female covers the eggs with brownish-yellow