• By |Published On: July 19, 2014|Last Updated: December 24, 2024|Categories: Lettuce, Macro nutrients, Micro nutrients, Physiological disorders|Tags: , |

    It is often quite difficult to identify a deficiency or toxicity symptom in the field because they never really occur as a single element deficiency or toxicity. Each of the elements are inter dependent and they influence each other within certain ratio’s. One would find for instance that phosphorus toxicity, is expressed as either a [...]

  • By |Published On: June 14, 2014|Last Updated: June 14, 2014|Categories: Pests|Tags: |

    Description Thrips tabaci and western flower thrips Frankliniella occidentalis are sap feeders. Common thrips as in the main image; Order: Thysanoptera, Family: Thripidae. They are extremely small and are difficult to spot, even by experts. They are experts in blending in and are shorter than 1.5mm. There are about 4500 species of thrips. Both winged and [...]

  • By |Published On: February 15, 2014|Last Updated: October 31, 2014|Categories: Pests|

    Description Russet mites (Aculops lycopersici, Aculus lycopersici) are so small that a 14X hand lens is needed to see them. Because of their size, these mites are rarely noticed until plants are damaged. At this time, there may be hundreds of yellowish, conical-shaped mites on the green leaves immediately above bronzed leaves. Aceria lycorespici is the tomato [...]

  • By |Published On: December 6, 2013|Last Updated: October 31, 2014|Categories: Pests|Tags: |

    Plusia looper description Plusia looper, also known as Cabbage looper or more correctly Trichoplusia ni are light green caterpillars with white or pale yellow stripes along the sides. It typically moves by arching the middle part of its body upward. The adult moth is active at night (about 1 ½ inches or 3.8 - 4.0 [...]

  • By |Published On: December 1, 2013|Last Updated: October 31, 2014|Categories: Pests|Tags: |

    Bollworm description Bollworm, also known as tomato fruit worm or American Bollworm, Helicoverpa armigera, are small caterpillars (about 30mm long, slightly more than 1 inch) that have prominent rows of dark bumps on their backs. Mature worm's colour varies from dark grey to light brown and have lengthwise stripes on their bodies. The adult form [...]

  • By |Published On: November 18, 2013|Last Updated: October 31, 2014|Categories: Crop protection, Cucumbers, Physiological disorders|Tags: |

    Physiological disorders caused by low temperatures Low temperatures injury only occurs with fruit that are in storage (either in transit or in storage rooms). Small circular pits each 3-9mm in diameter and up to 1 mm deep appear. They can coalesce to form large irregular sunken areas. The minimum temperature that cucumber fruits should be [...]

  • By |Published On: November 8, 2013|Last Updated: February 15, 2014|Categories: Pests|Tags: |

    Sweet potato whitefly description Sweet potato whitefly (Bemisia tabaci, order Hemiptera and family Aleyrodidae) is a sap feeder. The adults are about 4-5mm long with a pale yellow body. The sweet potato whitefly can easily be identified by their red compound eyes.  When feeding their wings are slightly apart creating a shallow "V" shape. The [...]

  • By |Published On: September 24, 2013|Last Updated: February 15, 2014|Categories: Pests|

    Red spider mite description Red spider mite, of the genus Tetranychus urticae, are sap feeders. Although there are several species of spider mites which attack plants, the red spider mite and the two-spotted spider mite are the most common. The red spider mite is often referred to as the “red spider”, the “red mite”, or [...]

  • By |Published On: August 31, 2013|Last Updated: February 15, 2014|Categories: Pests|

    Leaf hopper description Leaf hoppers are usually less then 13mm in length, with long slender tapered bodies. They tend to be pale green to tan in colour, and may have dark markings. They usually infest the lower surface of leaves and if disturbed move sideways very quickly. They also have a characteristic hop when disturbed. [...]