cabbage

My report Cabbage

        My report about cabbage; it is all about the cabbage. You will learn in this report all about cabbage. Its major pests like insects. Cabbage scientific name is Brassica olerace a member of the family Crucifers. It is a leafy green biennial plant, grown as an annual vegetable crop for its dense-leaved heads.  Biennial plant is a flowering plant that takes two years to complete its biological lifecycle. And it is Similar to many other vegetables cabbage is not indigenous to Asia. It originates in Western Europe, with temperate climates like here in the Philippines.

MAJOR CABBAGE INSECT PESTS

Diamondback moth - Plutella xylostella

Its description: They are grayish-brown in color and have three light brown to white, triangular marks on the edge of each forewing. When the moth has settled at rest, marks join together to form three diamond shapes along the middle of the back. This is why the moth is called diamondback moth.

Diamondback moth - Plutella xylostella

The caterpillars can be up to 13 mm long. DBM caterpillars vary in coloration from a light brown at hatching to dark green when fully grown. The body can have white patches and black spots. Caterpillars usually feed on the underside of leaves. Diamondback moths caterpillars destroy the foliage of most cruciferous crops. Severe infestations of DBM are particularly destructive when the caterpillars attack plants at the seedling or newly transplanted stage.

Its natural enemies

Has been successfully introduced in highland areas in Philippines. In the highlands of Cordillera, Philippines introduction and release of Diadegma semiclausum has reduced the use of chemical insecticide sprays by up to 80% in the dry season and 55% in the wet season.

Next pest of cabbage is Aphids ( Brevicoryne brassicae)

Its description: The wingless aphids are up to about 2.5 mm long, grayish-green in color, with a dark head and black stripes on the body. The aphid is covered with a grayish-white colored waxy powder, which is also secreted onto the surface of host plants. The first signs of attack are small bleached areas on the leaves of infested plants. The leaves then turn yellow and become crumpled. The aphid colonies are protected inside the crumpled leaves. The effects of infestation are worst on seedlings and young plants. Its natural enemy or its predator are  lady beetles and hover flies (Syrphids) and parasitoids like the wasp Diaeretiella rapae are important natural enemies of the cabbage aphid.

 Prevention activities: the best way of preventing many pests and diseases. for example just after transplanting, or when too much or too little fertilization is added or when the soil structure is poor. And the most effective prevention and control measure is to eliminate as many of these sources of infestation as possible to prevent the aphids from spreading to the new crop.

Next is Flea beetle - Phyllotreta sp

The description of this beetle: The adult beetles can be separated by color into two major groups: one in which the back is black with two longitudinal yellow bands (the striped flea beetle) and the other group in which the back is of one color, usually black. And Flea beetles are characterized by their enlarged hind legs with which they make long flea-like leaps. As their name implies, flea beetles have the habit of jumping when disturbed. Its plant damage by flea beetles is most evident on seedlings. Severe damage can be caused by beetles feeding on the seedlings below soil surface, before the seedlings emerge above the soil. Prevention can be use Solarization of the nursery soil may help to reduce the number of larvae and pupae in the soil. Weed control is another good prevention activity as flea beetles are often associated with weedy areas.

The Cutworm - Agrotis sp

The name ‘cutworm’ is given to caterpillars of various moth species that feed on plants at ground level, usually cutting young plants at soil level. There are two species of cut worm the

Agrotis ipsilon - black cutworm, greasy cutworm

 

Agrotis segetum - common cutworm, turnip moth

Larvae are usually active during the night and spend the day hiding in the litter or in the soil. They can be found to a depth of up to 12 cm. The caterpillars have three pairs of true legs just behind the head and five pairs of false legs in the middle and last part of the body. Cutworm caterpillars curl up when disturbed. Prevention activities that can be use are Weed removal: weedy land harbors most cutworms as the adult moths prefer these sites for egg laying. Weeds also serve as food for the first in star larvae. And Flooding of the infested field to drown larvae and other soil-inhabiting pests may be an option when irrigation facilities exist. This is an option when the field is known to contain many cutworms and should be applied before preparing the land for a new crop. And once cutworms are present Hand collection of larvae may be possible for small plots. Cutworms may also be trapped under small pieces of wood or pieces of rigid cardboard, placed in the field. When searching for shelter during the day, the cutworms may hide under these things and can be collected more easily.

Armyworm - Spodoptera sp.

The name ‘armyworm’ is the common name for a stage in the life cycle of certain moths. “Armyworm” is more a behavioral term: when the supply of food for armyworms is running out, they may “march off” over the ground like an army to find new feeding locations.

The main species of armyworms

Spodoptera exigua - lesser armyworm, beet armyworm

Spodoptera lituralis - common cutworm

Plant damage: Armyworms skeletonize host plant leaves. Egg batches are laid close together and in a severe year clusters of many caterpillars may rapidly defoliate of cabbage plants. This is usually a problem from seedling until cupping stage. When the cabbage head is formed, usually not much damage is done. Prevention activities such as Burning of crop stubble and removal of weeds help to lower the pest population. The armyworms may survive on crop stubble and weeds after harvest and infest a newly transplanted crop, causing crop injury. Flooding of the infested field to drown pupae and other soil-inhabiting pests may be an option when irrigation facilities exist. This should be done before preparing the land for a new crop. Ploughing the field will bring larvae and pupae to the soil surface for exposure to sunlight or predators like birds. And once armyworms are present Hand collection of larvae and egg masses may be possible for small plots. It is not practical for cabbage production on larger scale.

Cabbage heart caterpillar - Crocidolomia binotalis

These slightly hairy, small (15 - 25 mm) caterpillars have orange heads, a creamy-yellow underside and a light green back with fine, longitudinal white lines. Another name used for this insect is the webworm, cabbage head caterpillar or cabbage leaf-Webber. Plant damage: For the first 4 or 5 days from hatching, the small larvae feed on the underside of the leaf without eating through the upper leaf layer, creating window-like damage in the leaves. After this they move to the growing point of the plant center or bore to the center of the head. Its plant damage In the open center, groups of caterpillars will conceal themselves beneath silk webbing and frass. Crocidolomia damage results in a completely destroyed plant or false cabbage head with no real head or several small heads. Prevention activities it is preferable to plant cabbage during the rainy season when populations are reduced. However, cabbage crops in the rainy season may have more disease problems. Ploughing field to will expose pupae to drying sun and birds ·Removing plant debris after harvest and before transplanting to reduce populations. Once the Crocidolomia caterpillar is present Hand removal of egg masses and early in stars: trials done reflect that handpicking of caterpillars is a good way of control. During the first 40 days after cabbage transplant, while leaves are still open and relatively few, caterpillars are easy to spot in the field. The first symptoms are “windows” in the leaf. Handpicking was easier and quicker than spraying individual plants with insecticides because for good chemical control, the whole plant needs to be sprayed very thoroughly. Plant damage On hatching from the egg, the young Hellula larvae bore into the base of the leaf-midribs, and also into the stem, sometimes going down as far as the roots before emerging for pupation. Cabbages often develop small, multiple distorted heads of no commercial value. Prevention activities such as Burning of crop stubble and removal of weeds help to lower the pest population. Some webworms may survive on crop stubble and weeds after harvest and infest a newly transplanted crop, causing serious crop injury. The critical period for webworm attack begins when the first true leaves are forming. It is important to inspect the nursery every few days for presence of these caterpillars, especially during or shortly after the rainy season. Once the webworm is present Low populations in the nursery may still be controlled by handpicking the caterpillars or eggs. And Removal of infested leaves or even the growing point may be considered.

Cabbage looper - Trichoplusia ni

There are several English names for this insect: cabbage looper, cabbage semilooper, ni moth or the false cabbage looper. The cabbage looper is a smooth yellow-green caterpillar with a whitish line down each side, and the forepart of the body slightly narrower than the rest. It can have two white lines along the middle of the back. Plant damage:  The caterpillars of the semilooper eat large, irregular holes in the leaves.  Young larvae skeletonize leaves. The older larvae eat the entire leaves, sometimes causing plant defoliation. As loopers mature, they move deeper into the cabbage heads. They can consume large parts of the hearts of cabbages, and contaminating it with frass. Prevention activities such as Removing or burning of crop residues and removal of weeds help to lower the pest population. Cabbage loopers may survive on crop stubble and weeds after harvest and infest a newly transplanted crop, causing new crop injury. Ploughing the field may bury crop residues containing looper pupae in the soil where they die. Once cabbage loopers are present Hand collection of larvae may be possible for small plots. It may not be practical for cabbage production on larger scale.