Plant Manipulation In Fruit Bearing Vegetable Crops

Suckering and Trimming

A sucker is a small shoot, which forms between the petiole and the stem on crops such as tomatoes. Suckers drain plant nutrients, which would normally be channelled into fruit production. Suckers are removed when they reach approximately 2 to 5 cm in length.

The suckers are removed by simply snapping them off between the thumb and index finger. Alternatively, they can be removed using a knife, but this poses a potential of spreading disease.

Trimming of side-shoots is done regularly using a knife or shears. Always disinfect after each plant has been trimmed. If the growth tip is damaged the side shoots will grow profusely, one of the side shoots and can then be selected as a new leading shoot.

During growth the older, mature leaves die. These leaves are susceptible to diseases and should be removed. Removal of older leaves also improves the ventilation around the bottom of the plant. The number of leaves removed and depends on the grower and plant cultivated.

Fruit Manipulation

Fruit thinning is a process through which fruit that are malformed or poor colour developed are removed. Fruit are removed in areas where diseased leaves have been removed to allow for sufficient leaf development.

Fruit ripening may be manipulated using specialised chemicals. A compound such as Ethephon can be used to induce even ripening in tree crops. Similarly, chemicals such as HCN are used to induce bud break in crops that are require low temperatures for bud break.

Pollination

In most popular hydroponics crops pollination may be required. This is usually done by ventilation, insects or movement of workers through the glasshouse. By vibrating the stay wires on the trellising, the plants can be shaken, aiding pollination.

Trellising of Plants

Trellising is labour intensive and should be done taking care not to damage plants. It ensures that plants are kept upright and do not lie on the ground. Plants need to be manually twisted around the trellis system. Some trellises have removable supports which are removed to make the process easier.

Some plants are layered to keep the harvesting and handling height below 2.5m. Various trellising systems can be used on different species.

Creeping type plants require trellising. A trellis is a simple structure, which is used to support the plant. The simplest trellis is one in which wire is spun against a wall in a grid pattern. The plant is then threaded through the grid and allowed to grow.

This kind of trellis can be made to fit any shape that may be required. The wooden poles are secured in the ground by digging a suitable hole and inserting them into the hole. The poles are then laid against one another and fastened using string or wire.

Trellises can be manufactured from wood, which is nailed or screwed together in a square, or diamond shaped design.

The trellises are made in pre-determined width and height to suit its application.

A simple trellis is made by planting poles into the ground at pre-determined distances. Several horizontal wires are now spun parallel to one another. The plant’s main shoots are merely draped over the wires. In some cases, they need to be fastened to the wires.

In hydroponics systems trellising could be as simple as a wire that is spun from the roof to the floor of the tunnel. The primary shoots of a tomato; pepper or cucumber is then simply wound around the wire.

It is important that the shoot is fastened to the trellis, that the plant is not damaged with the binding being used. The binding could be specialised plant tape or thin wire