Judgment and treatment of disease in orchids

Orchids are plagued by diseases just like people in the process of growing. Regardless of the seriousness of the phenomenon, it is necessary to know for a beginner to raise orchids. Generally speaking, the disease of orchids may be based on the following factors: for example, "insufficient air circulation" where orchids are planted (placed); damage caused by "chemicals" (pesticides or fertilizers); and attacks by "bacteria", "viruses" and "insects". Here can only provide some common symptoms to discuss with the novice orchid farmers, as for the correct identification needs to have more knowledge and experience.

(1) Pseudocorm wilt

Orchids of any species have pseudobulbs, and the difference lies in the size of the corms. The main reasons for the long-term "water loss" of orchid plants are: insufficient humidity in the air, insufficient watering, poor root growth and inability to absorb water.

(2) the flowers wither quickly.

The flowering time of a flower depends on the variety. If the flowering time is much shorter than normal, there is a problem. If you lack two or three days, it may be due to climate, flowering season or poor plant health, don't worry, but if the difference is too much, it may be caused by the following reasons: too great changes in the cultivation environment (for example, orchids newly purchased from Orchid); affected by transport vibration (most commonly caused by accidental shedding of pollen); attacked by harmful gases (such as excessive ethylene in the air) The temperature changes from cold to hot (depending on the cultivation season and conditions).

(3) the leaves turn yellow.

If the yellowing leaves occur on old plants (especially newly transplanted) or older leaves, the yellowing rate is slower, it is a natural aging phenomenon, that is, the so-called metabolic effect, do not worry. If yellowing occurs on new leaves, there are the following reasons: too much sun exposure (shady varieties should not be exposed to direct sunlight), frostbite by cold wind and frost, injury by inappropriate pesticides, lack of nitrogen fertilizer, and root damage.

(4) the leaf tip blackened.

It usually occurs when there is too much fertilizer (or too much fertilizer). If this happens, you should stop fertilizing immediately and wash the soil in the basin with clean water. Other possible causes are: poor water quality and bacterial infection (the leaf should be cut off and fungicides should be applied).

(5) there are spots on the flowers

This situation is often caused by the following reasons: a sudden rise in temperature (the temperature should be lowered immediately); poor ventilation (ventilation should be increased to make the air flow), and if the disease is found, the diseased plants should be isolated immediately.

(6) Root damage

This is the most troublesome and common phenomenon for many reasons: too much watering; poor ventilation, making the cultivation site too wet; poor drainage; soil not renewed for a long time (in principle, it should be changed once a year); inappropriate fertilization (too high concentration or too dense times); too heavy pesticide spraying; poor water quality; parasitic insects in the basin; improper planting methods, etc.

(7) Flower deformation

This phenomenon is common in the following situations: genetic factors (caused by cross breeding); overuse of budding agents; being attacked by viral viruses; too high or too low temperature during flower bud formation; and flower buds damaged by foreign chemicals.

(8) Flowers, buds and roots are affected by insect pests

The most common ones are the larvae of snails, slugs, ants, moths and butterflies. Insecticides should be sprayed frequently, giving priority to prevention.

(9) the leaves have black spots.

It is generally caused by the following conditions: intense light after watering (spots do not expand, only affect appearance); caused by bacterial invasion (spots will expand, the damaged leaves should be removed).

(10) White powders or brown dots

This phenomenon often occurs in the case of poor ventilation and parasitic ants in the basin. Most of them are leaf back, pedicel and plant head. This is a scale insect, caused by ants sucking secretions. When the quantity is small, it can be scrubbed with a small brush and water, and then sprayed with insecticide, or the whole pot of orchid can be soaked in insecticide water. It is usually killed once a week for three consecutive weeks. It is still dominated by prevention and supplemented by treatment. (Mak Fen)