Phytotoxicity can simply be described as plant poisoning. This generally occurs when a substance or mixture of substances are sprayed or dusted onto plants and those plants suffer negative effects afterward. Since there is generally no guarantee that any lawn and garden product is safe for all plants, phytotoxicity can result from products such as plant foods, pesticides, and herbicides. The effects can include death, abnormal growth, or discoloration of plants.
There are many ways that phytotoxicity can occur, and there are often different time frames in which the effects will be seen. In some instances, plants react to substances like humans with food allergies react to certain foods. The substance can be applied, and within a short period, it will become evident that the plants are intolerant to it.
Over-spraying can also result in phytotoxicity. Sometimes plant growers over-spray when they use too much of a substance. The plants may be able to tolerate a substance in smaller doses, but a grower may consciously or unconsciously over-saturate her plants only to find that she poisons them. This is one reason why many lawn and garden products have directions and suggested application amounts.
A grower can also over-spray by mixing substances that her plants cannot tolerate. The plants may be able to handle those substances individually, or the plants may be completely intolerant of certain contents in a mixture. It is much the same as when products such as ammonia and bleach are mixed for cleaning purposes. Individually, those products can be used successfully, but mixing them results in a dangerous concoction.
Some substances will not cause plants harm the first time they are sprayed. Phytotoxicity can result after numerous uses although the initial use provided no negative indications. There may be several explanations for this.
It could be a situation where the grower is not allowing sufficient time between applications, so the chemicals are building up. There is also the possibility that weather has had an impact on certain substances. This can happen when there is a lack of rain or if chemicals that work best in cooler climates are exposed to excessive heat.
Another culprit that may cause phytotoxicity is dirty equipment. Growers can poison their plants simply because they have not properly cleaned spray bottles or tanks. When a grower puts a substance into a dirty container, she is unknowingly exposing it to traces of other substances which could have detrimental effects on her plants. This may not happen immediately, but eventually the plant could be affected by the undetected substance.
There are several ways to reduce the chances of phytotoxicity. Growers are generally encouraged to read labels or informational pamphlets before using a product. Growers are also typically advised to perform sample applications if they are not sure of the effects a product will have on a particular plant species. Furthermore, before mixing substances, an inexperienced grower should seek advice from a professional.