Pre Harvest Interval PHI

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Pre Harvest Interval PHI

The Pre-Harvest interval (PHI) for agricultural pesticides is the period that must be observed before the harvested produce becomes safe for consumption. Respecting this period aims to preserve the safety of the consumer by producing a clean crop that contains low percentages of sedimentation that does not endanger his health.

Accordingly, PHI is one of the most important references that must be noted before starting to use any pesticide on agricultural crops destined for consumption.

What is the Pre-harvest Interval?

It is the period between the most recent date of spraying the pesticide and the safe harvest.  and it is called the prohibition period because it is a period in which it is forbidden for a person to eat the sprayed product definitively for fear of the residual effect of pesticides on these products, which may lead to many diseases if ingested.

The safety period may differ from one crop to another, and from one pesticide to another, according to the period necessary to break down the active substance of the pesticide and its toxic efficacy. Each pesticide has a table that specifies this forbidden period, which may range from one day to 21 days, knowing that the grace period of most pesticides ranges between one and two weeks.

[mpc_quote]The safety period is not adopted in ornamental plants and small trees that do not or have not produced edible fruits yet, so the warning of approaching children is sufficient.[/mpc_quote]

Where can the PHI be found?

Each pesticide manufacturer puts a label on pesticide packages containing all the necessary instructions, especially the safety period or the prohibition period. Therefore, it is forbidden to purchase pesticides of unknown origin, as they do not include a clear and comprehensive label.

The instructions for the safety period are often found in the table attached to the package as indicated in the image below. Knowing that the safety period for one pesticide may differ from one crop to another, the instructions must be carefully read before use.

Table Banana

Are there any pesticides that do not have a safety period?

Many biological and organic pesticides have a “zero” safety period, which means that the crop can be harvested and consumed on the same day of application without causing any harm to the user. An example is Celtek, Novosafe and Novotreat distributed by Debbane. These pesticides are suitable for crops that are harvested almost daily, such as cucumbers.

In addition, international companies have developed new chemical pesticides that are safe for the consumer so that the safety periods are very short, i.e. one day on some crops such as Gatten, the fungicide for strawberries, Benevia, the insecticide for most vegetables, Avaunt the insecticide on tomatoes and others….

Dangers of pesticide residues in agricultural products

Eating agricultural products contaminated with pesticides and that contain pesticide residues increases the risk of infection with:


  • Cancerous diseases


  • Liver cirrhosis in the medium and long term. Because insecticides are considered one of the most dangerous pesticides in the world of agriculture, as they are highly toxic


  • Infertility in men, as it weakens and kills sperm


  • Kidney failure


  • Deformation of fetuses in pregnant women


Therefore, we find that many consumers today do not trust farmers due to what is often heard about the excessive use of pesticides. Some of them refrain from buying cucumbers, zucchini and molokhia from the market, as they are crops with a short growth period, knowing that most pesticides are sprayed without supervision or accountability.

In conclusion, we advise farmers to follow sustainable farming methods within the framework of the ICM (Integrated Crop Management), which requires the use of safe pesticides (with a low prohibition period) in an effective and timely manner, taking into account the safety periods. In this context, we encourage the adoption of preventive methods that reduce the incidence of diseases and pandemics, such as mechanical and physical control, agricultural quarantine, etc…

by Houzayfa El Sayyed

Agrotica Debbaneagri

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