BOTRY-Zen® is a biological control agent consisting of a live spore preparation of the non-pathogenic saprophytic fungus Ulocladium oudemansii.  BOTRY-Zen® competes for the same ecological niche as other pathogenic diseases, specifically Botrytis cinerea and Sclerotinia sclerotiorum. BOTRY-Zen® competes for nutrients and physical space to occupy the dead and senescing material that the pathogenic diseases would normally colonise.

BOTRY-Zen® has been through extensive trialling since 1997, proving its efficacy even under heavy Botrytis and Sclerotinia pressure.  The wettable granule formulation with a shelf-life of 12 months is easy to store and handle.  By following the ‘Best Practice’ information, control as good as a full-season chemical programme can be achieved with a BOTRY-Zen® programme.


Best Practice



BOTRY-Zen® is a biological control agent developed specifically for the control of Botrytis cinerea in grapes, blackcurrants, kiwifruit and ornamental flowers and forSclerotinia sclerotiorum in kiwifruit. BOTRY-Zen® is certified organic by BioGro, OMRI Listed (USA) and IFOAM (International).

The active ingredient in BOTRY-Zen® is a naturally occurring saprophytic fungus, called Ulocladium oudemansii. This means that in the wild it grows on and colonises, dead and decaying plant material. It is this important characteristic that makes it ideal for targeting decaying and damaged plant tissue that is also the same food source for Botrytis/Sclerotinia. By excluding Botrytis/Sclerotinia from these sites of early disease development within the crop, BOTRY-Zen® works naturally and out-competes the disease for the same ecological niche.

BOTRY-Zen® is non-invasive and causes no damage to live plant tissue. With this mechanism of action it is highly unlikely that resistance to BOTRY-Zen® will develop.

Trial data

BOTRY-Zen® has been trialed in New Zealand since 1997 in wine grapes, kiwifruit, blackcurrants and ornamentals. Trials in wine grapes have also been conducted in the United States, France, Germany, Greece, Slovakia and Spain. The results of these trials show that when BOTRY-Zen® is applied correctly, it provides protection against Botrytis/Sclerotinia infections comparable to a standard fungicide programme.

BOTRY-Zen® has recently been included in the product testing programme carried out by Kiwi Vine Health in their bid to control Pseudomonas syringae pv. actinidiae (Psa). In the test work under heavy infection conditions, plants were assessed after 15 days and BOTRY-Zen significantly reduced Psa leaf spotting.

In October 2013, after the good results from last seasons’ field trials, Botryzen (2010) Ltd applied to update its registration to include a Limited Claim for Psa – Not Fully Proven.  This was granted by ACVM.

In May 2014 BOTRY-Zen® was officially added to the KVH/Zespri spray charts for ‘Post Harvest’ usage in controlling Psa in Kiwifruit. On the recommended Product list it states:

“Apply post-harvest through dormancy. Should not be applied when fruit is on the vines as it can cause staining. Certified BioGro Status. This product is available for Psa-V control on orchards that have completed harvest”.


BOTRY-Zen® is applied through standard spray equipment. As with any spray application, coverage and timing are vital in obtaining a good result. BOTRY-Zen® can be tank-mixed with a number of fungicides, refer to the list of  compatible products or contact our technical team for further information.

Following approval for the use of BOTRY-Zen against Psa (Limited Claim for Psa – Not Fully Proven) applications are recommended from bud-burst to fruit-set, and then again after harvest and at pruning.