Phytophthora – which translates from Greek as “plant destroyer” – is one of the most common and destructive blights. It is difficult to manage with hundreds of Phytophthora species existing, each capable of destroying a host of different plants. Phytophthora blight can affect ferns, grasses, crops such as strawberries, curcurbits, tomatoes, potatoes, cocoa, onions, and soybeans, trees such as cedar, birch, dogwood, and citrus trees, and shrubs such as rhododendron and azaleas. In fact, it was Phytophthora infestans that caused the Irish potato famine in the 19th century.

Phytophthora is a water-mold made up of cellulose, therefore is behaves similar to a fungus but is actually more closely related to algae. Because of its preference for environments with excess water, it is most common in spring and fall, and in temperatures ranging from 59-82°F. In potatoes, phytophthora blight that happens later in the season can sometimes be accompanied by a virus making the damage as much as 125-times more detrimental (PotatoPro, 2019). It can be spread through wind-borne rain, runoff, irrigation, and through contaminated soil or equipment. Phytophthora can also overwinter and spread through plant debris. Phytophthora needs only a few hours (4-8) of standing water to take hold. It is also common for newly imported plants to infect others, particularly in greenhouses. Dependent on the plant variety, some symptoms of phytophthora blight include plant weakness, wilting, foliage discoloration, signs of drought-stress or other distress. Many plants also exhibit no symptoms. In trees and shrubs, younger trees are more vulnerable where it may take years for the infestation to kill older trees.

Because phytophthora blight is so proliferate, most management techniques include preparation such as ensuring proper drainage or mitigating damage through digging up infected soil and drying out roots. In trials with tomato seedlings, TerraClean 5.0, an environmentally-friendly fungicide/algaecide, has been found to reduce Phytophthora by 23-55%. It also reduced root-knot, where similar alternatives such as methyl bromide and Ridomil Gold reduced either Phytophthora or root-knot, but not both. Tomato seedlings were inoculated with Phytophthora in August, then the fungicide was applied via drip irrigation once every two weeks until November. Apart from receding the blight outbreak, tomato plant vigor and yield both increased. In a separate trial with strawberry plants, yield increased by 19%.

TerraClean 5.0 can be used to attack phytophthora blight during any plant stage. Composed of hydrogen peroxide and peroxyacetic acid, it kills pathogens, enhances nutrient uptake, and develops a healthier root zone. It can be applied via drip irrigation, drench, flood, and drip application. It is also EPA and OMRI approved as it has no mutational resistance and a 0-hour re-entry interval. While management techniques may work to battle phytophthora blight, it is also reassuring to know there are proactive solutions for the “plant destroyer” as well.

Have you recently noticed those pesky cankers typical of fire blight in your orchard? Fire blight is one of the most common diseases afflicting apples and pear orchards, with around 200 species being susceptible to its damage. Young trees are most vulnerable with complete loss possible in just one season. Even in more established trees, fire blight can kill blossoms, fruit, shoots, twigs and branches. Symptoms can be present in bark, leaves, flowers, and roots from pre-blossom through to blossom and onto fruition.

Fire blight is most adept to happen when trees are in flower, the weather is warm (70-95?), and in humid environments. At temperatures below 70? and higher than 95?, bacterial growth is still present, but grows at slower rates. As a general rule, fire blight is most likely to take root in three weeks following petal fall. This generally happens during May and June in North America. The fire blight bacteria is perpetuated by insects like bees and flies, and can also be transferred during wind-blown rain. Further, diseased cells can survive in plant tissue from one season to the next.

Now, taking this into consideration you may be wondering what your options are to attack this plight, particularly what organic-safe options are out there. Pruning is an option, but presents risks during warmer months where fire blight can actually proliferate from pruning. Fortunately, Enviroselects offers Oxidate 2.0 which can prevent, cure, and even rescue apple and pear orchards from fire blight. Its active ingredient is hydrogen peroxide, and this oxidizing fungicide kills bacteria, fungal pathogens and spores present in apple and pear trees. It can also be used for crops including beans, berries, nuts, potatoes, and herbs among others.

After six applications, more than 70% of fire blight bacteria or fungus was under control (BioSafe Systems, 2012). It begins to work on contact with apple and pear plants or trees. It can be applied every 5-10 days for preventative purposes, every 3-5 days for curative purposes, and depending on the crop variety even more frequently for rescue purposes. It can be applied on field crops or in greenhouses to seeds, growing plants, and mature fruiting trees.

Apart from its successes, Oxidate 2.0 also boasts approval from both the Organic Materials Review Institute (OMRI) and the EPA. It’s safe for both growers and consumers with a 0-day pre-harvest interval, as well as a 0-hour restricted entry interval. With a 2-year shelf life, and no refrigeration necessary, it can also be safely used next season should any fire blight bacteria survive the winter. This product is available right on our website, with further information on the specific pathogens exterminated and related resources.