With the continued sweltering summer heat and an increase in pest populations, stress to your plant’s weakened defense systems can lead to the loss of valuable growth and overall health of your plant’s transition into the approaching flowering stage.
Soil and Flower Health for Hemp
As we have said before, prevention is the first line of defense against troublesome pathogens and pests. We recommend inoculating the root zone, and spraying foliage consistently. Soil health care for hemp relies not only on the appropriate soil preparation prior to planting but also by means of maintaining healthy hemp roots. Hemp soil requirements for hemp include heavy organic matter, activated biological activity, mineralization, and carbohydrates to feed soil life. Additional plant health benefits for hemp also include; preventative biological fungicides, soil inoculants, consistent soil moisture, and organic foliar sprays for hemp.
Personal Experience with Summer Pathogens and Pests
Through my personal experience, this time of year caterpillars/Lepidoptera, leaf fungi, and soil-borne pathogens deter plant health the most. Lepidoptera species will compromise the flower formation and damage buds with their excrement that becomes a harmful mold. Higher heat and drought stimulate soil pathogens that can become systemic diseases in your plant. Humid air carrying fungal spores and bacteria colonize leaf tissue creating degradation of chlorophyll leading to reduced photosynthesis.
Plant Health Products for Hemp
As with any successful grower, knowing what to plan for and the ability to observe damage to plants will allow a quicker response to boosting your plant’s resistance to stress and disease. This week we are looking at three OMRI labeled products Rootshield Plus WP (soil pathogens), DiPel DF (caterpillars/Lepidoptera), and Regalia CG (induced resistance to fungal infections). All of these products can be applied until the fourth and fifth weeks of flowering. As always, read all labeled product instructions for personal safety and optimal application rates.
Understanding these treatments, and using our recommended plant health products for hemp, will reduce common soil-borne pathogens and pests that are prevalent during drought and high-heat for optimal soil health for hemp and pest resistance.
Common Soil-Borne Pathogens and Plant Disease
Fusarium, Phytophthora, Pythium, and Rhizoctonia are among the most common detrimental soil pathogens that can quickly decimate an entire crop. Most of these pathogens can be easily identified using a 40x microscope or sending plant and soil samples to laboratories. Above the ground, one of the most common pests we encounter at this time of year are caterpillar larvae, and leaf spot known as Septoria.
For Root Zone: OMRI RootShield Plus WP (Trichoderma harzianum strain T-22)
Trichoderma helps prevent and control soil-borne fungal diseases, such as Pythium, by colonizing plant root systems releasing enzymes that damage fungal pathogens. The best way to apply this product is through a root drench, directly covering roots or incorporating it into the root zone. One application provides up to 3 months of protection.
For Caterpillars: OMRI DiPel DF (Bacillus thuringiensis subspecies kurstaki (Btk))
DF stands for dry flowable insecticide that kills caterpillars and borers using the bacteria Bacillus thuringiensis v. kurstaki or Btk. OMRI Listed, it is labelled to control most Lepidopteran (caterpillar) insects on fruits, citrus, tropical fruits, vegetables, grains, bulbs, flowers, herbs, turf, ornamental trees and shrubs. After ingesting a lethal dose, larvae stop feeding within the hour and will die within a few hours to 3 days. It is best used when the larvae are actively feeding but before the plants are heavily damaged. Applications should be made in the evening, covering the top and bottom side of leaves. Re-apply after heavy rain, or at least once a week for 3-6 weeks.
For Leaf and Plant immunity Response: OMRI Regalia CG (Reynoutria sachalinensis)
Highly compatible with beneficial insects and beneficial nematodes, Regalia CG also helps the plants defense against the effects of Powdery Mildew, Fusarium, Phytophthora, Pythium and Rhizoctonia. Regalia CG contains an extract of Giant Knotweed (Reynoutria sachalinensis). which boosts plant vigor and growth while stimulating the plant's ability to develop resistance to plant pathogens (induced resistance). This developed resistance builds plant health as opposed to attacking the disease directly. Apply this product as a foliar spray 2-3 times a week in rotation with other products in your IPM.