It’s been about four weeks since we started the Hop Nutrient Deficiency Demonstration project.

If you remember, the demo has two hop cultivars (Cascade and Willamette), one plant each undergoing one of 9 fertility regimes (distilled water, complete nutrient solution, -N, -P, -K, -Mg, -Ca, -Fe, -B).

I didn’t expect to see much happen so early in this first season but I was wrong!

Plants receiving the complete nutrient solution have been very vigourous from the beginning of the demonstration, while plants receiving only distilled water and the -N treatment have remained small with limited growth and are exhibiting chlorosis (yellowing) of the leaves. Plants receiving other treatments are also starting to exhibit trademark deficiency symptoms. One of the most visual to date is the no Iron (-Fe) treatment. Below are some photos from this week of each treatment.

Nutrient Symptoms to Date:

-N: Plant stunting/slow to no growth, pale green to yellow leaves.

-N (L-R: Cascade leaves from complete nutrient solution (1x); -N; distilled water (dH2O)).

-P: Plant stunting/slow growth (not as severe as -N).

-K: Yellowing (tan colour) on leaves, scorching on leaf margins.

-Ca: Yellowing and necrosis of leaf margins, some necrotic spotting on leaves.

-Mg: Minor yellowing of older leaves.

-B: Minor yellowing in younger leaves.

-Fe: Severe yellowing between veins of leaves (veins have remained green – ‘interveinal chlorosis’), growing points dying back.

Other general comments to date: overall, the Cascade plants are much more vigourous compared to the Willamette. On May 3rd, thrips were identified on most plants and were controlled on May 4th. Some thrip damage was noted on the lower leaves (scraping and mottling of the leaves and frass on the underside of the leaves). Most plants have grown out of the minor thrip damage.

As you can see, some of the plants are starting to struggle on their nutrient solution regime. In the coming weeks many of the severely affected plants will receive a dose of the complete nutrient solution in order to keep them alive for the duration of the project.

Other posts related to this demonstration project: