Winter Crop Analysis
PrintWelcome to the first iteration of our hazelnut crop analysis in conjunction with weather for the Willamette Valley. First, we are only tracking and reporting on January up through to harvest since weather has very little measurable effect on orchards going into dormancy from October through December. These early months of the year are focused on pollination followed by bud and leaf development going into spring.
Of course, the main topic of concern to start the year is how the ice storm affected orchards and pollen. While there was some heavy breakage and splitting of trees in the south valley, this ice storm did not chalk up nearly the same amount of damage that we saw back in 2021. Orchards with good aspect and airflow did not accumulate much ice, so the damage we see is mostly in smaller orchards in the foothills. The difference between these two ice storms though is that in 2021 everything had been pollinized well in advance by March. We may have been just early enough with this storm that we avoided widespread damage to catkins and flowers, but two varieties could be impacted. Both Barcelona and Polly-O had set pollen and started pushing flowers around this time and I have seen and heard from other growers that saw catkins frozen off of trees in both varieties. That said, the crop set for these two varieties is dependent on their flower set and the pollen set of their pollenizer varieties. Major Barcelona pollenizers Hall’s Giant and J-5 had not set pollen yet, and neither had common Polly-O pollenizers Wepster and McDonald. We look to flower damage from there, which is much more difficult to gauge given how small hazelnut flowers are. This is something that time will tell once we start seeing clusters develop in the springtime.
As for the rest of January, pollen shed across all varieties began roughly a week earlier than last year. High humidity in the South Valley and low wind exposure in the North Valley have dampened pollen flight, but all these orchards really need is a nice dry day with a couple of solid wind gusts to set the crop. As for precipitation, this January has seen nearly three times the amount of last January totaling 5 more inches this water year (starting back in October) than last water year. Many young orchards have several acres planted below the high-water mark that we have sustained for a good part of the month thanks to the high amount of precipitation; and depending on soil and variety, this could spell root rot and stunted growth in these areas.
Given some warm days at the end of January and the start of February, we saw bud development occurring in the middle of February only a couple of weeks after pollen was done. This is an entire month earlier than last year when we saw bud break in late March. Last year’s growth developed quickly from bud development into leaf development, but luckily the trees are not pushing leaves yet given the snow/cold snap we had late in the month. Even with freezing temperatures, we are not concerned about bud damage since hazelnut plant cells remain hardy down to the teens without much damage.
Rainfall normalized in February from a very wet January and gave our growers good windows of opportunity to get in the orchards and spray for EFB prior to and during bud development. February, other than EFB sprays, can be an uneventful time for crop monitoring as spring still feels rather far away; however, with bud development underway, farmers are watching their crops closely in this cold weather as growth occurs earlier than expected. With soil temperatures hovering in the low 50s, we can expect trees to push leaves rather slowly until soil temperatures reach that ideal 60 degrees which is more likely to come in April or late March. Nonetheless, it appears we will have an earlier crop than last year which hopefully bodes well for increased time and energy spent on filling kernels.
March started off cold and wet, but we ended up with two nice weather stretches (including the one that followed us into April here). Barcelona orchards made big pushes on leaf growth in the middle of the month while our newer varieties are just now starting to show some vigor. With multiple windows to get important orchard tasks done, I believe this will yield good nut quality and potential kernel fill in the fall as we all know that quality stems from ample preparation. Last year was a challenging start to the growing season with growers facing difficult weather conditions going into spring. We are already 115 growing degree days ahead of last year and 7 inches on average higher on our water year beginning back in October) through March. With soil temperatures working closer to 60 degrees we re getting close to perfect conditions for vigorous growth in hazelnut trees, but be ready for when those temperatures surpass 60 degrees in the soil as weed seeds will germinate and explode onto the scene.
As we trend toward this drier, warmer weather, it will become increasingly important to look at the Vapor Pressure Deficit (VPD) in our orchards as this metric measures the capacity for leaves to perform gas exchange for growth. If you want to calculate your own VPD for your orchard, you can find VPD calculators online where you just need the temperature and percent humidity. Hazelnut trees seem to wake up and perform best with a VPD between 0.25 kPa and 1.0 kPa. Where you will see orchards stressed is when that pressure exceeds 1.25 kPa. We typically don’t see numbers like that outside of July and August. As of now, we are running an average VPD just above 0.25 kPa for the month of March. March of 2023 saw an average of 0.12 kPa, which is not conducive to leaf development. As the weather continues to improve, we will look forward to cell division when we see our nut cluster numbers and hopefully get a better idea of what our crop sizes and yields will be.
Please feel free to reach out any time with questions,
Garrett Gerding
Field Representative, Hazelnut Growers of Oregon
541-589-5037
garrett.gerding@hazelnut.com
