Sunday, February 4, 2024

RIMpro – to spray or not to spray using ‘virtual’ vs. weather station weather data

 RIMpro from their website (rimpro.cloud) “is a decision support system (DSS) for the sustainable management of pests and diseases in fruit and grape production. Every day, the cloud service together with the weather data system help thousands of growers and consultants worldwide to make the best decisions to protect their crops.” 

In 2023 I subscribed to RIMpro using both a hardware based weather station connected to NEWA (newa.cornell.edu, as Belchertown-2) and their virtual weather data service Meteoblue (meteoblue.com). My intent for using both was to be able to make a comparison of the weather station vs. virtual weather data ‘after the fact’ in terms of making spray decisions to manage apple scab, fire blight, and codling moth. It’s obvious the two sources of weather data  are going to differ, but that was not the point in making these comparisons. So I won’t belabor that, but I will discuss how using the two different sources of weather data may have made an impact on the decision-making process to “spray or not to spray” to manage the above-mentioned pests. The answer, of course, and as always, is “it depends.” Realize also this comparison was made at the end of the growing season when all the weather data was “in.” No attempt made to compare the forecasts in the midst of the growing season. (That’s a whole nother story.)

Apple scab

I just looked at primary scab using 1-April as a green tip date. Weather data that factor into the scab model include temperature (I presume but it does not show up in the RIMpro data file?), rainfall (to trigger spore release), and leaf wetness (duration). Looking at timing of spore maturity and last available spores to cause infection, there is not much difference there in the RIMpro chard (Figures 1 and 2) with an end date of approximately 10-June. I don’t care so much about that as long as they are close, but what I do care about is the RIM value(s) which are a measure of infection risk, being low, medium, or high. In Figures 1 and 2 I placed the arrows where I figured, based on what I know about RIMpro and primary scab management with fungicide sprays of some sort -- be it protectant, or protectant plus kickback fungicide – would have been required to manage a primary apple scab infection. Count how many fungicide spray black arrows there are in either plain old UMass Orchard or UMass Orchard-MB (MB = Meteoblue, virtual weather data). I count seven for each weather data source. No difference in number of sprays, right? (I'm sure my assumptions about spray timing will be argued.) But, what bothers me a bit, is it appears the RIM value is much higher for MB in several infection “events.” Looking at the raw weather data RIMpro uses, it’s clear that MB  “overestimated” by a factor of approximately two times both rainfall and leaf wetness compared to the weather station. “Overestimated” is assuming the weather station is correct? In particular, it’s likely the leaf wetness hours were the primary contributor to the difference in magnitude (as measured by the RIM value) of the infection events. Begs the question, which is correct, the leaf wetness sensor on the weather station – and we know there are issues there – or the modeled leaf wetness by MB? Good question. (Here's more on how RIMpro models leaf wetness duration for virtual weather station.) Just look at the duration of light blue which signifies leaf wetness in the weather data charts (Figures 3 and 4). What’s my inclination here? Well, looks like the MB output is a bit more conservative in the approach to manage apple scab = better safe than sorry? Know what I mean? Although not affecting the timing of fungicide sprays, the rate of fungicide might be adjusted upwards? I can see the plant pathologists out there shuffling in their seats.

Figure 1 - apple scab model output using weather station data

Figure 2 - apple scab model output using MB virtual weather data

Figure 3 - weather data chart using weather station

Figure 4 - weather data chart using MB virtual weather data. Note the extended periods of wetness (light blue) compared to Figure 3

Fire blight

I am no fire blight expert. We did have a significant fire blight outbreak in 2023 at the UMass Orchard. I don’t quite understand why MB showed that two more infection thresholds were reached compared to the weather station? Using the MB approach, three streptomycin sprays should have been applied vs. one for the weather station  (Figures 5 and 6). Which do you think would have been the better defense? Well, after the fact, and given our observed fire blight outbreak by early summer, following MB might have been the better strategy? I note that the prediction of visible symptoms was pretty much right on in RIMpro, as fire blight was indeed seen on June 5 (Figure 7).

Figure 5 - fire blight model output using weather station weather data. Date of strep spray is estimated
 
Figure 6 - fire blight model output using MB virtual weather data. Dates of strep spray are estimated

Figure 7 - fire blight symptoms observed 5-June, 2024 at UMass Orchard

Codling moth

I am no entomologist. But I do know something about codling moth management based on adult flight, mating, and larvae hatch, the latter being the ideal time to control codling moth with a targeted insecticide. So, looking at both outputs I see little difference in suggested insecticide timing between the two sources of weather data (Figures 8 and 9). Likely because the model is largely based on temperature, and we know that virtual weather data is pretty good at predicting/adjusting temperature such that over time the two sources of weather data end up being pretty closely aligned. That is about all I have to say about codling moth, I’d feel comfortable using MB there. And you have to love RIMpro’s approach of tagging ‘virgin’ females and ‘mated’ females. Maybe I am the only one that finds that amusing?

Figure 8 - codling moth model output using weather station weather data

Figure 9 - codling moth model output using MB virtual weather station data

A final note about Meteoblue, you can subsctibe to a free daily email from them that gives you a succinct graphical image of the weather forecast specific to your location. I get it daily, and have found the forecast to be about as good as anything else, although far from the perfect forecast. I particularly like their graphic which gives you a one-shot-in-one-place-in-your-face picture of the forecast as seen in Figure 10.

Figure 10 - Meteoblue Meteogram forecast for Belchertown, MA on 19-May, 2023 

So, although RIMpro is not for everyone as it's a bit dense unless you are really into it, I do highly recommend it as a 'precision' pest management tool. RIMpro has other models too numerous to mention here, but the stone fruit brown rot model might be worth mentioning. And, it can be site-specific (anywhere in the world) using the MB virtual weather data. Colleague Srdjan Acimovic at Virginia Tech University is a big proponent of RIMpro, and he is hosting a webinar about RIMpro on 20-February, 2024. I will be there. Rimpro also just launched on the App Store for iPhone and iPad...



Saturday, January 6, 2024

2023 - the year (that I would just as soon forget) in review

 OK, a little something different, not to sound cliche, but "2023 - the year in review." And this kind of sums up how I feel about 2023...Blow me one last kiss!

Month-by-tedious month, with some picts and comments...

January

Was the warmest January on record in Massachusetts, average temperature of 35 F. (max 55, min 32) at the UMass Orchard in Belchertown, MA according to NEWA. Trees have accumulated enough chilling hours to come out of dormancy and are not particularly at maximum winter hardiness either. So wait for it...

These Gala buds looked pretty good on 16-January. No snow to speak of.
Dr. Duane Greene gave the George A. Goodloing Memorial Lecture at the Mid-Atlantic Fruit & Vegetable Conference in Hershey, PA on 31-January.

February

...an arctic cold front brought record cold on 4-February, -13 F. at the UMass Orchard in Belchertown the day after we returned from Hershey. Following highs approaching 50 F. the last week in January. Bye-bye peach (and cherry) crop for 2023.

Peach buds hosed on 6-February at the UMass Orchard and across Massachusetts.

What a difference a day makes...

Honored at International Fruit Tree Association Annual Conference on 16-Februaryin Grand Rapids, MI after nine years on the Board of Directors. Along with Jeff Clerveringa and Dale Goldy, us "old guys."

March

Our winters seem to be "back-end" loaded lately, it snowed and was rather cold. Average March temperature was 38 F. It was 35 F. in January and 32 F. in February. All right, it warmed up a bit. Passed the time co-hosting Northeast Plant Growth Regulator meeting and spoke on Precision Apple Cropload Management and Apple Varieties at Maine Pre-season Fruit Meeting in Lewiston, Maine. And oh yea, I got my FAA Part 107 UAV Pilot license!

Looks like the most snow we had all winter on 15-March.

Northeast PGR meeting 7, 8-March, Wilkes Barre, PA. The group toasts PGR meeting fixtures of past who passed in 2023, Butch Palmer, and Jeff Alicandro. I think Jeff would approve.

Welcome to Lewiston, Maine. Although I love the place... one smart daughter of mine went to Bates College.

April

Struggled a bit here to come up with memories. Oh yea, pruned my quad-v peaches hard (no crop). Planted NC-140 Porters Perfection cider apple trees with a little experimental overlay using Biosafe pre-plant program. First apple bloom was a little early?

Pruned quad-V peaches hard on 11-April to reduce height, what's to lose with no crop?

Zestar! first bloom on 24-April, a bit earlier than ideal...

NC-140 Porters Perfection apple rootstock planting ready to be planted. Unfortunately, this second batch to trees -- after Fedex lost my first batch -- were less than ideal in uniformity.

May

Ugh, things were looking good until May 18. Apple bloom was the first week. OK. Things were looking pretty good. Did my first drone flyovers using the Outfield-Orchard Management Platform to map apple blossom density. Post-May 18, when the temperature dropped to 28 F. during late petal fall to fruit set, it got pretty depressing. Oh well, there is always 2024. Carnegie Melon University (CMU) crew plugged away with their robot at the UMass Orchard despite the freeze-damaged apples.

View from up above of apple block in bloom on 2-May at UMass Orchard. Outfield makes novice pilot like me (upper right) looks pretty competent. No crashes (yet).

Gala apple cluster on 23-May is hosed from the May 18 freeze.

CMU with their robot measuring apple fruitlet size using computer vision to attempt to predict fruit set. Hampered by the freeze though, had to move out of this frozen Honeycrisp block.

Zestar! (left) and Honeycrisp fruitlets severely damaged post-18-May freeze event.

 June

Fire blight -- result of May 18 freeeze trauma event -- first visited, then stuck around (uninvited). Quick visit to see orchards and friends in MN/WI. By the end of June, rootstock bark failure in several orchards was coming to light resulting in tree decline. Not good. 

Fire blight symptoms first observed on 5-June, then it got worse on Crimson Crisp by end of month.

Joe Ferguson, yours truly, and Thomas Bernard at Ferguson's Pepin Heights orchard overlooking Mississippi River/Lake Pepin.

Rootstock shank bark failure was becoming commonplace in several orchards
 by end of June, mostly M.9 and several Geneva rootstocks, resulting in apple tree decline by tree girdling.

July

Attended Essex Junction High School 50-year Reunion in Vermont on 15-July. Lots of woe up there though. IFTA summer study tour in Nova Scotia. That's about it.

It turned out to be a disaster in much of Vermont

Overlooking the Minas Basin from the "Lookoff"
in Canning, Nova Scotia, Canada, 24-July
 

August

Attended Reality Research/MAIA field day out in Wayne County, NY. Midwest Apple Improvement Association arguably the biggest apple breeder/tester in North America now? Dr. Jason Londo from Cornell visits to look at rootstock/tree decline issues in Massachusetts. We are all still scratching our heads but lead theory is winter cold damage. 

Bill Pitts discusses new MAIA apple 'Sweet MAIA' (among many other things);
apple selection test plot planted by Reality Research/MAIA, pretty ambitious IMHO. 


Physiologist Jason Londo from Cornell examines rootstock failure at the UMass Orchard in Belchertown, MA on 1-September, Londo had visited orchards on 31-August so this counts as August :-)

September

Not much happened here, althought it was alternately hot (92 F. on 6- and 7-September, as hot as it got all summer) and wet (9-10 inches of rain!). Wrapped up 2014 NC-140 Honeycrisp planting over several picks, it was no fun giving the condition of the apples (freeze damage, rots, inadequate thinning, oh no!)

Fruit Surface Temperature on Honeycrisp apples on 7-September, not quite high enough for sunburn damage on apples.

It was wet, wet, wet!

It's a wrap says 'Suaz' with final harvest (after 10 years) of 2014 NC-140 Honeycrisp trial at UMass Orchard, quality was 'meh' so it was a bit of a slog.

October

Depending on site, apple crop was generally better than expected after the May freeze event. But it was far from perfect. First and second of five meetings/trips stretching into December.

Lee Kalcsits from Washington State University discusses tree decline issues at Tougas Family Farm in Northboro, MA on 11-October. Lee was a guest speaker at the UMass Cranberry Station in Wareham, his topic bitter pit of apples. How'd that happen? Maybe had something to do with Giverson Mupambi being his post-doc at WSU?

With some persimmon trees outside the Musser Fruit Research Center prior to attending the MyIPM app working group meeing at Clemson University, 3-October. My rental wheels while there had Massachusetts plated, glad I didn't get pulled over by 'Smokie!'

The UMass 'fruit team' along with colleagues from NY and CT hike 'The Pinnacle' outside of Bolton Landing, Lake George, NY prior to our annual New York/New England/Canada IPM working group meeting at the Fort William Henry Lodge and Resort in Lake George, NY (23- and 24-October).

Despite the tough year for growing apples, these Suncrisp look pretty good on 30-October at the UMass Orchard in Belchertown.

November

Meetings 3 and 4, Great Lakes Fruit Workers (GLFW) centered in Buffalo, NY and NC-140 rootstock research project annual meeting in Holland, MI. Gave two talks at GLFW -- one on apple tree decline and one on my work with Outfield (drone). Keynote address by retired (and highly respected) Cornell entomologist Art Agnello at Clarksburg Cider (which was yummy). Agnello's address was both entertaing (humorous) as well as serious considering some of the groundbreaking apple IPM work done by Art and his colleagues at Cornell over the past 40 (+/-) years. At NC-140 presented our Massachusetts state report and had a nice-day tour of Michigan State University Clarksville and Southwest Michigan (Benton Harbor, my old stomping grounds) fruit research stations. Oh yea, I snuck in a talk at the Connecticut Pomological Society Meeting in Middleton, CT on 'Honeycrisp disorders' and I started one cut pruning on most of my older apple variety (not going anywhere) plantings at the UMass Orchard in Belchertown. Several reasons for this, I won't go into the details... 👎

Art Agnello keynote at GLFW, Clarksburg Cider, 2-November. Art is a true professional IMHO and I greatly respect him.

NC-140 group at MSU's Clarksville horticultural research station on 7-November where we visited the Great Lakes Cider Apple Collection.

One-cut pruning by me commenced on 21-November at the UMass Orchard.

December

May have been the trip of a lifetime, off to Australia to attend the ISHS Symposium Precision Management of Orchards and Vineyards (PMOV). Way too much to detail here, but you may want to look at the Book of Abstracts. And I survived driving on the wrong side of the road without an incident! (I learned my lesson pretty quick while driving wrong way once shortly after leaving the Melbourne airport, fortunately a grassy turnaround once I realized my mistake when I saw the white arrow on the pavement pointing in the direction -- wrong way -- I was driving!) The highlight of my trip was the weekend after PMOV spent with Garry Langford in Hobart where he treated me to an amazing tour of the surrounding area. Alas, I think we spent way more time sightsseing than looking at orchards in Tasmania, but that was just fine and dandy with me. Hobart is a great little city if you every have the opporutunity, go there! And thanks Garry for the Aussie hospitality!

With Luca Corelli at PMOV. Luca was on the ISHS Symposium scientific committee and a long-time fruit researcher at the University of Bologna, Italy.

Sweet cherries with rain covers and apples on 10-December near Grove, Tasmania. Cherries have been very lucrative (Asian export market) in recent years for growers there, allowing investment in modern, multi-leader apple plantings.

Garry and Jon atop Mt. Wellington (1,271 meters above seal level) on 9-December, Hobart city in the background.

I have a Flickr photo album with full res pictures of all of the above and a few more bonus pics.


Saturday, October 7, 2023

Half-baked research: Honeycrisp bitter pit and rootstocks, 2019 & 2020

 

Is this bitter pit?

Yea, this is pretty half-baked all right, but meaning to look and summarize it for quite some time now, recently pushed by colleague Win Cowgill to look at B.10 in this data set based on a recent publication suggesting B.10 was really good at NOT having bitter pit with Honeycrisp as the scion. Humph...

OK, so this work was part of a much larger NC-140 sub-trial honchoed by Cornell's Terence Robinson and WSU's Lee Kalcsits to assess the incidence of bitter pit on Honeycrisp as affected by (many) rootstocks in two NC-140 Honeycrisp plantings, 2010 and 2014. In addition to percent bitter pit in the apples as I will line out below, apple peels were also sent off to Lee for nutrient analysis and Lee and his/our team are working on a real scientific publication (not half-baked) which I will try to update here when it comes out.

For the purposes of my results presented below, basically, 50 Honeycrisp apples (or less if there were not that many on the trees) were evaluated for bitter pit at harvest and after three months regular cold storage. These apples were on trees in the 2010 and 2014 NC-140 plantings at the UMass Orchard in Belchertown. And this was done in 2019 and 2020, although in 2019 the crop was light and there were not enough apples in the 2014 planting to evaluate for bitter pit. You will see what the rootstocks are included in the results. When evaluating the apples for bitter pit incidence, no evaluation was made for severity of bitter pit, apples either had bitter pit (1 or more pits) or not (zero pits). Got it?

OK, so here are the results, pretty self-explanatory, but then I will bullet-list caveats and my take-homes after. 😉 Note you can click on any of the tables/graphs to get a larger image if these are difficult to read (too small) or blurry...

% Bitter Pit (BP) at harvest in 2019 in the 2010 NC-140 Honeycrisp apple rootstock planting. Capital letters (A, B, etc.) mean there is a siginificant difference when %BP is not followed by the same capital letter(s).

% Bitter Pit (BP) after 3 months cold storage in 2019 in the 2010 NC-140 Honeycrisp apple rootstock planting. 

% Bitter Pit (BP) at harvest in 2020 in the 2010 NC-140 Honeycrisp apple rootstock planting. 

% Bitter Pit (BP) after 3 months cold storage in 2020 in the 2010 NC-140 Honeycrisp apple rootstock planting. 

% Bitter Pit (BP) at harvest in 2020 in the 2014 NC-140 Honeycrisp apple rootstock planting. Capital letters (A, B, etc.) mean there is a siginificant difference when %BP is not followed by the same capital letter(s).

% Bitter Pit (BP) after 3 months cold storage in  2020 in the 2014 NC-140 Honeycrisp apple rootstock planting. Capital letters (A, B, etc.) mean there is a siginificant difference when %BP is not followed by the same capital letter(s).

OK, let's unpack this:
  • Although some general and obvious conclusions about rootstock effect on bitter pit incidence can be drawn here, there was missing data and different numbers of apples evaluated, i.e. not always 50 apples were available, so don't take these results to the bank. What follows though, I am pretty confident about saying.
  • In the 2010 planting, in both 2019 and 2020, the only time there was a significant difference in % BP by rootstock was at harvest in 2019. There G.41 had significantly more BP than B.9, G.214, and the two M.9 clones. G.41, got that?
  • I have been trained to not go here, but may we conclude a few things on the non-significant results in the 2010 planting in both years, 2019 and 2020? Yes, I have my reasons. G.41 is generally in or near the top of the list in % BP. B.9 is generally low or near the bottom of the list in % BP. Hmmm... B.10 exhibits more BP than B.9 but generally expressed less BP than most of the Geneva rootstocks. (Sorry Win and Sherif.) G.214 among the Geneva rootstocks seems less bitter pit prone and comparable to B.9 and M.9. I don't know what to say about M.26 but I don't generally recommend that rootstock for Honeycrisp. My theory on all this is the Geneva rootstocks are generally more vigorous than B.9 and M.9, set a lighter crop, and thus are more likely to have BP'd apples? Plus I understand research has shown some issues with various ratios of nutrient (Ca, Mg, and K in particular) uptake among the rootstocks.
  • In the 2014 planting, there were significant differences in % BP vs. the rootstocks both at harvest and after 3 months cold storage. After cold storage, G.11 and G.41 were the worse but technically did not significantly differ from many of the other rootstocks. How come I did not have B.9 or B.10 in this planting? Good question. I clearly remember technician Jim (I miss him now) commenting when evaluating the bitter pit how bad the bitter pit was in the apples from the 11's and 41's. Also in terms of severity (how much bitter pit) he said which was not taken into account here. The vigorous V. (Vineland) rootstocks were generally pretty bad, and once again, among the Geneva rootstocks G.214 (4214) did not have that much bitter pit. I really like that rootstock, however, have been recently made aware of some winter hardiness issues with it.
So, my/your take homes?:
  • Bitter pit research is so very hard to do, there are so many factors that contribute to bitter pit development it is not even funny. See Dan Donahue's Honeycrisp Playbook (to mitigate bitter pit risk).
  • For the reason mentioned above, Geneva rootstocks -- with maybe the exception of 214 -- are more pre-disposed compared to the less vigorous and heavy cropping (which has it's own downside) B.9. M.9's are in there with B.9 but might be more prone to bitter pit. The slightly more vigorous (than B.9) B.10 might be a better choice than G.11 or 41 with Honeycrisp (or any other bitter pit prone variety, Jonagold?) as the scion.
  • I have a saying "friends don't let friends plant Honeycrisp on G.41" largely based on my overall experience, including in a significant commerical planting of Royal Red Honeycrisp on G.41 where the bitter pit therein has just been untenable (to date). And this is a good grower, the planting otherwise looks spectacular, although the crops have been lighter than desired. Oh wait, until 2023. Which has looked a lot better, very little bitter pit in that block. But a heavier crop and a very wet summer? And I understand the grower really threw the calcium at them this year after last years ugly look. I also have noted that my NC-140 Honecyrisp trees seem to have a lot less bitter pit than last year. This year's weather effect and a heavier crop? Or maybe as the trees get older they are settling down more? Although this is the 10th leaf, BP was bad last year in the 9th leaf. So I will temper a bit my saying above going forward. And there are obvious benefits to using Geneva rootstocks.
Seems to me I had some other things on my mind regarding this BP issue, but that is enough and this is about as half-baked as it gets, but it also is what it is, and my field observations kind of align with the numbers which don't lie? You just have to question the procedures 🤣 and do some of your own unpacking... 😎