The plant research community has a valuable and practical new resource available: a rapid-cycling Brassica oleracea population that can be used to map the genetics of many traits simply by phenotyping. The population and related resources are described in a recent publication led by Zach Stansell in Thomas Björkman’s lab at Cornell University.
The map and reference genome are complete
Bioinformatic-analysis pipeline is available
Seed is available for free
Researchers only need to phenotype and analyze
The BolTBDH population is derived from a from a cross of rapid-cycling Chinese kale with broccoli. It is particularly valuable for studying reproductive development because progeny lines have inflorescences that range from non-heading to fully heading broccoli. Variation is documented for many other traits, such as architecture and glucosinolate content, and variation in many others remains to be explored and documented.
Zach Stansell has adapted his tool for breeders so that it is usable for any crop that has a highly subjective breeding goal.
We are sharing the information with various media outlets. The first pass is a publication in the Cornell Chronicle.
Many horticultural crops need to meet the quality criteria of a particular market or of the main breeder. They need to meet those criteria in many environments. How can you test for quality in many locations at the same time. This technique is good at predicting the reference person’s quality score by having trained raters make objective measurements.
The package is posted on GitHub so that anyone can use it for free. It is annotated and revised to work with just about any trait of interest or any crop. The revision was done with Deniz Akdemir, Cornell statistician. The development of the method is published in HortScience (Stansell, Zachary, Thomas Björkman, Sandra Branham, David Couillard, and Mark W. Farnham. 2017. Use of a Quality Trait Index to Increase the Reliability of Phenotypic Evaluations in Broccoli HortScience 32:1490-1495. doi: 10.21273/HORTSCI12202-17 )
One of the challenges with raising broccoli in the East is getting heads to stay dense. In the warmth of summer, the outer branches of broccoli tend to start elongating a little before harvest maturity. They “blow up” in the words of many producers. The result is a head that doesn’t pack tightly in the box and has soft edges that are prone to damage in handling.
The solution is to let growth slow a little during the week before harvest. Growth is promoted by the combination of warmth, water, nitrogen, and sunlight. Warmth is a given for harvests in July and early August, sunlight we have no control over, and abundant water sometimes comes whether we want it or not. The main management tool is nitrogen.
Slowing growth by reducing nitrogen is a considerable challenge because abundant nitrogen is needed during the vegetative growth to get strong, healthy, fast-growing plants. The best approach is to supply nitrogen relatively early in the growing period, and not add nitrogen in the last four weeks.
Many popular broccoli varieties are harvested starting only eight weeks after transplanting. Therefore, the last nitrogen application should be only four weeks after transplanting. At that time, the foliage is near full cover, which a good time for a traditional side-dress application as well as cultivation to get escaped or newly germinated weeds. Fertigation through a trickle-irrigation system would be during the fourth week. At that time, the plants are large enough to take up the nitrogen but not so far along that excess growth at harvest will cause loose heads.
Applying all of the nitrogen before planting is a possibility. Ordinarily, applying 120 to 150 pounds per acre of nitrogen preplant is ill-advised because of the high likelihood of leaching before the crop takes it all up. However, because broccoli is only in the ground for about nine weeks through the end of harvest, and reaches its maximum uptake five weeks after transplanting, the risk of leaching loss is relatively low compared to the typical situation. Pre-plant application of the fertilizer opens up production options that don’t allow side-dressing or liquid fertilization.
This early-nitrogen approach is also helpful in reducing hollow stem. Hollow stem is likewise a symptom of excessive late vegetative growth. The main tool for managing hollow stem is adjusting the plant population. If hollow stem is a problem, it’s likely that both yield and quality will be improved by spacing the plants closer together. In New York we have found an in-row spacing of 8 inches to work quite well. But limiting late nitrogen also tempers the growth rate at the right time.
This article was published in VegEdge on June 5, 2019. A publication of the CCE Cornell Vegetable Program.
The Eastern Broccoli Project is intended to supply some of the growth in broccoli consumption in the East. The bulk of supply comes from coastal California in the summer and the desert southwest in the winter. But now, imports from Mexico are playing a greater role.
When the project started in 2009, Mexico was not a significant supplier of fresh broccoli to the East. That has changed. The volume from Mexico to the US is over $200 million per year. The frozen market is almost entirely from Mexico and Central America.
Mexican imports primarily compete with winter production in Florida and Georgia. The volume in the winter months has been rising over the last five winters, more than the summer imports. Growers in those areas are also expressing concern about the effect of the USMCA trade deal, fearing that it would allow dumping in their market.
Eastern production is closer to the Northeast market than either Mexico or the desert, but it is significant. The distance to the terminal market in Bronx NY from Hastings, Florida is 1000 miles in 15h of driving. From San Luis Potosi, Mexico is 2400 miles in 36 hours, and from Yuma, Arizona is 2600 miles in 39 h.
There are some facilities to freeze broccoli in New York. Developing a frozen deal for New York growers would be needed for a customer like a school system that specified New York broccoli under the farm-to-school program, but needed ready-to use product in their kitchens during the school year. The frozen-food giant Bonduelle raises and freezes broccoli in Québec, so the economics can be made to work nearby.
Thanks to USDA-ERS economists Kamron Daugherty and Broderick Parr for compiling this important information.
We have eagerly awaited the 2017 Census of Agriculture to see whether the Eastern Broccoli Project is having an effect. Today, the results were released, allowing us to compare our early effect (2017) with the pre-project baseline. We are happy to see so many more Eastern farms finding a place for broccoli in their crop mix.
One consideration is that broccoli can get too big, and get hollow stem. Growers harvesting in the heat of summer find that making the last nitrogen fertilization four weeks before harvest helps avoid the excessive burst.
Some early varieties are maturing in 50 days in the summer. If you do the math, that means the last nitrogen side dress or fertigation is just three weeks after transplanting. Putting on ~150 lb/ac of nitrogen without burning the plants takes some planning.
The article show that wholesale buyers expect broccoli to look familiar. Local variants with slightly different color or flower-bud size were acceptable only to natural food reseller, not at standard supermarkets. The challenge for a new region is to meet standards that were developed for other production areas.
Eastern buyers are eager to source more Organic broccoli locally. Fortunately, broccoli is suited to Organic practices. Nevertheless, meeting that demand will require efficient production.
This webinar will cover management approaches for Organic production that help production efficiency. Prospective growers will come away with a better sense of how to achieve success, and current Organic broccoli growers are likely to pick up some useful ideas to increase their profitability.
Jeanine Davis, Margaret Bloomquist and Richard Boylan, North Carolina State University, experts on organic production systems
Thomas Björkman, Cornell University. Vegetable physiologist
Bryan Brown, NYS IPM. Weed management specialist and expert on organic weed management
Jill Eccleston, Cornell University, Integrated control of emerging insect pests
Organic nutrition for a nitrogen-hungry crop
Weed management in high fertility and short season
Insect management amid many hungry pests
Varieties suitable for organic production in the East
The market for organic broccoli
Join the webinar by clicking this link: https://cornell.zoom.us/j/855304241 on a computer, tablet or smartphone. To test your Zoom connection in advance, please visit https://zoom.us/test. It may take a minute or so to install the small software.
To get the audio only on a telephone, call +1 646 876 9923 and enter meeting id 855304241
Sponsored by the Eastern Broccoli Project (a multi-institutional project funded by USDA National Institute of Food and Agriculture, Specialty Crop Research Initiative).
Alternaria was widespread in the East this year. Unrelenting rain after mid-August created conditions in the Northeast that were conducive to this normally secondary disease. More important, the strain going around was not controlled by the most commonly used fungicide.
Christy Hoepting conducted a fungicide trial to test both our current fungicide program and new materials. Azoxystrobin (Quadris) is widely used, and a 2014 survey in New York showed no resistance. (Cornell pathologists Meg McGrath and Chris Smart are checking for known and novel resistance in 2018 isolates.)
This year, Tim Coolong reported in August that a Quadris-resistant strain was showing up in Georgia. Christy’s trial showed Quadris failing to control in New York. The good news is that the Alternaria was susceptible to fluxapyroxad and pyraclostrobin, the active ingredients in Priaxor. Priaxor is already labeled for use in New York, except Long Island.
The hot and humid weather with heavy rainfall from remnants of hurricanes during August was the perfect storm for Alternaria leaf spot (ALS) to rage out of control in brassica crops across Western New York in 2018. Cornell Vegetable Program fresh market specialists received several complaints about a disease that caused unsightly lesions on both leaves and marketable portions of brassica plants. When ALS attacks the head of broccoli or cauliflower, it renders them unmarketable. Hoepting visited with a grower who was planning to cut broccoli production by one-third, because he had just lost over 85% of his most-recent 5-acre planting to ALS head rot, a loss of $7,500. She immediately set up an ad hoc small-plot replicated trial on his farm in hopes of finding a fungicide that could control this devastating disease.
By the time the broccoli was ready to harvest, differences among treatments in side-by-side plots were striking. In the untreated check, 98% of the heads were unmarketable due to severe ALS, while the best fungicide in the trial, Merivon (fluxapyroxad and pyraclostrobin) had only 5% unmarketable heads. The fungicides that the grower had been using, Bravo and Quadris (azoxystrobin), resulted in 98% and 49% unmarketable heads, respectively. Commercially available fungicides Switch, Quadris Top and Endura had significantly lower unmarketable heads than Quadris with only 10 to 33%.
Priaxor can be applied at most 2 times sequentially and 3 times total. The only targeted fungicide that can be used with it in a program is Switch (cyprodinil and fludioxonil) because its active ingredients are in different chemical groups (FRAC groups 9 and 12) from those of Priaxor (7 and 11).
If the grower were to adopt a 4-week fungicide program with top-performing fungicides, he could expect to get at least 75% marketable heads. Compared to his Bravo/Quadris program, which only yielded 1470 pounds and net $1,323 per acre, the new program could increase both yield and net profit 5-fold by 5881 pounds and $5,562 per acre, despite a 5-fold increase in cost of fungicides from $44 to $223 per acre. After viewing the fungicide trial on his farm, the grower immediately adjusted his fungicide program to include the most effective fungicides in all of his remaining brassica plantings. He is planning to resume full broccoli production next year with the new fungicide program, which has potential to increase profit by $166,860 in his 30 acres of broccoli. Trial results will be shared with CVP growers over the winter, so all conventional growers can benefit from improved ALS control in their brassicas.
For a 2014 survey showing all 47 isolates being susceptible to Quadris, see Kreis, Dillard and Smart. Plant Disease. http://dx.doi.org/10.1094/PDIS-03-16-0414-RE
Note added January 11: Today at the Southeast Vegetable Conference, Dr. Bhabesh Dutta of the University of Georgia at Tifton showed that the pathogen present in Georgia this year is a different (new) species of fungus that it is not controlled by azoxystrobin. Pathologists around the East are testing isolates from their regions to determine whether this species is the one that cause unusually high losses in the region.
This result is useful in that Dr. Dutta has already identified a fungicide program that should be effective in 2019. If the other azoxystrobin-resistant isolates turn out to be the new species, it mean that there has not been a change in the usual Alternaria.
One fascinating thing about visiting Southwest Florida farms is seeing their distinctive seepage irrigation system. I had heard it described, but I didn’t really get it until I saw it in action.
Unique soils in Florida have allowed growers there to develop a an effective irrigation system that differs in many respects from what I have seen anywhere else. Sandy soils overlay a hardpan just below the maximum rooting zone. That situation allows lateral seepage of irrigation water over considerable distances with hardly any slope.
One of the significant advantages of this system is less disease. Because all the water stays underground, it is rarer for the foliage to be wet and the humidity, while naturally high, is lower. Thus the conditions for fungal spores to germinate and for hyphae to grow are considerably less common.
A couple other unique features make the system work. First, the land is very flat. Whole fields can be irrigated where the underground water table is maintained at an exact distance below the soil surface on the bed tops. In addition, field are interspersed with vast swamplands that serve as storage for irrigation water. Irrigation water can not only be drawn from these reservoirs, but it is also returned to them at the end of an irrigation cycle.
"Developing an Eastern Broccoli Industry through cultivar development, economically and environmentally sustainable production and delivery" is supported by the Specialty Crop Research Initiative of the USDA National Institute of Food and Agriculture, under Award No. 2016-51181-25402.