- Author: Alison Collin
How could one possibly refrain from trying a vegetable variety that goes by the intriguing name of Smooth Criminal?
One of the most exciting developments in squash breeding has resulted in a space-saving, vertically growing hybrid, and for those of us who are tired of the endless battles controlling the summer squash bug population this variety may go a long way to help reduce the problem.
For starters, Smooth Criminal which is the result of the breeding program at Seneca Vegetable Research and the University of New Hampshire carries the gl-2 mutant gene which reduces spines on the plant, both on the leaf petioles and stems. This makes harvesting and checking for squash bugs less skin-abrading for the grower, and the young tender fruits have less damage to their surface.
Not only that, but this plant has an upright habit, with the pale yellow fruits produced sequentially along the stem. Although it will need to be staked it has been found by some growers to be less attractive to squash bugs because the fruits are carried well off the ground.
However, none of the information regarding this prolific squash makes any mention of its flavor so time will tell as to whether the positive aspects of growing it are worthwhile.
To offset this I have decided to grow an AAS award winner, Caserta-type hybrid squash, Bossa Nova, (see photo above) which has a compact bush type habit and is said to have an excellent flavor with very smooth flesh. The fruits which are generally zucchini shaped are pale green with darker green patterning, are uniform, and produced early and over a long season.
For a few years I have been growing Tiana F1 butternut squash which has become my all-time favorite for its smooth texture, strong colored flesh, straight-sided blocky shape, prolific crop, and excellent keeping abilities. I have just eaten, in mid-February, my last fruit which was harvested in late September. However, it has one major downside – the sheer size of the plants. One plant covers almost half my vegetable plot, rampaging over any other crops that are in its way, rooting wherever a node touches damp soil and continuing on across the lawn.
I really needed to find something smaller so this year I will be trying Butterscotch. This is another AAS award winner that produces smaller fruits on compact, semi-bush plants needing only 6sq.ft of space each and is said to have a very complex sweet flavor. It should produce fruits weighing between 1-2lbs and will keep in storage for about 3 months. An added feature is that it is also resistant to powdery mildew. It will be interesting to see if the compact form with fruits closely produced in the center will make it harder to see and reach any squash bugs.
Links:
- Author: Mike Hsu
Population explosion of insect vector contributed to $100 million in losses in 2020
While most Californians are wholeheartedly embracing the wet start to winter, one group is welcoming the rain more warily (and wearily) – lettuce growers in the Salinas Valley.
“It's a blessing, yes, we need the water,” said Tony Alameda, managing partner of Topflavor Farms, which grows a variety of produce in Monterey and San Benito counties. “But, oh gosh: with that water, here come the weeds, here comes the habitat, here comes all the other problems that go along with it.”
Weeds are overwintering havens for a tiny insect called the Western flower thrips, which in turn carries the impatiens necrotic spot virus (INSV) – a plant virus that caused $100 million in lost gross revenue for Salinas Valley growers in 2020.
The agricultural community called it “the biggest problem we've seen in a long, long time,” said Mary Zischke, facilitator of a task force convened by the Grower-Shipper Association to address INSV and a related affliction, Pythium wilt.
Widespread crop failure in 2020
Since INSV was first observed in the state in 2006, the virus – which poses no threat to people – triggered significant crop losses in 2019, leading up to a catastrophic 2020. As Alameda's lettuces began to show the telltale “bronzing” of the leaves, efforts to bag up or remove the infected plants had no effect on the virus' implacable spread.
“Nothing seemed to work,” he recalled, “and you just watch those fields collapse, week after week, until you're just like, ‘Ugh, there's nothing here to even harvest.'”
After “100% crop failure” that year in his prime fields at the heart of the Salinas Valley, Alameda tried to dodge the virus in 2021 – shifting lettuce plantings to San Benito County and instead using his most valuable land for unaffected crops such as cilantro, leeks and radishes. By decamping to San Benito, Alameda was able to harvest 70% of his usual lettuce yield.
Generally, growers enjoyed a reprieve from virus pressures in 2021. Even in this “good” year, however, about one-third of all lettuce plantings in the Salinas Valley had at least a low level of infection, according to Zischke.
“Since we were attributing a lot of our so-called good fortune – on having less damage this year – to the cooler weather, we know we can't count on that to get us out of this problem,” Zischke said. “All the models point to the fact that we're in a warming climate, so we were fortunate this year.”
More research needed on thrips
Heat waves were a major driver of the INSV disaster of 2020. Although researchers have established a link between warmer temperatures and population increases of thrips, science still has a lot to learn about those disease vectors.
“Thrips are something we're trying to understand as much as we can, but it's pretty tough because they're a little mysterious in the way they get around and where they overwinter,” said Richard Smith, a University of California Cooperative Extension vegetable crops and weed science farm advisor for the Central Coast region.
Smith – along with U.S. Department of Agriculture research entomologist Daniel Hasegawa and California State University-Monterey Bay plant pathologist JP Dundore-Arias – provided an INSV update during an Assembly agriculture committee hearing in December.
Recent studies have identified several weeds as key “reservoirs” of thrips, including malva, marestail, and hairy fleabane. The ubiquitous mustards, fortunately, appear to be poor hosts for thrips, although their pollen serve as potential food sources.
Controlling those weeds – which are beginning to spring up as the days lengthen – is a top priority during the winter months, according to Smith. Aggressive weed management in the preceding winter was an important factor in limiting the virus' spread in 2021.
And because weeds recognize no boundaries, experts are also urging managers of non-agricultural lands to keep their properties as clean as possible, including industrial sites, equipment yards and the edges of roadways – namely U.S. Route 101, which runs through the center of the valley. Some growers have been volunteering to weed their neighbors' vineyards.
“We're encouraging everybody – as best they can – to knock down known weed hosts; that's really critical,” Zischke said.
Search for long-term solutions
Within the grower community, there is “nervous optimism” for the coming year, said Alameda, as he continues to hope for an innovation that would aid in the fight against INSV – whether a more targeted pesticide application or a beneficial insect that could deter the thrips.
However, both Alameda and Zischke pointed to the breeding of more resistant lettuce varieties as the ultimate solution to INSV – albeit one that is years away.
“We have a lot of different types of lettuce that we grow, so to move resistance into all the different types of lettuce we grow throughout the season … that's going to take time,” Zischke explained.
Research funding from the state and USDA – as well as projects supported by the California Leafy Greens Research Program – can help expedite that process. But, for Alameda, the INSV crisis underscores the need for more resources and farm advisors such as Smith, who has spent more than three decades cultivating relationships and building trust within Salinas Valley communities.
Alameda would like to see a renewed focus on bringing “bright, young, passionate people who live and breathe this stuff” to the region, so growers are better equipped to handle the inevitable next calamity.
“Hopefully this is a wakeup call to all,” he said. “This is a valued industry – you have to take care of it; it cannot be taken for granted. The ‘salad bowl of the world' cannot rest on its laurels.”
/h3>/h3>/h3>/h2>- Author: O. Adewale Osipitan
- Author: Bradley Hanson
- Author: Matthew Fatino
- Author: Mohsen Mesgaran
Article also published in California Weed Science Society Journal (March 2021 issue)
-Brad
In a previous article we gave a general background of branched broomrape (Phelipanche ramosa), a parasitic weed which was the focus of a $1.5 million eradication effort four decades ago in California, and now a re-emerging threat to California processing tomato (link, Figure 1). The threat posed by branched broomrape is different than most agricultural weeds due to its unique life cycle. Understanding its biology is an imporant first step in providing strategic and sustainable control of this weedy broomrape in California crop production systems.
Branched broomrape is an obligate parasite, meaning that all stages of its life cycle, right from germination to seed production depend entirely on the presence of a suitable host plant and a relatively narrow range of environmental conditions.
After germination, the radicle (immature primary root) of the broomrape seedling grows a few millimeters in length to encounter a host root. If it does not encounter and attach to a suitable host, it is likely to exhaust its energy reserves within a few days. Interestingly, not all plants that release stimulants for branched broomrape germination allow the penetration and connection of this parasite to their system. These plants are called false hosts or trap crops and these may include alfalfa (Medicago sativa),cowpea (Vigna unguiculata), green pea (Pisum sativum) and flax (Linum usitatissimum). These trap crops can be used to promote germination of branched broomrape without supporting their survival; thereby, reducing populations of the weed in the soil seedbank.
Following a successful attachment to a host plant such as tomato, the radicle develops into a specialized modified root called haustorium, a plant organ common to all parasitic plants.
Once it emerged above soil surface, branched broomrape rapidly proceeds to the reproductive stage; flowering within 3 to 7 days after
Effective control of broomrapes is difficult, largely due to its unique biology and complex life cycle. As indicated above, most of the broomrape life cycle occurs below the soil surface, which makes it difficult to detect and control before it causes damage to the host plant. The short time period between emergence and seed dispersal also makes detection and control difficult, while the absence of chlorophyll and photosynthesis limits potential herbicide target sites and complicates chemical management of the weed. The hard-to-detect, abundant, tiny seeds and ability of the seeds to remain viable for decades, promotes the spread and persistence of branched broomrape in crop production systems. Thus, effective management of broomrape requires a long-term integrated approach that involves sound understanding of its localized and general biology. Herbicide programs for management of a related species, Egyptian broomrape have been developed in other countries based on understanding of the parasitic weeds lifecycle. University and industry research is ongoing in California to develop similarly-effective practices for the California processing tomato industry (link).
- Author: Jeffrey P Mitchell
April 6, 2021
Four California organic farmers, Phil Foster of Hollister, Paul Muller of Guinda, Scott Park of Meridian, and Tom Willey of Madera, will participate in an hour-and-a half online workshop session on April 6, 2021 from 12:00 PM through 1:30 PM about the reduced disturbance work that they are conducting as part of an NRCS CIG project aimed at investigating and refining organic reduced disturbance techniques in California. The workshop will feature a Q & A session that follows a panel presentation that the four farmers made as part of the 2021 ECOFARM Conference in January. The workshop will be moderated by CASI Workgroup member, Dr. Cindy Daley of Chico State. An audio summary introduction to the workshop that ran on Don York's "Ag Report" radio program on KMJ580 on April 6th is linked below.
JEFF MITCHELL on KMJ 4-6-21
- Author: Harold McDonald
A gardener struggling to use mountains of zucchini is almost a meme in the gardening community, so it's very humbling to have to tell people you can't grow it—kinda makes you look like a grade down from a Master Gardener! And even though I know my conditions are extreme out here at the edge of the Volcanic Tableland, my pests normally come on four legs, not six. So, having to surrender growing squash to the bugs that stole their name is pretty frustrating. But I know this is a situation that many better gardeners than I have surrendered to!
The normally-more-than-daily examinations of each giant, sticky, rippy leaf for the glistening little bronze eggs, all while the progenitors scurry for safety in the folds of the struggling squash plant is just more than most of us are up for.
I know people have lots of strategies to deal with these pernicious pests, but none that have ever seemed worth the work to me. All require diligence. Leaving home for even a few days can throw momentum back to the bugs. More than that and the situation could get completely out of control!
But gardeners are always dreamers, and long before the days warm up in the spring, we are scheming, trying to solve seemingly unsolvable problems—at least I am—and squash bugs is a tough one. I started searching online, but again, the solutions weren't easy, realistic, or convincing.
Somehow, while researching squash I stumbled on parthenocarpy, a term I had learned somewhere back in a plant class, but certainly not a term I would have known to search for. Seedless watermelons are parthenocarpic—production of the fruit does not require fertilization of the ovule. For more about parthenocarpy and cucurbit sex, see this University of Nebraska pdf.here.
The important thing is that since fertilization is not required, you can keep the plants under floating row covers for their entire lives, physically protecting them from squash bugs. If you're inexperienced with row covers, they can really help in a number of situations, probably more commonly to raise temperatures in the shoulder seasons. Here's an introductory article on row covers from a MG blog in Wisconsin.
Yeah, but where do I find seeds? If they're parthenocarpic, do they even have seeds? Yes, they do have seeds, and some of the top varieties are ‘Cavilli,' ‘Venus,‘ and ‘Gold Rush.' I chose ‘Partenon'*—who can resist a squash that seems to have been named after a Greek temple? I planted the seeds in the ground in late May without a clear plan of exactly how I would cover the plants. But they did indeed come up. I improvised something from bits and pieces I had laying around, and eventually built a more robust but very simple portable hoop house (rebar and PVC) for them.
The results have been beyond what I could have imagined. So far, no squash bugs and plenty of zucchini! I'll do this again next year in a different part of the garden. I may look for an additional parthenocarpic variety. This field test from Cornell ranks ‘Dunja' as even more efficient than ‘Partenon.'
But with success, I'm now the one searching my cookbooks, Paprika (an excellent recipe database program for your digital devices) and online for good ways to use the bounty. Today I made zucchini pickles and a fabulous zucchini butter that will go great on crackers or bread, perhaps with a bit of pesto or fresh basil on top and—with any luck—tomatoes later in the season!
*By the way, in the University of Nebraska presentation, they refer to ‘Parthenon' zucchini from Thompson and Morgan. It is actually ‘Partenon'—no h in there!
Resources
https://agronomy.unl.edu/documents/parthenocarpic_zucchini2008.pdf
http://www.hort.cornell.edu/expo/proceedings/2014/Vine%20crops/Seedless%20squash%20Reiners.pdf