- Author: Cheryl Wilen
One point I always make is that the sooner you control annual weeds, the better. This reduces crop-weed competition, along with a host of other issues caused by weeds (we'll save that for another blog). But the real key to forward-looking weed management is to kill the weed before it produces seeds. Once seeds are produced, they contribute to the seed bank, pretty much ensuring that the weed population will be a continual problem.
But suppose you miss some weeds that are starting to flower but the flowers aren't open yet? I think most growers will just pull or cut the weed and leave it in or near the field.
I want to show you a time-lapse video I took. I cut the flowering stem off of an annual sowthistle plant and took a photo with a special camera every minute for 6 days. As you can clearly see, even though the stem was no longer receiving water or nutrients from the soil, at least the flower bud continued to mature and produce seeds. Now, having said that, I have not germinated the seeds to see if they are viable, but there is a good chance they are. Click HERE for video. It's about 1 1/2 minutes long, but most of the action happens in the first 50 seconds.
So the take home message - if the weeds have flower buds starting to open, remove them to covered piles, trash cans, or other area where they will not be a source of new weed seeds.
There was a lot of odd looking, water-soaked Satsuma fruit showing up this year along the coast. It was showing up as late as March since fruit can hang so much longer along the coast than the Central Valley and hotter areas. It turns out its an abiotic issue and is more associated with the cooler, coastal environment. Recently a "Gold Nugget" mandarin came in that had a very similar look to the rind. This variety doesn't have immediate satsuma parentage, but who knows what is in its past. The disorder is most commonly associated with cool, foggy or rainy conditions. In the fall we had those conditions and maybe that's what set it off. Later, secondary fungi move in to colonize, the depressions that first occur.
From Peru This Week, Hillary Ojeda:
Unfavorable climate conditions around the world have increased demand from Peru.
In February, the Ministry of Irrigation and Agriculture confirmed that Peru is the second largest exporter of avocados. This will prove crucial in the coming months, as production around the world is at a shortage.
“Prior to the season a higher production was expected in Peru for 2015 compared to 2014, but now it turns out that the total Peruvian harvest is a bit lower,” Ine Potting (Mission Produce) told Fresh Plaza.
The produce news portal reports that the avocado market is currently experiencing a shortage due to primary exporters struggling to produce up to expectations.
“Due to hail in Mexico, which affected a lot of the Flor Loca harvest blossom, and the drought in California, the harvests there will also be less than satisfactory. This means that there will be more demand from the United States for avocados from Peru,” says Ine.
Considering these circumstances, the price is increasing (of green varieties as well in addition to Hass avocados) and less shipments will make it Europe this season.
Peru's avocado industry made US$ 308 million in 2014 and exported a record amount of 177,800 tons of the and creamy Hass avocado variety. These results secured its place as second largest exporter of the large berry, after Mexico.
From The Packer:
South Florida university researchers are using dogs and drones to sniff out a disease that's killing the region's avocado trees.
The Florida International University researchers are sending dutch sheppards and belgian malinois into avocado groves to locate trees infected by the lethal laurel wilt disease, which is spread by the redbay ambrosia beetle.
Detection is a major problem and trees can start to wilt within two weeks.
By the time infected trees are detected, the fungus has likely spread to nearby trees via root grafting, said DeEtta Mills, a biological sciences professor.
She and Kenneth Furton, a university provost and forensic chemist, are leading research that trains and deploys five dogs into Miami-area groves.
Drones flying above the groves can detect symptomatic trees, which signal researchers to direct the dogs to infected areas.
The dogs run through the groves and with their powerful noses, have been 90% accurate in locating infected trees, Mills said.
Because of permitting paperwork delays by the Federal Aviation Administration, the researchers haven't been able to use the drones.
The researchers hope to receive approval for drones by August and are relying on growers to point them to infected trees.
The drones provide higher accuracy and can better cover larger areas because running the dogs too long can overheat them and wear them out, Mills said.
Their heavy panting can dull their sniffing senses so after about 20 minutes, the researchers return them to kennels in air conditioned vans, Mills said.
The dogs are trained with diseased wood and infected tree samples detected by the dogs are sent to researchers who examine DNA to verify contamination, she said.
“These dogs, they love to do this and it's amazing to watch them,” Mills said. “These ‘girls' come out of the kennels of the van and ask us where we would like to send them and what we would like them to do. They're extremely highly-driven dogs. If we can get permission to use the drones, it will help us identify areas we need to go in with the dogs and help us verify infection much faster so the dogs won't have to cover as much ground.”
Canine detection is another way of helping save the state's multi-million dollar avocado industry and ultimately, the North American industry.
Florida growers have lost about 4,000 of nearly 800,000 trees and the disease has spread throughout the Mid-Atlantic and into Mississippi.
If it travels farther west, the dogs and drones detection system could also help growers in California and Mexico protect their much larger production, she said.
The Miami university is also working with University of Florida researchers and growers.
N.B. These techniques could also be used to trace Polyphagous Shot Hole Borer infested trees, as well.
One adult (female) Asian Citrus Psyllid was identified from a trap in Hollister CA. Delimitation trapping will commence, along with visual survey, treatment and quarantine activities, following the newly approved Northern California protocol.