This study was conducted at the JV farms at Gila Valley. Lettuce variety ‘Guapo’ was seeded, then sprinkler-irrigated to germinate seed on September 19, 2023, on double rows 12 in. apart on beds with 42 in. between bed centers.  Rest of the irrigation was supplied by furrow irrigation or rainfall. Treatments were replicated five times in a randomized complete block design. Each replicate plot consisted of 25 ft of bed, which contained two 25 ft rows of lettuce. Plants were thinned on October 9, 2023 at the 3-4 leaf stage to a 12-inch spacing. Treatment beds were separated by single nontreated beds. Treatments were applied by incorporating in soil before seeding or with a tractor-mounted boom sprayer that delivered 50 gal/acre at 100 psi to flat-fan nozzles spaced 12 in apart.

 
Fusarium wilt (caused by Fusarium oxysporum f. sp. lactucae ) rating was done in the field by observing the typical symptom of lettuce wilt. Confirmation was done by cutting the cross section of roots. Disease scoring/rating was done on December 6, 2023. 
 
The data in the table illustrate the degree of disease control obtained by application of the various treatments in this trial. The disease pressure was extremely high in 2023, and most treatments showed little or no control against the disease. The treatments that showed some activity were Bexfond, Cevya, Rhyme, and Serifel. Plant vigor was normal and phytotoxicity symptoms were not observed in any treatments in this trial.

Keeping up to date with the latest developments in automated weeding machines is challenging. It’s a very fast-moving space with significant private and public investment. At the 2024 Southwest Ag Summit “Ag Tech: Innovations in Weed Control Technologies” breakout session, university experts and cutting-edge innovators will provide updates on laser weeding, high precision smart spot sprayers, robotic/automated weeders and band steam (agenda below).The session will be held TOMMOROW Thursday, February 22^nd from 1:30-3:30 pm at Arizona Western College in Yuma, AZ.
As I mentioned in the last newsletter, there will also be a Field Demo where several of these technologies and other state-of-the-art automated weeders will be demonstrated operating in the field. The Field Demo is scheduled for TODAY, Wednesday, February 21^st. Breakfast will be served at 7:00 am and demonstrations begin at 8:00 am. The event will also be held at AWC.
We will also have our 3^rd generation prototype steam soil disinfestation machine on display at the event (Fig. 3). It is a self-propelled machine designed for commercial field scale operations. The device injects steam into the soil prior to planting to raise soil temperatures to levels sufficient to kill soilborne pathogens and weed seed (typically 140 °F > 20 minutes). We have had very good results with our previous prototypes and would like to demonstrate soil steaming to interested growers next season with the new machine. In addition to obtaining grower feedback on the viability of soil steaming, a second objective is to validate our small plot research results at the field scale level. If you are interested in the technique and would like a demo on your farm, please let me know. I would be happy to collaborate with you.
For more information about the Southwest Ag Summit, visit https://yumafreshveg.com/southwest-ag-summit/.

Fig. 1. Agenda for the “Ag Tech: Innovations in Weed Control Technologies”
educational session at the 2024 Southwest Ag Summit. The session will be held
Thursday, February 22nd at Arizona Western College, Yuma, AZ.


Fig. 2. 2024 Southwest Ag Summit Field Demo agenda. The event will
be held at Arizona Western College in Yuma, AZ.


Fig. 3. Self-propelled machine designed for injecting steam into the
soil prior to planting to raise soil temperatures to sufficient levels to
control soilborne pathogens and weed seed. Unit will be on display at
the 2024 Southwest Ag Summit, Yuma, AZ. (Photo credit: Peter de
Groot).

The SW Ag Summit is taking place in Yuma this week. We will have the Weed Control breakout session on Thursday, 22 February 2024 at 1:30 pm in room AS 115 of  the AWC campus. Here’s what are we going to cover:
Do you know what the IR-4 Project is? 
Established in 1963 by the U.S. Department of Agriculture and land-grant universities this project helps ensure that specialty crop farmers have legal access to safe and effective crop protection products and contributes to developing data necessary for the registration products for best pest management. Do we have this project in Yuma?
A Weed Scientist and Principal Biologist from IR-4 and NC State University will explain what this process of making more tools available to growers takes.
 
Additionally, we will have a representative from BASF chemical company who will present NEW WEED CONTROL TECHNOLOGIES as well as active ingredients developed by his company.
 
We all know with the loss of DCPA (Dacthal) herbicide our weed management tools were reduced. You asked the Veg IPM Team to look for ALTERNATIVES for Broccoli and Onion. We are doing some Trials at the UA Yuma Ag Center with products Such as Napropamide (Devrinol), which has the Devrinol DF XT dry formulation and the Devrinol 2-XT liquid. 
Which one is more aggressive? How does water incorporation affect it? How good is it on goosefoot, lambsquarter, knotweed?
Other treatments we are looking at on broccoli are Goal Tender, Prefar, Prowl, Treflan, Enversa, Rinskor.
For direct seeded onion we are testing Prefar, Etothron SC, Dual, a combination of PREFAR+PROWL PREEMERGERGENCE at low rates, Outlook+Prowl.
 
We would like to share our observations if you honor us coming to our session. Again, it is TOMORROW Thursday, 22 February 2024 at the Arizona Western College AS 115 room. This session will start at 1:30 pm.

Get your free copy of the Weed Seedling Identification Pocket Guide at the Yuma Agricultural Center.