May 5, 2021Summer Sanitation Is Important as Ever
To contact John Palumbo go to: jpalumbo@ag.Arizona.edu
Puncturevine is a weed that even the most avid environmentalist has a difficult time liking. Fortunately, it is not a native plant and there are products available to control it. It was brought to California from Asia, Africa and the Mediterranean region and has spread across the county. It can be a serious problem in orchards, turf and on ditch banks. It is a summer annual and will die from frost, but the seed heads are most troublesome when they have matured. Puncturevine (Tribulus terrestris) is in the caltrop family and has several common names including goatheads, Mexican sandbur, caltrop and many other names that cannot be printed here. It is appropriately named because of the hard spike like seed pods that can puncture tires injure animal feet and mouths. It commonly has four spikes that are arranged so that when three of the spikes are on the ground, the fourth will point upward. It can grow in dry areas but thrives in wet summers. The seed heads that you see now will germinate in the pod next spring. One plant can form a dense mat running 20 feet or more and produce up to 5000 seeds. Seeds can survive around 5 years. The most common way that it is controlled in residential areas is by pulling and hoeing. In large landscaped parks, schoolyards etc. herbicides can be useful. Triluralin and Balan applied in the spring prior to emergence will provide partial but not complete control. After it is established the systemic growth regulators like 2,4-D, dicamba and others will work but they will injure other broadleaf plants if they come in contact. Biological control of puncturevine is possible but it might take up to two years to work. There are two weevils: A seed weevil (Miclarinus lareynil) and a stem weevil (Micarlinus lypriformis) that are specific to puncturevine. The seed weevil deposits its eggs in the immature seed head and feed on and destroy the seed before they pupate. The stem weevil lays its eggs in the stems, branches and root crown. They were imported in the mid 1970’s and released in both Arizona and California. Surveys conducted in California indicated that puncturevine decreased by as much as 80% in the years after release. It appeared to be effective in Arizona as well but puncturevine started to build up about 10 years ago and has continued. They both over winter as adults in plant material. Field borders and ditch banks are kept more weed free now than they were in the 60’s and 70’s and overwintering spots have declined. Part of the reason for the increase of puncturevine could be the reduction in overwintering sites. Weevils can be purchased but will be difficult to establish and maintain.
We talked a bit about INSV in last newsletter and the importance of the virus in produce industry.
Impatiens necrotic spot virus, also known as INSV is a tospovirus closely related to Tomato spotted wilt virus. Infected plants usually have leaves with brown to dark brown necrotic areas. Sometimes the symptoms may be confused with “chemical burn”. As necrosis progresses the leaf browns or die out. Plants infected in early stage may become stunted and die or become unmarketable.
As visual diagnosis of the virus is confusing and could even be misleading at times, it is very important to confirm a symptomatology via clinical diagnosis.
The good news is there are tools available for quick and easy diagnosis of INSV. You can order the immunostrips from Agdia (https://orders.agdia.com/agdia-immunostrip-for-insv-isk-20501)
The immunostrips cost anywhere from $5-20 depending on how much you buy. They perform better when they stay refrigerated until just before use.
Immunostrips are quick and easy tool to use. The kit comes with a buffer bag and immunostrip.
3. Let it sit for a minute and Insert the inmmunostrip on the side of the mesh bag in the tissue blended solution. You will see the plant sap going up in the immunostrip.
4. Results: 2 bands means positive and one band means negative!
One band means that the positive control worked which means the system worked. Sometimes you see no bands at all. This means the system did not work and you have to repeat the test.
Two years ago, Alphabet’s (Google) X-Labs initiated one of their infamous and far reaching “moonshot” projects focused on growing food sustainably on global scale. As you might expect, the project has been, and is kept pretty secret, but the company recently unveiled some details about the project through a company blog article (Grant, 2020) and their newly established website (https://x.company/projects/mineral/). The project is called “Mineral” and according to project lead Elliot Grant, the team has been working “alongside experts in the field – literally and figuratively…developing and testing a range of software and hardware prototypes based on breakthroughs in artificial intelligence, simulation, sensors, robotics and more”.
One of the tools the team has developed is a self-propelled “plant buggy” equipped with multiple cameras, sensors, GPS and other electronic equipment (Fig. 1). According to Mineral’s website, “Over the past few years, the plant buggy has trundled through strawberry fields in California and soybean fields in Illinois, gathering high quality images of each plant and counting and classifying every berry and every bean. To date, the team has analyzed a range of crops like melons, berries, lettuce, oilseeds, oats and barley—from sprout to harvest.” Stated objectives of Mineral’s software are to combine and analyze data collected from the field, soil health information and weather data to 1) predict how different varieties of plants respond to their environments, 2) allow growers to treat individual plants with fertilizers and pesticides to optimize production and reduce inputs and 3) help growers predict the size and yield of their crops.
It is exciting that a cutting-edge tech company like Alphabet is taking on an agricultural project like this. It will be fascinating to see what technical breakthroughs and solutions the company will be able to achieve for all crops, including vegetables.
Grant, E. 2020. Mineral: Bringing the era of computational agriculture to life. X Development LLC blog article. Mountain View, CA: X Development LLC. Available at https://blog.x.company/mineral-bringing-the-era-of-computational-agriculture-to-life-427bca6bd56a.
Results of pheromone and sticky trap catches can be viewed HERE.
Results of pheromone and sticky trap catches can be viewed HERE.
Corn earworm: CEW moth activity increased a bit in the past 2 weeks but remains well below average for late spring.
Beet armyworm: Moth counts increased slightly, but remain very low consistent with seasonal temperatures, and below average for this point in the season.
Cabbage looper: Significant increase in activity in Dome Valley, Gila Valley and Tacna, but moth counts remain unusually low for this time of year, as they have all season.
Whitefly: No adult movement recorded across all locations and overall low numbers consistent with temperatures.
Thrips: Thrips adult movement beginning to pick up considerably, particularly in Yuma and Dome Valleys. Movement is below average for late March.
Aphids: Seasonal aphid counts down considerably compared with the Feb and Jan. Counts highest in Bard and Gila Valley. Below average movement for this time of year. Majority of species found on traps were green peach aphid.
Leafminers: Adult activity up slightly in some locations, but well below average for late season.