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2012 News You Can Use


December

Guar- a Potential Specialty Crop in New Mexico

Image of Guar
Close-up of guar pods (Photo: K. Grover, NMSU)

Guar is not a word most of us hear or use on a daily basis. If we are familiar with guar at all, it is probably because we see guar gum listed as an emulsifying or stabilizing ingredient in many commercially produced food items, including ice cream and baked goods, and in other products like shampoos and hand lotions. Guar gum is actually the powdered endosperm from the seed kernel of the guar plant. A member of the pea family, it is also known as the cluster bean. Guar gum has become a big player in the oil and natural gas industry. Its unique viscosity properties have proven effective in stabilizing the water and sand mixture used in the extraction technique of hydraulic fracturing, or "fracking." Guar could become a viable crop for the Mesilla Valley and elsewhere in New Mexico. Given the tenfold price increase for guar gum over recent years, including it in the cropping system could help the bottom line of farmers looking for an alternative to crops traditionally grown here. What are the potential benefits of growing guar? For one thing, it is a legume, so its nitrogen-fixing properties are useful in maintaining soil health and reducing the need for nitrogen fertilizers with the crops that follow. Guar could be effectively rotated with non-legume crops like cotton or sorghum or other grasses. Alfalfa currently plays a similar role in local cropping systems in the area. Like alfalfa, guar is also a good forage crop. The word "guar" means "cow food" in the Hindi language and has a long tradition as a protein-rich feed crop for livestock in India. The young seed pods are also edible by humans. The guar gum can also be extracted as powder and incorporated into food - or used in fracking. Click here to find out more about guar as a potential specialty crop for New Mexico. Contact: Kulbhushan Grover

November

Black rot affecting butternut squash in New Mexico

Image of black rot on butternut squash
Black rot of butternut squash (Photo: Taylor Gobble, NMSU-PDC)

At the end of October, a butternut squash with classic symptoms on black rot was submitted to the NMSU-Plant Diagnostic Clinic or disease analysis. The fruit was incubated in a moist chamber and a few days later, Didymella bryoniae, was sporulating on the surface of the fruit. This pathogen is the causal agent of black rot. It is also the causal agent of gummy stem blight, a devastating disease of cucurbits in the field. Yield loss occurs from both pre-harvest and post-harvest losses. As a fruit rotting pathogen, Didymella bryoniae can be particularly damaging to winter squash (butternut, acorn, buttercup, hubbard, etc.) and pumpkins. Other cucurbits such as watermelon, cucumber, and grounds are also affected. The disease occurs worldwide in tropical, subtropical and temperate climates. It has also been reported in greenhouse production. More information about this disease can be obtained from the Black Rot of Cucurbits Fact Sheet. Contact: Natalie Goldberg

October

Bacterial Leaf Spot Affecting Pumpkins in New Mexico and Texas

Image of a pumpkin infected with bacterial leaf spot
Bacterial leaf spot on pumpkin fruit (Photo: Jason M. French, NMSU-PDC)

Recently, pumpkins from two different fields, one in New Mexico and one in Texas, were submitted to the New Mexico State University Plant Diagnostic Clinic for disease analysis. The fruit was exhibiting small, round, slightly sunken spots with tan to beige centers. On one of the fruits, spots were enlarging, becoming noticeably sunken, and the rind was cracked in the center of the lesion. Inside, the flesh was rotted all the way to the seed cavity. Infected tissue was plated for fungal and bacterial pathogens. No fungal pathogens were isolated, but pure cultures of Xanthomonas campestris pv. cucurbitae, the causal agent of bacterial leaf spot, were isolated from fruit from both fields. This disease causes sporadic losses in cucurbit crops grown in temperate climates. In New Mexico, the disease is not common, but can occur when warm, humid conditions are persistent. The disease attacks a number of different hosts including pumpkin, cucumber, gourds, and summer and winter squash. More information about this disease can be obtained from the Bacterial Leaf Spot of Cucurbits Fact Sheet. Contact: Natalie Goldberg

August

Alfalfa Mosaic Virus is Showing up in Chile Pepper Fields

Image of Alfalfa Mosaic Virus in Chile Peppers
Alfalfa Mosaic Virus on chile peppers (Photo: Natalie Goldberg, NMSU-PDC)

Over the past month, the New Mexico State University - Plant Diagnostic Clinic has received several plant samples that are exhibiting severe symptoms of Alfalfa Mosaic Virus (AMV). This virus is found worldwide on a wide variety of cultivated plants and weed species, and is particularly common on plants in the solanaceous (nightshade) and leguminaceous (pea) plant families. It is common in New Mexico on chile peppers and has also been identified on tomato, bean, alfalfa, peanut, cowpea and lavender. While this disease occurs every year in New Mexico, it rarely causes serious economic losses as the number of plants infected in any given field is usually low. It can, however, severely infect individual plants resulting in little of no fruit production. Symptoms caused by Alfalfa Mosaic Virus can be somewhat varied, but the most common symptom is white to yellow blotches in a mosaic pattern on the leaves. Other symptoms seen in peppers include white discoloration that occurs in a ringspot or curving mosaic pattern. When young plants are infected, they are stunted and produce small, deformed fruit. When mature plants are infected, the fruit produced before infection is normal, but little or no fruit is produced after infection. More information on this disease can be obtained from the Alfalfa Mosaic Virus Fact Sheet. Contact: Natalie Goldberg

Adaptable Cover Crops for Southwest Cropping Systems

Image of Pearl Millet
Pearl millet as a cover crop

Cover crops are non-cash crops grown by farmers to build organic matter and soil fertility, help improve soil health, control water and wind erosion, suppress weeds, and break the cycles of diseases and pests common to agricultural crops. However, selecting appropriate cover crops is very challenging in the Desert Southwest. Constraints include water availability, adaptable species of crops and appropriate cultural practices for raising cover crops. Cover crops can be grown during the off-season period such, as in the fall, or during the normal cropping season, in which case they are called "green manure." The present study is investigating the performance of selected cover crops (both grasses and legumes) as green manure candidates. Crops being tested include sorghum-sudan, pearl millet, buckwheat, lablab, cowpeas, Sesbania, hairy vetch and a mixtures of sorghum-sudan +lablab; Sesbania+ sorghum-sudan; Sesbania+pearlmillet; and cocktail mixture of all of the crops mentioned above. We are measuring water utilization of different cover crops and their impacts on weed suppression and soil quality. We are also studying their growth pattern to be able to develop appropriate cultural practices for utilizing these cover crops. The field for this study was planted in chile for several years and incidents of pests and diseases have been reported in the field. This gave us an added opportunity to evaluate the tolerance of the selected cover crops to pests and diseases. Preliminary results show that early planting of buckwheat and legumes except Sesbania were susceptible to soil-borne diseases and intense weed pressure. Promising covers that can be planted early in the spring include both grasses tested (sorghum-Sudan and pearl millet) and Sesbania. However, for late planted covers, cowpeas and lablab performed better than when they were planted very early in the spring. This study demonstrated the need to pay careful attention to adaptability, planting date and general management for a successful utilization of cover crops as green manures. Click here for more photos. Contact: Kulbhushan Groveror John Idowu

It's Time to Treat for Navel Orangeworm in Pistachios

Image of adult navel orangeworm
Adult navel orangeworm (Photo: cagardenweb.ucdavis.edu)
Image of navel orangeworm larvae in a pistachio nut
Larvae of navel orangeworm in a pistachio nut (Photo: www.ars.usda.gov)

Pistachio growers in southern New Mexico need to have their Navel Orange Worm (NOW) traps in their orchards as soon as possible to minimize risks of significant economic loss. In the last few years, Richard Heerema, Extension Nut Crops Specialist, Carol Sutherland, Extension Entomologist and Beth Gordon, Otero County Extension Agent have evaluated these traps in commercial pistachio orchards to demonstrate the increases in NOW moth activity over the growing season and the close association of NOW larvae with Aspergillus (fungus) infestation of early split nuts. Aspergillus contamination of harvested pistachio nuts significantly reduces prices paid to growers for their harvest. While development of early split nuts can be managed by growers to some extent through careful springtime irrigation management, late July through August is the prime time for early splits to occur and for them to attract NOW moths that bring Aspergillus spores with them. Click here for more information on navel orangeworm. Contact: Carol Sutherland or Richard Heerema

July

Grapevine Hedging or Summer Pruning

Image of grapevines ready for hedging
Grapevines ready for hedging (Photo: Bernd Maier, New Mexico State University)
Image of grapes wells protected from sun
Grapes well protected from the sun (Photo: Bernd Maier, New Mexico State University)

Grapevines will grow continuously if the conditions are right. This condition is referred to as indeterminate growth. In temperate climate conditions the plant shoot growth will eventually slow down and stop. Ideally a vine would stop growing after fruit set when the shoot has reached about 30 inches of length. This length also translates to about 10 to 15 leaves per shoot (cane). If the shoots grow much longer than that they should be hedged since a longer shoot with more leaves will not benefit the ripening of the current crop or the plant itself. Hedging the shoots will also have the effect that the lower leaves remain green and therefore active in supplying the crop and the plant with carbohydrates. There might be merit in keeping longer shoots if the shoots are needed to shade the grapes so they will not heat up, or as protection from possible hail. Empirical evidence also suggests that Baco Noir will tolerate a shorter hedging then other varieties and responds with a lower PH level in the grape juice, a desired characteristic by winemakers. Contact: Bernd Maier

Pink Root on Onions

Image of pink root on onions
Figure 1. Pink root on onions (Photo: NMSU-PDC)

Are your onions smaller than you'd like? Do the roots have a reddish-purple hue? If you answered yes to these questions, than your plants are suffering from a fungal disease known as pink root. Pink root on onions is caused by the soil-borne fungus Phoma terresstris. This pathogen is common in New Mexico and is problematic worldwide wherever onions are grown. The disease is especially devastating in warmer climates. Although many isolates of this fungus are specific to onion, some have the ability to infect other hosts including tomatoes, soybean, eggplant, pepper, spinach, carrots, corn, small grains, cucurbits, corn and ryegrass. The most noticeable symptom of the disease is the reddish-purple discoloration that occurs on infected roots (Figure 1). Roots of infected plants become dysfunctional and plants will suffer from nutrient deficiency and drought. When young seedlings are infected, they may die; however, death is not the end result when more mature plants are infected. In this case, plants are stunted, exhibit leaf tip dieback and bulb size is reduced affecting overall yield and marketability. More information on this disease can be obtained from the pink root fact sheet. Contact: Natalie Goldberg

June

Entomosporium leaf spot on Indian Hawthorne

Image of Entomosporium leaf spot on indian hawthorne
Entomosporium leaf spot on indian hawthorne (Photo: NMSU-PDC)

If you've noticed reddish purple spots on the leaves of your indian hawthorne or red tip photinia, your plants are most likely infected with a fungal disease known as Entomosporium leaf spot. This disease is common on plants in the rose (rosaceae) family, but is particularly problematic on indian hawthorne (Raphiolepis indica) and red tip photinia (Photinia fraseri). The disease is especially troublesome in locations were cool, wet springtime conditions prevail. In New Mexico, the conditions that favor disease development do not last very long. As such, this disease is usually fairly mild on plants grown in New Mexico. When infection is low or mild, the damage is cosmetic - the plants don't look good, but the overall health of the plant is not affected. The overall health of plants with severe infections is negatively affected. Heavily infected plants may prematurely defoliate weakening them to environmental stress, insects and other diseases. More information on this disease can be obtained from the Entomosporium fact sheet. Contact: Natalie Goldberg

May

Crop Load Management on Young Vines

Grapevine with thinned crop load
Image of grapevine with thinned fruit load
Grapevine with heavy crop load
Image of grapevine with heavy crop load

Young grape vines are generally very productive and there is a real danger that the plant can't carry and properly ripen as much fruit as it can set. The grower must adjust the grape yield to be in balance with the vegetative state of the vine. This is a very important task, which if neglected, can lead to severe vine damage that will require many years to recover from. As a general rule, in the first year all of the grapes should be removed from the plant. In the second year the vine can support four to five bunches of grapes. In the third year the plant can sustain eight to twelve canes with bunches and in the fourth year the full number of canes the vineyard spacing was designed for. This is a general guideline and may need to be adjusted in some cases. If the vine is not properly growing more grapes may need to be removed to reduce the burden on the plant. The establishment of a healthy vine early on is much more important than early yield. A healthy vine will produce more and higher quality yield for years to come. For more information, contact Bernd Maier

Lawn Irrigation

Image of city park with turf and trees

Temperatures in most areas of New Mexico have reached 90 degrees or higher and with little to no precipitation in sight, the landscape and turfgrass irrigation season is in full swing. Historically, turfgrass areas have been overwatered because homeowners and turf managers have lacked information on the amount of water lawns require to achieve acceptable colour, quality, and functionality. Two publications covering the subject matter of turfgrass irrigation have recently been posted on the College of Agricultural, Consumer, and Environmental Sciences web page. Guide H-504, 'How to Water Your Lawn' is a four page summary of the in-depth Circular 660,'Turfgrass Irrigation.'

Knowledge is also lacking on how to convert water requirement into irrigation run time. Hunter's MP Rotators, Toro's PrecisionTM Series, and Rainbird's MPR series (among others) are all pop-up sprinklers used to irrigate home lawns. An irrigation audit will provide the most accurate information about the uniformity and delivery rate of an irrigation system. However, for starters, the spec sheets of each of these sprinklers can also provide helpful information if the system is installed and operated properly. For example, based on the spec sheet, MP Rotators deliver approximately 0.45 inches of water per hour. The daily irrigation requirement in Albuquerque for cool season turf can reach 0.25" during the summer. In order to meet such a water requirement with MP Rotators, a daily run time of 35 minutes (0.25 / 0.45) is necessary. For more detailed information on how to irrigate most efficiently, please refer to the aforementioned Extension publications. Contact: Bernd Leinauer

April

Miller Moth Pollution Explodes

Image of army cutworm adult
Army Cutworm Adult. (Image Credit: Whitney Cranshaw, Colorado State University, Bugwood.org)

Many of us have been getting inundated with calls about miller moths. I know some of you have been talking to reporters with front page articles appearing in the Albuquerque Journal, the Las Cruces Sun-News, Alamogordo and Carlsbad newspapers, etc., and numerous tv and radio stories. Many of you are familiar with the issue but for those of you who aren't here is a brief summary about the pest.

While the term miller moth can refer to a number of species of moths, right now army cutworm is the issue. Until the fall it will only be a problem for homeowners. Army cutworm has only one generation per year. It is a potential problem for growers/gardeners in the spring and fall when the larval stage is feeding on plants including hay. Adult generally emerge in April and late spring /early summer, the moths move to higher elevations and don't return until fall. The phone calls are about adult moths who are bothering people by their sheer numbers. Normally, the adult moths are not a problem, but the numbers are much, much higher than normal. There could be a number of reasons for the higher than normal population including a mild winter and an early spring which likely flushed them all out at the same time. I think another big factor was very low predation by arthropod predators last summer and fall which gave us a higher than normal population which overwintered as larvae. Going in to winter with a large population we would expect big numbers this spring unless something else like weather took them out, which didn't happen. Normally we typically have high predation rates by arthropod predators (ladybugs, nabids, green lacewings, spiders etc) 70-80% in season is typical. In 2010 we averaged over 60% predation in our research trials but last year had less than half that rate. This combined with favorable weather (for the moths) produced what we are seeing now.

There is not a lot you can do about the moths except avoid outdoor lighting near the house particularly entryways. You can induce them to move to less annoying spots by playing with indoor lighting too, attracting the moths away from a patio door for example, by turning on a light that will light up a nearby window so that people can get in and out of the house. (this can actually be fun for the kids to 'herd' them). If there is a significant problem with moths getting into equipment, it could be worth putting out a simple light trap or even just for example, turning on an outdoor light away from the problem spot. You do have to balance that with potentially attracting them in from a distance.

We have been getting phone calls primarily from Albuquerque, Santa Fe, the Pecos Valley and Northeastern NM, but I've also heard of issues in Texas and Colorado, it seems to be less widespread in Las Curces but still made the front page of the paper. We don't have good data to predict exactly how long this will last but I think the worst will be over in a week or so. Some army cutworm moths will be with us until June but as the numbers go down they won't be noticeable to the general public. Birds and other animals are taking a lot of them out. Natural mortality for a variety of reasons is very high. As numbers go down in the next couple of weeks or so (by mid May), complaints will likely die off. For more information, contact Jane Pierce

Soil Testing Laboratories

With the upcoming closing of the NMSU Soil, Water and Testing Laboratory, many of you are searching for alternative facilities for sample processing. A list of potential laboratories has been assembled for your reference. This list notes 8 soil testing laboratories that should be able to meet any of your soil, water, and plant tissue analysis needs. All of the labs noted on the list participate in a national quality assurance program. Also listed on the table is what tests to request that come the closest to what the NMSU SWAT laboratory was able to do. The labs are listed in increasing distance from the NMSU campus. Dr. Robert Flynn can still offer assistance with interpreting results from these laboratories if questions arise from the results. Contact: Robert Flynn

Nutsedge Control in Alfalfa

Yellow and purple nutsedge are common weedy sedge species in New Mexico. These sedges are highly competitive species and can also host root knot nematodes. Despite being shade intolerant, yellow and purple nutsedge have been reported as problem weeds in alfalfa in the state. Although nutsedge stands can be significantly reduced during site preparation and proper agronomic practices that would give alfalfa the competitive edge over nutsedges, often additional herbicide treatments are required for the control of remaining plants. Prior to the summer of 2011 there was no effective post emergence herbicide registered for nutsedge control in alfalfa in New Mexico. However, as a result of our collaboration with the industry, Sandea herbicide (halosulfuron) was recently registered for weed management in alfalfa. Sandea controls several large-seeded broadleaf weeds and is currently the best option for the control of emerged nutsedge plants in the fields. By controlling these weeds, sandea will improve the existing stands of alfalfa. In addition, removal of nutsedge by sandea takes away an excellent host plant for nematodes, thus reducing their populations in the fields. Nematodes not only are detrimental to existing alfalfa stands, but will also impact subsequent crops, such as cotton and chile peppers, planted after the removal of alfalfa. It is important to know that between cutting application of sandea herbicide can cause crop injury. The injury could result in yield loss in the first cutting after the application, but the alfalfa will recover after the first cutting. For more information on weed management in alfalfa please see NMSU Extension Guide A-325. Contact: Jamshid Ashigh

The Cost of Season-Long Weed Control in Pecan Orchards

Image of pecan orchard with weeds

Is the cost of season-long weed management with glyphosate in pecan orchards less than with other registered herbicides? One of the obstacles to adoption of pre-emergence herbicides as part of the weed management program in pecan orchards has been the perception of higher weed management costs. As a result, many growers have been using glyphosate as the sole herbicide for weed management in their orchards. However, since resistance to glyphosate has been confirmed in two populations of Palmer amaranth in the state, it is important for the growers to include alternative herbicides as part of their weed management strategies. The alternative herbicides would not only control the resistant populations in infested fields, but also prevent the selection of glyphosate resistance in fields with no history of resistance. In fact, our two-year field study has shown that the cost of weed management with "glyphosate only" treatment was comparable, in 2010 season with normal precipitation, with many of the alternative pre-emergence treatments. Although the cost of each glyphosate application was minimal (estimated at $23/acre, for Honcho herbicide in 2010 and 2011), but season-long weed management required four to five glyphosate applications which increased the total annual cost. In the dry year of 2011, there was less need for glyphosate application throughout the season, due to less weed germination, and the cost of "glyphosate only" was less than 2010. But our results showed that this decrease was not substantial. More importantly, what needs to be considered is that the prevention of resistance to glyphosate among prolific weed species such as Palmer amaranth, even in a year where the cost of alternative herbicides are higher than normal (i.e., year 2011), will pay for itself by limiting the extra cost of alternative POST herbicides such as Ignite, Aim and Gramoxone that otherwise must be considered in management programs. For more information on weed management in pecan orchards please see NMSU Extension Guide H-656. Contact: Jamshid Ashigh or Richard Heerema

Application of Chateau Herbicide in Alfalfa

Image of weedy alfalfa field

Chateau (flumioxazin) is a non-selective soil residual herbicide that also exhibits foliar activity. This herbicide has been registered in several crops such as cotton, peanuts, pecan, grapevine, etc. In alfalfa, chateau is registered for dormant and between-cutting applications, and is used for pre-emergence and post-emergence control of major broadleaf weeds and some grasses. However, many studies have indicated inconsistent grass control with chateau. Therefore, to broaden the spectrum of weed management with chateau in alfalfa, the addition of a complementary herbicide with more grass activity (e.g., prowl, treflan) is often required. Our field and greenhouse studies indicated significant alfalfa injury (more than 75% yield loss in first cutting after application) following the between-cutting application of chateau (Chateau WDG herbicide) plus treflan (Treflan 4 EC herbicide). Consistently, application of chateau with other pesticides formulated as emulsifiable concentrate (EC) also showed the same injury. Combination of chateau and the EC formulated pesticides may result in significant yield reduction in alfalfa. For more information on weed management in alfalfa please see NMSU Extension Guide A-325. Contact: Jamshid Ashigh or Brian Schutte

February

Scout Small Grains Fields for Aphids and Diseases

Image of Barley Yellow Dwarf Virus
Fig. 2 BYDV on small wheat/triticale
Image of Big Cherry-Oat Aphid
Fig. 1. Big Cherry-Oat Aphid adults and nymph

While early indications of aphid pressure in area wheat, triticale, and now oats were encouraging due to low or non-existent numbers, it appears that certain aphid species are now being spotted in our small grain fields. One such aphid is the Bird Cherry-Oat Aphid (Fig 1). This species may not be as familiar to producers as the other aphid pests such as the greenbug or Russian wheat aphid. In our area, the bird cherry-oat aphid causes little economic damage from direct feeding on the small grains; however, the aphid is one of the best vectors of Barley Yellow Dwarf Virus (BYDV), a potentially harmful disease. Bird cherry-oat aphid is somewhat pear-shaped and varies in color and ranges from olive green to almost black. In some cases, orange or red coloration can be found around the cornicles on the hind end of the aphid. Heavy infestations can cause plants to become sticky with a liquid waste known as honeydew. Greenbugs can also vector the BYDV disease. Barley yellow dwarf is always present to some degree, but was extensive in the region in 2010. Severity of the disease is contingent upon when the plants are infected. Earlier, fall infections are much more detrimental than those occurring in spring. Inspection of fields this year has indicated that infection may already be present (symptoms appearing on small wheat/triticale; Fig. 2), implying infection this past fall or winter. Plants can be infected within a matter of hours of feeding by aphids. Disease symptoms appear as yellowing and purpling of leaf tips primarily, and plants in general will be stunted in growth. Forage yields and quality of severely damaged plants can be affected due to desiccation and death of leaves. Little information is available on the impact to grain production of small grains infected with BYDV in the region. Click here for more information on scouting for aphids and diseases. Contact: Mark Marsalis

January

Pink Bollworm Nearly Eradicated in New Mexico?

Image of pink bollworm larvae
Pink Bollworm Larvae (Photo credit: Peggy Greb, USDA-ARS, Bugwood.org)

Pink bollworm is a devastating insect pest of cotton. Losses to PBW prior to the availability of Bt cotton and the initiation of the eradication program were estimated at $32 million per year (NCC 2001). An eradication program was established in south central New Mexico beginning in 2001. Pink bollworm has been successfully eradicated from that area.

Now, data collected by NMSU entomologists in a joint program with Texas A & M University and USDA-APHIS indicate that populations of pink bollworm in eastern NM are, at least extremely low. Traps placed in commercial fields and in traplines in eastern New Mexico, in the Pecos Valley and Lea County, had zero captures in 2010 and 2011. Some pink bollworms were captured in 2010 and 2011 but were in a very limited area. In 2011, 729 pink bollworms were captured, but were limited to six fields south of Midland, Texas., In 2010, 1450 pink bollworms were captured, with only 11 outside of the Midland TX area. One moth was captured in Gaines County Texas adjoining New Mexico, but it likely had spread from source fields near Midland.

Bt cotton is virtually immune to pink bollworm, so the prevalence of Bt cotton clearly decimated pink bollworm populations even in areas outside the eradication zone. Weather related stress from record cold in the winter of 2010/2011 to record heat and drought in the summer of 2011 also likely reduced pink bollworm populations. This reduction in population resulted in zero yield losses from pink bollworm for growers, and set the stage for complete eradication from New Mexico. Click here for more information on the pink bollworm eradication program. Contact: Jane Pierce