Kaolin-based Foliar Reflectant Affects Physiology and Incidence of Beet Curly Top Virus but not Yield of Chile Pepper

Kaolin reflectant treatments have been shown to reduce stress due to the environment, pests, and pathogens in many plants. We tested the effect of kaolin on yield, beet curly top virus (BCTV) incidence, and physiological parameters (measured as hyperspectral reflectance) of field-grown chile pepper (Capsicum annuum L.) in southern New Mexico. Curly top incidence was significantly lower in kaolin-treated chile blocks than untreated blocks. Peppers treated with the kaolin-reflectant showed significantly less water stress and higher photochemical reflectance than untreated plants during active growth periods. Treated plants had significantly higher levels of chlorophyll a and higher reflectance than untreated plants. Yield from treated plants was not significantly different from that from untreated plants. We did not detect any deleterious effects on peppers due to application of kaolin. Kaolin treatments suppressed beet curly top virus on chile and reduced water stress parameters during the hottest months of the growing season, suggesting that it would be useful in New Mexico chile production in years with moderate disease pressure.

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Curtovirus Infection of Chile Pepper in New Mexico

Plant Disease ◽

10.1094/pd-89-0480 ◽

2005 ◽

Vol 89 (5) ◽

pp. 480-486 ◽

Cited By ~ 19

Author(s):

R. Creamer ◽

H. Hubble ◽

A. Lewis

Keyword(s):

New Mexico ◽

Amino Acid ◽

Geographical Area ◽

Amino Acid Identity ◽

Chile Pepper ◽

Acid Identity ◽

Field Isolates ◽

Beet Curly Top Virus ◽

Complete Sequences ◽

Chile Peppers

Chile pepper-producing areas of southern New Mexico (NM) were surveyed during 2001 and 2002 to identify which curtoviruses were infecting chile peppers and to determine the distribution of the viruses among fields. Plants with symptoms resembling Beet curly top virus (BCTV) were collected from 10 fields and tested for the presence of curtoviruses by polymerase chain reaction using primers designed to detect a portion of the coat protein (cp) gene, and tested for specific curtoviruses using primers designed to detect to a portion of the replication-associated protein (rep) gene. All amplicons were sequenced and compared with curtoviruses for which complete sequences were available. Amplification was successful from 79.5% of the chile pepper samples. Analysis of the CP sequences showed that more than 92% of the NM field isolates shared high (98 to 100%) amino acid identity with well-characterized curtoviruses. However, eight NM isolates displayed a distinct CP sequence that shared only 86 to 88% amino acid identity with those curtoviruses. Comparison of the rep gene sequence showed that 18.5% of the NM field isolates tested shared 98 to 100% amino acid identity with Beet mild curly top virus (BMCTV), 48% shared 96 to 97% amino acid identity with Beet severe curly top virus (BSCTV), and 32% shared 93 to 97% amino acid identity with BMCTV and BSCTV. Although the distribution of curtoviruses was not identical among all fields sampled, little or no spatial patterns were found among the field isolates. This study revealed the complexity of curtoviruses in a single crop and limited geographical area.

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Relationship between Relative Maturity and Grain Yield of Maize (Zea mays L.) Hybrids in Northwest New Mexico for the 2003–2019 Period

Agriculture ◽

10.3390/agriculture10070290 ◽

2020 ◽

Vol 10 (7) ◽

pp. 290

Author(s):

Koffi Djaman ◽

Curtis Owen ◽

Margaret M. West ◽

Samuel Allen ◽

Komlan Koudahe ◽

...

Keyword(s):

New Mexico ◽

Grain Yield ◽

Sprinkler Irrigation ◽

Growing Season ◽

Climatic Conditions ◽

Agricultural Science ◽

Production Optimization ◽

Science Center ◽

Early Season ◽

Climate Conditions

The highly variable weather under changing climate conditions affects the establishment and the cutoff of crop growing season and exposes crops to failure if producers choose non-adapted relative maturity that matches the characteristics of the crop growing season. This study aimed to determine the relationship between maize hybrid relative maturity and the grain yield and determine the relative maturity range that will sustain maize production in northwest New Mexico (NM). Different relative maturity maize hybrids were grown at the Agricultural Science Center at Farmington ((Latitude 36.69° North, Longitude 108.31° West, elevation 1720 m) from 2003 to 2019 under sprinkler irrigation. A total of 343 hybrids were grouped as early and full season hybrids according to their relative maturity that ranged from 93 to 119 and 64 hybrids with unknown relative maturity. The crops were grown under optimal management condition with no stress of any kind. The results showed non-significant increase in grain yield in early season hybrids and non-significant decrease in grain yield with relative maturity in full season hybrids. The relative maturity range of 100–110 obtained reasonable high grain yields and could be considered under the northwestern New Mexico climatic conditions. However, more research should target the evaluation of different planting date coupled with plant population density to determine the planting window for the early season and full season hybrids for the production optimization and sustainability.

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Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

Canadian Journal of Forest Research ◽

10.1139/x94-125 ◽

1994 ◽

Vol 24 (5) ◽

pp. 954-959 ◽

Cited By ~ 13

Author(s):

L.J. Samuelson ◽

J.R. Seiler

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Soil Fertility ◽

Net Photosynthesis ◽

Growing Season ◽

Red Spruce ◽

Fertility Treatment ◽

Sink Strength ◽

Growth Enhancement ◽

Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

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A Comparison of Indirect Watering Devices for Benefiting Newly Transplanted Urban Trees

Arboriculture & Urban Forestry ◽

10.48044/jauf.2019.010 ◽

2019 ◽

Vol 45 (4) ◽

Author(s):

Shaik Hossain ◽

H. Christoph Stuhlinger ◽

Matthew Olson ◽

Benjamin Babst

Keyword(s):

Water Stress ◽

Surface Runoff ◽

Root Zone ◽

Urban Trees ◽

Substantial Variation ◽

Water Release ◽

Purchase Cost ◽

Time Required ◽

Reduced Water ◽

Tree Stem

Three types of indirect watering devices were compared to evaluate their performance and to determine their benefits to newly transplanted river birch (Betula nigra) trees grown in containers with well drained compost in a controlled greenhouse experiment. Two examples of each device type were used to water trees in this study: upright bags, ring bags, and open tubs. Watering device characteristics, including purchase cost, weight, capacity, and drainage times, were measured prior to installing the devices around the trees. Tree stem heights and calipers, along with leaf coverage and leaf water potential, were measured to determine any growth or water stress differences associated with watering treatments. There was substantial variation in costs and drainage times among watering devices, with ring bags being the least expensive and draining water completely during the drainage test. However, there was no evidence that watering devices benefited tree growth, leaf rating, or water stress in comparison with direct watering, with the possible exception of Treegator ring bags, which may have reduced water stress marginally. Although water release from some of the indirect watering devices was much slower than direct watering, water release from all of the devices was completed within ten hours, which is too rapid to reduce the frequency of watering in our experiment. The major benefits of these devices are slower release of water to the soil, with reduced operator time required, and more infiltration into the soil and root zone, which avoids the surface runoff caused by quick hose (direct) watering.

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Prediction of Early Season Beet Leafhopper Populations in Southern New Mexico

Plant Health Progress ◽

10.1094/php-08-19-0051-fi ◽

2020 ◽

Vol 21 (1) ◽

pp. 71-76

Author(s):

Erik Lehnhoff ◽

Rebecca Creamer

Keyword(s):

New Mexico ◽

Weed Management ◽

Broad Host Range ◽

Insect Vector ◽

Early Season ◽

Beet Leafhopper ◽

Beet Curly Top Virus ◽

Circulifer Tenellus ◽

Sisymbrium Irio ◽

The Relationship

Curly top is an important widespread disease in semiarid regions that can be caused by several Curtovirus and Becurtovirus species. The strains of beet curly top virus (BCTV) have been some of the most widely reported to be associated with curly top. The viruses causing curly top are phloem limited and transmitted by the beet leafhopper (BLH), Circulifer tenellus Baker (Hemiptera: Cicadellidae). The BLH can also transmit other important pathogens such as phytoplasmas. Both the virus and insect vector have a broad host range of crops and weeds, including the winter annual weed London rocket (Sisymbrium irio L.). Prior prediction of disease would allow growers a window of opportunity to make informed management choices. A prediction model of BLH abundance was developed for southern New Mexico based on fall precipitation, which corresponds with London rocket emergence, and BLH sticky trap catch data for 2001 to 2018. Regression analyses showed positive associations between BLH numbers and October + November rainfall (P < 0.001) for two areas within southern New Mexico. A third area, where good weed management was used, had lower BLH numbers, and the relationship with precipitation was not significant (P = 0.190). Cumulative-season BLH abundance was correlated with BLH abundance in late April (r = 0.43) and late May (r = 0.56), indicating that early season knowledge of BLH abundance is useful for planning later season management. Although models based on October + November precipitation are good predictors of BLH abundance through June, they may not predict year-long BLH abundance because other environmental and biological factors contribute to subsequent BLH success and movement.

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Understanding Falling Municipal Water Demand in a Small City Dependent on the Declining Ogallala Aquifer: Case Study of Clovis, New Mexico

Water Economics and Policy ◽

10.1142/s2382624x18500157 ◽

2018 ◽

Vol 04 (04) ◽

pp. 1850015

Author(s):

Michael O'Donnell ◽

Robert P. Berrens

Keyword(s):

New Mexico ◽

Water Use ◽

Water Demand ◽

Fixed Effects ◽

Cost Effective ◽

Ogallala Aquifer ◽

Washing Machine ◽

Municipal Water ◽

Variable Approach ◽

Reduced Water

Municipal water demand has declined over the past several decades in many large cities in the western United States. The same is true in Clovis, New Mexico, which is a small town in arid eastern New Mexico, whose sole water source is from the dwindling southern Ogallala Aquifer. Using premises-level monthly panel data from 2006 to 2015 combined with climate data and additional controls, we apply a fixed effects instrumental variable approach to estimate municipal water demand. Results indicate that utility-controlled actions such as price increases and rebates for xeriscaping and water saving technology have contributed to the decline. Overall water demand was found to be price inelastic and in the neighborhood of [Formula: see text]0.50; however, premises receiving toilet and washing machine rebates were relatively more price inelastic and premises receiving landscaping rebates were more price elastic, though still inelastic. In addition, the average premises receiving its first toilet rebate reduced water use by 8.4%, washing machine rebates lowered use by 9.2%, and the average landscaping rebate reduced water use by less than 5.0%. From the utility’s perspective, and assuming a 5.0% discount rate, levelized cost analysis indicates that toilet rebates are 34% more cost effective than washing machine rebates and nearly 800% more cost effective than landscaping rebates over their respective lives per volume of water conserved. While this research focuses on Clovis, estimation results can be leveraged by other small to mid-sized cities experiencing declining supplies, confronting climate change, and with little opportunity for near-term supply enhancement.

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Difference in Canopy and Air Temperature as an Indicator of Grassland Water Stress

Soil and Water Research ◽

10.17221/6514-swr ◽

2013 ◽

Vol 1 (No. 4) ◽

pp. 127-138 ◽

Cited By ~ 2

Author(s):

Duffková Renata

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Moisture Content ◽

Air Temperature ◽

Temperature Difference ◽

Soil Moisture Content ◽

Growing Season ◽

Plant Residues ◽

Dead Plant ◽

Linear Correlations

In 2003–2005 in conditions of the moderately warm region of the Třeboň Basin (Czech Republic) the difference between canopy temperature (Tc) and air temperature at 2 m (Ta) was tested as an indicator of grassland water stress. To evaluate water stress ten-minute averages of temperature difference Tc–Ta were chosen recorded on days without rainfall with intensive solar radiation from 11.00 to 14.00 CET. Water stress in the zone of the major portion of root biomass (0–0.2 m) in the peak growing season (minimum presence of dead plant residues) documented by a sudden increase in temperature difference, its value 5–12°C and unfavourable canopy temperatures due to overheating (> 30°C) was indicated after high values of suction pressure approaching the wilting point (1300 kPa) were reached. High variability of temperature difference in the conditions of sufficient supply of water to plants was explained by the amount of dead plant residues in canopy, value of vapour pressure deficit (VPD), actual evapotranspiration rate (ETA) and soil moisture content. At the beginning of the growing season (presence of dead plant residues and voids) we proved moderately strong negative linear correlations of Tc–Ta with VPD and Tc–Ta with ETA rate and moderately strong positive linear correlations of ETA rate with VPD. In the period of intensive growth (the coverage of dead plant residues and voids lower than 10%) moderately strong linear correlations of Tc–Ta with VPD and multiple linear correlations of Tc–Ta with VPD and soil moisture content at a depth of 0.10–0.40 m were demonstrated.

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Time of sowing and fungicides affect blackleg (Leptosphaeria maculans) severity and yield in canola

Australian Journal of Experimental Agriculture ◽

10.1071/ea03178 ◽

2004 ◽

Vol 44 (12) ◽

pp. 1205 ◽

Cited By ~ 12

Author(s):

R. K. Khangura ◽

M. J. Barbetti

Keyword(s):

Foliar Application ◽

Leptosphaeria Maculans ◽

Growing Season ◽

Yield Losses ◽

Brassica Napus L ◽

Seed Dressing ◽

Maximum Protection ◽

Disease Pressure ◽

Seed Yields ◽

First Time

Three different times of sowing in conjunction with various fungicide treatments were evaluated for the management of blackleg in canola (Brassica napus L.) variety Karoo. The trials were conducted at 4 different locations in Western Australia: East Chapman, Merredin, Wongan Hills and Mt Barker, representing a range of environmental conditions. The first time of sowing was at the break of the season followed by 2 subsequent sowings about 3 and 6 weeks later. Blackleg severity was significantly reduced by 14% when sowing was delayed until the end of June or early July, however, there were yield penalties due to the shortened growing season. Yield losses from blackleg were 16, 38 and 34% for mid-May, early to mid-June and end June to early July sown crops, respectively. All the fungicide treatments substantially reduced blackleg severity and increased yields at all the locations except for East Chapman (low rainfall site). The maximum protection fungicide treatment (Jockey seed dressing at 6.6 g a.i./kg seed + Impact in-furrow at 100 g a.i./ha + 3 foliar applications of flusilazole at 100 g a.i/ha) improved seed yield by 47, 56, 46 and 16% at Merredin, Wongan Hills and Mt Barker and East Chapman, respectively, compared with the nil treatment. Averaged over time of sowing and locations, the treatments of Jockey and Impact reduced disease severities by 20 and 25% and increased seed yields by 19 and 24%, respectively. There is potential for some other fungicide treatments, such as seed dressing with Jockey in combination with foliar application of either flusilazole or prochloraz, for the control of blackleg. These investigations suggest that damage from blackleg, in some areas during some seasons, could be minimised by sowing canola crops as early as possible before the onset of maturation of pseudothecia thus avoiding major ascospore showers at the seedling stage of maximum susceptibility. However, in case of a late break of season, fungicide protection may be essential to minimise losses from blackleg, particularly if sowing moderately susceptible cultivars under moderate to high disease pressure situations.

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Plant Water Stress and Soil Depletion in Variable-Density, Red Alder/Western Hemlock Coastal Oregon Plantations

Forest Science ◽

10.1093/forsci/fxz077 ◽

2019 ◽

Vol 66 (3) ◽

pp. 304-313

Author(s):

Elizabeth C Cole ◽

Michael Newton

Keyword(s):

Water Stress ◽

Summer Precipitation ◽

Growing Season ◽

Variable Density ◽

Tsuga Heterophylla ◽

Western Hemlock ◽

Riparian Ecosystems ◽

Replacement Series ◽

Red Alder ◽

The Impact

Abstract Riparian ecosystems provide critical habitat and functions while being some of the most productive areas in forests. Both conifers and hardwoods contribute to maintenance of habitat and function. To determine the impact of water stress on growth of red alder (Alnus rubra Bong.) and western hemlock (Tsuga heterophylla [Raf.] Sarg.), we installed Nelder type 1a combined with replacement series plots on three Oregon Coast Range sites. Densities ranged from 988 to 85,400 trees/hectare, with ratios (hemlock:alder) of 100:0, 75:25, 50:50, 25:75, and 0:100. In the first 4 years after planting, alder used water in the growing season at greater depths earlier than western hemlock. Higher densities resulted in greater water stress later in the growing season in weeded areas (maintained by herbicide applications), but stress was similar across densities in unweeded areas. Water stress at early ages was correlated with decreased size 14 or 24 years after planting for both species, but these correlations were confounded with other effects of density. Increasing water availability in areas with low summer precipitation could enhance growth of red alder and western hemlock, even in highly productive riparian areas.

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Asexual Reproduction of Phytophthora capsici as Affected by Extracts from Agricultural and Nonagricultural Soils

Phytopathology ◽

10.1094/phyto-97-7-0873 ◽

2007 ◽

Vol 97 (7) ◽

pp. 873-878 ◽

Cited By ~ 2

Author(s):

S. Sanogo

Keyword(s):

New Mexico ◽

Chemical Composition ◽

Discriminant Analysis ◽

Phytophthora Capsici ◽

Organic Matter Content ◽

Discriminant Functions ◽

Chile Pepper ◽

Soil Extracts ◽

Significant Difference ◽

History Of

Formation of sporangia and zoospores in species of Phytophthora is known to be influenced by soil microbial and chemical composition. In Phytophthora capsici, the study of the relationship of soil chemical composition to production of sporangia and zoospores has been limited. P. capsici is a soilborne pathogen of a wide array of vegetable crops, including chile pepper (Capsicum annuum) in New Mexico. Production of sporangia and zoospores by P. capsici was evaluated in extracts of soils from three different environments in New Mexico: (i) agricultural environments with a long history of chile pepper cropping and occurrence of P. capsici (CP), (ii) agricultural environments with no history of chile pepper cropping and no occurrence of P. capsici (Non-CP), and (iii) nonagricultural environments consisting of forests and rangelands (Non-Ag). There was a significant difference in production of P. capsici asexual propagules, expressed as natural log (number of sporangia × number of zoospores), among the three environments (P = 0.0298). Production of propagules was 9 to 13% greater in Non-Ag than in CP or Non-CP environments. Stepwise multiple discriminant analysis and canonical discriminant analysis identified the edaphic variables Na, pH, P, organic matter content, and asexual propagule production as contributing the most to the separation of the three environments. Two significant (P < 0.0001) canonical discriminant functions were derived with the first function, accounting for ≈75% of the explained variance. Based on the two discriminant functions, ≈93, 86, and 89% of observations in CP, Non-CP, and Non-Ag environments, respectively, were classified correctly. Soils from agricultural and nonagricultural environments differentially influence production of sporangia and zoospores in P. capsici, and soil samples could be effectively classified into agricultural and nonagricultural environments based on soil chemical properties and the production of asexual propagules by P. capsici in soil extracts.

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