Early impacts of biological control on canopy cover and water use of the invasive saltcedar tree (Tamarix spp.) in western Nevada, USA

Abstract The northern tamarisk beetle Diorhabda carinulata (Desbrochers) was approved for release in the United States for classical biological control of a complex of invasive saltcedar species and their hybrids (Tamarix spp.). An aggregation pheromone used by D. carinulata to locate conspecifics is fundamental to colonization and reproductive success. A specialized matrix formulated for controlled release of this aggregation pheromone was developed as a lure to manipulate adult densities in the field. One application of the lure at onset of adult emergence for each generation provided long term attraction and retention of D. carinulata adults on treated Tamarix spp. plants. Treated plants exhibited greater levels of defoliation, dieback and canopy reduction. Application of a single, well-timed aggregation pheromone treatment per generation increased the efficacy of this classical weed biological control agent.

Download Full-text

Productivity and break crop effects of winter-growing oilseeds

Australian Journal of Experimental Agriculture ◽

10.1071/ea9910669 ◽

1991 ◽

Vol 31 (5) ◽

pp. 669 ◽

Cited By ~ 60

Author(s):

JF Angus ◽

AFvan Herwaarden ◽

GN Howe ◽

Herwaarden AF Van

Keyword(s):

Water Use ◽

Stem Elongation ◽

Wheat Yield ◽

Indian Mustard ◽

Canopy Cover ◽

Shoot Density ◽

Wheat Crop ◽

First Year ◽

Crop Species ◽

Previous Crop

Productivity, water use and nitrogen (N) use of the oilseeds canola, Indian mustard and linseed were compared with those of wheat and oats in a field experiment in the Riverina. In the following year wheat was grown on the same land and the same attributes were measured. In the first year, wheat productivity exceeded that of all other crops in terms of yield, dry matter production, uptake and the production value (expressed in the common units of the mass of glucose assimilated) of grain and straw. There was no association between productivity and water use, but the cereals had greater canopy cover and, presumably, a greater proportion of the water was transpired rather than evaporated from the soil. In the following year the wheat yield varied with the previous crop species in the order Indian mustard > canola > linseed > oats > wheat. The advantage of the oilseeds to the subsequent wheat crop was evident in terms of shoot density from the stem elongation stage. At the time of maturity, wheat following Indian mustard had extracted more soil water than wheat following canola or wheat following wheat. The early growth advantage to wheat following oilseeds was presumed to be associated with less soil-borne disease. The advantage to wheat following linseed did not persist after anthesis. The advantage to wheat following Indian mustard over wheat following canola appeared to be partly due to greater depletion of subsoil water during the later phases of growth.

Download Full-text

Host specificity of different populations of the leaf beetle Diorhabda elongata (Coleoptera: Chrysomelidae), a biological control agent of saltcedar (Tamarix spp.)

Biological Control ◽

10.1016/j.biocontrol.2005.09.008 ◽

2006 ◽

Vol 36 (1) ◽

pp. 32-48 ◽

Cited By ~ 30

Author(s):

Lindsey R. Milbrath ◽

C. Jack DeLoach

Keyword(s):

Biological Control ◽

Host Specificity ◽

Biological Control Agent ◽

Leaf Beetle ◽

Control Agent ◽

Diorhabda Elongata ◽

Different Populations ◽

Tamarix Spp

Download Full-text

Descriptions of Psectrosema spp. (Diptera: Cecidomyiidae) reared from galls on Tamarix spp. in Pakistan, including four new species

Bulletin of Entomological Research ◽

10.1017/s0007485300009068 ◽

1983 ◽

Vol 73 (3) ◽

pp. 447-456 ◽

Cited By ~ 1

Author(s):

K. M. Harris

Keyword(s):

Biological Control ◽

New Species ◽

North Africa ◽

Biocontrol Agents ◽

New Combinations ◽

Field Surveys ◽

Commonwealth Institute ◽

Tamarix Spp ◽

Diagnostic Key ◽

Eleven Species

AbstractIllustrated descriptions of galls, larvae, pupae and adults, with a diagnostic key, are given for five species of Psectrosema Kieffer (= Amblardiella Kieffer = Isosandalum Kieffer) collected from various species of Tamarix during field surveys of potential biocontrol agents undertaken by the Commonwealth Institute of Biological Control in Pakistan. The genus Psectrosema is re-defined and the eleven species previously described from Europe, North Africa, India and Kazakhastan, USSR, are listed, mostly as new combinations. The five species recorded from Pakistan are P. manü nom. nov., stat. rev., comb. n. (= tamaricis Mani) from T. dioica; P. indicum sp.n. from T. indica; P. reticulatum sp.n. from T. hispida, T. androssowii and T. arceuthoides; P. unicornis sp.n. from T. dioica; and P. parvum sp.n. from T. indica.

Download Full-text

Lysimeter-based Crop Coefficients for Young Highbush Blueberries

HortScience ◽

10.21273/hortsci.31.5.819 ◽

1996 ◽

Vol 31 (5) ◽

pp. 819-822 ◽

Cited By ~ 7

Author(s):

Craig A. Storlie ◽

Paul Eck

Keyword(s):

Water Use ◽

Canopy Cover ◽

Crop Coefficient ◽

Average Diameter ◽

Vaccinium Corymbosum ◽

Average Height ◽

Design Characteristics ◽

Highbush Blueberries ◽

June July ◽

Crop Coefficients

Inexpensive weighing lysimeters ($1475/unit) were constructed for measuring evapotranspiration of young highbush blueberries (Vaccinium corymbosum L.). The use of a single load cell and other design characteristics decreased lysimeter measurement accuracy but minimized lysimeter construction costs. Measurement error was within ±3%. Crop coefficient (CC) curves for 5- and 6-year-old `Bluecrop' highbush blueberry plants in their third and fourth year of production were generated using reference evapotranspiration and crop water use data from the 1991 and 1992 growing seasons. The CC increased during leaf expansion and flowering in the spring to its maximum value of about 0.19 in 1991 and 0.27 in 1992 and remained near these values until leaves began senescing in the fall. Water use on sunny days during June, July, and August ranged from (liters/bush each day) 3.5 to 4.0 in 1991 and 4.0 to 4.5 in 1992. During the second year of the study, plants had an average height of 0.9 m, an average diameter of 0.9 m, and covered 18% of the total cultivated area. The maximum calculated CC was equal to 1.5 times the measured canopy cover percentage.

Download Full-text

Water-efficient Urban Landscapes: Integrating Different Water Use Categorizations and Plant Types

HortScience ◽

10.21273/hortsci.47.2.254 ◽

2012 ◽

Vol 47 (2) ◽

pp. 254-263 ◽

Cited By ~ 15

Author(s):

Hongyan Sun ◽

Kelly Kopp ◽

Roger Kjelgren

Keyword(s):

Water Use ◽

Woody Plants ◽

Woody Plant ◽

Water Status ◽

Canopy Cover ◽

Urban Landscapes ◽

Herbaceous Perennials ◽

Different Types ◽

Herbaceous Perennial ◽

Optimum Water

Little research has examined water requirements of entire irrigated urban landscapes integrating different types of plants. Three landscape treatments integrating different types of plants—woody, herbaceous perennial, turf—and putative water use classifications—mesic, mixed, xeric—were grown in large drainage lysimeters. Each landscape plot was divided into woody plant, turf, and perennial hydrozones and irrigated for optimum water status over 2 years and water use measured using a water balance approach. For woody plants and herbaceous perennials, canopy cover rather than plant type or water use classification was the key determinant of water use relative to reference evapotranspiration (ETo) under well-watered conditions. For turf, monthly evapotranspiration (ETa) followed a trend linearly related to ETo. Monthly plant factors (Kp) for woody plants, perennials, and turf species under well-watered conditions in this study ranged from 0.3 to 0.9, 0.2 to 0.5, and 0.5 to 1.2, respectively. Adjusted Kp for each hydrozone was calculated based on landscaped area covered by plant types as a percent of total area, and landscape factor (Kl) was calculated based on adjusted Kp for each landscape treatment. Overall, Kl relative to ETo ranged from 0.6 to 0.8 for three water use classifications.

Download Full-text

Using sap flow data to assess variations in water use and water status of apple orchards of varying age groups in the Western Cape Province of South Africa

Water SA ◽

10.17159//wsa/2020.v46.i2.8236 ◽

2020 ◽

Vol 46 (2 April) ◽

Author(s):

NT Mobe ◽

S Dzikiti ◽

T Volschenk ◽

SF Zirebwa ◽

Z Ntshidi ◽

...

Keyword(s):

South Africa ◽

Water Use ◽

Sap Flow ◽

Water Status ◽

Canopy Cover ◽

Western Cape ◽

Stem Water Potential ◽

Sap Flux Density ◽

Growing Season Length ◽

Golden Delicious

No accurate quantitative information currently exists on how water use of apple (Malus domestica) orchards varies from planting to full-bearing age, leading to poor irrigation and water allocation decision making. This study sought to address this knowledge gap by investigating how the water use and tree water status vary with canopy cover, cultivar, and climatic conditions in 12 orchards growing in prime apple-producing regions in South Africa. The orchards were planted to the Golden Delicious/Golden Delicious Reinders cultivars which are widely planted in South Africa and the Cripps’ Pink/Cripps’ Red/Rosy Glow which are high-value late-season cultivars. The performance of two transpiration reduction coefficients, one based on sap flow (Ksf) and the other based on soil water depletion (Ks) (FAO approach) were evaluated against the midday stem water potential (MSWP) in all the orchards. While canopy cover had a clear effect on the whole-tree sap flow rates, there were no significant differences in the transpiration per unit leaf area among the cultivars. The daily average sap flux density under unstressed conditions was highest (~284 cm3∙cm-2) in the medium canopy cover orchards (30–44% fractional cover), followed by the mature orchards (~226 cm3∙cm-2), and was lowest in the young orchards (~137 cm3∙cm-2). Canopy cover rather than growing season length had a greater effect on seasonal total water use. Peak daily orchard transpiration ranged from 1.7 mm for young Golden Delicious Reinders trees to 5.0 mm in mature Golden Delicious trees that were maintained with large canopies to reduce sunburn damage to the fruit. For the red cultivars, the peak daily transpiration ranged from 2.0 to 3.9 mm, and the mature trees were maintained with less dense canopies to facilitate the development of the red fruit colour. The less dense canopies on the red cultivars had water-saving benefits since the seasonal total transpiration was lower relative to the Golden Delicious cultivar. The sap flow derived stress coefficient was strongly correlated to the MSWP (R2 ~ 0.60–0.97) in all the orchards while Ks was not able to detect plant stress due to over-irrigation.

Download Full-text