Influence of agro-ecological service crop termination and synthetic biodegradable film covering on Aphis gossypii Glover (Rhynchota: Aphididae) infestation and natural enemy dynamics

2017 ◽  
Vol 33 (4) ◽  
pp. 386-392 ◽  
Author(s):  
Serena Magagnoli ◽  
Laura Depalo ◽  
Antonio Masetti ◽  
Gabriele Campanelli ◽  
Stefano Canali ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Positive Impact ◽  
Nitrogen Concentration ◽  
Aphis Gossypii ◽  
Growing Season ◽  
Leaf Nitrogen ◽  
Biodegradable Film ◽  
Aphid Infestation ◽  
Growing Seasons ◽  
Ecological Service

AbstractAgro-ecological service crops (ASC) can increase the vegetation complexity of agroecosystems leading to a positive impact on natural enemies of arthropod pests and on weed control. In this study, two ASC terminations (green manure and roller crimper) and a Mater-Bi-mulched control (MB) were compared in order to describe the effects on pests and beneficial dynamics in an organic vegetable system. The trials were conducted over two consecutive growing seasons in 2014 and 2015. Zucchini were grown as cash crop and barley as ASC. Pests and natural enemies were monitored fortnightly by visual samplings along the whole zucchini-growing season. Zucchini plants showed a faster vegetative growth in MB treatment than in ASC terminations. In both years, MB plots were characterized by higher soil temperature and higher leaf nitrogen concentration resulting in plants more susceptible to Aphis gossypii infestations. In all the experimental plots, natural enemies controlled aphid infestations and no insecticide and sprays were necessary. In conclusion, the tested ASC techniques have been suggested as a tool to mitigate aphid infestation.

Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl
Keyword(s):  
Forest Floor ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Growing Season ◽  
Early Growth ◽  
Percent Cover ◽  
Foliar Nitrogen ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Needle Mass

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.

scholarly journals Effects of Citrus Overwintering Predators, Host Plant Phenology and Environmental Variables on Aphid Infestation Dynamics in Clementine Citrus

2019 ◽  
Vol 112 (4) ◽  
pp. 1587-1597 ◽  
Author(s):  
Juan Pedro Raul Bouvet ◽  
Alberto Urbaneja ◽  
César Monzó
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Natural Enemies ◽  
Environmental Variables ◽  
Aphis Gossypii ◽  
Colony Growth ◽  
Plant Phenology ◽  
Conservation Strategies ◽  
Phenological Stages ◽  
Aphid Infestation

Abstract The Spirea citrus aphid, Aphis spiraecola Patch, and the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are key pests of clementine mandarines in the Mediterranean basin. Severity of aphid infestations is determined by environmental variables, host plant phenology patterns, and the biological control exerted by their associated natural enemies. However, there is no information about the role these limiting and regulating factors play. Aphid densities, citrus phenology, and associated predators that overwinter in the crop were monitored weekly throughout two flush growth periods (February to July) in four clementine mandarin groves; relationships between these parameters and environmental variables (temperature and precipitation) were studied. Our results show exponential increase in aphid infestation levels to coincide with citrus phenological stages B3 and B4; shoots offer more space and nutritional resources for colony growth at these stages. Duration of these phenological stages, which was mediated by mean temperature, seems to importantly determine the severity of aphid infestations in the groves. Among those studied, the micro-coccinellids, mostly Scymnus species, were the only group of predators with the ability to efficiently regulate aphid populations. These natural enemies had the highest temporal and spatial demographic stability. Aphid regulation success was only achieved through early presence of natural enemies in the grove, at the aphid colonization phase. Our results suggest that conservation strategies aimed at preserving and enhancing Scymnus sp. populations may make an important contribution to the future success of the biological control of these key citrus pests.

Contribution of overwintering leaves to the growth of three broad-leaved, evergreen shrubs belonging to the Ericaceae family

1978 ◽  
Vol 56 (10) ◽  
pp. 1248-1261 ◽  
Author(s):  
R. J. Reader
Keyword(s):  
Growing Season ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Content ◽  
Nitrogen And Phosphorus ◽  
Southern Ontario ◽  
Plant Parts ◽  
Mature Leaves ◽  
Growing Seasons ◽  
Labrador Tea ◽  
Ledum Groenlandicum

Individual leaves of three bog ericads, leatherleaf (Chamaedaphne calyculata), bog laurel (Kalmia polifolia), and Labrador tea (Ledum groenlandicum), were retained for a maximum of two growing seasons in a peat bog in southern Ontario. The premature loss of mature leaves, resulting from artificial defoliation, significantly reduced the growth of new shoots of L. groenlandicum and K. polifolia but not of C. calyculata. Defoliation effects were directly proportional to the normal retention time for overwintering leaves. Mature leaves probably translocate photosynthate, nitrogen, and phosphorus to other plant parts. This would explain why leaf dry weights were greatest at the start, rather than at the end, of the leaves' second growing season. Net photosynthetic rates decreased with leafage, but in terms of leaf nitrogen content, new and old leaves fixed equal amounts of carbon.

scholarly journals Isoprene emission from wetland sedges

2009 ◽  
Vol 6 (4) ◽  
pp. 601-613 ◽  
Author(s):  
A. Ekberg ◽  
A. Arneth ◽  
H. Hakola ◽  
S. Hayward ◽  
T. Holst
Keyword(s):  
Growing Season ◽  
Leaf Nitrogen ◽  
Temperature History ◽  
Emission Rates ◽  
Photosynthetic Gas Exchange ◽  
Allocation Pattern ◽  
Isoprene Emission ◽  
Growing Seasons ◽  
Environmental Controls ◽  
Carbon Dioxide Co2

Abstract. High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO2) and methane (CH4), but fluxes of biogenic volatile organic compounds (BVOC) in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005–2006) in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene. Springtime emissions were first detected after an accumulated diurnal mean temperature above 0°C of about 100 degree days. Maximum measured growing season standardized (basal) emission rates (20°C, 1000 μmol m−2 s−1) were 1075 (2005) and 1118 (2006) μg C m−2 (leaf area) h−1 in E. angustifolium, and 489 (2005) and 396 (2006) μg C m−2 h−1 in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased with leaf nitrogen (N), which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

scholarly journals Factors affecting colonization and abundance of Aphis gossypii glover (hemiptera: aphididae) on okra plantations

2007 ◽  
Vol 31 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Germano Leão Demolin Leite ◽  
Marcelo Picanço ◽  
José Cola Zanuncio ◽  
Marcos Rafael Gusmão
Keyword(s):  
Organic Compounds ◽  
Natural Enemies ◽  
Aphis Gossypii ◽  
Leaf Nitrogen ◽  
Aphid Population ◽  
Mortality Factors ◽  
Total Rainfall ◽  
Bottom Part ◽  
Factors Affecting ◽  
Aphis Gossypii Glover

The control of Aphis gossypii Glover (Hemiptera: Aphididae) on okra Abelmoschus esculentus (L.) (Malvaceae) consist primarily in the use of insecticides, due to the lack of information on other mortality factors. The objective of this study was to determine the effects of predators and parasitoids, height of canopy, plant age, leaf areas, organic compounds leaves, levels of leaf nitrogen and potassium, density of leaf trichomes, total rainfall and median temperature on attack intensity of A. gossypii on two successive A. esculentus var. Santa Cruz plantations. Monthly number estimates of A. gossypii and natural enemies (visual inspection) occurred on bottom, middle and apical parts of 30 plants/plantation (one leaf/plant). Plants senescence, leaf areas and natural enemies, mainly Adialytus spp., spiders and Coccinellidae, were some of the factors that most contributed to aphid reduction. A higher number of aphids was found on the bottom part than medium and apical parts of okra plants. Total rainfall can reduce the aphid population. Trichomes non-glandular or low density, organic compounds leaves and levels of N and K were not important for reducing aphid population.

scholarly journals Changes in quality of selected red beet (Beta vulgaris L.) cultivars during the growing season

2014 ◽  
Vol 26 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Zofia Nizioł-Łukaszewska ◽  
Maria Gawęda
Keyword(s):  
Beta Vulgaris ◽  
Positive Impact ◽  
Soluble Sugars ◽  
Weather Conditions ◽  
Growing Season ◽  
Stages Of Growth ◽  
Growing Seasons ◽  
Red Beet ◽  
Health Related

ABSTRACT Red beet (Beta vulgaris L.) may be consumed at all stages of growth, both in the form of small early vegetable during spring and later, during winter, when stored. Therefore, knowledge of the dynamics of changes in the content of individual components in subsequent stages of growth is very important. The experiment was conducted for two consecutive growing seasons. The study included four cultivars of red beet ‘Boro’ F1, ‘Czerwona Kula’, ‘Nochowski’ and ‘Regulski Cylinder’. The aim of this study was to assess the dynamics of changes of selected components during the growing season. Particular attention was paid to the content of components having a positive impact on the quality of red beet, such as: antioxidant activity, the content of betalain pigments, soluble sugars and dry matter. On the basis of the survey it was demonstrated that the optimal harvest date of red beet roots, with respect to the favorable nutrient and health-related content, falls in the 8th and 11th week of the growing season depending on the weather conditions in a given year. A significant increase in the anti-radical activity, soluble sugars as well as betanin and vulgaxanthin (2009) was observed between the 6th and the 8th and also in the 11th week of the cultivation. A gradual drop in betanin to vulgaxanthin ratio was observed within the following weeks of the vegetation. On the basis of the research conducted we can conclude that the cultivar recommended for consumption is ‘Nochowski’.

Genotypic variation in Polygonum pensylvanicum: nutrient effects on plant growth and aphid infestation

1997 ◽  
Vol 75 (4) ◽  
pp. 546-551 ◽  
Author(s):  
C. M. Mabry ◽  
M. Jasieński ◽  
J. S. Coleman ◽  
F. A. Bazzaz
Keyword(s):  
Nitrogen Concentration ◽  
Genotypic Variation ◽  
Leaf Nitrogen ◽  
Environment Interaction ◽  
Aphid Infestation ◽  
Genotype Environment Interaction ◽  
Nutrient Effects ◽  
Reproductive Biomass ◽  
Vegetative Biomass ◽  
Polygonum Pensylvanicum

Variation in the performance of 20 genotypes of Polygonum pensylvanicum under two nutrient treatments was studied in a garden experiment. Nutrient fertilization enhanced vegetative biomass and fruit biomass production, but did not result in significant genotype–environment interactions, suggesting that nutrient variation of the range used in the experiment has little potential as a microevolutionary factor in this species. Leaf nitrogen concentration was not affected by a nutrient pulse. The degree of transient aphid infestation that occurred during the experiment had a weak positive correlation with final reproductive biomass of plants. Mean density of aphids per leaf was negatively correlated with percent leaf nitrogen and was not affected by genotypic identity of host plants. Key words: Polygonum pensylvanicum, genotype–environment interaction, phenotypic plasticity, aphids, nutrients.

scholarly journals Leaf isoprene emission in a subarctic wetland sedge community

2008 ◽  
Vol 5 (6) ◽  
pp. 5061-5091 ◽  
Author(s):  
A. Ekberg ◽  
A. Arneth ◽  
H. Hakola ◽  
S. Hayward ◽  
T. Holst
Keyword(s):  
Growing Season ◽  
Leaf Nitrogen ◽  
Temperature History ◽  
Emission Rates ◽  
Photosynthetic Gas Exchange ◽  
Allocation Pattern ◽  
Isoprene Emission ◽  
Growing Seasons ◽  
Environmental Controls ◽  
Carbon Dioxide Co2

Abstract. High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO2) and methane (CH4), but fluxes of biogenic volatile organic compounds (BVOC) in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005–2006) in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene, and springtime emissions were first detected after an accumulated diurnal mean temperature above 0°C of about 100 degree days. Maximum measured growing season standardized (basal) emission rates (20°C, 1000 μmol m−2 s−1) were 1075 (2005) and 1118 (2006) μg C m−2 (leaf area) h−1 in E. angustifolium, and 489 (2005) and 396 (2006) μg C m−2 h−1 in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased also with leaf nitrogen (N), which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

Variations in the relationship between maximum leaf carboxylation rate and leaf nitrogen concentration

2014 ◽  
Vol 38 (6) ◽  
pp. 640-652 ◽  
Author(s):  
YAN Shuang ◽  
◽  
ZHANG Li ◽  
JING Yuan-Shu ◽  
HE Hong-Lin ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Concentration ◽  
The Relationship

scholarly journals Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Root Biomass ◽  
Growing Season ◽  
Silver Birch ◽  
Shoot Biomass ◽  
Growth Responses ◽  
Growing Seasons ◽  
Simulated Climate ◽  
Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

Sign in / Sign up

Export Citation Format

Share Document