Release of native Trichogramma minutum to control grape berry moth

2003 ◽  
Vol 135 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Sudha Nagarkatti ◽  
Patrick C. Tobin ◽  
Michael C. Saunders ◽  
Andrew J. Muza

AbstractWe studied the effects of inundative releases of the egg parasitoid Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae) on economic injury by grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae). Trichogramma minutum originally collected from natural host populations near North East, Pennsylvania, was mass produced in tobacco hornworm hosts and Mediterranean flour moth. We released T. minutum in border rows, where grape berry moth infestation is typically high, of experiment field station and commercial vineyards from 1996 to 1999. We recorded significant reductions in economic injury in plots where parasitoids were released. In vineyards with low to moderate grape berry moth abundance, four releases during the growing season were adequate in reducing damage at harvest to below 3%. In high-risk vineyards, T. minutum releases reduced damage to levels below 15%. The use of buckwheat as a cover crop to provide nectar in combination with parasitoid releases showed potential benefits in parasitoid activity. A biocarrier and Biosprayer™ were used in mechanized parasitoid-release operations, and no adverse effect on parasitoid emergence was recorded from parasitized eggs using this approach.

2007 ◽  
Vol 4 (6) ◽  
pp. 985-1003 ◽  
Author(s):  
M. K. van der Molen ◽  
J. van Huissteden ◽  
F. J. W. Parmentier ◽  
A. M. R. Petrescu ◽  
A. J. Dolman ◽  
...  

Abstract. Carbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia. This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and leaf cuvettes. Net carbon dioxide fluxes were high compared with other tundra sites, with NEE=−92 g C m−2 yr−1, which is composed of an Reco=+141 g C m−2 yr−1 and GPP=−232 g C m−2 yr−1. This large carbon dioxide sink may be explained by the continental climate, that is reflected in low winter soil temperatures (−14°C), reducing the respiration rates, and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the frequency of light limitation (Rg<200 W m−2), whereas Reco depends most directly on soil temperature and time in the growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m−2 yr−1, so that the greenhouse gas balance was −64 g C-CO2e m−2 yr−1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to hydrological conditions and vegetation composition.


Author(s):  
N.S. Kozhushko ◽  
M.M. Sakhoshko ◽  
M.G. Bashtovyi ◽  
D.V. Smilyk ◽  
V.I. Avramenko ◽  
...  

According to statistic evaluation of the manifestation of signs of the economic suitability of state sort resources of 2019 registration potatoes when growing it in different agro-climatic conditions, a significant advantage of influence of the forest-steppe conditions was determined. Compared to Polesia the increase of yield rose for 4.1 t/ha or 18 % (НІР05 = 2.18, Ffact= 12.65 > F05 = 4.22) and the amount of trade potato for 22.72 ha or 20 % (Ffact = 58.87). There is also a tendency to increase the number of starch from unit of area for – 17 % and the total consumer properties for – 8 %.  However, there is a significant difference in the reduction of storability of products by 45 % and the lack of it’s resistance to macrosporiosis and late blight. It was proved that the yield of varieties for cultivation in the polesia zone by 25.7 % depended on the duration of the growing season (Ffact = 4.14 > F05  = 0.06). The relationship between yield and starch of potatoes in Polesia zone varieties  was determined – 23.6 % and in forest-steppe – 17.3 % and starch collection, respectively, 33.6 % and 28.0 %. The dependence of storability of potato which grew in the polesia zone and in forest-steppe from the amount of starch for 15 % was mathematically proved (Ffact = 2.11 > F05 = 0.17) і 11.3 % (Ffact = 1.52 > F05 = 0.24); the dependence of storability on the duration of the growing season in the Forest-Steppe conditions was confirmed(Ffact = 0.66 > F05  = 0.43). In addition, the 12 % of tasting grade of the Forest-Steppe varieties depended on the starch content amount (Ffact = 1.65 > F05 = 0.22). According to the results of the regression analysis, mathematical models have been developed to predict yields, culinary and consumer properties, and the storability of new potato varieties under different growing conditions. The project of a conveyor for the consumption of fresh product in summer  period with the involvement of varieties of early ripeness in the Forest-Steppe was presented: 80 days after planting – Sanibel, 90 days after planting – Medison, Paroli, 95 days after planting – Bazalia, Bernina, 100 days after planting – Donata, in the Polesia zone ‒ 80 days after planting – Sanibel, 90 days after planting – Paroli, 95 days after planting –Bazalia, 100 days after planting – Medison, Bernina, Donata. By distribution of varieties by predicted high content of phytonutrients there were bred varieties with red skin and creamy flesh – Bazalia and Sanibel, by high content with yellow flesh – Baltic Rosa and moderate content with white flesh – Oleksandrit, Fotynia, Ricarda. Introduction of new varieties with certain high adaptive potential of storability and content of bioactive compounds in potatoes will provide growth of potato production in the conditions of the northeast forest-steppe and increase its competitiveness in the domestic and foreign markets and will solve the problem of year-round consumption of fresh quality products.


Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 346-352 ◽  
Author(s):  
Nicholas E. Korres ◽  
Jason K. Norsworthy

Cover crops are becoming increasingly common in cotton as a result of glyphosate-resistant Palmer amaranth; hence, a field experiment was conducted in 2009 and 2010 in Marianna, AR, with a rye cover crop used to determine its effects on the critical period for weed control in cotton. Throughout most of the growing season, weed biomass in the presence of a rye cover crop was lesser than that in the absence of a rye cover crop. In 2009, in weeks 2 through 7 after planting, weed biomass was reduced at least twofold in the presence of a rye cover compared with the absence of rye. In 2009, in both presence and absence of a rye cover crop, weed removal needed to begin before weed biomass was 150 g m−2, or approximately 4 wk after planting, to prevent yield loss > 5%. Weed density was less in 2010 than in 2009, so weed removal was not required until 7 wk after planting, at which point weed biomass values were 175 and 385 g m−2in the presence and absence of a cover crop, respectively.


2019 ◽  
Vol 31 (1) ◽  
pp. 147-157
Author(s):  
Tomoki Hattori ◽  
Yang Chen ◽  
Shinichi Enoki ◽  
Daisuke Igarashi ◽  
Shunji Suzuki

AbstractBerry skin colour is a crucial determinant of red/black grape berry quality. We investigated the effects of combination treatments with amino acids and a low concentration of ABA on anthocyanin accumulation in grapes. Among the amino acids tested, isoleucine and phenylalanine resulted in high anthocyanin contents in grape cell cultures. The combination treatments with isoleucine or phenylalanine, and a low concentration of ABA enhanced anthocyanin accumulation in grape cells and detached grape berries. The combination treatment with isoleucine, but not with phenylalanine, and ABA upregulated MybA1 expression. Field-grown grapevines received combination treatments with isoleucine or phenylalanine, and ABA in two growing seasons. In the 2015 growing season, the combination treatments with isoleucine or phenylalanine, and a low concentration of ABA accelerated anthocyanin accumulation in grape berry skins of field-grown grapevines on days 10 and 31 post treatment. The effects on anthocyanin accumulation became negligible at harvest. The effect of the combination treatment with phenylalanine and a low concentration of ABA on anthocyanin accumulation was masked in the 2017 growing season due to the unexpected stimulation of anthocyanin accumulation by the low concentration of ABA, although the combination treatment accelerated anthocyanin accumulation on days 3 and 10 post treatment. Taken together, the results suggested that exogenous isoleucine and phenylalanine interacted with ABA-mediated anthocyanin accumulation in grape berry skins of field-grown grapevines when the activity of ABA used to treat the grapevines was inadequate.


2019 ◽  
Vol 15 ◽  
pp. 01013
Author(s):  
O. Viret ◽  
J.-L. Spring ◽  
V. Zufferey ◽  
K. Gindro ◽  
C. Linder ◽  
...  

Switzerland is a pioneer country in the development of integrated production (IP) and integrated pest management (IPM). The overall goal is sustainability at the ecological, economic and social level to produce high quality grapes. In 1993, the IP-IPM head-organisation VITISWISS was created. The starting points were the improvement of pest management by the biocontrol of spider mites and the control of grape berry moths by mating disruption and an optimal soil management, followed over the years by state-of-the-art sprayer calibration, development of disease forecasting models (AgroMeteo, VitiMeteo), leaf-area adapted dosage of plant protection products, enhanced biodiversity, water and cover crop management. The efforts and the results gained in a continuous education process by the growers are considerable, but not enough for consumers and politics concerned by the use of plant protection products. The absence of acaricides and insecticides as well as forecasting systems available on the internet (www.agrometeo.ch) for the control of downy and powdery mildew, represent the major progresses. Where mechanisation is possible, herbicides can progressively be replaced by mechanical technics, which is not possible in steep vineyards. The general irrational unscientific trend against “synthetic” plant protection products requests alternatives for the control of fungal diseases and for cover crop management under the vine rows to avoid excessive water-nitrogen competition particularly in the actual context of climate change.


2008 ◽  
Vol 88 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Elizabeth Pattey ◽  
Lynda G Blackburn ◽  
Ian B. Strachan ◽  
Ray Desjardins ◽  
Dave Dow

Nitrous oxide emissions are highly episodic and to accurately quantify them annually, continuous measurements are required. A tower-based micrometeorological measuring system was used on a commercial cattle farm near Cô teau-du-Lac, (QC, Canada) during 2003 and 2004 to quantify N2O emissions associated with the production of edible peas. It was equipped with an ultrasonic anemometer and a fast-response closed-path tunable diode laser. Continuous measurements of N2O fluxes were made during the spring thaw following corn cultivation in summer 2002, then during an edible pea growing season, followed by cattle manure application, cover crop planting and through until after the next spring ploughing. The cumulative N2O emissions of 0.7 kg N2O-N ha-1 during the initial snowmelt period following corn harvest were lower than expected. Sustained and small N2O emissions totalling 1.7 kg N2O-N ha-1 were observed during the growing season of the pea crop. Solid cattle manure applied after the pea harvest generated the largest N2O emissions (1.9 kg N2O-N ha-1 over 10 d) observed during the entire sampling period. N2O emissions associated with the cover crop in the fall were mostly influenced by manure application and totalled 0.8 kg N2O-N ha-1. For the subsequent spring thaw period, N2O emissions were 0.8 kg N2O-N ha-1. This represents approximately 15% of the annual emissions for the edible pea-cover crop system, which totalled 5.6 kg N2O-N ha-1 over the measuring periods. There was little difference in spring thaw N2O emissions between the two growing seasons of corn and edible pea-cover crop. Key words: Nitrous oxide emissions, legumes, snowmelt, dairy manure, tunable diode laser, flux tower


1990 ◽  
Vol 122 (S153) ◽  
pp. 56-81 ◽  
Author(s):  
S.M. Smith ◽  
D.R. Wallace ◽  
G. Howse ◽  
J. Meating

AbstractThe ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.


1988 ◽  
Vol 78 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Philip J. Newton

AbstractInundative releases of the indigenous egg parasitoid Trichogrammatoidea cryptophlebiae Nagaraja were made against Cryptophlebia leucotreta (Meyrick) in two sweet orange orchards in the Transvaal lowveld, South Africa. The rate of parasitism was raised to similar levels in the two release areas, but there was a significant decrease in crop damage in only one of them. Although the larval population was twice as large in a control orchard, the losses there were compensated for by a larger total crop. Three explanations for the different performances of the parasitoids are examined. Movement away from release areas was not apparent. Rates of parasitism at the tops or bottoms of trees or at the four cardinal aspects were not significantly different overall but should have been to compensate for the linear increase in numbers of host eggs with height, and the larger numbers on the warmer northern and eastern sides of trees. Parasitism was higher at the tree tops than at the bottoms in the orchard that lost the least fruit. The stochastic processes governing host-egg distribution on fruit were also important. Pest density was higher in the release areas than the control, and eggs were distributed more contagiously in the orchard with the most crop loss.


1979 ◽  
Vol 111 (8) ◽  
pp. 955-957 ◽  
Author(s):  
H. J. Herbert

AbstractThe pear rust mite, Epitrimerus pyri (Nal.), overwinters in a semi-active state in old leaf scar crevices and under bud chips of the leaf clusters. It becomes active within the bud in mid-April, as soon as the weather warms, and passes through three generations in the growing season as indicated by distinct peak egg populations observed in May, June, and July. The first generation eggs are laid within the swelling bud. The mites feed on the ventral surface of the leaves causing bronzing and on the calyx end of the fruit resulting in russeting of the epidermal tissue. Deutogynes of the third generation begin to enter hibernation by mid-August. Occasionally population levels reach economic injury level resulting in the downgrading of fruit.


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