An insect bioassay method to determine persistence of bacillus thuringiensis var. Kurstaki (B.t.k.) protein in oak foliage, following application of a commercial formulation under field and laboratory conditions

1992 ◽  
Vol 27 (1) ◽  
pp. 73-112 ◽  
Author(s):  
K. M. S. Sundaram ◽  
A. Sundaram
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Bioassay ◽  
Commercial Formulation ◽  
Bioassay Method ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

scholarly journals Effectiveness of Bacillus thuringiensis Berliner var. kurstaki on the grape berry moth Lobesia botrana Den. and Shiff. (Lepidoptera, Tortricidae) under field and laboratory conditions in Crete

2017 ◽  
Vol 4 ◽  
pp. 31 ◽  
Author(s):  
Ν.Ε. Roditakis
Keyword(s):  
Bacillus Thuringiensis ◽  
Lobesia Botrana ◽  
Grape Berry ◽  
Egg Laying ◽  
Field Conditions ◽  
Egg Hatching ◽  
Laboratory Conditions ◽  
And Control ◽  
Trap Catches ◽  
Field And Laboratory Conditions

The effectiveness of Bacillus thuringiensis Berliner var. kurstaki (Dipel Abbot Lab.) against the grape berry moth (Lobesia botrana Den. & Shiff.) was evaluated under laboratory and field conditions. Under laboratory conditions (24±0.5°C, 55±5% r.h., 2,000 Lux, and 16 hours light daily) B. thuringiensis was compared to triflumuron and methomyl on egg hatching and shallow entries per grape berry. B. thuringiensis had no effect on egg hatching while methomyl and triflumuron had ovicidal action. Shallow entries per grape berry were 0.9-1, 0, 0 and 4.55 for B. thuringiensis, triflumuron, methomyl and control, respectively. Under field conditions, using as criteria for the timing of sprays: a. pheromone and food trap catches and b. visual counting of egg laying and a threshold of 20-30 eggs/100 grapes, two applications of B. thuringiensis at Kastelli Pediados in 1981 and four at Peza in 1982 were made both at the 2nd and 3rd flights. Its effectiveness was 96-100% and 92% at Kastelli Pediados and 73-75% at Peza.

scholarly journals Larvicidal activity of Bacillus Thuringiensis Kurstaki against Tuta Absoluta (Lepidoptera: Gelechiidae)

2019 ◽  
Vol 20 (3) ◽  
pp. 352-362
Author(s):  
Abdelkader harizia ◽  
◽  
Abdelkader Benguerai ◽  
Yahia Boukhari ◽  
◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Larvicidal Activity ◽  
Larval Mortality ◽  
Mortality Rates ◽  
Tuta Absoluta ◽  
Commercial Formulation ◽  
Larval Stages ◽  
Laboratory Conditions ◽  
High Concentrations ◽  
L1 And L2

A commercial formulation of Bacillus thurengiensis var Kurstaki (BTK) (IAB Bt) has been shown to be effective in controlling Tutaabsoluta Zeller larvae under laboratory conditions. Five concentrations are tested ((200, .350;500;650et800ppm)by ingestion, on the various larval stages (L1, L2, L3, L4 and L5). The larval mortality caused by BTK swelledwith increasing concentrations. The high concentrations of 650 and 800 ppm give 100% mortality rates for the early stages L1, L2, L3 and L4. Theacute toxicity (LC50) of BTK calculated for all larvae is 517 ppm. The lethal efficacy of BTK is noted 02 days, after the ingestion treatment, for the young stages (L1 and L2) and 04 at 6 days for the older larvae (L3 and L4) with a LT50, all larval stages combined equal to 2.6 days.

Heavy metal depuration in flat tree oystersisognomon alatusunder field and laboratory conditions

2004 ◽  
Vol 86 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Katayon Saed ◽  
Ahmad Ismail ◽  
Hishamuddin Omar ◽  
Misri Kusnan
Keyword(s):  
Heavy Metal ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

scholarly journals Electrical conductivity of the seed soaking solution and soybean seedling emergence

2004 ◽  
Vol 61 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Roberval Daiton Vieira ◽  
Angelo Scappa Neto ◽  
Sonia Regina Mudrovitsch de Bittencourt ◽  
Maristela Panobianco
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Seedling Emergence ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Seed Vigor ◽  
Soybean Seedling ◽  
Seed Soaking ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

Vigor of soybean [Glycine max (L.) Merrill] seeds can be evaluated by measuring the electrical conductivity (EC) of the seed soaking solution, which has shown a satisfactory relationship with field seedling emergence, but has not had aproper definition of range yet. This work studies the relationship between EC and soybean seedling emergence both in the field and laboratory conditions, using twenty two seed lots. Seed water content, standard germination and vigor (EC, accelerated aging and cold tests) were evaluated under laboratory conditions using -0.03; -0.20; -0.40 and -0.60 MPa matric potentials, and field seedling emergence was also observed. There was direct relationship between EC and field seedling emergence (FE). Under laboratory conditions, a decreasing relationship was found between EC and FE as water content in the substrate decreased. Relationships between these two parameters were also found when -0.03; -0.20 and -0.40 MPa matric potentials were used. EC tests can be used successfully to evaluate soybean seed vigor and identify lots with higher or lower field emergence potential.

scholarly journals Selección para calidad fisiológica de la semilla y rendimiento en líneas S2 derivadas de cuatro poblaciones tropicales de maíz (Zea mays L.)

2016 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Enrique Navarro ◽  
Cristina Vega ◽  
Fernando Narváez ◽  
Hugo Córdova
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Agronomic Traits ◽  
Reciprocal Recurrent Selection ◽  
Laboratory Conditions ◽  
Flower Plant ◽  
Ear Height ◽  
Field And Laboratory Conditions

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.

Annual dormancy cycles in Lesquerella fendleri (Brassicaceae) seeds stored under both field and laboratory conditions

2000 ◽  
Vol 77 (11) ◽  
pp. 1648-1654
Author(s):  
Laura A Hyatt ◽  
Ann S Evans ◽  
Carol C Baskin
Keyword(s):  
Seed Storage ◽  
Storage Conditions ◽  
Perennial Species ◽  
Lesquerella Fendleri ◽  
Laboratory Conditions ◽  
Fluctuating Environments ◽  
Growth Chambers ◽  
Field And Laboratory Conditions ◽  
Dormancy Cycles ◽  
Over Time

Patterns of germination over time were investigated in a short-lived desert perennial species, Lesquerella fendleri (Gray) S. Wats. Field-collected seeds were either buried in the field in cloth bags or stored in a glass jar under laboratory conditions. Regular germination tests were conducted under a range of alternating temperatures (buried seeds) or under differing water regimes (laboratory-stored seeds). Testing revealed Lesquerella fendleri to have an annual dormancy-nondormancy cycle, which was manifest regardless of seed storage conditions, suggesting that cycles may be partially endogenously regulated. Increasing seed germinability in field-stored seeds (maximum of 30% in year 1 and 95% in year 2) leads to the formation of a seed bank for at least 1 year and enhances the possibility of spreading germination events through time. This allows parent plants to maximize fitness in randomly fluctuating environments. The existence of two seedling flushes in the field and single germinability peaks in growth chambers suggests that dormancy cycling may support the formation of a metapopulation with subpopulations which are, although physically intermingled, genetically distinct.

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