نتایج جستجو برای: net reproductive rate r0

تعداد نتایج: 1131888  

2017
P. Mohamadi J. Razmjou B. Naseri M. Hassanpour

The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest associated with tomato. In this study, effects of tomato plants treated with vermicompost (20, 40, and 60%), humic fertilizer (2, 4 and 6 g/kg soil) and plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 2...

2005
Guihua Li Zhen Jin

In this paper, we studied the global dynamics of a SEIR epidemic model in which the latent and immune state were infective. The basic reproductive rate, R0, is derived. If R0 6 1, the disease-free equilibrium is globally stable and the disease always dies out. If R0 > 1, there exists a unique endemic equilibrium which is locally stable. Furthermore, we proved the global stability of the unique ...

Journal: :journal of agricultural science and technology 2014
t. moadeli m. j. hejazi gh. golmohammadi

the beet armyworm (spodoptera exigua hübner) is an important pest of many agricultural crops all over the world. most of the sugar beet growing regions in iran are infested. in this study, the acute lethal effects of pyriproxyfen, spinosad, and indoxacarb as well as sublethal effects of pyriproxyfen on the 1st instar s. exigua were assessed by leaf dip bioassay method. mortality was recorded 48...

Journal: :دانش گیاه پزشکی ایران 0
سعیده قادری دانشجوی ارشد کامبیز مینایی استادیار دانشگاه شیراز محمدعلی اکرمی دانشیار دانشگاه شیراز مریم آل عصفور استادیار دانشگاه شیراز

the effect of fenpyroximate on life table parameters of two-spotted spider mite tetranychus urticae koch was evaluated under laboratory conditions (25±20c, 60±5% rh and 16:8 l:d). data were analyzed on the basis of age-stage, two-sex life table theory. the estimated value of lc50 for t. urticae was found to be 380 ml/l. durations of total preadult stage and preoviposition period in t. urticae t...

Journal: :journal of ornamental plants 2014
saeid modarres najafabadi

the life table parameters of macrosiphum rosae l. (hemiptera: aphididae) on five vermicompost-tea (tea-compost) concentrations (20, 40, 60, 80 and 100%) and control treatment (0%) on rosa hybrida l. were determined under laboratory conditions. there were significant differences among pre-imaginal period and adult longevity of the aphid on the five teacompost concentrations. the highest mortalit...

Journal: :دانش گیاه پزشکی ایران 0
عماد مهاجری پاریزی دانشجوی ارشد دانشگاه یوعلی سینا حسین مددی استادیار بوعلی سینا همدان حسین الهیاری دانشیار دانشگاه تهران محمدرضا مهرنژاد دانشیار موسسه پسته رفسنجان

ladybird beetles are of a special standing in aphid biological control. they attack different aphid species and play an important role in suppressing aphid populations. one of the most conspicuous coccinellids namely hippodamia variegata, occurs in such different crops as alfalfa and vegetables. life history parameters of this predator at 25 ± 1 ?c and 16:8 (l: d) photoperiodicity were evaluate...

Journal: :Agriculture 2023

The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is one of the main pests small-grain cereal crops, including bread wheat, Triticum aestivum (Poaceae). In a series glasshouse experiments, we evaluated systemic effect endophytic Beauveria bassiana strain PPRI 7598 on D. biotype RWASA1 using three South African cultivars, Gariep, Molopo, and Kariega. objectives study were: (a) to deter...

1997
Mark Hoddle Roy Van Driesche John Sanderson

The effectiveness of inundative releases of the parasitoid Encarsia formosa for control of Bemisia argentifolii on poinsettia was determined in replicated experimental greenhouses. We evaluated two release rates of E. formosa: a low release rate (1 wasp/plant/week, released in two greenhouses, in spring 1995) and a high release rate (3 wasps/plant/week, released in two greenhouses, in fall 1993...

Journal: :Mathematics 2021

In this paper, we study the dynamics of a fractional-order epidemic model with general nonlinear incidence rate functionals and time-delay. We investigate local global stability steady-states. deduce basic reproductive threshold parameter, so that if R0<1, disease-free steady-state is locally globally asymptotically stable. However, for R0>1, there exists positive (endemic) which A Hollin...

2017
Qi Chen Ni Li Xing Wang Li Ma Jian-Bin Huang Guo-Hua Huang

Parapoynx crisonalis is an important pest of many aquatic vegetables including water chestnuts. Understanding the relationship between temperature variations and the population growth rates of P. crisonalis is essential to predicting its population dynamics in water chestnuts ponds. These relationships were examined in this study based on the age-stage, two-sex life table of P. crisonalis devel...

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