جستجوی مقالات مرتبط با کلیدواژه « cabbage » در نشریات گروه « گیاهپزشکی »

Due to environmental pollution caused by chemical pesticide application, the use of eco-friendly methods such as induced resistance to manage insect pests is necessary. In this study, the induced resistance potential of gibberellic acid, with a concentration of 0.125 g/L, in cabbage was investigated against cabbage aphid Brevicoryne brassicae L. Population growth parameters of cabbage aphid, including intrinsic population growth rate (r), net reproduction rate (R0), finite population growth rate (λ), gross reproduction rate (GRR), and population doubling time (DT) affected by gibberellic acid were significantly reduced compared to the control group (P < 0.05). However, there was not any significant difference between gibberellic acid treatment and the control for mean generation time (T) and the mean fecundity per adult female. The mortality rate of nymphs and adult females, age-specific survival rate (lx), and age-specific fertility (mx) in gibberellic acid treatment were significantly decreased compared to the control (P < 0.05). The mortality rate of first-stage nymphs was higher than the control and other stages. The dispersal percentage of first-stage nymphs and adult females treated with gibberellic acid was increased compared to the control (P < 0.05). Based on the results of this study, gibberellic acid was effective for decreasing the population growth parameters of cabbage aphid, and it can be considered in the integrated management of the pest.

Root-knot nematodes are economically important plant pathogens in the world. The use of biocontrol agents usually is more stable and safe for environment. In this study the effect of Glomus mosseae (Gm) and chopped cabbage (C) tissue as well as mixes of treatments to control of tomato root knot nematode, Meloidogyne javanica were studied in greenhouse experiments. In mixed treatments, colonized tomato seedlings by Gm were transferred to the pots in which amended with chopped cabbage tissue (0.5 &1%). All treatments were inoculated by nematode after one week. The results showed, applying of Gm 1% C could significantly (P

Reports have proved that Pieris rapae with 40% annual damage is the second destructive pest of cabbage after Plutella xylostella. As there are frequent chemical spray operations against the pest and due to environmental and public health hazards, an investigation was carried out to introduce a species of Trichogramma for future bio-control programs in cabbage. All experiments were carried out at 25± 0.5°C, 60± 10% RH and 16:8 L: D. Based on field observations and greenhouse rearing of P. rapae, it was revealed that egg incubation took 5-7 days. Five larval instars development enlonged 20-30 days and pupal stage period was about 6-9 days. Longevity of male and female butterflies was 7 and 10 days, respectively.Preliminary results demonstrated that immature stage development took 10.43±0.15 and 10.07±0.11 days and 10.48±0.099 and 10.17±0.093 days for female and male individuals of T. brassicae and T. evanescens, respectively. Moreover, female and male longevity was 2.03±0.20 and 1.40±0.24 days and 1.68±0.16 and 1.85±0.40 days for both species, respectively. Further analysis showed that gross and net fecundity and fertility for T. brassicae and T. evanescens were 51.92 and 39.46 eggs/ female and 83.04 and 77.19 eggs/female, respectively. Similarly, mean age net fecundity and fertility in the same order species were 0.36 and 0.39 days and 0.162 and 0.162 days, respectively. Data analysis on reproductive attributes revealed thegross and net reproductive rates for T. brassicae and T. evanescens on eggs of P. rapae obtained as 22.77 female egg/female and 12.95 female progeny/female and 66.14 female egg/female and 29.32 female progeny/female, respectively. Similarly, intrinsic (rm) and finite (l) rates of increase were calculated as 0.238 (day-1) and 1.269 female progeny/day and 0.305 (day -1) and 1.357 female progeny/day for T. brassicae and T. evanescens, respectively. Doubling times were 2.90 and 2.265 days and generation times were calculated as 10.74 and 11.04 days for the same species, respectively. Also results proved that in both parasitoids immature stages accounted for about 98 percent and adults for 2% of the population in the age distribution of the stable population. For final conclusion, it could be said that almost all T. evanescens life history parameters on eggs of P. rapae were superior compared to those of T. brassicae. Therefore, it would be a potential candidate for future bio-control programs for small cabbage butterfly.

In this study, 223 isolates of Sclerotinia sclerotiorum, the causal agent of cabbage head rot, were collected from different fields in Urmia. Identification of mycelial compatibility groups (MCGs) was done on Potato Dextrose Agar (PDA) culture medium amended with McCormick's red food coloring. A total of 36 MCGs were identified. 23 MCGs (63.88%) had one isolate and the others had more than one isolate. Aggressiveness of the isolates was done on detached cabbage leaves in laboratory conditions and lesion development was determined on treated leaves. All tested isolates were pathogenic on cabbage leaves and disease symptoms were developed, but the aggressiveness was varied greatly among isolates. There was not any correlation between aggressiveness of the isolates, MCGs and isolation location. Isolates obtained from one field were grouped in different MCGs, and there was a difference in aggressiveness, MCGs, and isolation location. The Obtained isolates from one field were grouped in different MCGs, and there was a difference in aggressiveness of isolates within and among MCGs. Results showed that there was a high level of mycelial incompatibility among the Sclerotinia sclerotiorum isolates which were obtained from cabbage fields in Urmia. The high level of mycelial incomtibility indicates the genetic heterogeneity in this fungus and should be considered in management strategies especially using resistant cultivars.