Plant Protection
Year:2014 | Volume:37 | Issue:1|Papers Count:7

Monilia Laxa pathogen is the most common cause of the brown rot disease and it is prevalent in the most stone fruit production areas, particularly in the different regions of the Caspian Sea. If a management strategy is not developed for this disease, it will become the limiting illness for producing stone fruits in the North Country province. In order to investigate the effects of chemical pesticides and biological products on the blossom burn rate and intensity of fruit brown rot, a factorial experiment based on a completely randomized design with six treatments and three replications was performed in the Bonyad garden of the Aliabad city. Mean comparisons were performed with using the Duncan method. Results of the variances analysis and evaluation of the disease control by comparing the effects of the toxins and different biological products on the blossom burn rate and intensity of fruit brown rot indicated that the difference between treatments was significant (p<0/01). In the blooming stage, the most impact (%7/083) was related to the toxin Rvral- TC and the least affected (%15/417) was related to the combination Trichodermin. But in the fruits, the rate of the contamination with Trichodermin reached to %25 and with R vral- TC reached to % 166/9 and intensity of the contamination (lesion diameter) with Trichodermin, it was 5/22mm and with toxin copper oxy chloride, it was 27/667mm, respectively.

Fumigant toxicity, repellency and durability of insecticidal effect of Arizona cypress leaves essential oil were investigated against adults of two Coleopteran stored product pests; rice weevil, Sitophilus oryzae L. and saw-toothed grain beetle, Oryzaephilus surinamensis L. The essential oil was extracted by Clevenger-type apparatus. The bioassays were conducted by using 40 ml glass vials as container and Whatman filter paper (1x2 cm) as the essential oil release source. Repellency effect was evaluated by comparing the number of adults in both treated and not treated portions. The adult's mortality was increased in consequence of raising the concentrations. The LC50 values of essential oil for these two pests were 456.3 and 235.3 ml/L air, respectively. Adults of sawtoothed grain beetle were more susceptible than rice weevil. The average repellencies of the essential oil against the insects were 72.5 and 94.16%, respectively. These repellencies were as grades of IV and V respectively, of tile sextet classification. The essential oil persistence was different depending on the concentration and exposure time of the treatments. Based on the results, C. arizonica essential oil had acceptable efficacy for controlling these stored product pests.

Lemon balm (Melissa officinalis) is one the beneficial medicinal plants that has a long history in curing various human diseases. In this study, while assessing the pathogenicity of root-knot nematode, Meloidogyne javanica, on lemon balm medicinal plant, the effects of various initial inoculum density of nematode in host plant growth indices and nematode reproduction were investigated. Then chemical compounds in the plant leaves were assessed after 90 days of nematode infection using Gas- Chromatography (GCIMS). Results showed the susceptibility of the lemon balm to the target nematode. While increasing the nematode initial density, shoot fresh and dry weight and shoot and root length decreased, while root fresh and dry weight increased. There was an inverse relationship between the initial nematode density and reproduction factor (RF). The highest and the lowest RF observed with the lowest and highest nematode initial density respectively. (Z)- caryophyllene, hydroxyl citronellal, borneol,-humulene a, carophyllene oxide, terpinene-a, isoborneol, trans-pulegol, trans-carveol, citronellol and dihydro citronellol acetate are those compounds which increase in inoculated host plants.

The lady beetle, Nephus arcuatus Kapur is one of the most important predators of spherical mealybug, Nipaecoccus viridis (News.) in Khuzestan province, Southwest of Iran. The development time of immature stages (eggs, larvae, prepupa and pupa), males and females and the voracity of the 41h instars larvae and adults of N. arcuatus on 1st instar nymph of mealybug were studied in incubator (30±1oC, 65±5% RH, and 14:10 L: D photoperiod). The number of larval instars was determined based on Dyars rule. The head capsule width increased from 0.15±0.002 (1st instar larvae) to 0.33±0.002 (4th instar larvae) as the larval stages increased. According to our results, the head capsule width of N. arcuatus followed Dyars rule, but a second degree polynomial equation (In y=-0.040 x2+0.456 x -2.316) can more accurately describe it. The 4th instar larvae, adult male and female consumed 177.8±5.46, 58.7±2.96, and 86.5±7.42 1st instar nymph, respectively during 24 hours. The periods of egg incubation first, second, third and fourth larval instars, and prepupal and pupal stages were 3.92±0.02, 2.17±0.05, 1.29±0.03,1.52±0.03, 2.57±0.05, 1.05±0.03 and 5.09±0.12 days, respectively. Female and male longevity was 113.88±6.3 and 86.08±6.29 days, respectively and females laying an average of 660.47±37.97 eggs.

Root knot nematodes Meloidogyne spp. are important parasitic nematodes of tobacco in almost all tobacco-growing areas. Application of non-volatile nematicides is one of the effective means of root knot nematode control. In this study, in the years 2008 and 2009, the effect of nematic ides Rugby 10G (Cadusafos) and Nemacure 10G (Fenamiphos) was applied to control root knot nematode in infested tobacco field in Tagartapeh area of Golestan province in the north of Iran. The Experimental design was completely randomized block with 20 treatments and 4 replications. Treatments included two nematicide at concentrations 40, 60 and 80 Kg/ha and each nematicides was applied at three different times: before, synchronized and after transplanting seedlings of tobacco cultivar Virginia Coker 347. The experiment also involved nema infested soil (no nematicide) and no infesed (vapam treated) soil as control. Initial populations of nematode were assayed by checking soil samples of each plot. After 2 times of harvesting, nematodes were extracted from soil (Jenkines, 1964) and root (Coolen, 1979) and the number of nematodes in root and soil, gall index, reproduction factor (Rf) was counted. The growth factors (fresh and dry weight of leaves, height of plant, fresh and dry weight of root, length of root), sugar and nicotine percent, income and terms of average price were measured and data were analyzed with MSTAT -C program. The results showed that treatments were significantly different (P<01) from the control (check), but the fresh and dry weights and Sugar and Nicotine percent were not significantly different. It was also revealed that treatments of vapam and nemacure 80 Kg/ha (before transplanting) resulted in reduction of population of eggs and (h) whereas in the controls, the nematode population increased. On the basis of overall results, concentrations of 80 Kg/ ha of each of the nematicides had the best efficiency in controlling the disease and that Nemacure was a more effective nematicide than Rugby.

Essential oil from aerial parts of Tanacetum polycephalum Schultz Bip. subsp. polycephalum at the rates of 8000, 4000, 2000, 1000, 500, 250, 125, 62.5 and 0 mg 1-1 was tested for its nematicidal activity against the second stage juvenile (J2) of Meloidogyne incognita (Kofoid and White) Chitwood. 100 percent J2 mortality was achieved with essential oils of 8000 and 4000 mg 1-1. Nematicidal activities were recorded as 44.4, 22.8 and 6 percentages for concentrations of 2000, 1000 and 500 mg 1-1 respectively. No nematode mortality was seen in treatments of 250, 125, and 62.5 mg 1-1 of the oil. Analysis by Gas Chromatography (GC) and GC-Mass Spectrometry (GC-MS) led to identification of 39 major compounds from T. polycephalum oil. Among the chemical components, the main components were trans-Thujone (74.483%), 1,8-Cineole (3.135%), Terpinene- 4-01 (2.316%), Borneol (2.351%), cis-Thujone (1.880%), Camphor (1.832%), trans-Pinocarveol (1.333%), and y-Terpinene (1.059%).

A faunistic survey of cryptostigmatic mites (Acari: Oribatida) was conducted in Ahvaz during 2010-2012. A total of 19 species belonging to 17 genera and 12 families were collected among which 2 species weres new records for Iran fauna (as shown by 1 asterisk) and 3 families, 8 genera and 12 species were new for the Khuzestan province (as shown by 2 asterisks). Macropylina, Euphthiracaridae: Acrotritiaardua (Koch, 1841); Acrotritiasinensi/ Jacot, 1923; Nothridae: Nothrus anauniensis" Canestrini & Fanzago, 1876; Haplochthoniidae: Haplochthonius sanctaeluciae Bernini, 1973; Cosmochthoniidae: Phyllozetes emmae (Berlese, 1910); Lohmanniidae: Lohmanniaturcmenica" Bulanova-Zachvatkina, 1960; Papilacarus chamartinensis "Perez-inigo, 1967; Crypacaruspromecus Grandjean, 1950; Epilohmanniidae: Epilohmanniacylindricacylindrica (Berlese, 1904); Epilohmanniainexpectata' Schuster, 1960; Pycnonothic Brachypylina, Tectocepheidae: Tectocepheusvelatus' (Michael, 1880); Oppiidae: Microppia minus" longisetosa Subias & Rodriguez, 1988; Multioppia wilson(' Aoki, 1964; Lasiobelbaneonominata" (Subias, 2004); Discoppia (Cylindroppia) cylindrica (Perez-inigo, 1965); Pronothic Brachypylina, Zetomotrichidae: Zetomotrichus lacrimans' Grandjean, 1934; Scheloribatidae: Scheloribatesfimbriatus' Thor, 1930; Oribatulidae: Oribatula (Zygoribatula) connexaucrainica (Iordansky, 1990); Galumnidae: Galumairanensis" Mahunka & Akrami, 2001.