نشریه گیاه پزشکی کاربردی
سال یازدهم شماره 1 (پیاپی 31، شهریور 1401)

The plum bud gall mite, Acalitus phloeocoptes (Nalepa, 1890) (Eriophyoidea: Eriophyidae) is one of the new and destructive pests on plum trees of West Azerbaijan province. In this study, with the aim of assessing the phenology of the hibernating mites’ emergence in the plum orchards, Shablon cultivar, the mites were trapped with the sticky bands and counted every seven days. At the same time, the phenology of the plum trees was considered and photographed. Also, the effects of five useful pesticides including Propargite 57% (Omite® EC), Abamectin 1.8% (Vertimec® EC), Fenpyroximate 5% (Ortus® SC), Diflovidazin 20% (Flumite® SC), and Sulfur 80% (Sulfur® WP) were evaluated against population dynamics of this pest in the plum orchards of Miandoab region. These chemicals were sprayed on the aerial parts of the trees at the recommended rate and the live mites were captured using the sticky bands. The phenological results showed that most individuals emerged on 4th May, during the falling petals. In addition, the sampling after seven and fourteen days post-spraying illustrated that all of the pesticides had a significant effect on the mite (P<0.01). Thus, all of the five chemicals could be useful for control of the bud gall mite in the condition of the Miandoab region. Also, additional studies are necessary for the management of this pest during longer intervals in different climatic conditions.

Two spotted spider mite Tetranychus urticae Koch is one of the most important pests of agricultural products that damages many plants, including cucumber in greenhouses. A new acaricide Oberon Speed®) abamectin, EC 8.1% + spiromesifen, SC 24% (0.4 ml/l and 0.5ml/l was compared to Kanemite® (acequinocyl, SC 15%) 1.25 ml/l, Danisaraba® (Cyflumetofen, SC 20%), 1 ml/l and control treatment (Water spraying) for efficacy against spider mite under greenhouses condition in Kerman (Jiroft city) and Isfahan (Isfahan city) provinces. Sampling of each treatment was done at one day before spraying then 3, 7 and 14 days after spraying respectively. The percentage of efficiency was calculated using Henderson-Tilton formula and statistical analysis was conducted using SAS software with randomized complete block design. In two provinces, the mean mortality of treatments was significant. In Jiroft, the mean mite mortality of Oberon Speed® 0.5 ml/l at 3 and 7 was 89.57% and 91.57% and the efficacy declined on 14th day (63.90%). During the test, Kanemite® and Oberon Speed® 0.4 ml/l caused mortality in the range of 76.30-89.04% and 56.89-75.63%. In Isfahan, the efficacy of Oberon Speed® 0.4 ml/l and 0.5 ml/l was 74.08-63.99% and 91.9.-79.61% respectively and Danisaraba® effected 71.98-87.38%. Result showed that mite mortality of Oberon Speed® 0.5 ml/l recorded more than 74.73% in both provinces and it can be recommended for control of spider mite in greenhouse cucumbers; there were no residues of Oberon Speed® 0.4 ml/l and 0.5 ml/l, after 7 days spraying.

Bell pepper with the scientific name Capsicum annuum L. belongs to the Solanaceae family. Among the major pepper diseases, root rot caused by the fungus Rhizoctonia solani has the economic importance. The common method to control this disease is to use the chemical fungicides. In order to control Rhizoctonia root rot disease of bell pepper, a number of commercial biological agents based on Trichoderma harzianum, Glomus sp. mycorrhizal fungus, Bacillus sp. and Pseudomonas sp. bacteria and three chemical fungicides Tebuconazole, Copper oxychloride and Mancozeb were investigated in greenhouse conditions. The analysis of variance showed that the treatments had significant difference (P≤ 0.01) in all the examined traits. The mean comparisons of the treatments were evaluated based on disease inhibition traits including the length of the necrotic tissue with the largest wound and the disease index and plant growth promotion traits, including plant fresh weight, plant height, root dry weight and shoot dry weight. The treatments of negative control (no pathogen) and fungicide tebuconazole had the greatest effect on most of the traits, and the treatments of Potabarvar and Mycoroot and positive control (with pathogen) had the least effect. Among the biological control treatments, based on the lowest disease index and the lowest wound length, the combination of biological agents, Parsbacil, Probio96, Alkagreen, Trichoran-P and Tricho were ranked respectively. In the study of agricultural traits, biological treatments, combination of biological agents, Parsbacil and Probio-96 showed the highest values. In the management of this disease, apart from the chemical control method (Tebuconazole), the best option with a relatively similar statistical level was Parsbacill combination (SC) containing Bacillus velezensis strain M11-RTS, and Probio-96 containing Bacillus subtilis bacteria (P≤ 0.01).

The dieback disease of mulberry tree caused by Sclerotinia sclerotiorum is one of the important diseases of mulberry trees in the world and Iran. The aim of this research was to prepare a suitable extract to combat the disease-causing fungus with the least side effects for silkworms. The effect of the extract of five plants (garlic, thymus, peppermint, tea and neem) in three solvents (water, ethanol and methanol) was studied by mixing method in culture medium during 2018-20. The extracts were tested in three concentrations: 1000ppm, 100ppm, and 10ppm. Among the aqueous extract, garlic extract showed the highest inhibitory effect with more than 80% on the disease-causing fungus. In the second group, tea and peppermint showed the highest retention with 54.16% and 66.66%, respectively. Among the methanolic and ethanolic extracts, tea and neem showed the highest inhibition rates, (48.91% and 61.5%) and (56.32% and 51.5%) respectively. As the concentration of the extract decreased, the inhibitory rate decreased. The inhibitory rate of extracts depends on various factors such as solvent, concentration and mushroom type.

Chemical control and biological control are an important part of integrated pest management (IPM). Insecticides affect the physiology or behavior of insects, posing risks to non-target organisms. The green lacewing, Chrysoperla carnea which is the best predator natural enemies to control pests on farms, orchards and forests of the country widely perceived to be in nature and play an important role in preventing the rapid proliferation of pests and shall have the vital balance The green lacewing most attention as a promising biological control agent released against pests in greenhouses, farms and gardens has attracted. In this study, the effects of sublethal doses of Primicarb, Imidacloprid and Oxydemetonmethyl against Chrysopa carnea Stephens (Neuroptera: Chrysopidae) were determined and compared. The results showed that these insecticides at LC30 had significant effect on the stable population parameters. Intrinsic rate of population increase (r) values for control‚ Primicarb, Imidacloprid and Oxydemetonmethyl were 0.142‚ 0.141‚ 0.140 and 0.134 (day-1), respectively. According to our results, there was significant differences in Imidacloprid and Oxydemetonmethyl rate of population increase (P≤0.5) compared to the control; also, three insecticides had significant effect on survival rate and life expectancy compared to control. These results provided that Primicarb had lower toxicity on C. carnea but theoretical basis for the rational use of Imidacloprid and Oxydemetonmethyl insecticides and the utilization and protection of C. carnea.

Bacteriophage refers to viruses that specifically infect bacteria. Bacteriophages are mainly used in medicine and veterinary medicine and have recently been considered for the control of plant diseases. The use of phages in the biocontrol strategy of plant pathogens is due to their ability to kill bacteria, as well as the observation of phages in the same bacterial host environment, which indicates their ability to survive in the same host environment. Phages have been used as a part of the integrated management of diseases due to their easy and convenient use, the possibility of being combined with other bactericides or alternating use with pesticides, and having a relatively low price. Although there are considerable doubts about the use of bacteriophages as effective biological control agents, the emergence of antibiotic-resistant bacteria and the concern about the possibility of transferring antibiotic resistance from plant pathogens to human pathogens and the emergence of copper-tolerant strains among plant bacteria have led to a renewed desire to control disease based on bacteriophages in modern agriculture. So far, phage therapy has been successfully used against agents such as bacterial spot of edible mushrooms (Pseudomonas tolasi), bacterial leaf spot of mango beans, soft rot caused by Pectobacterium species, apple and pear blight (Erwinia amylovora), potato scab (Streptomyces scabies), geranium bacterial blight (Xantomonas hortorum pv. Pelargonii), tomato bacterial spot (Xantomonas campestris pv. vesicatoria) have been used. It is true that bacteria can become resistant to phages in a manner similar to that seen in antibiotics, but the advantage of phages over antibiotics for treating pathogens is their ability to mutate and infect new hosts. The major problem of phage-based biological control is the conversion of successful laboratory experiments into effective control methods against the pathogen at the field level. For this purpose, it is necessary to gain a complete understanding of the ecology and the complex host-phage interaction in different plant environments in order to maximize the use of phages as a biocontrol method. In this article, an attempt has been made to review the potential of bacteriophages in the biological control of plant pathogens and introduce its advantages and challenges