نشریه کنترل بیولوژیک آفات و بیماری های گیاهی
سال دوازدهم شماره 1 (بهار و تابستان 1402)

Root and stem rot of greenhouse cucumber due to Fusarium oxysporum f. sp. radicis-cucumerinum causes a lot of damage to greenhouse cucumber every year. In this research, the Bacillus mycoides LUTUUS-AF1 (BmL) from Lotus Co. was compared to Pars Bacil internal biological fungicide (BvP) based on Bacillus velezensis bacteria and an imported biological fungicide (SAS) based on Bacillus velezensis (BvB) bacteria to evaluate its antagonistic ability in laboratory and under greenhouse conditions. The results showed that among the three samples in laboratory condition, B. mycoides strain exhibited the highest inhibitory power at 48%. The imported biological fungicide (SAS) and Pars Bacil treatments provided 30% and 29% inhibition against Fusarium fungus, respectively. In greenhouse conditions, the mortality rate in the control treatment was close to 70%. B. mycoides strain, at concentrations of 0.3% and 0.5% with three repetitions (0, 96, and 192 hours), demonstrated the best efficiency during the 50-day period, with disease incidence close to zero and no observed mortality in the plants. (0, 96, and 192 hours) yielded similar results and both were significantly different from Pars Bacil. highest inhibitory power of BmL and effective control of Fusarium fungusOverall, due to the strong inhibitory effect of B. mycoides in both laboratory and greenhouse conditions, further research is recommended for the production and commercialization of this bacterium.

The aim of this research was the laboratory production of two efficient and native strains, Metarhizium anisopliae var. acridum and Beauveria bassiana Z1, using a diphasic fermentation method using solid substrates (wheat, cooked rice, barley, sorghum and wheat bran) followed by a liquid substrate (whey) at 25 ºC. The maximum number of submerged conidia was significantly produced in 50 ml whey compared to dextrose agar liquid medium. The solid substrates were then inoculated by submerged conidia obtained from whey. After 14 days, 1 gram of each solid substrate was immersed in 100 ml of Tween. The highest average number of aerial conidia of M. anisopliae in one ml was obtained in rice substrate (1.08×107±2.42×105) and wheat bran (1.06×107 ±1.86×105) without any significant difference. The survival percentage was 100% for all solid substrates except sorghum (98.90%). The highest number of conidia produced by B. bassiana was observed on the wheat bran (5.14×106 conidia/ml). However, it was much easier to handle the wheat, which produced 4.30 × 106 ± 3.71 × 104 conidia per ml, than wheat bran for mass production of B. bassiana. The lowest percentage of survival (39.20%) was observed in barley. The number of conidia in one gram of M. anisopliae obtained by sieving rice and B. bassiana obtained by sieving wheat was 2.85×1010 and 3.09×1010 conidia, respectively. The results clarified that the diphasic method using whey with the applied concentration was successful for both strains and produced an appropriate amount in the solid fermentation phase.

Sugarcane is an important commercial product for sugar production in the world. A perennial plant from the cereal family, which is susceptible to various pests and diseases due to the long cultivation period, which affects its production. Pokkah boeng disease caused by Fusarium species is one of the important and developing diseases of sugarcane worldwide. In this research, the pathogenicity of Fusarium species related to this disease, F. verticillioides, F. proliferatum, F. sacchari, F. andiyazi, F. acutatum in sugarcane, with two methods of pathogenicity test of cut stems under laboratory conditions and pathogenicity test in Greenhouse conditions were carried out. To calculate the severity of the disease in different species, the length of the wound area on the canes was measured. The results showed that the intensity of pathogenicity in three species F. verticillioides, F. proliferatum and F. sacchari was higher than other species. In another part, the antagonistic property of the endophytic fungus Trichoderma afroharzianum isolated from healthy sugarcane plants was used for biological control of this disease in greenhouse conditions. The effectiveness of the biocontrol agent was determined by measuring the fusarium index, the length of the wound area and plant growth factors, which indirectly contribute to the reduction of disease damage. The results showed that all the treatments applied with endophytic fungi were successful in reducing the disease and increasing the growth factors of the treated plant compared to the control.

The behavior and survival of soil-borne pathogens like Fusarium oxysporum f. sp. lycopersici (FOL) are affected by soil salinity. Therefore, salinity could be an important factor in the increasing disease incidence in crops such as tomato plants. However, plant probiotic bacteria can improve plant growth in saline soil. This research was carried out to control the Fusarium wilt disease in tomato under salinity stress by using Bacillus velezensis UTB96. We investigated the effect of salinity stress on FOL behavior and survival at 75 mmol NaCl. Moreover, the inhibition effect of B. velezensis UTB96 on Fusarium wilt disease was investigated in laboratory and greenhouse conditions. The results showed that salinity stress positively affected fungal biomass and sporulation, but it did not affect radial growth. In greenhouse conditions, the Disease Index (DI) of Fusarium wilt increased by 12% in the presence of 75 mmol NaCl compared to control plants. Application of B. velezensis UTB96 reduced DI in tomato plants to the extent of 48% under saline stress as compared to 68% in the control treatment (no saline condition). The present study demonstrates that saline stress positively affects FOL behavior and pathogenicity, and B. velezensis UTB96 can improve tomato plant health against Fusarium wilt disease under salinity stress.

The edible mushroom mosquito Lycoriella auripila (Dip.: Sciaridae) causes quantitative and qualitative reductions in crop yield worldwide, that is, Iran. The present study was conducted to estimate the efficacy of the entomopathogenic nematode Steinernema feltiae and the bacterium Bacillus thuringiensis, separately and simultaneously, in controlling this mushroom mosquito. In the laboratory study, the efficacies of different concentrations of S. feltiae (Sf), B. thuringiensis subsp. israelensis (Bti) and Dichlorvos pesticide were investigated. Then, nine treatments, including the interaction between Sf and Bti, were performed in addition to the laboratory treatments in the field test. The mushroom production yields in the control and treatment groups were compared. Statistical analysis of data was done based on the number of whole insects caught in sticky yellow card traps and larvae attracted to potato slices. In the conducted tests, the reductions in the insect population in the treatments compared with the control were calculated. The laboratory experiments showed positive effects of all treatments on pest control. The concentrations of 1×106 IJ/m2 Sf and 2/1000 Bti had the highest mortality rate of pest larvae with 81.6 and 77.4% mean mortality, respectively. Nematode Sf at this concentratration acted better than Dichlorvos for the control of this pest. In the field measurements, the highest population decreases were recorded in Bti with 75.7% control efficacy based on yellow sticky cards and in treatments of Dichlorvos and half-dose of two-biocontrol agent based on potato slices data with 75.3 and 74.8%, respectively. No significant difference was observed between Dichlorvos and Sf treatment for the control of this pest based on yellow sticky card data in field study. The obtained results recommend using these two biological control agents to control the L. auripila mosquito in edible mushroom cultivation halls.

Cabbage aphid, Brevicoryne brassicae (L.), is one of the most important pests of cabbage crops. The use of plant-based insecticides, as well as biological control agents such as insect pathogenic fungi, has been considered as complementary methods in integrated pest management. In this research, the effect of Bino2 and two types of entomopathogenic fungi, Metarhizium anisopliae AB and Lecanicillium lecanii 229, as biological insecticides on the protein content, digestive protease activity, chitinase enzyme, acetylcholinesterase and glutathione-S-transferase enzymes of the cabbage aphid adults were examined at a temperature of 25±2 °C, relative humidity of 60±5% and a photoperiod of 16:8 h (L: D). The results indicated that the use of lethal concentration (LC50) of the fungal isolates caused the digestion of protein and chitin in the aphid cuticle, which in turn increased the sensitivity of aphids to these agents by increasing the secretion of protease and chitinase enzymes.  Also, the Bino2 insecticide had an anti-nutritional effect by reducing the amount of protein and inhibiting the activity of digestive enzymes. In parallel to the decrease in the activity of digestive enzymes, the activity of detoxifying enzymes also decreased under the influence of the Bino2. The results of this research showed that the tested entomopathogenic fungi and Bino2 insecticide led to an increase in the mortality of cabbage aphids, thus the obtained information can be used in the management of this pest.