Journal Of Crop Protection
Volume:10 Issue: 3, Sep 2021

The inflorescence rot is an essentially high impact (or damaging) disease of date palm. The current research was carried out to help develop a decision-making system in Abadan, Khorramshahr, Shadegan, Ahwaz, Mahshar, and Behbehan regions of Khuzestan province Iran based on climatic and geostatistical models using five-year data from 2011 to 2015. Samples were taken randomly from 10 date palm trees within one orchard in each of 33 villages. The disease started in March, and the damage reached its peak values in April. The forecasting model of damage factors has been significant at levels 1 and 5%. The model nuggets for disease in Abadan-Khorramshahr, Shadegan, Ahwaz, Mahshar, and Behbehan regions were 2.1, 1.1, 0.09, 2.60, and 0.27 km, respectively. These results show that the disease damage estimation errors were low at distances less than within sampling space. The effective ranges of variograms were 4.9. 8.3, 9.1, 5.1, and 4.2, respectively, indicating the disease distribution in the region. The sill of models were 0.41, 0.46, 0.46, 0.29, and 0.58, respectively, indicating that correlations between the damage data were at the lowest level and could be monitored at distances more than these thresholds. Findings are fundamental steps in creating a decision-making system in the date palm protection network. Therefore, it could be concluded that the date inflorescence rot disease can be monitored, forecasted, and controlled correctly before the maximum damage occurs.

Pistachio psylla, Agonoscena pistaciae Burkhardt & Lauterer (Hem.: Psyllidae) is one of the most important pests of pistachio orchards in Iran. The application of chemical pesticides early in the growing season until harvest has affected farmers’ and consumers’ health. In this research, the efficacy of arugula Eruca sativa cold press seed oil, methanolic spinach Spinacia oleracea seed extract, and dayabon® (SL 10%) was studied against nymphs and adults of pistachio psylla in a laboratory at 26 ± 2 °C, 65 ± 5% RH, and photoperiod of 16: 8 (L: D) h. LC50 values of nanoemulsion formulation (NEF) of spinach seed extract and its nonformulated extract on the early nymphal stage were 468 and 4381 mg/l, respectively. In contrast, the LC50 value of arugula seed oil and dayabon was 2281 and 4380 mg/l, respectively. NEF of spinach seed extract (LC50 = 124 mg/l) was significantly more toxic than other compounds against the 5th nymphal stage. There was no significant difference in nonformulated spinach seed extract (LC50 = 3946 mg/l), arugula seed oil (LC50 = 3189 mg/l) and dayabon (LC50 = 3930 mg/l) against 5th instars. The efficiency of dayabon and arugula seed oil and a chemical pesticide fenitrothion was studied in the field located in Dehmolla County, Shahrood, Iran. Sampling was carried out before and after treatment. There were no significant differences between days after treatments. It means that the botanicals were effective until 21 days after treatment. Findings indicated that botanical pesticides used in this study could be effective against pistachio psylla.

Carnation is an ornamental plant of economic importance worldwide. Fusarium fungus is one of the critical infectious agents of Carnation in Mahallat city. Some species of Fusarium cause wilting and crown and root rot in carnation. In this study, 20 fungal isolates of Fusarium were isolated from diseased carnation plants and rhizosphere samples from Carnation greenhouses in Mahallat. The isolates were identified morphologically using Leslie and Summerell’s identification key. Amplification of the TEF-1α gene region was done using ef1 and ef2 primers. Amplified fragments were purified and sequenced, and the nucleotide sequences were introduced in the Fusarium ID database for molecular identification of isolates based on the TEF-1α gene. A phylogenetic tree was also drawn. The results showed that Fusarium isolates were categorized into five species: F14 was identified as Fusarium brachygibbosum morphologically and F. solani molecularly. F6 was morphologically and molecularly identified as F. solani, F10 identified as Fusarium culmorum. All crown and root isolates (F11, F12, F13, F15, F16, F17, F18, F9, and F20) were identified as F. oxysporum. The rhizosphere isolates of F1, F2, F3, F4, F5, F7, F8, and F9 were identified as Fusarium proliferatum. This study shows that the use of the TEF-1α gene for molecular identification of Fusarium isolates is a relatively accurate, fast, and straightforward method for detecting species and can be used in plant pathological studies. Identifying the pathogen is the first step to controlling the disease.

The cabbage aphid, Brevicoryne brassicae (Hemiptera: Aphididae), is an important pest of rapeseed. In this study, the effects of a silicon-based fertilizer, silicate potassium (SP), and salicylic acid (SA) on inducing resistance in rapeseed to the aphid were studied under field conditions. The rapeseed plants were directly sprayed with SP and SA at two application rates, and the population density of alive and parasitized aphids by Diaeretiella rapae (Hymenoptera: Braconidae) was recorded every three days. The results showed that the aphid population densities in SP and SA treatments were significantly lower than in control (2.21 and 3.53 folds, respectively). The lowest population density was observed in the SP treatment (1200 g/ ha). Moreover, the parasitized aphid densities in the treatments were significantly increased, and the highest parasitism was recorded in the SP treatment (1200 g/ha). The rapeseed yield in the SP-treated plants was significantly more than control, and the highest yield increase was observed in SP treatment (1200 g/ha). According to the results, SP at 1200 g/ha is recommended for cultural control of B. brassicae in the rapeseed fields.

Our study aims to evaluate the physicochemical mechanism involved in the adhesion of Fusarium oxysporum f. sp. albedinis (Foa) on date palm root of resistant (Aziza M) and susceptible (Boufegouss) varieties by determining their surface properties. Hydrophobicity of Date palm root and Foa was evaluated by contact angle measurement (θw) and free energy of interaction determination (∆Giwi). Our results showed that Foa surface is hydrophilic (θw = 30.57° and ΔGiwi = 15.51 mj/m2) and has an important electron donor character (γ- = 53,99mj/m2), whereas its electron acceptor property is low (γ+ = 8.95 mj/m2). Regarding date palm, the surface of sensitive variety’s root is hydrophilic (θw = 62.97°), while that of resistant variety is hydrophobic (θw = 69.50°). This character was confirmed by quantitative approach (ΔGiwi = 6.84 mj/m2 for sensitive variety and ΔGiwi = -20.61 mj/m2 for resistant variety). Also, it was noted that both resistant and sensitive varieties are weak electron acceptors (γ + = 0.15 mj/m2 and γ + = 0.08 mj/m2 for resistant and sensitive varieties respectively). The two varieties are relatively important electron donors, but the sensitive variety is more donor (γ- = 30.5 mj/m2) than the resistant one (γ- = 16.57 mj/m2). These results suggest that hydrophilic character and electron donor/acceptor character may be responsible for the adhesion of Foa on sensitive date palm root and therefore causes its susceptibility to bayoud disease. In contrast, the hydrophobic character of the resistant variety could explain its resistance.

Root-knot nematodes, Meloidogyne species are among the most critical plant-parasitic nematodes attacking okra Abelmoschus esculentus (L.) Moench in tropical and subtropical regions. In the present study, the effects of various levels of zinc and iron on okra infected with M. javanica were investigated under greenhouse conditions in a completely randomized factorial design with five replications. Four-leaf stage seedlings of the susceptible okra, cv. Clemson Spineless were inoculated with 8000 eggs of M. javanica per pot. Five days later, the soil of each pot was treated with a combination of iron or zinc (0, 1, 3, and 6 mg∙kg-1 soil) from nano chelated iron and zinc fertilizer sources. Sixty days after inoculation, plants were harvested, and okra growth indices and nematode population indices were determined. Results showed that vegetative indices increased in most cases compared to non-treated plants. Fruit fresh weight of inoculated plants treated with iron at the rate of 1 mg∙kg-1 soil + zinc at the rate of 3 mg∙kg-1 soil from nano chelated iron and zinc fertilizer sources increased by 205%, compared to inoculated control plants. Combined application of iron at the rate of 6 mg∙kg-1 soil + zinc at the rate of 6 mg∙kg-1 soil from nano chelated iron and zinc fertilizer sources reduced the number of eggs, galls, and egg masses per root system and the reproductive factor (224, 415, 455 and 231%, respectively) compared to non-treated plants.

New data on the distribution of eight Sphecid wasps species (Hymenoptera: Apoidea: Sphecidae) collected from different localities in southern areas of Kerman province (southeast Iran) are presented. The specimens were collected at 21 localities using Malaise traps from April to September 2017. The identified species belong to three subfamilies, Ammophilinae André, 1886 (three species, two genera), Sceliphrinae Ashmead, 1899 (a single species), and Sphecinae Latreille, 1802 (four species, two genera, two tribes). Palmodes parvulus (Roth, 1967) is newly recorded for the Iranian fauna, and its diagnostic characters are presented.

The previous works have addressed selecting the nozzle to minimize the hazard of pesticide drift by producing large spray droplet sizes. However, this spray application with the largest sizes does not effectively impact insects either, as it needs many pesticides. Several studies have demonstrated that the small spray droplet sizes can affect the insects and be obtained by selecting the appropriate nozzle size and height. This study sheds light on the nozzle sizes and heights, and insecticide types for controlling the cabbage aphid to ensure efficient insect control. Different parameters including three sizes of flat fan nozzle 01, 02, and 03, two nozzle heights 35 and 70 cm above the plant top, and two insecticide types 20% wide plus WP and 90% methomyl SP were investigated to measure spray deposition, coverage percentage, and droplets density in different locations of the cabbage plant for improving control efficacy. The outcomes showed significant differences in the spray deposition and coverage percentage using different nozzle sizes, nozzle heights, and insecticide types. The best spray deposition, coverage percentage, and control efficacy (0.321 µm.cm-2, 15.05%, and 84.83%, respectively) were achieved using the 02 nozzle size, nozzle height of 35 cm methomyl SP insecticide type on the fourteenth day after spraying application in comparison to the others. The fourteenth day was the most effective to control aphids compared to the first and the seventh days.

The use of a multi-site fungicide in cucumber downy mildew protection programs are recommended to ensure crops are adequately protected and delay a possible resistance development of high-risk groups of single-site fungicides. Commercially available dicopper chloride trihydroxide (also known as copper oxychloride) based fungicides (M FRAC Group) were assessed for their efficacy against cucumber downy mildew in comparison to a commonly used phosphonate (Fosphite® 53 WSL, P7 FRAC Group) and untreated control. Foliar treatments started with the onset of disease symptoms and were repeated weekly. Disease severity was calculated twice during crop development. Significant differences between the treatments were detected. Fosphite® was the most effective among other treatments, with a reduction in disease severity of 82.6%. Among the copper oxychloride-based fungicides, statistically significant differences were detected. Copertox® and Oksavit® were significantly effective than the other products at the first disease assessment, and Copertox® being the most efficient fungicide at the second disease assessment. Significant differences were also detected among control plots. The efficiency of commercial brands of copper oxychloride in control of cucumber downy mildew was 53-67%. This efficiency is acceptable in normal disease conditions but not desirable in an epidemic situation. If the conditions are favorable for a severe disease epidemic, it is necessary to combine them with more effective fungicides such as Fosphite.

Resistance of eight almond genotypes/cultivars, including Sefid, Mamaei, Rabie, Shahrood7, Ferragnes, Shahrood13, Nonpareil, and Hooreh, to almond fruit wasp (AFW) Eurytoma amygdali Enderlein, was investigated using choice and no-choice tests. The infested fruits ranged from 4.60 ± 1.45% in the Hooreh genotype to 86.87 ± 2.01% in the Ferragnes cultivar in the choice test. The highest and lowest premature dropped fruits were recorded in Ferragnes (80.70 ± 3.21%) and Hooreh genotype (2.43 ± 1.12%), respectively. The highest and lowest numbers of alive larvae were observed in Nonpareil (1.27 ± 0.70 larvae/fruit) and Ferragnes cultivar (0.04 ± 0.02 larvae/fruit). The No-choice test indicated the highest premature dropped fruits (79.21 ± 3.76%) and the lowest number of alive larvae (0.09 ± 0.03 larvae/fruit) in the Ferragnes cultivar. The olfactory response revealed that E. amygdali females were strongly attracted to fruits and fruit extracts of Mamaei and Ferragnes cultivars compared to the Hooreh genotype. Our finding demonstrated that certain chemical stimuli emitted from the unripe fruits of almond might influence the host finding behavior of AFW females.

Pepper Capsicum annuum is one of the important vegetable crops in Iran, especially north of Iran. Various symptoms of stolbur, including limited growth, small and chlorotic leaves, spoon-shaped leaflets, and sterility or fruit alterations, were detected in samples collected from the pepper field in Qazvin province. DNA was extracted from midribs and petioles of pepper leaves using CTAB-based methods. The phytoplasma in all symptomatic pepper plant parts was detected by direct and nested polymerase chain reactions (PCR) using primer pairs P1/P7 and R16F2n/R16R2. The 16S rDNA sequences of phytoplasma isolate were deposited in GenBank (MN877916). Based on phylogenetic studies of the 16S rDNA region, the results of enzymatic digestion of the fragment obtained by amplification with R16F2n/R16R2 primer and virtual RFLP, phytoplasma agent associated with stolbur pepper disease was detected to belong to 16SrXII group and 16XII-A subgroup. According to our knowledge, this is the first report of pepper stolbur disease in Iran.

Beet virus Q (BVQ) is a soilborne pomovirus (family Virgaviridae) associated with rhizomania syndrome in sugar beet. In the present study, BVQ was investigated in sugar beet farms of 12 provinces in Iran by RT-PCR. Thirty-five out of 214 root samples resulted in a positive reaction to BVQ (16.3%). Moreover, 501-bp- long fragments of the coat protein gene of 11 Iranian isolates were purified, cloned, and sequenced. Phylogenetic analysis using the 501 bp fragment of 17 BVQ isolates (11 from this study and six retrieved from GenBank) showed that all isolates clustered in two main groups. Iranian isolates belonged to group I alongside isolates from France (AJ810289) and Germany (AJ223597). Iranian isolates shared 98.80–100% nucleotide sequence identity (98.19–100% amino acid identity) and 97.21–99.60% nucleotide sequence identity (96.99–99.40% amino acid identity) with the corresponding sequence of six other BVQ isolates available in the GenBank. Iranian isolates displayed the highest nucleotide and amino acid sequence identities of 98.80-99.60% and 98.19-99.40%, respectively, with the French isolate FP71 (AJ810289). To our knowledge, this is the first molecular characterization of BVQ in Iran. This information can be used in plant breeding to obtain virus-resistant plants.

More than 104 aphid species are living on Rosa spp. in the world. So far, only 14 of them were reported from Iran. In this study, besides the species already living on Rosa in Iran, two aphid taxa, i.e., Maculolachnus sijpkensi Hille Ris Lambers, 1962, and M. submacula (Walker, 1848) (Hem.: Aphididae) living on Rosa beggeriana are reported for the first time from Iran. Biometric data and biological characteristics of these two aphid species are given. An identification key to the apterous viviparous female aphids living on Rosa in Iran is provided.

Ditylenchus azarbaijanensis n. sp. is described and illustrated based upon morphological and morphometric characters. The new species is mainly characterized by having six lines in the lateral field, rudimentary postuterine sac (PUS) ca. 0.2 vulval body width long, anteriorly inclined vagina and conical female tail with a pointed terminus, 48-70 µm long (c = 15-21, cʹ = 2.4-3.7). It is further characterized by having fine stylet 7.5-10.0 µm long with small knobs, small pyriform pharyngeal bulb offset from the intestine, and males with 26.5-31.0 µm long spicules. By having a rudimentary PUS, the new species is morphologically compared with three closely related species, namely Ditylenchus apus, D. deiridus and D. khani. Moreover, morphological differences of the new species with eight similar species of the genus, namely D. arachis, D. convallarie, D. dauniae, D. medicaginis, D. silvaticus, D. tenuidens, D. valveus, and D. virtudesae are presented. The status of the rudimentary or absent PUS of D. deiridus and the new species is also discussed.

Organophosphates (OPs), one of the most important pesticide groups, are used worldwide to control pests. Acetylcholinesterase (EC 1.14.18.1) (AChE), an enzyme from insects’ nervous systems, is the leading target site of this group of pesticides, such as Acephate. Inhibition of enzyme activity through Acephate-derived compounds can control both resistant and non-resistant pests to OPs. In this research, the toxicity of these compounds was assayed regarding the control of Xanthogaleruca luteola (Muller). Results of the in vivo screening test revealed that two derived compounds of phosphorhydrazides (PHA) (i.e., NH2-C(O) NH-NH P(O)(OC6H5) and OC4H3-C(O)NH-NHP(S)(OCH3)2) showed the most significant insecticidal potential. AChE was purified and isolated from the third instar larvae of elm leaf beetle, X. luteola, using affinity chromatography. IC50 values, inhibition mechanisms, and inhibitory constant (Ki) of NH2-C(O) NH-NH P(O)(OC6H5) and OC4H3-C(O)NH-NHP(S)(OCH3)2 as inhibitors were calculated for the purified AChE. These compounds inhibited acetylcholinesterase (AChE) and general esterases of third instar larvae of elm leaf beetle. These compounds, by mix inhibition mechanism, inhibited AChE enzyme, and Ki obtained was 1.16 and 0.88 µM-1 min-1 for NH2-C(O) NH-NH P(O)(OC6H5) and OC4H3-C(O)NH-NHP(S)(OCH3)2, respectively. QSAR study based on multiple linear regressions (MLR) and principal component analysis (PCA) showed that the non-descriptor net charge of the nitrogen atom influenced by the polarization of N-H group had the most significant effect on the insecticidal potential. Therefore, designing new compounds that control the N-H polarization of the nitrogen atom could be an excellent option to study insecticidal properties of Acephate-derived compounds.