Journal of Applied Entomology and Phytopathology Journal of Applied Entomology and Phytopathology

Chickpea pod borer (CPB), Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), is the most important pest on chickpea (Cicer arietinum), which causes substantial yield losses. This study was carried out to screen resistance of 40 chickpea accessions against CPB in a field trial in a randomized complete block design (RCBD) with three replications in Eslamabad-e Gharb. Plant infestation with this pest was done at the podding stage. In this experiment several traits including pod borer's population, percentage of pod damage and grain yield were measured. The results indicated that genotypes responded differently to CPB. Also, the yield of all lines in infestation condition decreased, but there was a significant difference between the lines. FL IP99-48C demonstrated to be the most susceptible with the least yield. FL IP07-40C (that is Kabuli type) and Pirouz (that is a Desi genotype) recorded as the most resistant genotypes in terms of reducing the CPB population and the highest yield that can be used in breeding programs in the future .

Fruit russeting has been recently widespread on apple fruits cultivar Golden Delicious, resulting in decreased quality and value, in Semirom, Isfahan province, Iran Two groups of fruit russetting have been reported on the Golden Delicious cultivar. The first group has a genetic origin (Falginella et al., 2015) and the second group is related to environmental conditions, physical, mechanical and chemical factors, pests, pathogens and management practices. The amount of russet is affected by various factors such as weather conditions (rainfall, coldness, relative humidity, light quality on the fruit surface), chemicals (nutrients, hormones or fungicides), mechanical injury and pests' damage (Goffinet et al., 2002). In addition, fruit russet could be formed by epiphytic bacteria or yeasts (Goffinet et al., 2002; Heidarianet al. 2020), causative agent of apple powdery mildew (Podospha eraleucotricha (Ellis & Everh.) E. S. Salmon) and apple rust mite, Aculus schlechtendali.  The present study aimed to investigate the factors affecting the occurrence and development of fruit rust on Golden Delicious apple cultivar. Therefore, random sampling was performed from three major cultivation regions of Semirom city, having different climates. In each region three orchards were selected and in each orchard, 50 fruits were sampled three times in two consecutive years, from the time of symptom occurrence until harvest time. Samples were inspected in the laboratory in terms of rust type, percentage of russetted fruits (RI%) and fruit russeting index (FRI), based on predetermined scales. The results showed that based on the typical symptoms, there are four types of rust as follows on apple fruit in Semirom orchards. 1) Caused by a yeast-like fungus: It occurs in the stem-end cavity of the fruit, forming a brown fluffy tissue. The pathogenicity of this agent was proven (Heidarian et al. 2020). 2) Rust caused by powdery mildew: It is tan or gray color and has a mesh-like appearance. 3) Physiological rust: It is a type of sunburn called brown sunburn. 4) Rust caused by spraying chemicals such as fertilizers and pesticides: It usually occurs in places of the fruits where there is a possibility of accumulation of particles and is usually associated with burning of foliage. Mean Comparison indicated that the highest percentage of russetted fruits (73.25%) and fruit russeting index (37.7%) belonged to the yeast-like fungus Aureobasidium pullulans and the lowest of these values, 1.66% and 1.45%, respectively belonged to chemical spraying. Moreover, the results showed that 80% of Golden Delicious fruits have russetted with varying degrees of contamination, of which 53.6% were russetted by one factor and 36.83% by two or more factors.

Evaluation of single and integrated effects of diatomaceous earth and neem fruit extract, Melia azedarach, against 1-to-3-day-old insects of flour weevil, Tribolium confusum (Col., Tenebrionidae) and cowpea seed beetle Callosobruchus maculatus (Col., Chrysomelidae). Three replications were performed by contact toxicity by filter paper residue test and the mortality was measured 24 and 48 hours later. After 48 hours interval, the LC50 level of Permaguard ® formulation of diatomaceous earth against flour weevil was 4.6 times less than 24 hours interval. In the case of other species, this amount decreased by 3.2 times. Over time, from 24 to 48 hours intervals, the effect of the neem extract on both species increased. Also, there was a synergistic relationship between neem fruit extract and diatomaceous earth in both species and both times studied, which increased with increasing exposure time. Therefore, the simultaneous use of these two compounds could improves the effectiveness of these compounds.

Charcoal rot disease caused by Macrophomina phaseolina is the most destructive disease of sesame (Sesamum indicum) in Iran and other countries as well. The fungus has been more important in recent years because of climate change and global warming. In this research, 81 genotypes of sesame were sown in a hot spot farm at Behbahan Agricultural Research station in south of Khuzestan province as a simple lattice design during three successive years. Damping off was observed at all growth stages. None of the genotypes were immune of the disease. M. phaseolina was the dominant pathogen of sesame in soil of the disease plot. Damping-off was observed during all growth stages. None of the genotypes were immune to the disease. The corrected data were subjected to simple and compound analyses. The results indicated that Tarom landrace and Darab2 line had the highest level of resistance. 22 genotypes were determined as moderately resistant genotypes among which Potak-e-musian landrace had the lowest 3-years average of infection percent. The rest were recongnized as moderately susceptible, susceptible and highly susceptible genotypes .

During ten-year study (2009-2018), rainfed wheat fields were selected to evaluate disease and examine associations of climatic data with wheat yellow rust disease epidemics across four regions, Sarpolzohab and Gilangharb (tropical), Eslamabad Gharb and Mahidasht (temprate). No disease was evident in 2009-2010, 2016-2017 and 2017-18 and there was low and sparce disease levels in remainder years. Principal component analysis of climatic and disease data indicated that number of rainy days from October to May, periods of consequential days with minimum temperature within 6-9˚C and maximum relative humidity > 60%, and longest period with these climatic characters were the best indicators of yellow rust disease epidemics occurrence across four study regions. Two characters of monthly average of maximum relative humidity for February and minimum temperature of March were also identified as important disease epidemics predictors. Two characteristics, number of icy days and days with minimum temperature under-10˚C were recognized as best indicators to predict disease onset time. To test efficiency of developed stripe-rust-predicting model, lack of or low disease occurrence for two years of 2017 and 2018 were predicted correctly.