آسیب ناشی از Callosobruchus maculatus بر دانه‌های لوبیا چشم بلبلی حاصل از کودهای مختلف

Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) is a significant pest of legume seeds in the field and storage. Plant fertilization may enhance the resistance of seeds against post-harvest insects. Improving host-plant resistance by using a suitable fertilizer would be beneficial in reducing C. maculatus infestation in storage. Cowpea seed (c.v. Mashhad) was planted in the field and fertilized with chemical fertilizer triple superphosphate (TSP) (200 kg/ha) and urea (70 kg/ha) and bio-fertilizers, Bradyrhizobium japonicum (1 L/kg seed), Pseudomonas putida (1 L/kg seed), mycorrhizal fungi (1 kg/kg seed), and a mixture of them (1 L/kg seed), and cultivated at a farm with three plots and 7 treatments. The weevil rearing and tests were carried out in a growth chamber set at 28±1°C, relative humidity of 65±5%, and 24 h darkness. Ripe seeds were harvested and used in the experiments. Evaluation for resistance of fertilized cowpea to C. maculatus performed by a no-choice test and analyzing the population growth. The bioassay was performed in plastic containers that were 10 cm in diameter. The lids of the dishes were perforated and wrapped in voile fabric to enable ventilation. 20 grams of cowpea beans from the different treatments and 5 adult insects (1-day-old) were placed in each dish. After 30 days, the dishes were opened, and the following variables were quantified: number of emerged insects (alive and dead), final grain mass, consumed bean mass and instantaneous rate of population growth (ri). The General Linear Model was utilized to analyze the data using Minitab version 18.0. A significant effect was observed on percentage of dry biomass consumed and ri growth between different treatment. Therefore, among 7 treatments, there was a significant difference in the percentage of weight loss on treatments. The lowest percentage of seed weight loss was on the seeds obtained from TSP fertilizer treatment (12.5 ± 0.77) and the highest percentage was on the seeds obtained from urea fertilizer treatment (19.05 ± 1.66), combinations of biofertilizers (18.06 ± 1.26) and control (19.38 ± 0.54). The highest amounts of ri was on urea (0.111 ± 0.002), P. putida (0.111 ± .002) and combination of biofertilizers (0.109 ± 0.002) and the lowest was on the grains obtained from TSP fertilizer (0.099 ± 0.001). According to the results of this study, using B. japonicum on Mashhad cultivar is recommended to decrease the damage of C. maculatus in storage.