جستجوی مقالات مرتبط با کلیدواژه "کرج" در نشریات گروه "گیاهپزشکی"

Cultivation of diverse crops is a strategy key in sustainable agriculture. Increasing plant diversity in intercropping systems can be suitable for biological control of pests. In order to investigate the effect of mixed cultivation of sugar beet and red clover on the population of Aphis fabae Scopoli, natural enemies including Coccinella septempunctata Linnaeus, Hippodamia variegata Goeze, Orius niger Wolf, O. minutus Linnaeus, and Chrysoperla carnea Stephens, and some agricultural traits of sugar beet, an experiment was conducted in the form of completely randomized block design in four replications. Experimental treatments included monoculture of sugar beet (control) and seven types of strip cultivation systems including: 1) two rows of sugar beet  and four rows of red clover, 2) two rows of sugar beet and three rows of red clover, 3) one row of sugar beet and two rows of red clover, 4) two rows of sugar beet and two rows of red clover 5) three rows of sugar beet and two rows of red clover, 6) two rows of sugar beet and one row of red clover, 7) four rows of sugar beet and two rows of red clover. The results of this research showed that the different treatments of sugar beet and red clover intercropping on the aphid population, natural enemies, and agricultural traits including root yield, leaf yield, and shoot yield are significant at 1% probability level. The results of this research showed that the treatment of two rows of sugar beet and four rows of red clover can be useful in integrated pest management and biological control of A. fabae in sugar beet fields and improve agricultural traits.

Valerian medicinal plant (Valeriana officinalis) is a perennial succulent plant that is natural lenitive and good ingrained of diazepam. This study was conducted in order to identify the fungal agents of rhizome and root rot of valerian. Infected plant samples that showed the symptoms of rotting and necrosis were collected from Karaj and used in order to isolate disease agents. Symptomatic samples were sterilized with sodium hypochlorite (1%) and cultured on PDA medium in Petri dishes. Two fungal colonies grown from tissue segments and single hyphal tip or monoconidial isolates were obtained on PDA medium followed by incubation in dark. The fungal isolate identified as Rhizoctonia solani based on the following test. Staining was done for hyphae of Rhizoctonia isolate, number of nuclei in each cellule and hyphal diameter was determined. The hyphae contained several nuclei. Single spore culture, were obtained from macroconidia of Fusarium isolate. After 24 hours of incubation, single spores were transferred to selective medium, CLA, for detection of Fusarium isolates and also, were transferred to PDA medium for sufficient mass production of spores and sporulation. After 7 days colonies appeared as white cream on top and cream at the bottom of Petri plate with abundant micro and macro conidia. Based on morphology and dimension of conidia and also, production of chlamydospore, the fungus was identified as Fusarium solani. This is the first report of these fungi on V. officinalis in Iran.