antifungal and antibacterial activity of some heterocystous cyanobacteria from paddy-fields in the north of iran was studied. soil samples were collected from paddy-fields of gillan, mazandaran and golestan provinces and cyanobacteria were isolated. supernatants, methanolic and hexane extracts from biomass of 150 strains of cyanobacteria were isolated and screened against six strains of bacteri...

Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. C...

abstract bacterial blight of rice, causes by xanthomonas oryzae pv. oryzae , is one of the most devastating disease of rice after blast disease. during the spring and summer of 2005-2006 different paddy fields in guilan province (roodsar, langrud, lahijan, rasht, anzali, fooman, soomeesara and roodbar) were surveyed and samples were collected from rices showing blight and yellowing in leaves. t...

the algal flora of five stations from paddy-fields of golestan province was investigated between october 2006 and september 2007. eight filamentous heterocystous nostocacean are recorded here for the first time from paddy fields of iran: cylindrospermum licheniforme, cylindrospermum stangnale, cylindrospermopsis raciborskii, calothrix ghosei, gloeotrichia longiarticulata, aulosira implexa var. ...

The documentation process is very important for identifying yield constraint factors and yield gap. For this purpose, all managing practices were recorded by monitoring of paddy rice fields in Sari region, Iran from 2015 to 2016. Field identifications were undertaken in such a way that they included all the main production procedures with variations in management viewpoints. The results reveale...

The management and improvement of paddy soils fertility are key factors for the future capacity of rice production. The return of rice straw to paddy soils is the best alternative to the application of industrial fertilizers for rice production sustainability. The best strategy for applying rice straw to improve soil nutritional capacity during rice growth has not yet been investigated. We comp...

Part (I) of this study presented field and laboratory experimental data on soil characteristics and hydraulic parameters that are related to water infiltration in rice paddy fields. Part (II) includes a series of numerical simulations that are based on the in situ data, which three-dimensional finite element computer model for simulating density dependent flow and transport (FEMWATER) produced ...

one of the crucial issues before the second cropping is having enough knowledge about the residue effect of first crop herbicides on second crops. this experiment was conducted to investigate the possible inhibitory effect of some selective paddy herbicides residues to second cropping. experimental factors were included common paddy herbicides (thiobencarb, butachlor, oxadiargyl, bensulfuronmet...

Four paddy fields in Guilan province in the north of Iran seasonally were sampled from April 2008 to January 2009. Twenty-two morphospecies belonging to three families of the heterocystous blue-green algae were identified. Fourteen species and one variety of these taxa are new record for Iran. Among the families Nostocaceae with six genera and 16 species showed the highest species richness.