Aim:  To investigate the role of biofilm‐forming Paenibacillus polymyxa strains in controlling crown root rot disease. Methods and Results:  Two plant growth‐promoting P. polymyxa strains were isolated from the peanut rhizosphere, from Aspergillus niger‐suppressive soils. The strains were tested, under greenhouse and field conditions for inhibition of the crown root rot pathogen of the peanut, as well as for biofilm formation in the peanut rhizosphere. The strains’ colonization and biofilm formation were further studied on roots of the model plant Arabidopsis thaliana and with solid surface assays. Their crown root rot inhibition performance was studied in field and pot experiments. The strains’ ability to form biofilms in gnotobiotic and soil systems was studied employing scanning electron microscope. Conclusion:  Both strains were able to suppress the pathogen but the superior biofilm former offers significantly better protection against crown rot. Significance and Impact of the Study:  The study highlights the importance of efficient rhizosphere colonization and biofilm formation in biocontrol.

-Weed control is consider the major obstacle for the growers in the organic farming. Lower plant productivity in organic farming mainly related to the poor weed control. It is widely known, in most cases, that losses caused by weeds exceeded the losses from any category of agricultural pests. Under water-stress condition, weeds can reduce crop yields more than 50% through moisture competition alone. In the light of the environmental and toxicological problems created by herbicides, it has become necessary to develop the safety methods for controlling weeds. Soil Solarization, Mulching, Biodegradable Mulch, Natural Herbicides, Hot Water, and Agronomic Practices have been successfully adopted in many countries as safe methods for controlling weeds in the organic farming. In addition, there are some promising new and non-traditional measures such as Fresnel Lens, Electrical Weed Control, Lasers, etc which could be employed for controlling the weeds in organic farming. Also the agronomic practices such as choice of competitive varieties, stale seedbeds had a significant impact on weeds. The growers in organic farming should keep these three points in mind: 1) start clean stay clean successful, 2) Prevention is always better than treatment and, 3) One year's seeds will lead to seven year's weed infestation. Successful and sustainable weed management systems are those that employ combinations of techniques rather than relying on one method. The objectives of this paper are to review some safe weed control methods in the clean agricultural.Keywords: weeds, Safety methods, Mulch, Soil solarization, Natural herbicides, hot water, non-traditional methods. Palavras-chave: sementes, métodos de segurança, cobertura morta, solarização do solo, herbicidas naturais, água quente, métodos não tradicionais. RESUMO -O controle de plantas daninhas é considerado

Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11). Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, β-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.

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Mango (Mangifera indica L.) is universally considered one of the most important fruit crop in Egypt. Egypt produces 232,000 tone of mangos annually and exports moderate amounts (1500 tones) to 20 countries in the near East and Europe, FAO, 2000. It is expected that commercial and backyard plantings of mango trees will continue to increase. Mango suffers from several diseases at all stages of its life. All the parts of the plant, namely, trunk, branch, twig, leaf, petiole, flower and fruit are attacked by a number of pathogens including fungi, bacteria and algae. They cause several kinds of rot, die back, anthracnose, malformation, scab, necrosis, blotch, spots, mildew, etc. This fact sheet concentrates on the symptoms of the important mango diseases, the weather conditions conducive to disease development, and methods for control.