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Biological control is considered as an alternative strategy to chemical tool for controlling either nematodes or weeds. So, two pot experiments were carried out to evaluate the role of two native isolated bacteria Bacillus cereus, Pseudomonas aeruginosa and their three fusant strains namely (fusant7, fusant 20 and fusant 35) as biocontrol agents against root knot nematode Meloidogyne incognita and two weeds Portulaca oleracea and Echinochloa crus-galli infecting Solanum lycopersicum. Revealed results on nematode population, weeds and S. lycopersicum seedlings growth were recorded seven weeks after nematode inoculation. The results exhibited that, all bacterial strains suspension at the rates of (1.25x107 and 2.50x107cuf/ml) significantly suppressed M. incognita parameters, decreased fresh and dry weights of weeds and improved S. lycopersicum growth. In general, undiluted concentration of all bacterial suspensions was more effective than diluted one. Additionally, fusants were more effective than their parents in reducing nematode population and controlling both weeds. Combination of two strains was more effective than the individual application in controlling nematode and P. oleracea weed. But, it was less effective in controlling E. crus-galli weed. P. aeruginosa was more effective than B. cereus in suppress nematode and weeds parameters. The fusant 7 was more effective than all other treatments in suppressing M. incognita J2 in soil, galls and eggmasses/root system by 91.30%, 92.50% and 90.91% reduction, respectively as compared to control. Also, fusant 7 was the highly effective strain in decreasing the fresh and dry-weights of E. crus-galli, by 75.87% and 75.55%, respectively and of P. oleracea, by 84.68% and 86.17% consecutively as compared to unweeded control treatment. This in turn reflected on S. lycopersicum seedlings by improving growth parameters. In conclusion, the genetically improved bacterial strains could be used as biological alternative safe method to chemical pesticides for suppressing root knot nematode reproduction and weed seedlings growth. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the bioherbicidal properties of orange peels against canary grass and cheese weed mallow and the response of common bean plants. Two successive pot experiments were conducted with twelve treatments. The first four treatments were applied by incorporating of orange peels powder with the soil surface at successive rates (10, 20, 30 and 40 g/pot) one week pre-sowing of common bean. In the other corresponding four treatments, the orange peels powder was incorporated with the soil surface at the same rates but directly at the same time with sowing of common bean seeds. Additionally, four untreated control treatments were applied for comparison. The recorded results revealed the inhibitory allelopathic effects of orange peels powder on both weeds with direct relationship between the orange peels rate and it's inhibitory effects. However, the pre-sowing treatments were more effective than the others which applied at the time of sowing. Orange peels at 40g/pot at one week pre-sowing gave the highest inhibitory effect on both weeds. This superior treatment subsequently recorded the highest growth parameters and yield traits of common bean. Estimated phenolic compounds, flavonoids and essential oils in orange peels may be responsible for this inhibitory effect. [ABSTRACT FROM AUTHOR]

Two pot experiments were carried out during two successive winter seasons of (2016/2017) and (2017/2018) at the green house of National Research Centre (NRC), Giza, Egypt. The experiments were conducted to compare the allelopathic effect of Beta vulgaris (shoot and root aqueous extracts at 3%, 6%, 9%) to chemical herbicides (Topik and Basagran) at recommended doses (140 g fed-1 and 1 L fed-1, respectively) in controlling weeds (Phalaris minor and Malva parviflora) associated with Lupinus albus plants. Results showed that all applied aqueous extracts caused reduction in two weeds biomass under investigation. Meanwhile, root aqueous extract was more effective than shoot aqueous extract in controlling weeds. It is worthy to mention that phenolic compounds and flavonoids in B. vulgaris root aqueous extract were higher than that in B. vulgaris shoot aqueous extract. In addition, all applied aqueous extracts increased growth, yield and yield components of L. albus plant. The inhibitory effect of B. vulgaris aqueous extract on weeds or its stimulatory effect on L. albus plants increased by increasing the extracts concentration. The two applied herbicides gave complete eradication of both weeds depending on selectivity of each herbicide followed by root aqueous extract of B. vulgaris at 9%; this in turn reflected on L. albus plants by scoring highest results as compared to unweeded treatment. [ABSTRACT FROM AUTHOR]

Allelopathy is a complex phenomenon which depends on allelochemical concentrations. So, two pot experiments were carried out to investigate the allelopathic effect of alcoholic fresh shoot extract of Eruca sativa (foliar spray) and E. sativa shoot powder (mixed with soil) on Pisum sativum plants and two associated weeds, Phalaris minor and Beta vulgaris. The experiments were conducted in the greenhouse of the National Research Centre, Giza, Egypt during two successive winter seasons (2016-2017 and 2017-2018). Ten treatments were applied in this study. Four treatments were applied before sowing, that E. sativa shoot powder was mixed with the soil at rates of 15, 30, 45 and 60 g · pot-1. The other four treatments of E. sativa alcoholic fresh shoot extract were sprayed twice on both plants and weeds at 5, 10, 15 and 20% (w/v) concentrations. Additionally, two untreated treatments, healthy (P. sativum only) and unweeded (untreated infested P. sativum plants with weeds) were applied for comparison. The results indicated that both alcoholic extracts and powder reduced growth of both weeds. Moreover, there was a direct relationship between concentration and weed reduction. Eruca sativa alcoholic extracts increased yield parameters of P. sativum plants. The maximum yield attributes were recorded by spraying of E. sativa alcoholic extract at 20%. On the other hand, it was clearly noticed that the high powder rates affected negatively P. sativum yield parameters. But the lowest powder rate (15 g · pot-1) stimulated P. sativum yield parameters as compared to unweeded treatment. Chemical analysis of E. sativa shoot powder ensured that the abundant amount of glucosinolates (9.6 μmol · g-1) and phenolic compounds (46.5 mg · g-1) may be responsible for its allelopathic effect. In conclusion, spraying of alcoholic fresh shoot extract of E. sativa at 20% (w/v) and mixing E. sativa shoot powder at 15 g · pot-1can be applied as natural bioherbicides for controlling weeds. [ABSTRACT FROM AUTHOR]