Population behavior ofRotylenchulus reniformisas artificial infestation on winter crop i.e. Egyptian clover,Triffoliumalexandrinumor broadbean,Vicia fabapreceding cotton cv. Giza 45 as summer crop through crop rotation system as well as its management using certain organic matters i.e. camel, horse manures, dried leaf powder of perwinkle and adhatoda in comparison with a herbicide (Emax) and a nematicide, (oxamyl) during the growing season 2005/2006 was studied within cement binzes under outdoor conditions. Results reveal thatR. reniformispopulation fluctuated in soil of winter crops, increased from 200 individuals per250 g. soil as the initial population to 264 or 300 individuals per250 g. soil of Egyptian clover or broadbean in December 2005 and then declined down to 170 or 190 individuals /250 g. soil in March, 2006 where soil temperature reached 19±5ºC, respectively, after cotton cv. Giza 454 seeds sowing. With respect to its management on cotton, oxamyl sharply suppressed nematode population below the economic threshold level that was 125 individuals per250 g. soil throughout the growing season. Periwinkle dried leaf powder ranked second to oxamyl in suppressing nematode count, followed by Emax and camel manure with values of 78.92%, 69.95% 68.35% and 56.87%, respectively. Also, rate of nematode build-up on cotton roots under stress of the various tested treatments was adversely affected with range between 0.11 to 1.4 vs 1.04 folds for the check one . Oxamyl treatment had the lowest rate of nematode build-up (0.11), while adhatoda powder had the highest one (4.20). Meanwhile, cotton yield, percentage increase values was 41.6%, 33.0%, 25.0 and 15.0% for oxamyl, periwinkle powder, Emax and camel manure , whereas, the lowest values were recorded by horse manure (8.3%) and adhatoda powder (5.0%), respectively.
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