EMERGENCE AND REDUCTION: THE SAME COIN?

Zygon® ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Willem B. Drees
Author(s):  
Shefali . ◽  
Jyoti Yadav ◽  
R.K. Gupta

The present study of 28 days was carried out to assess the effect of arsenic and chromium on biomass gain and reproduction parameters (cocoon and hatchling production) of E. eugeniae. The worms were cultured in substrate having different concentrations of arsenic and chromium alongwith control in triplicates. Dose and time dependent decreased in number of adults, cocoon production and hatchling emergence and reduction in growth was observed. In worms exposed to Cr (0.1 ppm), reduction in population (24.66%), body weight (2.44%), cocoon production (47.14%) and hatchling emergence (39.99%) was observed. While As (0.1 ppm) exposure resulted in reduction of adult population (10.66%), body weight (0.24%), cocoon production (37.05%) and hatchling emergence (28.53%) was observed. Cocoon production was observed to be the most sensitive parameter for heavy metal exposure in all treatments. Chromium was observed to be more detrimental to earthworms when compared with arsenic.


Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 535-537 ◽  
Author(s):  
K. E. Conway ◽  
R. Mereddy ◽  
B. A. Kahn ◽  
Y. Wu ◽  
S. W. Hallgren ◽  
...  

Two field trials at Stillwater and Bixby, OK, evaluated the efficacy of solid matrix priming techniques, alone or in combination with fungicide seed treatment on seedling emergence and reduction of damping-off of okra in field soil naturally infested with Pythium ultimum. The following treatments were evaluated: thiram + carboxin (chemo-primed) (commercially applied), biological seed treatment (bio-primed) (Trichoderma harzianum isolate OK-110, 1 g suspended in 1% carboxymethylcellulose [CMC]), untreated seed (control), and a 1% CMC control. Chemo-primed seeds had a more uniform and faster emergence compared with untreated seeds at both field sites. Within 3 days, 92 and 78% of chemo-primed seeds had emerged at Stillwater and Bixby, respectively, compared with 84 and 71% emergence in the untreated control. Mean emergence of chemo-primed seeds was lower (P ≤ 0.05) than the untreated control. Chemo-primed seeds had greater vigor (P≤ 0.05) at both locations compared with either fungicide-treated or priming alone, at both locations. There were no differences (P ≤ 0.05) in yield among treatments at both locations. P. ultimum was consistently isolated from damped-off seedlings and surrounding soil at both locations. Isolates of P. ultimum were more pathogenic on okra in laboratory tests than isolates of Rhizoctonia spp., Fusarium spp., and other Pythium spp. also isolated from seed or soil.


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