Table 5.

Effect of potash on the toxicity of carbaryl and carbofuran to Cylindrospermum sp.

Carbaryl (ppm)	Potash (ppm)
	0	100	200	300	400	Mean	r value
0	0.208	0.226	0.186	0.153	0.07	0.169	−0.89
20	0.18	0.17	0.17	0.146	0.07	0.147	−0.85
40	0.046	0.051	0.05	0.045	0.036	0.046	−0.69
70	0.04	0.05	0.045	0.04	0.033	0.041	−0.59
Mean	0.118	0.124	0.112	0.096	0.052	0.101
r value	−0.90	−0.91	−0.9	−0.89	−0.89
CD	Carbaryl mean	Potash mean	Interaction
5%	0.0032	0.0036	0.0074
1%	0.0043	0.0048	0.01
Carbofuran (ppm)	Potash (ppm)
	0	100	200	300	400	Mean	r value
0	0.23	0.3	0.213	0.193	0.09	0.205	−0.80
25	0.283	0.28	0.233	0.18	0.038	0.203	−0.92
100	0.256	0.25	0.213	0.151	0.026	0.179	−0.92
250	0.041	0.041	0.108	0.113	0.016	0.0638	+0.07
Mean	0.202	0.217	0.192	0.159	0.042	0.183
r value	−0.89	−0.97	−0.93	−0.99	−0.75
CD	Carbofuran mean	Potash mean	Interaction
5%	0.0036	0.004	0.0078
1%	0.0048	0.0043	0.01

Note: OD on zero day = 0.01 for carbaryl, 0.025 for carbofuran.

Data presented are averages of triplicate cultures. 25 ppm carbofuran was the growth enhancing dose.