Toxicity to Tylenchorhynchus dubius and Hoplolaimus galeatus of newly unwrapped plastic containers.

were seven replications of each of tile five treatments. T h e exper imenta l design was randomized complete blocks. In a second similar experiment , aphids, Aphis gossypii Glover, were placed on the leaves of each plant just after t ransplant ing and before the aldicarb was appl ied (4). After the aphids became established on the plant, s and were uniformly distributed, technical aldicarb was applied in 25 ml water at the rate of 4 t tg/g soil. T h e following day the number of surviving aphids was counted. T h e low survival of aphids on plants treated with aldicarb (upper roots 7%; lower roots 18%) compared with tile relatively high survival of aphids on untreated plants (85%) confirmed that aldicarb was translocated to the leaves from upper and lower roots. After two weeks there were no significant differences in average plant weights in the various treatments. Root-knot nematodes were controlled only when aldicarb was in contact with them in the same container. The re was no evidence that aldicarb moved from upper to lower roots, or vice versa, in amounts sufficient to control tile nematodes (Table 2). Relationships between nematode survival or death and dose of aldicarb are allied with the means by which aldicarb comes in contact with nematodes: In the soil, it disperses by mass transfer in the water in the direction of water movement (3). In the nematodes ' envi ronment there October 1978