|Venditti, Maria - UNIV OF ILLINOIS|
Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 1994
Publication Date: N/A
Interpretive Summary: In a recent report, Tylenchorhynchus zambiensis was described as a new species of plant-parasitic nematode from Africa. In this paper, the ability of the nematode to damage corn was evaluated under greenhouse conditions. The nematode is a weak parasite. Under field conditions, it probably would not be capable of causing significant damage to corn and should not be considered of economic importance. This information is valuable in that agriculturists will not apply pesticides or use unnecessary crop rotation to control a nematode pest which is of minimal economic importance.
Technical Abstract: Two greenhouse experiments were conducted to determine the effect of Tylenchorhynchus zambiensis on growth of maize (Zea mays) hybrid MO17 X A634 and to determine the population levels required to adversely affect maize. Initial nematode population levels (Pi) evaluated were 0.0, 0.4, 4.0, or 42 nematodes/cm3 of soil (respectively, 0, 500, 5,000, or 50,000/pot). An additional treatment evaluated the effect of nematode associated microorganism (AM) which accompanied the highest level of nematode inoculum. After 60 days, plant height, fresh and dry top and root weights and numbers of nematodes were determined. In both experiments plant height, fresh and dry top weight, and total plant weight were reduced significantly (P < 0.05) by T. zambiensis at the highest inoculum level. In both experiments when Pi = 500 or 5,000 nematodes, effects of T. zambiensis on maize growth were inconsistent. Although roots appeared healthy, the AM treatment had a significant effect on root weight in experiment 1 and was numerically less in the second experiment. The highest final population (Pf) of T. zambiensis (Pf = 1,825,000) was obtained when Pi = 5,000 (4.0 nematodes/cm3 of soil). The reproductive factor (R = Pf/Pi) was 1184.0, 365.8, and 25.2, respectively for Pi = 500, 5,000, or 50,000. The data indicate that T. zambiensis can reduce maize growth, but is weak pathogen, which requires a large population to affect maize growth.