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0 174 Bułgaria, B'tgarska Akademiya na naukite [Tbird National Confereoce of Parasitology, Albena, Bułgaria, 12-14 Oct. 1977. Summnries.] Treta Natsionaina Konferentsiya po Parazitologiya, Albena. Bułgaria. 12-14 X 1977. Rezyumeta. Bułgaria. (1977) 253 pp.

The following 20 papers on plant nematology were presented at this conference.

STOYANOv. D. [Rotylenchulus borealis - a new parasite of maize in Bułgaria.] [Abstract]. 111-112 [Ru]    110

*0171 Gooof.i.L, P.; Ferris, H- Plant-parasitic nematode distribution in an alfalfa field- Journal ot Nematology (1980) 12 (2) 136-141 (En. 23 ret*.] Univ. of Califomia. Riverside, CA 92521, USA.

Systematic samp/es taken from a field of Mcdicago sativa m Califomia, USA. showed Mehidogyne arenana, Pratylenchus minyus, Merlinius breridens. Helicotylenchus digonicus and Parał richodorus minor to be consistently present. Ali species had a highly ske’.ved frequency distribution that departed significnntly fron ramlomness. M. arenaria. M. brevidens and H. digenieus were descr.bed by a negative binomial in samples from Che eniire field. Whcn categorized by soil texture, all populations in the fineteztured areas and 3 populations (M. arenana, P. minyus and M. brevidens) in the coarse areas fitted a neguiive binomial distribution.

0 17 2 Caubel, G.; RiyoaL, R. [E>aluation of action ot pesticides against rarious nematodes in maize fields.] fcvaJuation de l’action de pesticides sur divers nematodes en culture du mais. In Sciences Agronomiąues Rennes. Rennes, France; £cole Nationale Superieure Agronomique. (1977) 33-49 (Fr, en) I.N.R.A, Lab. de rechcrcbe dc la cbaire de Zoologie. E.N.S.A., Rennes, France.

In field experiments in France various nematicides Were tested for control of Ditylencbus dipsaci. Heterodera avcnae and Pratylenchus spp. on maize. Treatment with aldicarb or carbofuran inhibited nematodc infestation over a 50 day period and stimulated maize growth. Maize was hypersensitive to populations of D. dipsaci and H. a^enae above 30 and 50 nematodes/plant respectively. but was a very bad bost and could be used in cereal rotations to reduce nematode populations.

017.1 VaZQUEZ, J. T.    [IofesUitions of parasitic

nematodes as a factor limiting the production of maize in the Mezican aUipiano.] Infeslaciones de nemśtodes fitoparasitos como factor limitante en la producción de maiz en el altiplano Mezicano. Xalapa, Veracmz, Mexico; DGEM. (1976) 79 pp. [Es]

Maize rabnoculturc. a system whieb favours the multiplicalion of patbogens, is typicaJ of the regions of the high plain of Mexico. Studies on the distribution and prevalence of nematodes in tbese areas and on the pathogenicity and control of nematodes. especially Punctodera punctata [Heierodera punctata in text), are reported. In 1962 and 1963. a total of 94 soil samples were collected from maize plantations, all of whieb were infested witb P-    punctata;    Helicotylenchus erythrinae,

Tylenchorbyncbus [Quinisulcius] acri and Pratylenchus penetrans were also very comroon. EzperimentaJ studies on tbe pathogenicity of P. punctata on 3 varietie$ of maize grown in field plots showed a relationship between the degree of infestation and plant beighl as well as shoot and root weighl. Applications of manure and/or ammonium sulphate improved the yield of maize in ezperiroental plots but, with the ezeeption of Tylcncborhynchus, did not significantly affect nematode populations. It is concluded that morę work is Deeded to eztend tbese preUminary studies and it is rrcommended that certain traditional agricultural practices (including monoculture) whieb favour the nematodes should be discontinued. 4 pages of references are given and 12 pa ges of colour photographs. mainly illustrating tbe pathogenicity ezperiments, are included-

0 175 KJiANI., P. J. Diseases of legunics rclevant to Papua New Guinca. Science in New Cuinea (1974) 2 (I) 112-125 (En) From Wingcd Dcans, JDRC Abs. World Lit. 1900-1977, (1978), 169.

Mcloidogync bas bcen found on Psophocarpus tetragonolobus at the Univcrsity of Papua New Guinea.

017 6 Bos, W. S. A preliminary report on the distribution and host-range of the nematode Aphelenchoides arachidis Bos. in the north of Nigeria. Samaru Agricultural Newsletter (1977) 19 (1) 21-23 (En)

Examination of samples of seed of Arachis hypogaea from difTerent parts of Northern Nigeria revealed Aphelenchoides arachidis in significant numbers only in samples from a limited area around Samaru. In a generał survey A. arachidis was found in large numbers in the roots of sugarcane, maize. sorghum, millet, rice and some wild grasses. All but 2 samples of groundnut had no infestation; the 2 infested samples were from areas which were regularly supplied with seed from Samaru. Groundnuts intereropped in fields with heavily infested maize or sorghum were not infested. It is suggested that 2 biotypcs of A. arachidis are present, one occurring on cereals and the other on both cereals and groundnuts.

0 17 7 LOCKE, E.; Saefkow, M. Maize vorieties as hosts of the cereal cyst-nematode (Heterodera arenae Woli.). (Abstract). In International Congrcss of Plant Pathology (3rd), Miinchen, GFR, 16-23 August, 1978. Abstracts of papers. Berlin and Hamburg; Paul Parey. (1978) 150 (En) Inst. fur Angewandte Botanik, Abt. Pflanzenschutz, Univ. Hamburg, GFR.

In tests of 11 maize cvs. used for ensiloge with different pathotypes of Heterodera avenac, pronounced differences were observed between the pathotypes in numbers of cysts produced and in crop yields.

O 1 7 8 RODRIGUEZ-KABANA, K.; INGRAM. E. G. (Susceptibility of pigeon peas to plant parasitic nematodes in Alabama.] Susceptibilidad del gandul a especies de fitonematodos en Alabama. Nematropica (1978) 8 (1) 32-34 [Es, en] Dep. of Botany, Aubum Univ., Auburn, Alabama, E.E.U.U. 36830, USA.

Infected field soils were used in pot tests with Cajanus cajan seedlings to assess nematode soil populations after 8 weeks. C. cajanus roots in a sandy loam from a soybean field contained Pratylenchus brachyurus, TyJenchorhynchus claytoni, and Hoplolaimus galeatus; soil contained T. claytoni, H. galeatus and Trichodorus christiei. Roots of plants grown in a sandy loam from a cotton field contained P. scribneri and H. dihystera\ the soil contained H. dihystera and T. christiei but no P. scribneri. Pigeon peas were severely attacked by Meloidogyne arenaria when planted in a sandy loam from a peanut field. Results indicate that pigeon peas or at least the cultivar tested, are not suitable for inclusion in rotalion schcmes in S.E. United States.

0 17 6 Wood, F. H. Biology, incidence and generał control of the lucerne stem nematode. In Proceedings of the 25th New Zealand Weed and Pest Control Conference Christchurch, New Zealand, 15-17 August, 1972. New Zealand; New Zealand Weed and Pest Control Society Inc (1972) 116-121 (En) Plant Diseases Div., DS1R., Auckland. New Zealand.

The symptoms, life-history and disease cycle of Ditylcnchus dipsaci on lucerne in New Zealand are described. The nematodc is present in both North and South Isiands. The minimum generation time is 25 days at 15 to 20 C on seedlings. In South Island, infestation may exceed 30% as indicated by examination of seed samples. Control melhods are discussed with emphasis on preventio» of spread by careful cleaning of lucerne seed.

0 18 0 GOSWAMI, B. K.; RaYCHAUDHURI, S. P. Interaction of root-knot nematodes and riruses in maize and