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O0O7HAGUE, N.G.M. 6 CLARK, W.C., 1959. ^łrFumigation with methyl bromide and chloropicrln to control seed-borne lnfesta-tlons of the 8 ten telwonm (Dltylenchus dlpsacl) on luceme (Medlcago 8atlva).^IT Mededellngen van de Landbouwhogescfiool en de Gpzoeklngsstatlons van de Staat te Gent, 24 (3/4), 628-636. iFrench & German sum-maries p.635.1

Hague 6 Clark descrlbe fumlgatlon experi-ments with methyl bromide and chloropicrln to control seed-borne lnfestations of stem eeIwono on luceme. Adequate control ls obtalned with both gases at concentratlon-tłme products not appreclably phytotoxlc to the seed. Technice 1 problems involved in the U8e of these gases and seed mólsture content levels are also discussed.

080- RHOADES, H.L. & LINFORD, M.B., 1961. "Blologlcal studles on some meobers of the genus Paratylenchus." Proceedlngs of the Helmlnthologlcal Society of Washington, 28 (1), 51-59.

The life-cycle of Paratylenchus prołectus was studled on red cloyer seedlings growing ln agar. Four moults occurred, the flrst wlthin the egg. The second and thlrd-stage larvae fed as ectoparasltes on epldermal cells and root halrs slmllarly to adults, but the fourth-stage larvae dld not feed. Thls stage ls morphologlcally dlstlnct with a short dellcate stylet and weakly developed oesophagus. The stage was of short duration on red clover in agar and young pot cultures, but accumulated for unknown reasona ln o ld pots and was the predomlnant stage under most field condl-tlons. Fourth-stage larvae were morę tolerant of desiccation and exposure to Iow temperaturęs.

0809ELCIN, J.H., JR.; EVANS, D.W.; FAULKNER, L.R. (FAULKNER, L.R.] Yariations ln pathogenlcity of reglonal stralns of sten neaatodes on alfalfa. (Abstractl. In Twenty-fourth alfalfa Łmproves>ent confer-ence, Unlverslty of Arizona, Tucson, 8-10 October, 1974. Peorla, USA; US Department of Agriculture. (1975) 19-20. (EnI ARS, USDA, Wash•, Prosser, USA.

Elght of 9 lsolates of Dltylenchus dlp8acl froo dlfferent areas ln the USA and Canada performed aimllarly at 3 temperaturę 8 and in 4 luceme yarletles; Lahontan and Callverde were reslstant to the lsolates and Ranger and Hoapa were susceptl-ble. It was concluded that reslstant luceme developed ln a breedlng programme uslng one isolate wcmld be llkely to be reslstant to lsolates froo other reglons.

0810MANKAU, R. 6 LINFORD, M.B., 1961. ^,rHoat-para8ite relatlonshlps of the clover cyst neoatode, Heterodera trifol11 Goffart." Bulletln. Illinois Agrlcultural Experlment Statlon, No. 667, 50 pp.

Mankau & Llnford revlev the literaturę on the cytology of the host-paraslte relatlonshlps ln specles of Heterodera and Meloldogyne and descrlbe thelr own oethods used ln the study of the developoent of H. trlfolll ln plants of various host status. They descrlbe fully the entry of larvae Into the roots of a good host, Lad Ino clover, and the process of feedlng by larvae and maturę females, the development

of the syncytla or glant cells ls traced froo the earllest stages and there are numerous photographa shcrwing thelr appearance ln varlous posltlons in the root and at dlfferent stages of root develop-roent. Some syncytla reached a length of 2 om. and sooe occupled the entlre stele In the vlclnlty of the stylet. A nematode falled to thrive when a syncytlum arose ln the cortex unless lt extended into the stele. No nuclear divlslon was observed wlthin a syncytlum and, except in the early stages, the number of nuclel was less than the number of cells that had merged, because dlslntegration of nuclel occurred. The development of H trlfolll ln pea, red clover and soya beań (all poor hosts), amongst other plants, ls discussed and a new host Polygomnp perslcarla, also a host of H. welssl Stelner. Ii recorded. H. trlfolll and M. hapla developed close together in rooFs of Ladino clover without apparently InfluencIng each other. The syncytla developed in assoclatlon with each specles differed strlkingly from one another, even when the two types of patho-loglcal tlssue lay in contact.

0811 MARTIN, G.C., 1961. 'The susceptibili-ty of clovers (Trlfollum spp.) and trefoils (Lotus spp•) to the comoon root-knot nematode Meloldogyne jayanlca." Rhodesla Agrl-cultural Journal, 58 (1), 62-65.

Martin grew two specles of Lotus and 17 of Trlfollum in a field heavTTy lnfested with Neloldogyne Jayanlca. All were heavily galleH except three yarletles of L. coralculatus. namely Cascade, Empire and Granger, which had a few galls; Douglas, Vlklng and Tana were modem te ly to heavily galled. The other heavily galled test plants were: Lotus ullglnosus, Trlfollum alexandrinum_% T. cheranganlense. T. hirtumT T. hybrldum (two yarletles), T. Tncamatum Ttwo yarletles), T. Iappaceum7 T. pratense (17 yarletles), T. masaTense, T. repens (nlne yarletles), T. nieppeTIlanma (norma1 and smali types) 7 T. reaupinatum. T. ateudnerl. T. semlollosum, T. subterraneum (two yarletles), X. usambarense, and T7 tembense.

081200STENBRINK, M., 1961. "Nematodes in relatlon to plant growth. III. Pratylenchus penetrans (Cobb) in tree crops, potatoes ań3 red^- clover." Netherlands Journal of Agrlcultural Science, 9 (3), 188-208.

The results of five rotatlon and fumiga-tion experlments together with addltlonal field surveys show that Pratylenchus penetrans ls a serlous cause of slckness symptoms and has crop rotatlonal effects on many woody plants, red clover and potatoes. It ls wlde-spread in light and medium solls especlally in nurserles and fruit orchards; 9% of the flelds examlned contalned morę than 100 speclmens per 100 ml. of soli. Results demonstrate a slgnlflcant llnear relatlonshlp between the log. of lnltlal population density or of populatlon density wlthin roots and growth deflclt of susceptible crops. There was some Indica-tion that heavy lnfestatlons of P. penetrans in red clover roots lmpalred nltrogen fixation. The cultlvatlon of rye, oats and red clover should be avolded ln Infested land as they are good hosts. Beet 197 or mangolds are advised to be grown on