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asscsscd by thc numbcr of mai es extracted from maize roots after about 9 weeks growih. At one locality, where 0.8 raales/ g roots were eztracted from untreated plants, aldicarb and carbofuran reduced infestation to le&s than 10% of that in the Controls. In another locality with 0.4 males/g roots in untreated plota, treatment with thiofanox resulted in 0.2, Curaterr SK in 0.1, Curaterr G in 0.04 and aldicarb 0.03 males/g roots. Increases in root and shoot growth and in yields were also recorded in pesticide-treated plots.

#0212 Castillo, M. B.; Alejar, M. S.; Litsinger, J. A.

Notę: increased effi ciency of determining populations of RotyJencbnlas reniformis and Meloidogyne aciita througb błoassay. Philippine Agriculturist (1977, publ. 1978) 61 (1/2) 64-69 [En] Dcp. of Plant Path., Coli. of Agric., UP. at Los Bań os. College, Laguna.

The efficiency of a bioassay for quantifying populations of Rotylenchulus reniformis and Meloidogyne acrita has been compared with a routine extraction method combining sieving and the Baennann funnel technique. The bioassay consisted of growing 3 nematode-susceptible mung bcans [Phnscolus mungo] in the test soil in 3 cm clay pots for 19 days prior to routme extraction. At the end of the bioassay nonę of the nematodes was in the egglaying stage indicating that all the estimated nematodes were first generation. Recovery of R. reniformis and M. acritn growing together was 2.4 and 90 times higher, respectively, when using the bioassay. In soils where M. acritn was alone recovery was 1.8 times higher by the bioassay technique. The ezperiment was madę on pot, microplot and field samples. The bioassay is not considered to be rei łabie when nematode populations are very high.

0 2 13 Bułgaria, B”lgarska Akademiya na Naukite Third National Conference of Parasitology, Albena, Bułgaria, 12-14 Oct. 1977. Summaries.] Trcta NaUionalna Konfercntsiya po Parazitologiya, Albena, Bułgaria, 12-14 X 1977. Rezyumcta. Bułgaria. (1977) 253 pp.

The folłowing 20 papers on plant ncmatology were ;:resented at this conference.

Stoyanoy, D. [Rotylenchulus borealis - a nciv parasite of muzc in Bułgaria.] [Abstract]. 111-112 [Ru]

0214 Maas. P. W. T.; Brinkman, H. [Damage to mml** by Heterodera arenae.] Schade door het havercysteaaltje {Heterodera avenae) bij mals. Gewasbescbenning (1977)    8    (4)    139-144 [NI]

Plantenziektenkundige Dienst (PD), Wageningen, The Netherlands.

In 1971/1972 in Holland a correlation was found between soil populations of Heterodera avenae and poor growth areas of maize: cyst numbers varied from 22 to 137/ 200 ml soil. Nearby, in healthy maize, the mazimum population was 16 cysts/200 ml. soU. The root systems of the mni7n ezhibited many side roots at the infected point. In one study, 770/eggs and larvae/200 ml soil resulted in a yield reduction ot 48% compared with non-infested maize. Inoculation with 1300 larvae 4- eggs/200 ml soil resulted in 276 cysts/30 g maize roots and a yield reduction of 35%. Maize sown in PVC rings containing steamed soil inoculated 2 to 3 months previously with H. avenae showed few cysts on the roots and no reduction in growth when compared with the eon troi plants in July, whereas in similar conditions harley sown in April was heavily infested and growth was reduced. Damage to maize depends on the period of actwity of the nematode larvae. When maize is sown in May many H. avenae larvae have been free in the soil for some weeks and are no longer able to invade the roots.

a o 11 5 Alam, M. M.; Khan, A. M. New host rccords of me root-knot nematode in North India. Indian Phytopathology (1975, publ. 1976) 28, 540-541 [En] Dep. of Bot., Ali garh Muslim Univ., Aligarh 202001, India.

Meloidogyne incognito, from Uttar Pradesh, India, is reported on the followmg planu for the first time: Abutilon indicum, Commelina nudiflora, Corchorus acuinngulus.

Cynodon dactylon, Euphorbia genie uh ta, Lippia nodiflora, Pbyllanthus fratemus, Physalis pawiana, Setoria verticilhta.

0 2 16 GONZALEZ F., L. [Płant-parasitic nematodes associated with rice and corn in sereral agricultural areas of Costa Rica.] Ncmatodos fitoparasitos asociados eon la rizosfera de arroz y maiz en varias zonas agricolas de Costa Rica. Agronomia Cost&rricense (1978) 2 (2) 171-173 [Es, en) Lab. de Nematol., Fac. de Agronomia, Univ. de Costa Rica, San Josć, Costa Rica.

In samples of rice soils from 5 localities in Costa Rica the nematodes most frequently found belonged to the gen era Tylenchorhynchus, Cnconcmoidcs, Helicotylenchus and PratyJenchus. In maize soils from 4 localities the commonest were Helicotylenchus, Meloidogyne and Crieonemoides.

0 217 Khan, T. N. Problems and progress in improTement of winged beans in Papua New Guinea. Meeting on Winged beans, Nat. Acad. Sci., Washington DC, 24-26 Oct. 1974. Mimco. (1974) 21 pp. [En] From Winged Beans, JDRCAbs. World Lit. 1900-1977, (1978), 109.

Among diseases of winged beans observed in Papua New Guinea is root knot caused by Meloidogyne incognito.

0 2 18 LOCKE, E.; Saefkow, M. pnvestigations on the infection and cyst-deveIopment of Heterodera arenae Woli. In maize.] Untersuchungen uber Befall und Zystenbildung durch das Getreidezystenalchen am Mais. Zeitscbnft fur Pflanzenkrankheiten und Pflanzenschutz (1978) 85 (7) 385-392 [De, en] lnst. Fiir Angewandte Botanik der Univ. Hamburg, Marseiller Strasse 7, D-2000 Hamburg 36, GFR.

The development of Heterodera avenae race E was observed in the glasshouse in the roou of maize cv. Primeur. Larvae invaded only those roou up to 0.6 mm in diameter; they bccamc orientated with heads towards the root tip and for 2 weeks followed root growth kecping in the region of celi elongation, usually causing necrosis but in a few cases the root reacted with hyperplasy. In severely necrotić roou 2nd-stage larvae left the decayed tissue and attacked healthy roou thus inereasing damage. Males left the roou 39 days aftei larval invasion and 8 days later the first eggs appeared in the females. 2nd-stage larvae were found 12 weeks aJfter invasion. New cysU contained an average of 98 eggs and larvae. In a Field experiment 10 varieties of silage maize were grown in lightly (40 viable eggs and larvae/100 cm⁵ soil) and heavily (590 viable eggs and larvae/100 cm* soil) infested plou. Very few cysU were formed on planu in the lightly infested field: on the heavily infested field cv. Forla (maximum 18 cysU/ plant) and Primeur (maximum 26 cysu/plant) were the most heavily infested. All varieties may be judged resistant as regards cyst formation. However, yield losscs yaried from 5.5% in cv. Anjou to 39.2% in Limac and 38.9% in Primeur; quality, as measured by starch cquivalent, varied from an inerease of 4.9% in Inrafriih to a loss of 23.1% in Limac.

i) 21 9 Powell, J. M. Traditional legumes of the New Guinea blghlands. (Proceedings of seminar workshop: The deyelopment of legumes in Papua New Guinea). Science in New Guinea (1974) 2 (1) 48-63 [En] From Winged Beans, JDRCAbs. World Lit. 1900-1977. (1978), 38.

The winged bean Psophocarpus tetragonolobus, an im port ant seasonal food in some areas of Papua New Guinea. has been recorded as infested with Meloidogyne incognito.

0 2 2 0 VaLOCKa. B.; SabOvA. M. [Parasitic nematodes of lucernę in castcrn Słovakia.J Vyskyt parazitickych nematódov na lucernc na yychodnom Slovcnsku. !n Sympóz. o rezist. viacroćn. krmovin proti chorobom, śkodcom a infm nepriazn. podmienk. prostredio. Piesi ińy, J974. Zb. referatov. Pirflany. Czcchoslovakia_; Vyd. VURV. (1974) 136-140 (Sk, en] From Referativnyl Zhumal, Biologiya (1976), 7 E770.

0 2 2 1 Griffin, G. D. Effect of temperaturę on the root-115 knot nematode/alfalfa stem nematode interaction on alfalfa.