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concentration of 32000 ppm there was no inlection.

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and most widely distributed ncmatodcs were Pntylcnchus brachyurus, P. zeae, P penctrans, Scutcllonema brachyurum, Rotylenchus spp., Rotylenchulus spp. and Trichodorus spp. Most of the gen era were morę common in the sandier soi h. Pot trials and field obsenrations indicated that growth of maize was adversely afFected by Pratylenchus spp. and Trichodorus spp. Preliminary field trials with methyl bromide and granular nematicides have resulted in inereased growth in treated plots. Further investigations into the occurrence of nematodfs in maize culture in South Africa is needed.

0 2 5 6 SlNGH, J.; Rao, A. S. H. Ouantitatire estimatioo of riable Heterodera cyst in Arhar {Cąjanos cąjan) field at YaranasL Indian Journal of Zootomy (1974) 14 (1) 19-21 (En) Dep. of Entomology, Fac. of Agric., Banaras Hundu Univ., Yanmasi 221005, India.

A survey of Hetcrodcra ca jaw in a Cajanus cąjan field in Varanasi, Uttar Pradesh, India from October 1970 to April 1971 showed that the cyst population was lowest in January when soil temperatures were Iow and high in April when soU temperatur es had inereased.

0 2 6 7 Badra, T.; Elgindi, D. M. Single and double combinations of nematicides against Rotylenchulus renlformis and* Tyleocbolus semipenetrans infecting cowpea and ci truś.

Revue de Nematologie (1979) 2 (1) 23-27 [En, fr] Nematol. Res. Centrę, Fac. of Agric., Cairo Univ., Giza, Egypt.

In a glasshouse e^periment, the effects of 7 nematicides singly and in combination on Rotylenchulus reniformis on Vigna sinensis and Tylenchulus semipenetrans on Citrus aurantifolia were tested. Ali treatments decreased nematode numbers and most inereased plant growth. Plants treated with ethoprop (24 and 36 kg/ha) or phenamiphos (24 and 36 kg/ha) did not arów well. Tne best results were obtained with fensulphothion (18 kg/ha) plus DBCP (18 kg/ha) or oxamyl (18 kg/ha) plus DBCP (18 kg/ha).

0 26 8 Johnson, A. W.; Dowler, C. G; Morgan, L. W.

Influence of organie pesticides on nematodes, weeds, and insects and on yield of field corn. Research Bulletin, Georgia University, Agricultural Eaperiment Stations (1978) No. 223, 16 pp. [En]

In a 2-year field experiment the efTect of ethoprop, fensulphothion or carbofuran at 6 lb/acre on control of nematodes on maize (Zea mays) was tested. Ali nematicide treatments reduced Criconemoides ornatus and Meloidogyne incognita populations, in 1973, and Pratylenchus spp. were reduced by ethroprop or carbofuran treatment. In 1974. only fensulphothion treatment reduced M. incognita populations, which were Iow, and the Iow populations of Pratylenchus

Sp. were only reduced on plots which had been treated by e herbicide butylate in addition to a nematicide. Belonolaimus Jongicaudatus populations were reduced on butylate and nematicide treated plots. Average yields were inereased 12% by nematicide treatment and the inerease was related to .the control of C. omatus, Af incognita and Pratylenchus spp.

£0269 Lucas, L. T. Control of Belonolaimus longicaudatus on bermudagrass golf greens. Ann. Meet. Araer. Phytopath. Soc., S. Div., 4-7 Fcb., 1979. Abstract S-35. Phytopathology (1979) 69 (1) 1A6 [En] Dep. of Plant Path., NC State Univ., Raleigh. NC 27607, USA.

Poor growth of Tifton 328* bermudagrass (Cynodon dactylon) on golf greens with sandy soil along the coast of North Carolina was associated with Belonolaimus longicaudatus. An average of 400 B. longicaudatus and 966 Macroposthonia oma ta /500 cm¹ of soil were found in soil samples before treatment with nematicides. Phenamiphos, fensulfothion and l,2-dibromo-3-chloropropane (DBCP) were applied as granules at 0.2, 0.2 and 0.64 kg (a.i.)/93 m^J, respcctively, on August 8, 1977. Turf quality ratings (9 being the best quality) were 6.2, 6.2, 4.7 and 2.7 4 weeks after treatment and 8.7, 4.0, 4.0 and 4.0 40 weeks after treatment in phenamiphos, fensulfothion, DBCP and non treated plots, rcspectively. Densities o$B. longicaudatus were 160, 100, 315 and 1390 4 weeks after treatment, and 106, 823, 406 and

752 40 weeks after treatment in phenamiphos, fensulfothion, DBCP and non treated plots, respectively. Densities of M. o ma ta were reduced in DBCP treated plots only.

*0 2 60 Townshend, J. L.; Potter, J. W. Inhlbiting infection of alf alfa seedlings by Pratylenchus penetrans by treating seed with ozamyl. Canadian Journal of Plant Science (1979) 59 (2) 519-520 [En] Agric. Canada, Res. Sta.. Yineland Sta., Ontario, Canada LOR 2E0.

Soaking lucerne seeds in aqueous ozamyl Solutions for 17 hours at concentrations ezceeding 2000 ppm reduced infection of seedlings by Pratylenchus penetrans. At a

herc was no infecti

0 2 6 1 Turner, G. O. Effects of soli fumlgation with

1,3-dJ chloro propene and l^-dfbromo-3-chloropropane on

yields of cotton, Uma beans and tomatoes. Down to Earth (1979) 35 (3) 4-8 [En] Dow Chemical USA, Davis, Califomia, USA.

Soil fumigation of cotton crops with 1,3-D or DBCP gave yields of 1.86 and 1.74 balea/acre respectively with 1.43 for the untreated control. Contro! of Meloidogyne spp. averased 81% for 1,3-D treatment and 85% for DBCP. Lima bean [Phaseolus lunatus] yield was inereased 36% by 1,3-D and 9% by DBCP. Nematode control was 96% with both Chemicals. Higher tomato yields were obtained with 1,3-D (45%) than with DBCP (20%) and nematode contro) was approzimately 70%.

0 2 6 2 Walters, M. C. Present status of Itnowlcdge of nematode damage and control in South Africa. Proc. 3rd S.A. Maize Breeding Symp., Dep. Agric. Tech. Serv., Potchefstroom, 21-23 Mar. 1978. Ed. by: J. G. Du Płessis. Publ. No.3. Tech ni cal Communication, Department of Agricultural Technical Senices, Republic of South Africa (1979) No. 152, 62-66 fEn]

In a number of field trials at sites where Pratylenchus zeae was always and Trichodorus spp. usually present, nematicides were evaluated by measuring maize yield inereases after treatment. Methyl bromide fumigation applied under plastic at 0.5 kg/10 m* gave a 128% yield inerease and carbofuran at 2 g/m row gave a 33% inerease. Carbofuran was the most promising of the non-fumigant nematicides tested. In an indicator trial with D-D the average yield inerease for the 7 tested sites was 37.6% and the rangę from 14 to > 60%. In fertilizer trials nematicide treatment inereased nutrient uptake by 2.6% for N, 12.7% for P and 17.9% for K. The peroent yield inerease following fumigation was higher on plots of Iow nutrient status than on those of high nutrient status. Nematode damage to maize was morę scvere when there was an interaction with root-rot organisms or under dry conditions.

0 26** Shesteperoy, A. A. [Dynamics of parasitic nematodes on Trifnlium pratensc.] Byullcten* Vscsoyuznogo Instituta GeTmintologii im. K.I. Skryabina (1981) No.31, 98-104 [Ru, en, 8 ref.)

The seasonal variation in the numbers of the specific plant pathogcnic nematodes of T. pratensc — Pratylenchus pratensis, Tylcnchorhynchus dubius and Paratylaichus rojectus — in the roots, rhizosphere and soil were studied in the European SSR]. Vcgetative stages (flowering and preparation for winter), humidity < 16%, large numbers of predatory nematodes, antagonism, numbers of bacteria and fungi, ploughing and crop rotation had a limiting efTect on P. projectus populations. Often, 4th stage larvac were the dominant stage in the soil Migration from roots to rhizosphere to soil, and vicc-versa and into dcep soil layers. was often observed. Ali these factors and, especially antagonism with P. projectus and with species of Tylcnchus, Aglenchus and Filencbus also infiuenced the population dynamics of T. dubius. Peak numbers of T. dubius coincided, with Iow numbers of P. projectus. Pratylenchus pratensis had littlc influence on population dynamics and was found mainly in smali roots at 25 to 60 cm.