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Division Meetings, IV/O. Abstract N. PA-14. Procecdtngs of the American Phytopathological Society (1976, publ. 1977) 3, 317 (En) USDA, ARS, Crops Rcs. Lab., Utah State Univ., Logan. UJ 84322, USA.

biological control agent for $ilTer-leaf mghtshade. Journal of Nematology (1978) 10 (4) 362-366 [En] Sci. & Education Admin., USDA, Texas Agricultural Experimcnt St., Lubbock, Texas 79401, USA.

A 64,000 sq. km area in Texas, USA was surveyed for the common weed, Solanum elaeagnifolium and the parasite, Nothanguina phyllobia. Nematodc galls were found at 42% of the locations in 1975 and 64% in 1976. Of 21 soil samples taken, 15 contained infective-stage larvae. Larvae were concentrated at the soil surface and at a depth of 15 cm. N. phyllobia was never found in root tissue. Infective-stage larvae remained viable in desiccated galls. Larvae were transmitted in water films to non-infected plants and the soil where they infested pre-emergent shoots. Parasitism by N. phyllobia, which is specific to S. elaeagnifolium resulted in reduced plant size and numbers of berries and seeds and could, therefore, be used as a biological control agent.

*022 2 Griffin, G. D.; Thyr, B. D. Interaction of Meloidogyne hapla and Fusarium oiysporum on alfalfa. 17th Ann. Meet., Soc. of Nematol., Hot Springs, Arkansas, 7-10 Aug. 1978. Abstract. Journal of Nematology (1978) 10 (4) 289 [En] USDA, Sci. & Education Administration, Crops Res. Lab., Utah State Univ., Logan, Utah 84322, USA.

When 14-day-old seedlings of a Meloidogyne hapla susceptible luceme variety were inoculated with Af. hapla larvae and 30 days later with Fusarium oxysporum the combination significantly reduced growth. The same treatment did not reduce growth of a Af. hapla resistant variety neither did F- oxy$porum affect resistance to Af. hapla.

0 2 2 3 Roth, F. The role of Pratylenchus spec i es in the root rot of dent corn in late season. Dissertation Abstracts International (1978) 39B (4) 1565-1566 [En, Order No. 7817805)

Apparently the deve!opment of fungal root rot of dent com in late season in New York State, USA, is not influenced by the presence of Pratylenchus sp. or P. penetrans.

0 2 24 Roth, F.; Boothroyd, C. W. Com root rot is not caused by the interaction of species of Fusarium and Pratylenchus. 68th Ann. Meet., Kansas City, Missouri, 11-15 Juły, 1976. Abstract No. 183. Procccóings of the American Phytopathological Society (1976, publ. 1977) 3, 244 [En) Dep. of Plant Path., Comcll Univ., Ithaca. NY 14853, USA.

In experiments Pratylenchus penetrans ot P crenatus infestation caused extensive root damage to maize at high population levels but Fusarium spp. did not cause root rot in the presence or absencc of Pratylenchus spp.

022 5 Gray, F. A.; Schonhorst. M. E.; Thompson, R. K. Occurrence of stem nematode resistance in non-winter-hardy alfalfas. 68th Ann. Meet., Kansas City, Missouri 11-15 July, 1976. Abstract No. 184. Proccedings of the American Phytopathological Society (1976, publ. 1977) 3, 244 [En] Univ. of Arizona, Tucson, A2 85721, USA.

Luceme varieties which are non-winter-hardy have been used to develop strains with resistance to Ditylenchus dipsaci.

*0 2 26 IbraHIM, 1. K. A.; Rezk, M. A. Reaction of corn to Meloidogyne ja rani ca and M. incognito. 17th Ann. Meet., Soc. of Nematol., Hot Springs, Arkansas, 7-10 Aug. 1978 Abstract. Journal of Nematology (1978) 10 (4) 289-290 (En) Dep. of Plant Path., Coli. of Agric., Alexandria Umv., Alexandria. Eevnt.

0 2 2 7 Kehr, W. R. Multipłe pest resistance in alfalfa. Agricultural Research (1978) 26 (10) 3-4 [En) 333 Keim

Hall, Univ. of Nebraska, Lincoln NE 68583, USA.

The estimated annual loss in crop value resulting from diseases and nematodes on luceme is 25%. There are varieties resistant to 9 pests including stem nematode [Ditylenchus dipsaci). Resistance screening procedures for 18 pests. including northem root-knot nematode, [Meloidogyne hapla] exist.

*02 2 8 CASTILLO, M. B.; AlEJAR, M. S.; LlTSINGER, J. A. Pathological reactions and yield loss of mung bean to known popuiations of Rotylenchulus reniformis and Meloidogyne acrita. Philippine Agriculturist (1977, publ. 1978) 61 (1/2) 12-24 [EnJ Dep. of Plant Path., Coli. of Agric., U.P., Los Banos Coli., Laguna. Philippines.

The pathological reactions of mung bear. [Phascolus mungo] to a combination of Rotylenchulus reniformis and Meloidogyne acrita and to Af. acrita alone in pot, microplot and field conditions in Laguna, Philippines were studied. Seedlings were grown for 22 days in 5 cm diameter pots contaimng 250 cc of baked soil with or without an inoculum of R. reniformis and Af. acrita together or Af. acrita alone. Plants and soil were then transferred to 30 cm diameter pots or lm^J microplots containing baked soil or to field plots which were almost ncmatodc-frcc following trap-cropping and application of carbofuran. At transplanting there were no apparent difTerences in top growth between non-infected

glants and plants infested with R. reniformis and Af. acrita. Loots of infested plants were lightły neerotie and darkly coloured. Leaf chlorosis was observcd 4 days after transplanting. Stunting began between the 5th and 6th days. Dcalh occurced after 11 days in the field. The root Systems were reduced, very severely neerotie, lightły galled and partly rotted. Infested plants flowered 2, 5 and 2 days earlier than non-infested plants in pots, microplots and field plots, respectively. The nematode population inereased during the experimental period: R. reniformis 9.7 times, Af. acrita 16.4 times in pots. 4.4 and 7.2 times respectively in microplots and in the field there were 109 R. reniformis/250 cc soil and 1 g root sample and < 1 Af. acrita. Yield loss from infested plants in the field was at least 61.5%. Plants infested with Af. acrita only showed leaf chlorosis 5 days after transplanting and the extent of chlorosis was relatcd to moisture content in the field. Stunting first showed 8 and 12 days after transplanting in pots and field, respectively. Some plants died after 15 days. The root system was reduced, moderately neerotie, very severely galled and partly rotted. The nematode population inereased 24.4 times during expcriments in pots. A 28% yield loss was estimated to have resulted from infestation in the field.

<*0 2 29 Upadhyay, K. D.; Swarup, G. Reaction of some małże varieties against Tylencborbynebus rulgaris. Indian Journal of Nematology (1976 publ. 1978) 6 (1) 105-106 [EnJ Div. of Nematology, Indian Agric. Res. Inst., New Delhi 110012, India.

Tylenchorhynchus vulgaris was inoculated on 10-day-old seedlings of 17 varieties of maize grown singly in pots and the nematode population was estimated after 90 days growth. From an inoculum of 1,000 nematodes the population built up to over 40,000 on 3 varicties and to 11,000 to 12,000 on 3 others, showing that the nematodes had difFerem preferences for the difTerent maize varieties. Growth of all varieties but one (Ganea-2 with 21,700 nematodes, and the most stunted) was equaJly a/Tected.

<-0230 TownshEND, J. L. In/ectirity of Pratylenchus penetrans on alfalfa. Journal of Nematology (1978) 10 (4) 318-323 (En) Res. Sta., Res. Branch. Agric. Canada, Vineland Sta., Ontario, Canada LOR 2EO.

Penetration by Pratylenchus penetrans, females, males and 3rd-stage larvae, occurred along luceme roots from behind the root-cap to the junction of the root and hypocotyl. Females penetrated from 5 to 35*C with a maximum between 10 to 30*C. Males and larvae could only penetratc between 10 to 30*C with a maximum at 20‘C. In a 96 h period, at 20’C, 80% of females penetrated, 43% of males and 30% of larvae. Ratę of penetration showed a iogarithmic inerease with a 116 plateau at 48 h (females), 60 h (males) and 84 h (larvae). The