8342937203

sheddlng of leafleta and poor pod fonaatlon coopared vith plants lnoculated wlth 0, 10 or 100 M. lncognlta. In outdoor plots lnfested wlth Meloldogyne spp., D-D, DBCP, fensulphothlonaldlcarb, and nethomyl at, respectlvely, 75 1, 15 1, 10 kg, 4 kg and 8 kg a. 1. /hec tarę gave good eon troi and inereased ylelds by 15 (methorayl) to 37% (fensulphothlon).

0739—NIGH, Jr., E. L., 1966. “Rhizobium nodule formation on alfalfa as influenced by Meloidogyne javamca.” (Abstract.) Ncmatologica, 12 (l), 96.

0740    —SHER, S. A., 1966. “Rcvision of the

Hoplolaiminae (Nematoda). VI. Helicotylenchia

Steincr, 1945)." Nematologica, 12 (1), 1-56.

[French summary p. 55.J

Htlicotyienchus dihysttra, H. multicinctui, H. ery-ihrinae, H. pseudorobusius, H. ajncanus_t H. platyurus, H. digonicus, H. canadensis, H. coiicawu, fi. snenus, H. indicus, H. tunisienris, H. rciusus, H. digitarus, H. aegypiiensis, H. oulgaris, H. paxilli and H. vari• caudaiui arc redescribed. 10 new ‘ śynbnyms are proposed. The following new species are described and figured: H. lobus n.sp. from soil around roots of Verairum calijornicum and Pinus pondtrosa in California; H. crcnacauda n.sp. from soil around roois of Oryza saiiva Ln Indonesia; H. longi-caudaius n.sp. from soil around roots of Jmperata cylindrica and Sporobolus pyramidatus in Nigeria; H. tnicrocephalus n.sp. from soil around the roots of Elacis guineensis in Nigeria; H. canahs n.sp. from junglc soil in Ceylon; H. Iciocephalus n.sp. from soil around unkr.own grass in South Dakota; Ii. roiundicauda n.sp. from soil around the roots of Cynodon daciyltm in California; H. cavenessi n.sp. soil from around roots of Manihoi uiilissima in Nigeria; H. caroliniensis n.sp. from swamp soil in South Carolina; H. manini n.sp. from soil around the roots of Thea sinensis in Southern Rhodesia; H. exallus n.sp. from Trilicum aestivum soil in South Dakota; Ii. hydrophilus n.sp. from swamp soil in South Carolina; H. calijornicus n.sp. from soil around roots of Tamarix peniandra in California; H. nigeriensis n.sp. from bush soil in Nigeria; H. dolichodoryphorus n.sp. from virgin forest soiJ in Nigeria; H. anhelicus n.sp. from soil around the roots of Salix sp. in California; H. minzi n.sp. from soil around the roots of Citrus sp. in Israel; H. bclli n.sp. from soil around the roots of Cedrus sp. in Utah; H. labiodiscinus n.sp. from soil in uncultivaied woods in Yirginia; H. clarkei n.sp. from uncultivated soi) around the roots of Pinus cenibroidcs and Pinus sp. in New Mexico. H. sicueriy H. neoformis and H. imcnntdius are excludcd from the genus Hclicotylenchus. A key to the species is given.

0741    GRIFFIN, G.D., 1964.. "Aasoclatłon of nematodes vlth com in Wisconsin." Plant Diseaae Reporter, 48 (6), 458-459.

In a survey of the chief maize-growing areas of Wiaconsin, U.S.A., 13 apeciea ln 6 genera of plant-parasitic nematodes were found. The consnonest were Hclicotylenchus dlgonicus,    Tyl enchorhynchua" aaxłmus and

XlphlnetM amerłcamia. in greenhouse experi-menta tEe First 7 caused reduction in helght and dry weight of malze plants. Fumigation of field plota of a black pralrie loam lnfested vith X. amerlcamim and H. dlRonlcua vith 25 or" 40 gal. per acre "of dlchloropropene gave 76% or 88% control, respectlvely, but no increaae in yield of allage or shelled malze.

0742CHAPMAN, R.A., 1964. "Effect of clover cyst nematode on growth of red and wbite clover8.^,ł Phytopathology, 51 (4), 117-118.

In a serles of green-house pot experi-ments, the growth of red clover Trifollun pratense varled inversely wlth the nunber of Heterodera trifol11 present and wlth the length of time ln lnfested soli. The nema-todes reproduced well on red clover reach-ing the populatlon "celling level" ln 129 days. Sinilar results were obtained wlth Ladino and wbite clover (T. repens) except that whereas virtually afl the red clover had died after 265 days, the Ladino and wbite clovers were stlll growing, altbougb 8lgnlflcantly less well than the Controls. Although H. trlfolil initially reproduces well on red cTover it cannot maintaln Itself on the host over a long period of time because of the severe lnjury it causes. The ratę of development of lnjury on T. repens ls sooewhat slower and the nematode can maintaln itself for a longer period.

0743    DICKERS0N, O.J., DARLING, H.M. &

GRIFFIN, G.D.,    1964. "Pathogeniclty and

populatlon trends of Pratylenchus penetran8 on potato and com." ^ytopathol -ogy, 54 (3), 317-322.

This is an lllustrated account of the pathogencity and populatlon trends of Pratylenchus spp. on potato and malze. A 8urvey showed that P. penetrans and P. crenatus were common "in potato fields Tn wIsconsTn, U.S.A., but only P. penetrans was associated %rtth reduced ylelds. Neither soil type nor potato variety Influenced populatlon densitles of P. penetrans. Tn mlxed populatlons, one speclea was dominant and large populations of P. crenatus occurred in only sandy solls. *Righ popula-tions of P. penetrans in the field were characterlzed bv circular areas (30 to 150 ft. In dlameter) of stunted yellow plants. As the season progressed the populatlon of P. penetrans Inereased in the potato roots of tubers and in the soli, but the populatlon fell ln the wlnter. P. penetrans entered and fed ln the roots, rhizooes and tubers, but the rhlzomes were not so severely attacked as the roots and nema-todea were not found reproduclng ln tubers. Only cortical tlssues were affected. The populatlon of P. penetrans Inereased faster on D8ize than" on potatoes. The greateat populatlon Increase was at 16°C. on potatoes and at 24°C. on malze. The length of malze roots, atalk helght and stalk dlame-ter were reduced by P. penetrans.

0744    NIGH. Jr., E.L., 1964. 'TChe Influence of host nutritlon on the development of Xlphlnema amerlcamra." Dlasertatlon Abstracts, 24 (11), 4340-4341.

The influence of host nutritlon on the development of Xlphlnema anerlcanum was lnveatigated by culturlng the nematode on luceme plants (Medlcago satlva var. Moapa) In 8and contalnlng varlatIons of mlnerals ln Hoagland'8 mitrlent solution. After 30 days* lncubatlon, adult populations from complete and nltrogen-deficlent treatments were slgnlflc^ntly greater than those defl-clent ln other minerałs. Whcn K, Mg, or Fe were ellmlnated from the host'a nutritlon a greater mmber of adults were found than when P or Ca were ellmlnated. The nutri-188 tlonal adjustment of the lucerne host did