Impact of fungicides on the performance of ten varieties of 4 potato newly introduced in Algeria

The potato is an increasingly important food in Algeria. Domestic production has  increased in  recent years due to high consumption. Faced with this increase in  consumption, it is necessary  to produce quality potatoes from the point of production yield. The present work aims to study the variability of potato production in relation to the production areas. On the other hand, newly introduced variety trials are conducted treated with fungicides. The yield results  show that the Challenger and Synergy white-skinned varieties are the most profitable, the  production has reached more than 350Qx / ha with a yield index greater than 100%, they have  shown resistance to fungal  diseases in contrast to varieties Lusa and Senna, which reacted  negatively even with the foliar treatment, their yield is very low. Keywords: Algeria, fungicide, potato, yield, varieties

Led-NPF-1 stimulates ovarian development in locusts

For more than a decade, immunohistochemical results on FMRFamide related peptides (FaRP's) have been reported extensively, suggesting many possible roles for these peptides associated with behavioural and physiological events as well as reproduction. This study provides a clear effect in vivo of members of this family of insect neuropeptides. The effect of two neuropeptide F-related peptides from the Colorado potato beetle, Leptinotarsa decemlineata, Led-NPF-1 and Led-NPF-2 as well as the locusts myotropins, Lom-PK-1, Lom-PK-2 and Lom-SK, was screened in an ovarian development assay in the African migratory locust and the grey fleshfly, Neobellieria bullata. Led-NPF-1 (Ala-Arg-Gly-Pro-Gln-Leu-Arg-Leu-Arg-Phe-NH2) was shown to be a potent gonadostimulin in Locusta migratoria, but not in Neobellieria bullata. A minimal dose of 0.05 mu g of Led-NPF-1 per animal, every 12 h, during 5 consecutive injections into 6 day old virgin females, could accelerate egg development. Higher doses of prolonged injections were demonstrated to be even more potent in the ovarian development assay. Led-NPF-2 (Ala-Pro-Ser-Leu-Arg-Leu-Arg-Phe-NH2) was far less active. The other tested peptides scored no reproducible effect what so ever on ovarian growth, in locusts, nor in flies. The gonadotropic action of a NPF-like peptide on oocyte growth implies a complex regulation of oogenesis in the locust and adds to our knowledge of insect neuroendocrinology in general. The results also suggest that a peptide of similar sequence also resides in the locust. (C) 1999 by Elsevier Science Inc.status: publishe

The annual cycle of Saharan populations of Locusta migratoria cinerascens (Orthoptera: Acrididae: Oedipodinae) in Algeria

Chantier qualité GAUntil recently, the Algerian populations of Locusta migratoria cinerascens were considered as sedentary and solitarious. In the Central Sahara and bordering areas, the extension of pivot-irrigated areas since 1980, has resulted in the creation of biotopes favourable to the reproduction of this acridid, particularly in the cereal crops of the Adrar and Ouargla regions. From analysis of the archives of the National Institute of plant Protection, and our personal work carried out from 1995 to 2004, we can provide new information on the life cycle of L. m. cinerascens. We show that, in the cereal crops of the regions studied, there are three generations of this acridid per annum: the first one developing on corn in the spring, until the harvest; the second a spring-summer generation in market gardens in the vicinity of wheat stubble, or in early-growth Sorghum crops, and a third, summer-autumn generation, that develops on summer cereal crops and probably over-winters as diapausing adults until the following February.Jusqu’à une période récente, les populations algériennes de Locusta migratoria cinerascens étaient considérées comme sédentaires et solitaires. Au Sahara central et dans les régions limitrophes, l’intensification des périmètres irrigués sous pivot depuis les années 1980, ont entraîné la création de biotopes favorables à la reproduction de cet acridien, particulièrement dans les périmètres céréaliers à Adrar et Ouargla. L’analyse des archives de l’Institut National de la Protection des Plantes et de nos travaux personnels entre 1995 et 2004 nous ont permis de relever certains points originaux sur le cycle biologique de L. m. cinerascens. Dans les zones anthropisées des régions d’étude, nous argumentons que le cycle de cet acridien pourrait présenter une succession de 3 générations : une première génération printanière qui se développe sur les blés jusqu’aux moissons, une seconde printano-estivale étant dans les maraîchages avoisinant les chaumes de blé ou dans les pivots de Sorgho au début du développement des plants, et une troisième estivo-automnale établie sur les céréales d’été et susceptible d’hiverner probablement à l’état d’adultes diapausants jusqu’au mois de février suivant