الفهرس | Only 14 pages are availabe for public view |
Abstract Faba bean, Vicia Faba L. ranks the first food legume in Egypt as it is considered the main source of plant protein. However, production of this crop has been constrained by the limitations imposed by insect pests and diseases. Several insect pest species attack the crop, the serious pests are aphids and the leafminer L. congesta (Beck). The study presented in this thesis was carried out at the Experimental farm of Zarzora Agricultare. Research Station, Beheira governorate region for three successive seasons 2013 / 2014, 2014 / 2015 and 2015/ 2016. 1- Population fluctuation of the leaf miner Liriomyza congesta infesting faba bean plants. Six varieties of faba bean were evaluated to the infestation with the larvae of leaf miners L. congesta during three seasons. To estimate the population densities of L. congesta larvae, weekly samples of leaflets were picked and transferred to the laboratory for inspection. The obtained results may be summarized as follows: Faba bean leaflets of 2014 / 2015 season showed the highest overall infestation rate ( 50.42- 64.16 larvae/ 25leaflets) follwed by those of 2013 / 2014 season of infestation rate (42.52 – 61.86 larvae/ 25 leaflets )and 2015 / 2016 seasons of infestation rate (41.75 and 58.33 larvae / 25 leaflets, respectively. omparing the asseyed faba bean varieties for infestation by Liriomyza congesta; the highest infested varieties were, Noubaria 3 variety in 2013- 2014 season (61.85 larvae/25 leaflets); Noubaria 2 during 2014/2015 season (64.16 / 25 leaflets) and Nobaria 3 during 2015/2016 (58.35 / 25 leaflets). On contrary the lowest infested variety was Giza 40 Variety (42.52, 50.4 larvae / 25 leaflets) and (41.75 larvae / 25 leaflets) in the these seasons 2013, 2014, 2014/2015 and 2015 / 2016 season, respectively. 2- Survey and Population fluctuation of Liriomyza congesta parasitoids, In this study, three hymenopterous parasitoids were detected attack larval and pupal stage of L. congesta, namely Diglyphus isaea (Walker) (ecto-parastoid), Opius pallipes and chrysocharis paraksi (Grwperds) (endoparasitoids) The larval ectoparasitoid; Diglyphus isaea In the first season, two peaks of D. isaea were occurred; on 23rd February (14.23%) and 9th March (14.67%). But the two peaks that in second season occurred on 8th and 15th March reached 34.97 and 29.37%, respectively. Natural dead Larvae percentage of L. congesta occurred 12.31% during the 2014 / 2015 season and 12.93% during 2015/2016 season. Natural die of larvae is sharing in decrease the infestation of L. congesta. The normally died larvae percentagem and parasitism percentage of D. isaea equal 20.47% without using any insecticides. Statistical analysis of the two seasons shows positive correlation and highly significant between the number of ectoparasitoid D. isaea and L. congesta larvae (r = 0.81118) The endoparasitoid, Opius pallipes The endoparasitoid, O. pallipes exhibited the highest abundance in 4th week of January with 27 indiv. / 100 leaflets. This parasitoid recorded four peaks during 2014/2015 season. Statistical analysis show the positive correlation and significant between the number of parasitoid and the number of L. congesta. The percentage of pupal parasitism caused by the larval pupal parasitoid, O. pallipes varied between 0.00 on 24th December and 9.31% (on 28th January) during the first season. In the second season, 2015 / 2016, the parasitoid recorded two peaks, in 19th December (6.67%) and 23rd January (6.33%) L. congesta pupae showed three peaks on faba bean during 2015 / 2016 season. Statistical analysis showed that the correlation between the number of O. pallips and the number of L. congesta pupae is positively significant. The endoparasitoid, chrysocharis parksi Crawford In 2014 / 2015 season, data showed the percentage of pupal parasitism caused by the endoparasitiod, C. parksi on faba bean plants varied between 0.00% on 10th Dec. and 14.44% in 7th January. In 2015 / 2016 season data showed the percentage of parasitism, caused by C. parksi on faba bean plants varied between 0.00 and 7.4%. Correlation between parasitoid number and pupae number of L. congesta was negative and insignificantly. 3- Effect of certain compounds against the faba bean leaf miner, Liriomyza congesta larvae under field conditions. Obtained data showed the effect of five compounds as reduction on the faba bean leaf miner, L. congesta larvae / 25 leaflets during 2013 /2014 season. There are significant differences between all treatments. Marshal 25% WP., Dizynoxe 60% EC. and Potassium Sulphate 0.5% gave the best reduction in larvae number. Reduction percentage for three compounds reached with 92.18%, 91.23% and 86.75 %, respectively. On the other side, Caple 2% and Sessy 2% with reduction 85.14% and 84.44 % was the least effective compounds against L. congesta infestation. In the Second season (2014 / 2015) data presented that Marshal 25% WP and Dizynoxe 60% EC were the best in reduction the number of larvae followed by Potassium Sulphate 0.5% and Sessy 2%, where the reduction of larvae / leaflets were 88.29% and 84.44%, respectively. Caple 2% compound provide moderate reduction percentage of larvae / leaflets. In the last season (2015 / 2016) data showed that Marshal 25% WP was the best in reduction the number of larvae (90.48%) followed by Dizynoxe 60% EC was recorded 89.98%, while Potassium Sulphate 0.5% and Sessy 2% were moderate reduction percentage of larvae / leaflets were recorded 88.33% and 87.65% where Caple 2% compounds showed the least reduction 86.43% on larvae / leaflets. In general, it can be concluded that Marshal 25% WP, Dizynoxe 60 % EC and Potassium sulphate 0.5% are placed at the top rank of tested compounds, so they can be considered as highly effective compounds in reduction the infestation with L. congesta on faba bean fields. |