الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 282 |  |  |
| | | from | 282 | | |
Abstract
Hana Saleh Abu-baker Faraj: Role of Certain Biotic and Abiotic Environmental Factors in Managing Major Tomato Insect Pests. Unpublished Ph. D. Thesis, Department of Plant Protection, Faculty of Agriculture, Ain Shams University, 2014.
The present study aimed at following up the seasonal fluctuation in the population densities of certain tomato pests and testing the susceptibility of certain tomato cultivars and the effect of Trichogramma spp. as biological control agent.
Obtained data during winter 2011-2012 on two tomato cultivars indicate that B. tabaci had 2-3 peaks of abundance on cultivar 888 and Tomaland and three peaks on both cultivars during winter 2012-2013. In summer 2012, B. tabaci had two peaks on both cultivars Hybrid Super and Crystal HYB; while in summer 2013, the pest had three peaks of abundance on both cultivars.
Regarding population densities of aphids (Aphis gossypii, Glover and Myzus persicae Sülzer) and E. decipiens during winter of 2011-2012, data revealed the presence of 1-2 peaks of abundance on both cultivars. In 2012-2013, aphids had three peak of abundance on both cultivars. E. decipiens had two peaks of abundance on both cultivars. During summer seasons, only one peak was recorded for aphids and E. decipiens on both cultivars.
For T. absoluta, only one peak was recorded during winter plantation (2012) on both cultivars (888 and Tomaland). In summer plantations, two peaks of abundance were recorded on both cultivars with equal size population. During summer 2013, this pest had one peak on both cultivars (April and May).
Correlation coefficient values demonstrated that the population densities of B. tabaci, E. decipiens and aphids were negatively affected by the numbers of hairs (Trichomes) on both tomato cultivars; while the effect of hairs on population of T. absoluta was insignificant positive. The length of hairs had significant negative effect on population of sap sucking insects and significant positive effect on T. absoluta during winter plantation. In summer cultivation, all investigated pests were highly and negatively affected.
The correlation coefficient values between major nutritional components in tomato leaves and the population densities of the tested insects during winter revealed that the effect of nitrogen (N) was not accurate on the presence of aphids and E. decipiens; while on B. tabaci and T. absoluta the effect was positive and insignificant. The effect of phosphate (P) was negative and highly significant on B. tabaci, aphids and E. decipiens but positive and highly significant on T. absoluta. The effect of either potassium (K) or calcium (Ca) fluctuated according to the pest and cultivar. The effect of magnesium was positively and highly significant on B. tabaci and E. decipiens on both cultivars. For summer plantation, data revealed that N had positive and highly significant effect on all tested pests on both cultivars. P had a positive and highly significant effect on all pests on cultivar Crystal. K had a negative and highly significant effect on all considered pests on both cultivars. Ca had a positive and highly significant effect on all considered pests on both cultivars. Mg had a positive and highly significant on the cultivar Hybrid; while the effect was significant on the population of sap sucking pests on the cultivar Crystal.
The effect of minor nutritional components on the population densities of the tested insects during winter plantation revealed that the effect of (Fe) was positive and significant on aphids and E. decipiens on both cultivars, insignificant on B. tabaci and negative insignificant on T. absoluta. The effect of Zinc greatly varied among pests and cultivars. Manganese had a negative and highly significant effect on B. tabaci and E. decipiens; while the effect on T. absoluta was significant and positive. Cupper (Cu) had a positive and highly significant effect on B. tabaci and E. decipiens. During summer; the effect of Fe, Zn and Mn was positive and highly significant on both cultivars.
The effect of mean minimum temperature during winter plantation was positive and highly significant on B. tabaci, aphids and E. decipiens and insignificant effect on T. absoluta. The effect of mean maximum temperature was positive and significant on B. tabaci, aphids and E. decipiens and insignificant on T. absoluta. R. H. % had negative effect on all investigated pests.
For the efficiency of the egg parasitoid, T. evanescens, data revealed that the parasitoid is more efficient against S. cerealella as compared to T. absoluta according to the produced black eggs/female, percent of adult emergence, sex ratio, frequency of egg contacts, mean of adult female longevity and emergence percentage.
The net reproductive rate (Ro) of the T. evanescens was 27.204; generation time (days) (Gt) was 11.755; intrinsic rate of increase (rm) was 0.281; finite capacity for increase (λ) was 1.324 and doubling time (days) (Dt) was 2.466.
Results also demonstrated that the application of egg parasitoids T. evanescens has a significant effect in suppressing the population density of T. absoluta male moths in tomato fields as appeared in pheromone traps.
The application of the egg parasitoids, T. evanescens achieved a significant reduction of infestation level of tomato fruits ranged between 34.12 and 42.15% during both seasons.