An Evaluation of Two Tomato Cultivars to Infestation by Certain Insect Pests

Abstract

Experiments were carried out at tomato field at Qalyubyia Governorate, Egypt cultivated with two different cultivars to test its susceptibility to infestation with Bemisia tabaci (Gennadius); aphids {Aphis gossypii and Myzus persicae (Sülzer)}; Empoasca decipiens Paoli and Tuta absoluta (Meyrick) in addition to the seasonal abundance of these pests on the two cultivars in two successive summer seasons (2012 and 2013). Results indicated that B. tabaci and aphids had two peaks of abundance in May and June in both years on both cultivars. E. decipiens also had two peaks of abundance in May and June in both years with no significant difference between the two cultivars. The two tested cultivars almost harbored the same population density of the immature stages of T. absoluta during summer season, 2012. The pest had only one peak during the last week of May. There was negative and highly significant correlations between the population densities of all considered pests and the numbers of hairs (trichomes) present on tomato leaves sampled on 20 May and 4 June except for aphids which disappeared during hot summer months on the cultivar Hybrid Super. In the third sampling date (20 June, 2013), the correlation was also negative and highly significant with the population of B. tabaci and positive with the population of T. absoluta. The same trend was observed on the cultivar Crystal HYB. The effects of (N), (P) and (Ca) were positive and highly significant on all considered pests on both cultivars. The effect of (K) was negative and highly significant on all considered pests on both cultivars. The effect of (Mg) was positive and highly significant on the cultivar Hybrid; while it was negatively correlated with sap sucking pests only on the cultivar Crystal. Data indicate that the effect of Fe, Zn and Mn was positive and highly significant on both cultivars and Cu was negatively affected these pests on both cultivars.

Change of the Density-Independent and Dependent Environmental Factors on The Population Dynamics of Bemisia tabaci and Empoasca fabae Under the Potato Agroecosystem

“…Low numbers of Empoasca decipiens in spring plantation. (Abdallah & Faraj, 2015) in Egypt revealed that B. tabaci recorded 2-3 peaks of abundance whereas leaf hopper had 1-2 peaks in summer plantations for seasons 2012&2013. (Abdallah & Faraj, 2015) indicated that densities of B. tabaci remained at a low level during the winter but increased steadily from February to March until migration into field crops in April.…”

“…(Abdallah & Faraj, 2015) in Egypt revealed that B. tabaci recorded 2-3 peaks of abundance whereas leaf hopper had 1-2 peaks in summer plantations for seasons 2012&2013. (Abdallah & Faraj, 2015) indicated that densities of B. tabaci remained at a low level during the winter but increased steadily from February to March until migration into field crops in April. Population fluctuation of white fly and leafhopper was somewhat similar (Rawat Scholar et al, 2020) as there was a non-significant positive correlation between maximum temperature and relative humidity of morning but minimum temperature showed a non-significant negative correlation and for Hopper population was a non-significant positive correlation with maximum temperature & relative humidity of morning and non-significant negative correlation with minimum temperature.…”