Effect of Nitrogen Fertilizer and Different Host Plant to the Biology and Population Dynamic of Melon Aphid Aphis gossypii Glover

If you are interest on Aphid, here is the paper that may (hopefully) bring benefit to you, it discussed about the effect of nitrogen fertilizer and different host plant cultivar to the biology and population dynamic of Aphis gossypii.
This paper also submitted to the committee of King Saud University Student Research Conference (KSUSRC). It conducted during enrolling in Insect Biology Course Supervised by my lovely Lecturer Dr. Yousif Aldryhim.


Effect of Nitrogen Fertilizer and Different Host Plant to the Biology and Population Dynamic of Melon Aphid Aphis gossypii Glover.
By Soffan, Alan*2 and Yousif N. Al Dryhim*3.

Fertilizer and certain host plant cultivar are commonly used by farmers to increase the crop production. However those inputs have an effect to the pest infestation. In cucumber and squash, Aphis gossypii is one of the economic major pests that may reduce the yield. The economic losses are by inducing direct injury to the plant or indirectly as a vector for many plant diseases. An inappropriate use of nitrogen fertilizer and host cultivar may lead the farmers to have economic losses instead of a maximum yield. This experiment is going to measure the effect of different level of nitrogen fertilizer and different host plant cultivar (cucumber Cucumis sativus L var. Beit Alpha and squash Cucumis pepo var. Bianca Di Trieste) to the biology and population dynamic of Aphis gossypii Glover.

The experiments were conducted from April 21st to May l1, 2009. Two growth chambers were used and maintained at 21¬¬+1˚ C with photoperiod 16L:8D. The biology study of A.gossypii was carried out by using C. pepo var. Bianca Di Trieste and C.sativus var. Beit Alpha with 4 to 5 true leaves. They were grown in plastic pots with diameter and height 14 cm and 11 cm respectively, while the medium was a mixture of soil, sand and peat most (1:2:1). A Newly born of A. gossypii nymph were introduced to single leave for each plants. Observation was carried out every 24 hours for nymphal period, prenymphal position period, nymphal position period, post nymphal period and the number of progeny. Additional biology study of A. gossypii was conducted by providing them single fresh squash leaves in Petri dish (diameter 9 cm, and 1.5 cm height) instead of the whole squash plant. The temperature maintained at 21¬¬+1˚ C with photoperiod 24h light. The population dynamic study of A.gossypii was carried out in squash plant (C. pepo var. Bianca Di Trieste). Three level of nitrogen fertilization 0, 1, and 2 gr were applied in each plant including the control. Aphid infestation was made by introducing five individual of three days old of A. gossyipii to the plant. After 16 days all aphids were examined for the number of apterous nymph, alatae nymph, alatae adult and apterous adult. Data were analyzed using SAS program.
Performance of A. gossypii on different hosts (squash and cucumber) were significantly different. A. gossypii performed better on cucumber than on squash, which was indicated by higher value of nymphal position period, number of progeny and total life span. The quality of the plant supposed to be responsible for A. gossypii performance, as well as the presence of secondary metabolite substances that may influence negatively to the aphid performance on squash. When the biology of A. gossypii on whole squash plant and on single squash leaves in petri dishes were compared, it was found that the total nymphal period of A. gossypii on single squash leaves in petri dishes were shorter than on whole squash plant, on the other hand the nymphal position period, total lifespan and number of progeny had a higher value on single leaves in petri dishes. The different performance of aphid in whole plant and on single leave in petri dishes, it may be due to the photoperiod, or by defensive allelochemical produced by whole squash plant during the aphid infestation. Population dynamic of A.gossypii on squash varied among the level of nitrogen fertilizer, positive correlation occurred between level of nitrogen and their density, as well as the presence of alate form either nymph or adult. Nitrogen fertilizer significantly increase the density of A.gossypii on squash plant (LSD α:0,005).