AEJSA Volume 18, Number 1: January, 2024
----------------------------------------------------------------------------------------------------------------------------------
Efficacy of three winter crops in a rotation system for better summer crops and lower infection with RKN Meloidoigyne incognita
Imad H Abdmousa and Basil H Kandouh
ABSTRACT: Crop rotation is one of the oldest, most cost-effective and effective methods to maintain soil fertility, improve crop yield and reduce pests and diseases, even in the case of the widespread plant-parasitic root-knot nematodes (RKN) Meloidogyne spp. The study investigated the possibility of reducing RKN Meloidogyne incognita by alternating selected winter and summer vegetable crops. Plant yield and M. incognita nematode population were evaluated in a mini-plot on winter vegetables (Beta vulgaris, Vicia faba and Allium cepa) and on successive summer vegetables eggplant (Solanum melongena), cucumber (Cucumis sativus) and okra (Abelmoschus esculentus) to the to determine the best crop rotation for lower nematode density and better plant yield. The results showed that the yield of winter chard, onions and faba beans decreased due to M. incognita infection. The highest percentage yield reduction was 30% in chard, followed by faba bean with a yield reduction of 17%, while onions had the lowest weight reduction of 9% due to nematode infection. Onions also significantly led to the lowest nematode population, followed by faba beans and chard. The latter recorded the highest nematode reproduction factor (Rf) of 2, followed by faba beans at 1.9, compared to the lowest Rf of 0.84 in onions, for the successive summer crops of cucumber, eggplant, or okra, plant growth and yield were influenced by the type of previous crop and initial nematode density. The largest declines in plant growth and yield were recorded in summer crops grown after Swiss chard, while moderate declines were typically seen in crops grown after broad beans and onions, respectively. The nematode population was highest in okra, followed by cucumber and eggplant. The highest nematode densities were recorded in summer crops grown after chard, followed by faba beans and onions. The best approach to reduce the M. incognita population was eggplant after onion, while okra after chard or broad beans are not recommended.
[ FULL TEXT PDF 1-6 ] DOI: 10.22587/aejsa.2024.18.1.1
----------------------------------------------------------------------------------------------------------------------------------
Chemical pesticides impact on free-living nematodes and okra plants performance
Mohammed A. Shedhan and Fadhl A. Alfadhl
ABSTRACT: The study aimed to demonstrate the importance of the practices of using organic and chemical pesticides and fertilizers in relation to density and distribution of free-living nematodes, and the impact of these practices on soil health and quality. This is to develop a potentially successful sustainable agricultural system to prevent plant diseases and support plant health. The experiment was conducted in the field for the 2021 agricultural season after plowing, leveling, and dividing the soil into furrows. Then add the pesticide Carbofuran 10%, the pesticide 50% Chinosol, and a mixture of both, while the control furrows were left without addition. Okra seeds were planted at a distance of 30 cm, in three furrows (replicates) for each treatment. During and at the end of the season, growth, yield and plant health indicators were measured based on nematode diversity and numbers. It was found that not adding pesticides led to a significant increase in the values of plant height, total fruit weight, and the chlorophyll and nitrogen content of leaves, and the emergence of greater numbers of free-living nematodes, which showed significant differences in their numbers over the period of time between the two seasons. The soil not treated with pesticides recorded a significant increase in all indicators under study compared to the soil treated with chemical pesticides. Most plant growth indices showed a strong correlation with the number of free-living nematodes, especially at the end of the season.
[ FULL TEXT PDF 7-12 ] DOI: 10.22587/aejsa.2024.18.1.2
----------------------------------------------------------------------------------------------------------------------------------
Laboratory evaluation of the efficacy of Canfor oil, Bifenthrin, and predatory beetle Stethorus gilvifrons on the two-spotted spider mite Acariformes (Tetranychidae) (Kock) Tetranychus urticae on cowpea
Husham R. Meteab, Hussein R.S. Naji, Haider H.G. AL-Challabi and Neran M. Gwad
ABSTRACT: Experiments were conducted to evaluate the efficacy of Camphor oil applied at rates of 0.5, 1, 1.5 and 2 ml/L and Bifenthrin applied at rates of 0.25, 0.5, 0.75 and 1 ml/L on adult's life stages and eggs of the two-spotted spider mites Tetranychus urticae (Acariformes: Tetranychidae) on cowpea plant Vigna unguiculata L. The results of the laboratory experiment showed that eucalyptus oil at concentrations 0.5, 1, 1.5 and 2 ml/L, respectively, caused the morality of adult mites at a rate of 37.21, 67.43, 83.72 and 95.34 % after 72 hours of treatment. It led to a reduction in the egg hatching to rate of 63.33, 43.33, 30 and 20% at the same mentioned concentrations, respectively, after 7 days of treatment, while the control treatment recorded a hatching rate of 100% after the same time period. As for Bifenthrin, where was used at concentrations of 0.25, 0.5, 0.75 and 1 ml /L, respectively, resulted in adult mite morality by 37.21, 93.02, 100 and 100% after 72 hours of treatment. And it reduced the hatchability rate of eggs to 63.33, 43.33, 40. and 26.66% at the same concentrations mentioned, respectively, after 7 days of treatment compared to hatching rate of 100% in the control. The practical results indicated that the interaction treatments of 0.75 ml/L or 1 ml/L Camphor oil with 2 ml/L Bifenthrin were the most effective and resulted in mites' adult mortality of 97.77 and 100% after 24 hours of treatment, and reduced eggs hatching to 20 and 10% after 7 days of treatment, respectively.
[ FULL TEXT PDF 13-19 ] DOI: 10.22587/aejsa.2024.18.1.3
----------------------------------------------------------------------------------------------------------------------------------
|
