Evaluation of some Faba Bean Cultivars Yield under Chemical Control to Common Insect Pests and Fungal Diseases under El-Beheira Governorate Environmental Conditions

Abstract

In order to investigate six faba bean cultivars Nubaria 1, Sakha 1, Giza 716, Giza 843, Misr 1 and Giza 40 under foliar spraying with Actara insecticide (thiamethoxam), Sumi-8 fungicide (diniconazole) and thiamethoxam + diniconazole compared to control for yield and its components, some biochemicals, leaf miner (Liromiza congesta) numbers, aphid (Aphis gossypii) numbers, chocolate spot disease severity caused by Botrytis fabae Sard. and pesticides residue in green pods. The results showed that, Giza 716 cv. surpassed other cultivars in plant height, number of branches/plant, number of pods/plant, seed yield/plant and seed yield/plot in both seasons. Giza 40 cv. showed the highest values for chlorophyll a, chlorophyll b, total carbohydrate %, total protein %, peroxidase activity and polyphenoloxidase activity in both seasons respectively. Faba bean plants under the Actara insecticides (thiamethoxam) recorded the highest mean values for plant height, number of branches/plant, number of pods/plant, 100-seed weight, seed yield/plant, seed yield/plot and lowest aphid and leaf miner (Liromiza congesta) numbers in both seasons. While, the control treatment gave the highest mean values for chlorophyll a, total protein, peroxidase activity and polyphenol-oxidase activity in both seasons respectively. Diniconazole and thiamethoxam + diniconazole treatments showed the lowest disease severity of chocolate spot caused by Botrytis fabae. The lowest numbers of leaf miner (Liromiza congesta) in both seasons were counted in Misr 1 cv. followed by Nubaria 1 then Giza 40. In the same way, the lowest numbers of aphid were collected from Giza 40 followed by Misr 1 then Nubaria 1 in the two seasons. Also, Nubaria 1 cv. was the most resistant one to chocolate spot where it scored the lowest disease severity among all cultivars in both seasons followed by Misr 1 cv. in both seasons. With regard to residues analysis, the half-life value of thiamethoxam was 3.02, 3.59, and 2.57 days of the application with degradation rate of 0.138, 0.051 and 0.269 for pods, peels and seeds, respectively.