Investigation the Effect of Reduced Doses of Glyphosate and Sulfosulfuron on Broomrape (Phelipanche aegyptiaca Pers.) Control in Cucumber (Cucumis sativus L.)

Broomrape has no chlorophyll and is absolute parasites for dicotyledonous plants that Its more scattered range in warm and dry and semi-arid areas in temperate and Mediterranean countries, eastern Europe and south America and the middle east, including Iran. parasitic weed especially broomrape due to reduced yields and increased production costs in cucumbers has special importance. The aim of this study was to determine the susceptibility of cucumber to glyphosate and sulfosulfuron herbicides and determining the appropriate rate and frequency of application. So, an experiment was performed in research field of university of Kurdistan.

The experiment in the spring and summer (25 May to the end of September) was carried to potted method the field in the free space in 2018 in a randomized complete block design with four replications in each iteration consists of 25 herbicide treatments, as follows: treatment 1) controls were infected with broomrape and without of application herbicide, treatments 2-5) glyphosate herbicide (SL36%) 20, 40, 60 and 80 g.ai/ha one time application, treatments 6-9) sulfosulfuron herbicide (WG 75%) 25, 50, 75 and 100 g.ai/ha one time application, treatments 10 and 11) glyphosate herbicide 20 and 40 g.ai/ha twice application, treatments 12 and 13) sulfosulfuron herbicide 25 and 50 g.ai/ha twice application, treatments 14-16) glyphosate herbicide 20, 40 and 60 g.ai/ha three times applications, treatments 17-19) sulfosulfuron herbicide 25, 50 and 75 g.ai/ha three times applications, combined treatments 20-22) herbicides sulfosulfuron 25 + glyphosate 20 g.ai/ha twice application, glyphosate 40 + sulfosulfuron 50 g.ai/ha twice application and sulfosulfuron 50 + glyphosate 40 g.ai/ha twice application, combined treatments 23-25) herbicides glyphosate 20 + sulfosulfuron 25 + glyphosate 40 g.ai/ha three times applications, sulfosulfuron 25 + glyphosate 40 + sulfosulfuron 50 g.ai/ha three times applications and glyphosate 40 + sulfosulfuron 50 + glyphosate 40 g.ai/ha three times applications. The first stage of application of the treatments was 15 days after emergence of cucumber seeds and the interval between two replications was 14 days.

The results of this study showed that cucumbers were more susceptible to sulfosulfuron herbicide. Application of sulfosulfuron 75 g.ai/ha with one-time application, sulfosulfuron 25, 50 and 75 g.ai/ha with three times application, sulfosulfuron 50 + glyphosate 40 g.ai/ha with twice application, and combined treatments were used three times in all studied traits in host and broomrape compared to control at 1% level. However, control broomrape effect phytotoxicity on plant host and therefore their application was not recommended. due to the sensitivity of cucumber and the lower toxicity effect, glyphosate treatments of 20 one time application and three times application (g.ai/ha) and glyphosate 40 one time application (g.ai/ha) respectively with 247%, 215% and 151% increase compared to control treatment and in addition to control of broomrape, less Phytotoxicity was observed on the host plant.

The best results considering both broomrape (P. aegyptiaca) control and selectivity in cucumber was obtained by one times application and three times application at 20 (g.ai/ha) and one times application at 40 (g.ai/ha) of glyphosate.