The Companion effect between Salicylic acid and Glutamine on the growth and yield of water-stressed cucumber (Cucumis sativus L. )

Abstract

Trial was conducted in greenhouse of the Department of biology / College of Science/University of Diyala during autumn season 2016. The study included two levels of water stress ( S1 /Irrigation for 14 minutes and S2 / Irrigation for 7 minutes/7 ml of water per minute ), three foliar application levels of Salicylic acid SA (0, 75, 150) mg. L−1 and three foliar application levels of Glutamine acid G (0, 1000, 2000) mg. L−1. Some growth indicators viz., (Plant height, Stem diameter, Relative growth rate and Plant Yield were registered. The experiment was designed as a factorial experiment using an RCBD design with three replicates. Water stress decreased the means of all studied indicators, Plant height record 232.44 cm, Stem diameter 8.28mm, Relative growth rate 0.019 g.day−1 and yield 1358 gm plant−1 at the first stress level (Irrigation for 14 minutes / S1 ) while the means of the indicators decreased to183.82 cm, 7.41 mm, 0.016 g day−1 and 972 g plant−1, respectively at the second stress level (Irrigation for 7 minutes / S2 ). Salicylic acid and Glutamine acid increased all the studied indicators. the third level of salicylic and Glutamine spraying (150 mg. L−1, 2000 mg. L−1 ) has exceeded the second level (75 mg. L−1, 1000 mg. L−1 ). The role of Salicylic acid and Glutamine acid was positive to decrease the passive effect of water stress, Plant height record 236.17 cm, Stem diameter 8.57mm, Relative growth rate 0.021 g.day−1 and yield 1893 gm plant−1(the percentage of increase was 37.57%, 40.95%, 50.00%, 179.62%, respectively), also the triple interaction between the second stress level(S2 ) and the spraying at high levels the Salicylic acid and Glutamine SA3 G3 was positive to decrease the effect of water deficit stress, 262.00 cm, 9.22 mm, 0.024g.day−1 and yield 2317gm plant−1 (percentages of increase were 75.05%,58.97%,100.00%and286.17%, respectively).

Using of immunomodulating substances in optimizing cucumber nutrition in protected soil conditions

“…In modern systems of protection of greenhouse crops from diseases, fungicidal and protective-stimulating drugs that activate mechanisms for increasing plant disease resistance at the biochemical level play an important role. Immunomodulating substances are used to prevent diseases of greenhouse crops, reduce their prevalence, they have a positive effect on the energy of germination and germination of seeds, stimulate root formation [14].…”