ALLEVIATING ADVERSE EFFECTS OF SOIL SALINITY STRESS ON GROWTH, BIOCHEMICAL COMPOSITION AND YIELD OF CUCUMBER BY USING HUMIC ACID AND CHITOSAN AS FOLIAR APPLICATION

Document Type : Original Article

Authors

1 Plant Physiol. Section, Agric. Bot. Dept., Fac. Agric., Cairo Univ., Giza, Egypt

2 Veg. Crops Dept., Fac. Agric., Cairo Univ., Giza 12613, Egypt

10.21608/zjar.2024.367230

Abstract

The alleviating effect of foliar application of both humic acid and chitosan on cucumber plants grown in saline soil were elucidated. A pot experiment was conducted at the greenhouse of Plant Physiology Division, Faculty of Agriculture, Cairo University. Giza. Egypt during the two successive seasons of 2020/2021 and 2021/2022. Two factors were studied and designed in Randomized Complete Block Design (RCBD) in each season. Cucumber seeds were sown on 20 Sept. at both seasons, in four levels saline soil (Control, 2000; 4000, 6000 ppm), and treated foliar with five treatments; 1: control (sprayed by tap water), 2, 3: humic acid at two levels (10 ml/L and 20 ml/L) and 4, 5: chitosan at two levels (0.25g and 0.5 g per liter), all of them applied twice. Tween 20 was used as a wetting agent. The plant growth parameters and biochemical components were recorded in two samples of different ages, at the vegetative and flowering growth stages, as well as fruit quality traits and total yield / plant. Results obtained that increasing salinity level affected the seeds germination in which the 6000 ppm had not recorded any seed germination. In addition, increasing salinity level led to reducing plant growth parameters, on the other side chlorophyll a and b increased, and proline accumulation, sugars, amino acids and phenols. A significant reduction was observed in average fruit weight and yield. In addition, chitosan and humic acid application enhanced the growth and biochemical components of cucumber. These inducers were found to have dose dependent effect. Moreover, chitosan showed superiority, mainly in concentration of 0.25 g. L-1 as compared to all studied treatments in respect of growth characters, dry matter and biochemical response of cucumber as well as yield and fruit length.

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