Development and Physiological Response of Bittergourd to Boron Level

Abstract

At some concentrations boron (B) is toxic to bittergourd (Momordica charantia L.).There is a need to determine how bittergourd responds to B concentration. Plants of cv. Jhalari were exposed to 0.003 to 3.3 mg·L −1 of B for 32 days in refined sand. Plants exhibited best growth and total biomass at 0.33 mg·L −1 of B. Visible B deficiency symptoms were observed in plants treated with 0.003 mg·L −1 of B at day 25 manifest as blackening of the growing tip, reduction in size of plants, development of necrotic areas in young leaves, and thickening of the lamina of mature leaves, which later became leathery and eventually brittle. Toxicity symptoms developed at 3.3 mg·L −1 of B and at d 21 margins of old leaves became chlorotic. Exposure to <0.33 and >0.33 mg·L −1 of B reduced total biomass, chlorophyll a and b, carotenoid, and proline contents and activity of catalase and enhanced activities of the antioxidant enzymes peroxidase, superoxidase dismutase, ascorbate peroxidase, and polyphenol oxidase in leaves. Lipid peroxidation decreased, and tissue B concentration increased with an increase in B supplied. Values for deficiency, threshold of deficiency, threshold of toxicity, and toxicity were 5.4, 8, 58, and 120 mg·g −1 dry matter, respectively, in young leaves of bittergourd, which could be helpful in predicting the B status of bittergourd under field conditions.

Classification of agricultural land consolidation types based on soil security to improve limiting factors adapted to local soil conditions

“…According to Ryals et al (2014), SOM is an essential indication of soil quality and is directly related to soil aggregation. Increased microbial activity in the rhizosphere may be caused by higher SOM (Sinha et al, 2009). The distributions of the soil earthworms and aggregate stability across the whole study area were consistent with the SOM distribution, which supported this association in our investigation.…”