Effect of foliar application of humic acid against terminal heat stress in wheat (Triticum aestivum L.) genotypes
Loading...
Date
2023
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University
Abstract
Terminal heat stress in wheat (Triticum aestivum L.) is a major threat on account of global climate change that significantly affects the yield. To investigate the present study, wheat varieties viz PBW 725 (timely sown) and PBW 752 (late sown) were sown in randomised block design as per PAU‟s package and practice in PVC cylinders (PAU) and field (RRS, Bathinda) conditions. Foliar application of two concentration of humic acid (2000 ppm and 4000 ppm) was done ten days prior to tillering, booting and flowering stage. The treatment without any spray served as control. At all stages morpho- physiological and biochemical parameters were recorded whereas yield and yield attributes were recorded at maturity. The present study found that foliar spray of 2000 ppm and 4000 ppm humic acid significantly increased plant height in flowering and grain filling stages. The booting stage exhibited the maximum dry weight (0.089 g) in PBW 752 at 4000 ppm dosage. The 4000 ppm foliar spray
significantly increased the relative growth rate of PBW 725 (15 %) at Bathinda. Humic acid reduced electrolyte leakage in PBW 725 and PBW 752 plants at Bathinda, and increased cellular viability (72 %) along with leaf relative water content (99 %) at 4000 ppm foliar spray The chlorophyll a (25.84 mg g-1 FW), chlorophyll b (10.96 mg g-1 FW), total chlorophyll content (33.5 mg g-1 FW) and carotenoids (10.46 mg g-1 FW) spiked after 4000 ppm foliar spray of humic acid. The flowering stage showed an unprecedented value of total soluble sugars for PBW 725 (49.8 mg g-1 FW) on 4000 ppm treatment of humic acid. The study found that starch content (52.9 mg g-1 FW) increased significantly PBW 752 after 4000 ppm of foliar spray of humic acid. The highest α-amylase activity (133.1 nanomoles of glucose formed min-1 g-1 FW) was observed in PBW 752 at booting stage after 4000 ppm of foliar spray of humic acid. On the other hand, foliar spray of humic acid did not depict any
significant effect on yield components.
Description
Keywords
Citation
Aishwarya Rawal (2023). Effect of foliar application of humic acid against terminal heat stress in wheat (Triticum aestivum L.) genotypes (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.