Effect of Planting Distance and Humic Acid on Growth, Yield and Antioxidant Activity of Safflower Petals and Seeds

Abstract

A field experiment was carried out at winter season of 2020-2021 in Babylon Governorate, region of Bernon, at 8 km north-east of Hilla town between 44.27 ° north and 36.32 ° east latitude, to study the effect of planting distance and Humic acid on growth, yield and antioxidant activity of petals and seeds of the safflower, the treatments were distributed in a factorial experiment with randomized completely block design (RCBD) with three replicates, the first factor was the distance between plants (10, 15 and 20 cm) and second was spraying Humic acid at concentrations (0, 125, 250 and 500 mg.l-1), data were collected and means were tested according to least significant difference test (LSD) at probability level 0.05.The results showed superiority significant of planting distance at 20 cm and spraying humic acid at concentration 500 mg.L-1 on growth and yield parameters, while plants distance at 10 cm excelled on plant height and content of petals and seeds of antioxidant activities. The results showed superiority significant at interaction treat 20 cm × 500 mg.L-1, it produced the highest rates in most considered qualities and yield of dry petals and seed yields were 79.658 and 2197.5 kg. ha-1, while interference treat 10 cm x 500 mg.L-1 produced the highest means on total phenolic compounds and total oxidative activity and scavenging free radicals reached 41.47, 212.7, 58.07, 38.72 and 33.59 mg.g-1 DW, 67.7 and 47.0% in petals and seeds respectively.