Effect of foliar nutrition with humic, fulvic acid and proline and their interaction between them on the vegetative growth characteristics of sunflower Helianthus annuus L.

Abstract

A field experiment was carried out in one of the agricultural fields belonging to Al-Khalis district / Diyala governorate, which is located 14 km north of Baquba district, during the autumn season of 2022, in soil with clay loam texture in order to study the effect of organic fertilization with humic and fulvic acid and spraying the amino acid proline on vegetative groswth. for sunflower plants (Helianthus annuus L.) A factorial experiment was carried out with two factors according to the randomized complete block design (RCBD) and with three replications. The first factor was sprayed with humic acid and fulvic acid at concentrations of 6 gm.L.-1 For each of them as well as the control treatment, the second agent was sprayed with proline acid at four levels: 0, 10, 20, and 30 mg.L-1 The results showed that there was a significant superiority when adding humic acid + fulvic acid at a concentration of 6g.L-1 In the average characteristic of plant height, stem diameter, plant dry weight, chlorophyll index, leaf area of the plant, and the number of leaves per plant, which were 160.60 cm, 21.57 mm, 174.25 g, and 57.43 SPAD and 687.31 cm2 and 38,81 leaves. Plant-1, respectively. The results showed that there was a significant superiority when spraying with proline at a concentration of 30 mg.L-1 In the mean of plant height, stem diameter, plant dry weight, chlorophyll index, plant leaf area, and number of leaves per plant, which were 166.95 cm, 21.10 mm, 180.00 g, 54.07 SPAD, and 704.01 cm.2 and 40,05 leaves. Plant-1 respectively, the results showed that the interaction between the levels of foliar fertilization with humic and fulvic acids and foliar fertilization with proline acid had a significant effect on all traits, as the overlap treatment gave 6 ml.L-1 Humic + Fulvic X30 mg.L-1 Proline has the highest mean of plant height, stem diameter, plant dryness, chlorophyll index, leaf area of the plant, and number of leaves per plant, which were 171.80 cm, 23.76 mm, 197.00 g, 64.23 SPAD, and 802.82 cm.2 And 41,80 leaves-1 respectively. Keywords: Humic acid, fulvic acid, proline acid, organic acids, foliar nutrition, sunflower.