Responses of tomato hybrid cultivars to soil application of humic acid under greenhouse conditions

Responses of three tomato (Lycopersicon esculentum Mill.) hybrids viz. 'Luanova', 'Savarona' and 'Tessera' to various doses (0, 0.5, 1.0, 1.5 and 2.0 g L-1) of soil application of humic acid (HA) were evaluated in terms of plant growth, productivity and quality of fruits, under greenhouse conditions, during 2011-12 and 2012-13. In addition to improved quality characteristics, higher values for yield and yield components were recorded for tomato fruits harvested from plants of 'Tessera' cultivar compared to those harvested from other hybrids tested, regardless of growing seasons. Plants from 'Luanova' cultivar were, however, earlier in fruiting with higher number of fruits per plant. Soil application of HA presented positive effects on yield and physicochemical quality of tomato fruits irrespective of the dose of HA and the cultivar investigated, in both seasons. Soil application of HA at higher dose 1.5 g L-1 exhibited better results in all the three tomato cultivars tested, in terms of their vegetative and reproductive growth, and significantly improved the physicochemical quality of their fruits. Conclusively, the tomato hybrid 'Tessera' was found suitable for cultivation under greenhouse conditions while soil application of aqueous solution of HA @ 1.5 g L-1 substantially resulted in higher production of quality tomato fruits.

Effect of Different Enriched Vermicomposts, Humic Acid Extract and Indole-3-Acetic Acid Amendments on the Growth of Brassica napus

Humic acid (HA) is a specific and stable component of humus materials that behaves similarly to growth stimulants, esp. auxin hormones, contributing to improving growth indices and performance of plants. As a rich source of HA, vermicompost (VC) is also a plant growth stimulating bio-fertilizer that can enhance growth indices and performance in plants. The purpose of the present study is to compare the influence of VC enriched with bacterial and/or fertilizer, commercial humic acid (CHA) extract, and indole-3-acetic acid (IAA) on improving growth characteristics and performance of rapeseed under greenhouse conditions. The results showed the complete superiority of VC over the CHA and IAA (approximately 8% increase in the dry weights of root and aerial organ and nearly three times increase in seed weight). The highest values of these indices were obtained with VC enriched with Nitrogen, Sulfur, and Phosphorus, Azotobacter chroococcum and Pseudomonas fluorescens; the lowest value was obtained with VC enriched with urea. Additionally, the application of 3% VC and the control involved the highest and lowest values in all traits, respectively. The SPAD (chlorophyll index) value and stem diameter were not significantly affected by different application levels of VC. Overall, the applications of IAA and the CHA were not found to be suitable and therefore not recommended.

How Does the Addition of Biostimulants Affect the Growth, Yield, and Quality Parameters of the Snap Bean (Phaseolus vulgaris L.)? How Is This Reflected in Its Nutritional Value?

Recently, the use of biostimulants as natural and eco-friendly fertilizers has received increasing attention because of their efficiency in terms of improving crops’ qualitative and quantitative parameters, i.e., growth, yield, and chemical composition. We studied the effect of four biostimulants—humic acid (20 g/L), vermicompost tea (15 mL/L), moringa leaf extract (1:30 v/v), and yeast extract (5 g/L), with tap water as a control treatment—on the qualitative and quantitative characteristics of snap beans. The experiment was designed using a complete randomized block with triplicates. The results showed a significant improvement in treated plant performance (growth and yield), chlorophyll, and chemical composition compared to untreated plants. Using moringa leaf extract increased the plant height, number of leaves and branches/plant, and fresh and dry weight. Additionally, the diameter of the treated plant stems and the quality of the crop and pods were also significantly higher than those of plants treated with vermicompost or humic acid extract. It is also noted that the profile of amino acids was improved using all tested biostimulants. This leads to the conclusion that the addition of moringa leaf extract and vermicompost tea not only positively affects the qualitative and quantitative properties of snap bean but is also reflected in its nutritional value as a plant-based food.

Humik Asit Uygulamalarının Zambak Bitkisinin Gelişimi, Bitkideki Fenolojik ve Pomolojik Gözlemler Üzerine Etkisi

In this study, a pot study was carried out to reveal the effects of direct and foliar applications of humic acid to the growing medium in addition to basic fertilization on the development and plant quality characteristics of lily plants grown in peat + perlite medium. The experiment was carried out in an unheated greenhouse during the summer, in a greenhouse environment with a shade net on it. In the experiment, in addition to the control, the humic acid doses were 3.5 lt/da from soil, 7.5 lt/da from soil, 1.75 lt/da from leaf, 3.75 lt/da from leaf and soil + 3.5 lt/da from leaf + 1, It was applied 3 times as 75 lt/da. In the pot experiment established in three replications according to the randomized plots trial design, 10 lily bulbs were planted in each pot and humic acid applications were made at two-week intervals following plant emergence. In order to see the effect of the applications when the plant is harvested, the length of the flower stem (mm), the thickness of the flower stem (mm), the fresh weight of the branch (mm), the number of buds (pieces), the bud length (cm), the number of leaves (pieces), Full bloom stem (mm) and vase life (days) were examined. As the doses of humic acid increased, the vegetative weight of the lily plant increased, while the effect of the applications on the investigated properties was different. With the mineral elements, hormones and plant growth regulators in humic acid, it has the feature of promoting the increase of biomass in the plant.