Effect of foliar fertilization of microelements on highbush blueberry (Vaccinium corumbosum L.) nutrient status and yield components in cutover peatlands

ArticleThe commercial cultivation of highbush blueberry in Latvia was successfully started during the last 20 years. In 2018, there was an estimated 280 ha of highbush blueberries planted in Latvia with increasing annual hectarage. In general, blueberry is a highly specialized crop that has definite soil agrochemical and climatic requirements: it has low nutrient needs and is sensitive to excessive nutrient levels in the soil. However, balanced and precise mineral nutrition is essential for producing high and quality yield. The study was conducted in the producing planting of highbush blueberry, cultivar ‘Patriot’, during the vegetation season of 2018. The research was carried out to determine the effect of foliar fertilization with micronutrients (Fe, Zn, Cu, Mo, B) on the productivity, the content of mineral elements in leaves and photosynthesis of blueberries. Field experiment design included foliar fertilizer treatments 0 to 3 times per season. In general, our results revealed that foliar sprays with micronutrients had a positive effect on the berry yield, parameters of photosynthesis and microelement content in leaves of highbush blueberry. It was determined that the application of the foliar fertilizer 4 times per season provided the highest berry yield (134% compared to control) and the highest photosynthetic activity of plants. Our study suggests that correct foliar fertilization can optimize the content of Fe, Zn and B in blueberry leaves

Leaf nutrient status of tomatoes in coconut coir medium – differences in cultivars, impact on yield and quality

Received: January 29th, 2021 ; Accepted: May 12th, 2021 ; Published: June 22nd, 2021 ; Correspondence: [email protected] coir as an alternative to rockwool is increasingly used as a substrate for soilless hydroponic greenhouse production of tomatoes. However, little is known about the nutrient status of tomatoes in coconut coir, especially under intensive production conditions. The aim of this study was to investigate the nutrient status of different tomato cultivars (orange plum ‘Organza F1’, red cherry ‘Daltary RZ F1’, red large fruit-sized ‘Securitas RZ F1’ and pink large fruit-sized ‘Fujimaru F1’) under industrial greenhouse production, using coconut coir as a substrate to reveal nutrient imbalances, their impact on tomato yield and quality, and cultivar differences. Essential nutrient and leaf SPAD value was detected for the youngest fully developed leaves and the old still vital leaves twice per month from April to August 2020. The total yield, marketable and non-marketable yield was regularly determined. During the crop cycle, the content of most of the nutrients in tomato leaves corresponded to the standard range reported for tomatoes. Only some imbalances were found: all cultivars were characterized by low Zn and high S levels in both young and old leaves. The obtained results identified several differences between the cultivars: cherry tomatoes 'Daltary' had significantly higher N, K, Fe and Zn in leaves compared to other cultivars. The lowest N, Fe and Cu were determined for large fruit-sized ‘Securitas’. Regardless of the nutrient status and microclimate conditions, the marketable yield of ‘Daltary’, ‘Organza’ and ‘Securitas’ was almost 100%, indicating on high suitability of these cultivars for hydroponic cultivation in coconut coir

Research on the mineral composition of cultivated and wild blueberries and cranberries

ArticleEuropean cranberry ( Vaccinium oxycoccos L.) and European bilberry ( Vaccinium myrtillus L.) are among the most popular wild - harvested fruits in Latvia, traditionally used in folk - medicine and food. The commercial cultivation of American cranberry ( Vaccinium macrocarpon Ait.) and highbush blueber ry ( Vaccinium corymbosum L.) was successfully started during last 20 years. With a berry production increase due to considerable hectarage of plantings and growing consumer interest in health - improving foods cultivated blueberries and cranberries have foun d a place in a daily intake as an excellent source of phenolic and nutritive compounds, vitamins and minerals. As the chemical composition of Vaccinium spp . has an important implication on human health, detailed information on the nutritional content of berries are of special importance. The aim of this study was to compare the contents of twelve biologically essential elements (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B) in b erries of four Vaccinium species: cultivated and wild blueberries ( Vaccinium corymbosum and Vaccinium myrtillus ) and cranberries ( Vaccinium macrocarpon and Vaccinium oxycoccus ). Together 136 (leaf and berry) samples were collected from 7 main cranberry and blueberry producing sites and 17 native woodland areas and bogs in Latvia. A comparison of wild and cultivated species showed similar concentrations for the macroelements K, Ca and S in cranberry and N, P in blueberry fruits. While statistically significa nt differences were found for N, P and Mg in case of cranberries and Ca, K, Mg and S for blueberries. The research revealed statistically significant differences of most micronutrients in cultivated and wild berries. Plant leaf and fruit analysis revealed the organ - specific distribution of mineral elements in all species studied. In most of the cases, leaf analysis supported concentration differences in fruits

Effect of fertilization on growth of lingonberry (Vaccinium vitis-idaea L.)

Received: January 29th, 2021 ; Accepted: April 10th, 2021 ; Published: April 20th, 2021 ; Correspondence: [email protected], most of the global berry crop of Vaccinium vitis-idaea L. is obtained from wild berries. In recent years, however, their cultivation has become slightly more widespread, especially as demand has increased. As the commercial production of lingonberries is a completely new fruit-growing sector in Latvia, research on mineral nutrition, development of the crop production system and proper fertilizer management is critically important. The objective of this study was to elucidate the effect of different fertilizer rates on the nutrient status of lingonberry plant tissues and plant growth performance. Field experiments with the lingonberry variety ‘Runo Bielawskie’ were carried out during the 2019 and 2020 cropping season. Experimental plantations were established on an excavated peat bog in Latvia. Lingonberry plants received 4 different levels of complex and foliar fertilizers. Leaf analyses and soil (peat) testing were used as diagnostics tools to reveal nutrient (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B), soil pH and EC status. In general, plant growth characteristics were significantly affected by different levels of fertilizer. The results showed that the highest fertilizer rates resulted in a larger shrub diameter, the highest total number of rhizomes and shoots of a mother plant

The effect of cadmium and lead pollution on growth and physiological parameters of field beans (Vicia faba)

ArticleResearch on the impact of soil contamination on crops is important as plants directly take up heavy metals from the soil through the roots, so heavy metals can enter the food chain. The aim of this study was to investigate the impact of cadmium (Cd) and lead (Pb) pollution on growth and physiological parameters of field beans. Plants in the vegetation experiment were grown under controlled conditions. Changes in growth and physiological parameters were studied at five levels of Cd (0–25 mg L -1 ) and at 6 levels of Pb in substrate: from (0–1,000 mg L -1 ) at the first day of the experiment, to (0–2,000 mg L -1 ) at the end of the experiment after gradual Pb additions after every sample collecting day. Methods used for analysing the plant material: the content of amino acid proline and photosynthetic pigments were determined by spectrophotometry; chlorophyll a fluorescence parameters – using continuous excitation chlorophyll fluorimeter. The fresh weight of plant above-ground parts and roots was detected. The growth and development of field beans was slightly influenced by increasing amount of Cd and Pb in substrate only at the end of the experiment. The highest Cd treatments (Cd20 and Cd25) caused 2.5 and 1.3 times increased proline concentration in bean leaves. The chlorophyll a + b content and chlorophyll a fluorescence parameter Fv/Fm changed differently throughout the experiment. In general, during the experiment, there was a tendency for the content of proline in leaves for Pb treatments to be increased compared to control. At the end of the experiment the content of proline in field bean leaves of the highest Pb treatments (Pb600 + 100 + 400 + 500, Pb800 + 100 + 400 + 500 and Pb 1,000 + 100 + 400 + 500) was 1.66, 1.44 and 1.55 times higher, respectively, than that of the control plant leaves. The negative impact of exposure to Pb on chlorophyll a + b, chlorophyll a fluorescence parameter PIndex and Fv/Fm in bean leaves was less pronounced compared to Cd. The obtained results confirm that field beans until their flowering stage can grow and develop in the presence of a large amount of Cd and Pb in substrate without significant growth inhibition and detrimental impact on physiological parameters, if optimal cultivation conditions are provided

The effect of cultivation technology on the plant development of organically grown garlic

Received: February 3rd, 2021 ; Accepted: May 31st, 2021 ; Published: June 7th, 2021 ; Correspondence: [email protected] new technological solutions for the hardneck garlic production were tested to prevent the influence of unfavourable soil and climatic conditions on the rooting, sprouting and wintering ability of hardneck garlic - factors that affect significantly the hardneck garlic production in Latvia. Field studies were carried out at the experimental field of the organic farm, located at the Koknese district, Latvia, during the seasons of 2018/2019 and 2019/2020, on sandy loam soil using hardneck garlic cultivar `Liubasha` and local clones. Two variants of garlic growing were compared - traditional planting in the autumn in the field as control, and planting in the trays as an innovative solution. Results indicated that low temperature treatment (below +7 °C) for the period of at least 50 days initiates cloves primordia development. The using of trays is effective technology to prevent unfavourable agroecological conditions on the field in the case if controlled conditions are available and technically feasible in the farm

Effects of fertilization on Picea abies stands situated on drained peat soils

ArticleNorway spruce used for afforestation of drained peat soils frequently has low productivity and decay in a long - term, which could be related to soil chemical composition and nutrient status. The research aim was to elucidate the effect of PSM on new Norway spruce plantings (1st experiment) and 20 - year - old spruce stands (2nd experiment) on drained peat soils by evaluating: (1) nutrient accumulation in soil - plant system, (2) soil microbiological activity, (3) health status of spruce individuals, (4) growth int ensity and productivity of spruce, (5) changes in composition of vascular plant and moss species. The study was conducted at two forest ( Myrtillosa turf.mel .) sites in Latvia, each consisting of two plots: control and treated with PMS (100 g m - 2 in Septemb er 2007, 50 g m - 2 in April 2008). During 2008 – 2016, regular analysis of soil, spruce needles, soil microbiology, assessment of tree crown vitality, stand productivity, inventory of vascular plant and moss species were done. The results showed that the fert ilization with PMS resulted in a significantly improved K, Ca, Zn, and N status of trees, crown vitality and up to three times increased tree growth parameters at both experiments during the study period. The average count of bacteria and fungi in soil of fertilized plots, accompanied by a remarkable variability in the study years, was significantly higher only for the 1 st experiment. Fungi : bacteria ratio for the fertilized and control plots differed significantly only for the 1 st experiment. Significant i ncrease of cover with nitrophilic plant ( Urtica dioica, Antriscus sylvestris, Rubus idaeus ) and moss ( Plagiomnium cuspidatum , P. ellipticum ) species at both fertilized sites were stated

Effect of zeolite, clay and peat on salt stress tolerance of lettuce (Lactuca sativa L.)

Received: January 31st, 2024 ; Accepted: April 14th, 2025 ; Published: April 16th, 2025 ; Correspondence: [email protected] present study aimed to investigate the effects of natural zeolite, clay and peat amendments on the growth and NaCl absorptions of lettuce (Lactuca sativa L.) under gradually increasing salinity. Four different growing media based on quartz sands with 10% additions of zeolite, clay and peat were tested. The worst effect of NaCl on plant biomass was evident at the highest salinity levels for zeolite applications. While adverse salinity impact on leaf and root biomass was least pronounced in treatments with peat additives. As expected, the lowest Na concentrations in plant tissues were found in the growing media supplemented with zeolite. In the case of Cl, however, it was the opposite - lettuce leaves accumulated significantly higher chloride concentrations in the zeolite variants in salinity treatments above 20 mM NaCl. In the control, clay and peat treatments, as the substrate salinity increased, the Cl level in the plant increased similarly. Adverse changes in leaf chlorophyll concentration (SPAD) and photosynthetic rate (µmol m-2 s-1) parameter appeared under salinity concentrations above 20 mM and were more pronounced in zeolite and sand substrate. According to the obtained results, peat additives can effectively mitigate the harmful effects of excessive salts by binding and immobilizing them as well as improving the water-holding capacity and nutrient availability. The study also concluded that natural zeolite successfully immobilizes cationic sodium, but the harmful effect of chlorine significantly reduced plant growth and photosynthetic performance. Clay additives to the growth medium showed the potential to reduce the adverse effects of salinity on lettuce, however, under the experimental conditions implemented, the effect was small

Effect of shade treatment on the growth and vitality of cloudberry Rubus chamaemorus

Received: February 20th, 2025 ; Accepted: May 27th, 2025 ; Published: June 19th, 2025 ; Correspondence: [email protected] Rubus chamaemorus is a promising new berry species for cultivation in Latvia. This study aimed to assess how different shade levels influence cloudberry growth and vitality in semi-controlled conditions. Cloudberries (variety ‘Nyby’) were planted in enclosed planting area and grown under four shading treatments, using shading nets: control (no shade), 30%, 50%, and 80% shade for two years. Non-destructive SPAD measurements were taken weekly during the growing season (from May to August) in both years. Leaf size was measured at the end of August in both years, while leaf density and leaf nutrient concentrations were determined at the end of August in 2024. The results revealed significant differences between treatments for all of the measurements, with the highest values observed in plants under the 80% shade in both years. In the second year, the 50% an 80% shade treatments had similar results. Overall, the highest plant vitality was observed under 50% and 80% shade, demonstrating that netting effectively protects cloudberries from excessive sunlight. While larger leaves might improve light capture, they also require additional energy, potentially reducing resources available for fruit production. Thus, we suggest the 50% shade to be the most effective for cloudberries in the Latvian climate, as it balances protection with optimal energy conservation. Additionally, optimal fertilizing in the field could improve plant health and yield, therefore further studies regarding the combined effects of shade and fertilization on cloudberry production are required