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

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

The spread, intensity and invasiveness of the Acer negundo in Riga and Kaunas

Ashleaf Maple (Acer negundo L.) was first introduced in Latvia and Lithuania at the beginning of the 19th century. It is the most widely distributed alien maple species to be found in the parks and greeneries of Riga and Kaunas. In recent decades, the spread and invasion of this species has been observed. The aim of this research was to determine the extent and effects of the invasiveness A. negundo in Riga and Kaunas. The degree of invasion by this species’ was estimated by applying the Pest Plant Prioritization Process, which is based on the Analytic Hierarchy Process method. The results showed that the invasive degree of box elder was very high (0.788); the present compared to potential distribution rating was medium high (0.71) and the social, environmental and economic impact score was low (0.23). The Final Pest Plant Score for A. negundo was medium (0.4506). The obtained estimates indicated that box elder was invasive and was able to spread rapidly into new riparian areas

Leaf Nutrient Status of Commercially Grown Strawberries in Latvia, 2014–2022: A Possible Yield-Limiting Factor

The present study was carried out to evaluate the leaf nutrient status of commercially grown strawberries in Latvia during 2014–2022. The results of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo and B in 200 strawberry leaf samples from different strawberry-producing farms were analysed over three periods: 2014–2016, 2017–2019, and 2020–2022. According to leaf analyses, plant fertilization was only partly well managed by the growers. During the research period, strawberries in Latvia were generally sufficiently supplied with N, P, K, Mg, Fe, Mn, Mo, and B, while the level of Ca, S, Zn, and Cu was considered low. The deficiency of these nutrients was characteristic for more than 50% of the samples. Since Ca, S, Zn, and Cu are essential for berry formation and quality and contribute to stress resistance; their deficiency could be one of the limiting factors for strawberry yield. The significant positive correlations found between nutrients, including deficient ones, confirmed their close relationship in the uptake process and the importance of sufficient supply. The results clearly indicated that fertilization could currently be an issue that limits the strawberry harvest in Latvia, and adequate provisions of Ca, S, Zn, and B should be the main focus

The spread, intensity and invasiveness of the Acer negundo in Riga and Kaunas

Ashleaf Maple (Acer negundo L.) was first introduced in Latvia and Lithuania at the beginning of the 19th century. It is the most widely distributed alien maple species to be found in the parks and greener¬ies of Riga and Kaunas. In recent decades, the spread and invasion of this species has been observed. The aim of this research was to determine the extent and effects of the invasiveness A. negundo in Riga and Kaunas. The degree of invasion by this species' was estimated by applying the Pest Plant Prioritization Process, which is based on the Analytic Hierarchy Process method. The results showed that the invasive degree of box elder was very high (0.788); the present compared to potential distribution rating was medium high (0.71) and the social, environmental and economic impact score was low (0.23). The Final Pest Plant Score for A. negundo was medium (0.4506). The obtained estimates indicated that box elder was invasive and was able to spread rapidly into new riparian areasVytauto Didžiojo universitetasŽemės ūkio akademij

Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas

In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia andAcer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas.Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of thevascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samplesof the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at ninesystematically distributed points in each sample plot. The soil pHKCL, exchangeable bases, total nitrogen,total organic matter, C/N ratio, and concentrations of the elements (P, K, Ca, Mg, Fe, Mn, Zn, Cu, Na, Pb, Cd,and Ni) were estimated. Canonical correspondence analysis was used to analyse the vegetation data. Anindicator species analysis was carried out. The relationship between the soil chemical parameters wasassessed by principal component analysis, and the results showed that structure and composition of theplant communities of A. negundo and R. pseudoacacia differed. The number of species was lower and theherb layer was more developed in R. pseudoacacia communities, whereas the structure of communitiesdiffered between Riga and Kaunas. The cover of the shrub layer was more developed in Riga. The numberof species in A. negundo communities was similar, whereas the number of species in R. pseudoacaciacommunities was lower in Kaunas. Alien species were more frequent in Riga. Neophyte communitiesin Kaunas were more homogenous. The soil in communities in Riga had more carbon, was richer innutrients and more acidic than in Kaunas. R. pseudoacacia grew in more fertile soils than A. negundocommunities. The differences between the neophyte communities in Riga and Kaunas were caused bydiffering geological parameters, soil development and urbanization effectsUniversity of Latvi

Nutrient characteristics and proline accumulation in relation to Picea abies status on drained peat soils

Monocultures of Norway spruce widely used for afforestation of drained peat soils often have low productivity and decline in vitality. The research aim was to elucidate: (1) imbalances in the nutrient status of soil and plants in relation to Norway spruce crown status and annual increment on drained peat soil in the sub-boreal zone; (2) the suitability of using proline accumulation as a biomarker for Norway spruce vitality and stress in nutrient imbalance conditions. The study was conducted at five forest (Oxalidosa turf. mel.) sites in Latvia, each containing trees with different crown condition status. Chemical analyses of soil and spruce needles, assessment of tree crown vitality and annual increment measurements were done. Our results revealed serious disturbances in the supply of nutrients, which is an important factor in the decline of Norway spruce in monoculture stands on drained peat soils. Deficiency of K, Fe, Cu, B, N and P was found in the current year needles for all trees, but in damaged trees (≥61% defoliation, ≥61% discoloration) Zn deficiency was also found. For 2-year-old needles, deficiency of K, P, S, Zn, and Cu was found in all trees, additionally, deficiency of Fe was found in healthy and medium damaged trees (26–60% defoliation, 21–60% discoloration), and N deficiency was found for medium damaged and damaged trees. Thus, K, Cu, B, Fe concentrations had significant negative correlations with crown status parameters – defoliation, discoloration, and density. K and B deficiency could play the most significant causal role in decreased stem increment. The results revealed that the stress amino-acid proline is a reliable biomarker, having a significant relationship with spruce crown condition parameters, annual increment and nutrient status in needles – low levels of K, Fe, S, Cu, B, N. The increase in proline content in spruce needles was pronounced in moderately damaged trees, indicating the potential for the use of proline accumulation as early stress indicator for spruce. Therefore, further studies on the identification of early stress and factors affecting nutrient uptake and accumulation in needles are particularly valuable for evaluation of stand management options before significant decline of spruce stands

Pest plant score of alien Robinia pseudoacacia in Riga (Latvia) and Kaunas (Lithuania)

Robinia pseudoacacia is an alien tree species that has wide distribution in green areas of Rîga and Kaunas. In recent years, the spread and invasion of this species was observed. The aim of this study was to determine the relative importance of invasiveness of R. pseudoacacia in Rîga and Kaunas. The degree of species invasion was estimated by applying the Pest Plant Prioritization Process, which is based on the Analytic Hierarchy Process method. The results showed that the invasive degree of R. pseudoacacia was near medium (0.4); the present compared to potential distribution rating was medium (0.57) and the social, environmental and economic impact score was very low (0.17). The Final Pest Plant Score for R. pseudoacacia was near medium (0.426). The obtained estimates indicated that black locust was medium invasive, and that well-lit conditions favour its establishmentUniversity of Latvi

Comparison of Robinia pseudoacacia and Acer negundo plant communities in cities of Riga and Kaunas

Vytauto Didžiojo universitetasŽemės ūkio akademij