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

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

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