Thinning as Method to Regulate Sweet Cherry Crops – a Review

In perennial fruit crops, bearing can be influenced by various factors, including environmental conditions, germplasm, rootstocks, and cultivation methods. Cherries, one of the most important and popular fruit species from the temperate climate zone, achieve high prices on the market. New agricultural technologies and environmental factors force a change in the approach to cherry cultivation. Old-type cherry orchards with their high demand for water, nutrients and manual work are replaced by orchards of self-pollinating cherry cultivars grown on dwarf rootstocks. These changes make it necessary to search for ways to regulate fruiting, in particular to thin buds, flower and fruit. In view of environmental regulations and consumer pressure, thinning methods are being sought that either do not involve the use of chemicals or that use eco-friendly chemical agents. This review examines recent progress in understanding the effect of thinning methods on the physiology, tree growth and fruit quality of cherries, discusses horticultural practices aimed to ensure regular cropping and their influence on fruit quality, and provides suggestions for future research.

Mobile Host mRNAs Are Translated to Protein in the Associated Parasitic Plant Cuscuta campestris

Cuscuta spp. are obligate parasites that connect to host vascular tissue using a haustorium. In addition to water, nutrients, and metabolites, a large number of mRNAs are bidirectionally exchanged between Cuscuta spp. and their hosts. This trans-specific movement of mRNAs raises questions about whether these molecules function in the recipient species. To address the possibility that mobile mRNAs are ultimately translated, we built upon recent studies that demonstrate a role for transfer RNA (tRNA)-like structures (TLSs) in enhancing mRNA systemic movement. C. campestris was grown on Arabidopsis that expressed a β-glucuronidase (GUS) reporter transgene either alone or in GUS-tRNA fusions. Histochemical staining revealed localization in tissue of C. campestris grown on Arabidopsis with GUS-tRNA fusions, but not in C. campestris grown on Arabidopsis with GUS alone. This corresponded with detection of GUS transcripts in Cuscuta on Arabidopsis with GUS-tRNA, but not in C. campestris on Arabidopsis with GUS alone. Similar results were obtained with Arabidopsis host plants expressing the same constructs containing an endoplasmic reticulum localization signal. In C. campestris, GUS activity was localized in the companion cells or phloem parenchyma cells adjacent to sieve tubes. We conclude that host-derived GUS mRNAs are translated in C. campestris and that the TLS fusion enhances RNA mobility in the host-parasite interactions.

IMPROVEMENT OF HYDROPON INSTALLATIONS

Hydroponics is a promising area of development of modern agriculture, which provides long-term cultivation of basic vegetables and greenery in small areas with minimal consumption of water and fertilizers. This technology allows you to get a fairly large harvest of fresh vegetables within large cities, including office and residential premises. Entrepreneurs and researchers are paying close attention to developing more efficient hydroponics methods and equipment to implement them in order to reduce usable space, save water, nutrients and increase air supply and plant capacity. Several hydroponics systems are known: static solution culture, continuous flow solution (NFT) culture, deep water culture, passive irrigation, underwater and drainage irrigation systems, wastewater drainage system, deep-water fertilized culture, rotary system, aeroponics, wick system. The first three of the above methods were used commercially and industrially. The system of static culture solution does not provide the necessary saturation of plant roots with air. With the implementation of the method of continuous solution culture, minor buffering is possible due to interruptions in the flow (power outage), flooding of water in some canals, in addition, there are restrictions on the maximum length of canals (12 - 15 m). The system of deep-water culture on an industrial scale is used mainly for growing lettuce. Other mentioned systems are not efficient enough in terms of commercial use. The improved hydroponic installations presented in the article were developed taking into account the following requirements: universality of use (possibility of growing different types of plants); harmonization of optimal supply of crops with water, nutrients, light and air; maximum use of space; increasing the area for each plant and maintaining its stems and shoots. Also in the article the equation for definition of the basic parameters of the developed installations is given.

CNN for Image Processing to Detect Weeds Using IOT

One of the major issues in today’s agriculture fields is detecting weed plants in between the crops. Weeds consume more water, nutrients, and light compared to crop plants. Being hardy and vigorous in growth habits, they grow way to faster than crops and consume a huge amount of water and nutrients, results causing heavy losses in yields, the process of removal of weeds manually is a difficult job and it requires more manpower. To date, weed removal can’t be automated without manpower. Herbicides play a crucial role in removing the weeds but that leads to soil infertile and later the weeds dominate the field automatically. In solution to reduce the weeds is using herbicide in a higher amount than normal day by day. Usage of herbicides in that amount causes the land infertile. This paper deals with detecting the weeds in the crop using a convolutional neural network, Image processing, and IoT. The weeds in the field and between the crops are detected and removed by using the image processing technique. CNN algorithm is implemented in Matlab software to detect the weed areas in the fields. A robot model is connected to the controller through the motor driver which is also used to carry the camera through the field to detect the weed. The videos and images taken by the camera send to the Matlab and they are trained by using the CNN algorithm and that classifies whether it is a weed or a normal crop. And the necessary instructions send to the Arduino through Zigbee. If the camera detects any weed then the cutter is on 10 seconds to cut the weeds. And the robot model moves further until it finds the next weed. Users can also control the robot model whenever itneeds. Keywords: CNN; Weed cutter; Matlab; Zigbee; Image processing.

Nature-Based Units as Building Blocks for Resource Recovery Systems in Cities

Cities are producers of high quantities of secondary liquid and solid streams that are still poorly utilized within urban systems. In order to tackle this issue, there has been an ever-growing push for more efficient resource management and waste prevention in urban areas, following the concept of a circular economy. This review paper provides a characterization of urban solid and liquid resource flows (including water, nutrients, metals, potential energy, and organics), which pass through selected nature-based solutions (NBS) and supporting units (SU), expanding on that characterization through the study of existing cases. In particular, this paper presents the currently implemented NBS units for resource recovery, the applicable solid and liquid urban waste streams and the SU dedicated to increasing the quality and minimizing hazards of specific streams at the source level (e.g., concentrated fertilizers, disinfected recovered products). The recovery efficiency of systems, where NBS and SU are combined, operated at a micro- or meso-scale and applied at technology readiness levels higher than 5, is reviewed. The importance of collection and transport infrastructure, treatment and recovery technology, and (urban) agricultural or urban green reuse on the quantity and quality of input and output materials are discussed, also regarding the current main circularity and application challenges.

Thinning Response and Potential Basal Area—A Case Study in a Mixed Sub-Humid Low-Elevation Oak-Hornbeam Forest

Competition for resources (light, water, nutrients, etc.) limits the size and abundance of live trees a site can support. This carrying capacity determines the potential carbon sequestration in live trees and the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment, and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as a case study. We expected lower increment for heavily thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, in which two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. Over ten years, the heavily thinned stand had a similar increment as that of the moderately thinned and unthinned stands. The basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning, suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands led to a much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.

Salicylic Acid Induced Physiological Responses of Microchaete Sp. NCCU-342 Under PQ Stress

Weeds are the worst category of agricultural pests as they compete with crops for water, nutrients, and light, grow faster than crops and eventually reduces the crop productivity thereby increasing the production cost. Herbicide has been used as a management tool to control weeds, by modifying their physiological activities like reducing photosynthesis, increasing protease activity and free radicals etc. The application of non-selected herbicides kills not only the weeds but also non-target organisms including the main crop. Herbicides like paraquat have been used in rice fields but its toxic effects on other organisms is at par. Salicylic acid, a plant growth regulator, is known to regulate oxidative stress in plants subjected to unfavourable environmental conditions. Given this, the present study was designed to study the effect of salicylic acid in Microchaete sp. NCCU-342 exposed to paraquat. The results obtained demonstrated that the paraquat toxicity elevated MDA and H2O2 levels, indicating free radical formation. However, supplementation of salicylic acid in the culture medium reduced the paraquat toxicity. The content of MDA and H2O2 in presence of salicylic acid was similar to the control. It enhances phenolic compound (29.07%) and phytohormones content (IAA-2.96%, SA-96.59%) and regulate the redox state of the cells. A significant change (recorded in percentage) was observed in the antioxidant enzyme activities including SOD (121.62 %), CAT (30.38 %), APX (74.38 %), GPX (127 %) and GR (141%) in presence of paraquat and after supplementation of salicylic acid. Antioxidant assay confirmed the change in antioxidants in form of phenolic compounds. Salicylic acid supplementation also enhanced the antibacterial activity of cyanobacteria, highlighting that it induces resistance against biotic stress as well as the abiotic stress. This work provides evidence for the ability of salicylic acid to alleviate the paraquat-induced toxicity, maintain redox state and resist the cell against both biotic and abiotic stress.

Tools for Edible Cities: A Review of Tools for Planning and Assessing Edible Nature-Based Solutions

In the last five years, European research and innovation programmes have prioritised the development of online catalogues and tools (handbooks, models, etc.) to facilitate the implementation and monitoring of Nature-Based Solutions (NBS). However, only a few catalogues and toolkits within European programmes are directly related to mainstreaming of NBS for food production (i.e., edible NBS). Therefore, the main aim of this paper is to present existing NBS tools through the eyes of productive urban landscapes. We reviewed 32 projects related to NBS and 50 tools were identified and characterised. Then, the six tools already available and provided indicators were further analysed in terms of their format and knowledge domains. Our main conclusion demonstrates that there is a lack of tools capable of supporting users for planning and implementing edible NBS; calculating the food potential of a city and/or of individual edible NBS, including the needed resources for implementation and operation (water, nutrients, energy); and assessing their urban design value, environmental and socio-economic impacts. Moreover, when they do exist, there is a resistance to share the models and equations behind the tools to allow other projects to reuse or validate them, a fact which is contrary to the open science principles upheld by many public research agencies.

Systemic regulation of nitrogen acquisition and use in Oryza longistaminata ramets under nitrogen heterogeneity

Oryza longistaminata, a wild rice, vegetatively reproduces and forms a networked clonal colony consisting of ramets connected by rhizomes. Although water, nutrients, and other molecules can be transferred between ramets via the rhizomes, inter-ramet communication in response to spatially heterogeneous nitrogen availability is not well understood. We studied the response of ramet pairs to heterogeneous nitrogen availability by using a split hydroponic system that allowed each ramet root to be exposed to different conditions. Ammonium uptake was compensatively enhanced in the sufficient-side root when roots of the ramet pairs were exposed to ammonium-sufficient and deficient conditions. Comparative transcriptome analysis revealed that a gene regulatory network for effective ammonium assimilation and amino acid biosynthesis was activated in the sufficient-side roots. Allocation of absorbed nitrogen from the nitrogen-sufficient to the deficient ramets was rather limited. Nitrogen was preferentially used for newly growing axillary buds on the sufficient-side ramets. Biosynthesis of trans-zeatin, a cytokinin, was up-regulated in response to the nitrogen supply, but trans-zeatin appears not to target the compensatory regulation. Our results also implied that the O. longistaminata ortholog of OsCEP1 plays a role as a nitrogen-deficient signal in inter-ramet communication, providing compensatory up-regulation of nitrogen assimilatory genes. These results provide insights into the molecular basis for efficient growth strategies of asexually proliferating plants growing in areas where nitrogen distribution is spatially heterogeneous.