13 research outputs found

    Comparison of vapour pressure deficit patterns during cucumber cultivation in a traditional high PE tunnel greenhouse and a tunnel greenhouse equipped with a heat accumulator

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    Plant productivity in protected cultivation is highly influenced by air temperature and humidity. The conditions relating to the moisture content of the air in protected plant cultivation are preferably defined by vapour pressure deficit (VPD), which describes the difference between the maximal and actual water vapour pressure (kPa). VPD is widely used as the parameter describing the climate conditions favourable for the development of fungal diseases and for highlighting conditions unfavourable for plant development. In protected cultivation, both the air temperature and the humidity are influenced by heating systems, and one such system is a heat accumulator, which may store the excessive heat produced during the day by converting the solar energy inside the plastic tunnel, and using it when plant heating is required. The tunnel equipped with a heat accumulator maintained an optimal level of humidity for a longer period, and significantly reduced the time of excessive air humidity. The longest time with an optimal VPD was recorded in August in a tunnel with an accumulator – 30.5% of total time vs. 22.3% of time for control tunnel. The highest difference of total time where the VPD was too low (below 0.2 kPa) was recorded in July – 12.4% of time in a tunnel with an accumulator vs. 39.1% of time for control tunnel. The highest difference of total time with an excessive VPD (over 1.4 kPa) was recorded in May – 12.1% of time in a tunnel with an accumulator vs. 17.9% of time for control tunnel. However, a situation beneficial for plant growth occurred every month during the investigated season

    Morphological and Physiological Responses of Strawberry Plants to Water Stress

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    The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’) under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Water stress was imposed by reducing the irrigation according to substratum moisture readings. Water stressed plants had the lowest values of water potential and showed strong decrease in gas exchange rate. Also, biomass and leaf area were the lowest in this group of plants. No differences in the length of root system were observed between control and water stressed plants. The lack of water in growing medium resulted also in a decrease of density and reduction of dimensions of stomata on plant leaves. These changes contribute to optimizing the use of assimilates and water use efficiency in periods when water availability is decreased

    Morphological and Physiological Responses of Strawberry Plants to Water Stress

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    The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’) under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Water stress was imposed by reducing the irrigation according to substratum moisture readings. Water stressed plants had the lowest values of water potential and showed strong decrease in gas exchange rate. Also, biomass and leaf area were the lowest in this group of plants. No differences in the length of root system were observed between control and water stressed plants. The lack of water in growing medium resulted also in a decrease of density and reduction of dimensions of stomata on plant leaves. These changes contribute to optimizing the use of assimilates and water use efficiency in periods when water availability is decreased

    Comparison of vapour pressure deficit patterns during cucumber cultivation in a traditional high PE tunnel greenhouse and a tunnel greenhouse equipped with a heat accumulator

    No full text
    Plant productivity in protected cultivation is highly influenced by air temperature and humidity. The conditions relating to the moisture content of the air in protected plant cultivation are preferably defined by vapour pressure deficit (VPD), which describes the difference between the maximal and actual water vapour pressure (kPa). VPD is widely used as the parameter describing the climate conditions favourable for the development of fungal diseases and for highlighting conditions unfavourable for plant development. In protected cultivation, both the air temperature and the humidity are influenced by heating systems, and one such system is a heat accumulator, which may store the excessive heat produced during the day by converting the solar energy inside the plastic tunnel, and using it when plant heating is required. The tunnel equipped with a heat accumulator maintained an optimal level of humidity for a longer period, and significantly reduced the time of excessive air humidity. The longest time with an optimal VPD was recorded in August in a tunnel with an accumulator – 30.5% of total time vs. 22.3% of time for control tunnel. The highest difference of total time where the VPD was too low (below 0.2 kPa) was recorded in July – 12.4% of time in a tunnel with an accumulator vs. 39.1% of time for control tunnel. The highest difference of total time with an excessive VPD (over 1.4 kPa) was recorded in May – 12.1% of time in a tunnel with an accumulator vs. 17.9% of time for control tunnel. However, a situation beneficial for plant growth occurred every month during the investigated season

    The influence of irrigation on growth and yield of plum trees cv. Valor grafted on Myrobalan and Wangenheim Prune

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    The climate of Poland is characterized by a high variability, especially regarding the sum of precipitation and its distribution in the season. Dry years occur periodically. Repeated negative climatic water balance for vegetative season is insufficient for proper growth and development of plants. In this experiment we studied the effectiveness of drip irrigation in plum tree cultivation. The study was carried out since 1990 to 1998 in the orchard of the Institute of Pomology and Floriculture in Skiemiewice. Trees of plum cv. Valor, grafted on Myrobalan and Wangenheim Prune seedlings were planted in the spring 1990 at a distance 4,2 m x 2,9 m. Influence of drip irrigation on trees growth changes, yield and fruit quality depended on weather conditions in the individual years. Generally, drip irrigation significantly increased the tree growth, yield and fruit quality. Higher positive effect of irrigation was obtained for plums grafted on Wangenheim Prune seedlings than on Myrobalan seedlings. Drought conditions clearly decreases the average weight of the fruit of the trees grafted on Wangenheim Prune. The rootstocks had no effect on fruit size

    Assessment of rainfall efficiency in an apple orchard

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    Atmospheric precipitation is the major input to the soil water balance. Its amount, intensity, and temporal distribution have an indubitable influence on soil moisture. The aim of the study (conducted in the years 2010-2013) was to evaluate soil water balance in an apple orchard as determined by daily rainfall. The amount and intensity of rainfall and daily evapotranspiration were measured using an automatic weather station. Changes in soil water content was carried out using capacitance probes placed at a depth of 20, 40 and 60 cm. The most common were single events of rainfall of up to 0.2 mm, while 1.3-3.6 mm rains delivered the greatest amount of water. A significant correlation was found between the amount of daily rainfall and changes in water content of individual soil layers. The 15-45 cm and 15-65 cm layers accumulated the greatest amount of high rainfall. The study showed a significant influence of the initial soil moisture on changes in the water content of the analysed layers of the soil profile. The lower its initial moisture content was, the more rainwater it was able to accumulate

    Evaluating the suitability of a new telemetric capacitance-based measurement system for real-time application in irrigation and fertilization management

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    The suitability of a new wireless smart farming system for controlling irrigation and fertilization of horticultural plants was assessed in the study. The system (name: AGREUS® ) includes sensors (soil moisture, salinity, weather data), executive modules (valve modules), and an application available on the web portal (accessed through computers and mobile devices). The studies were performed under laboratory and field conditions. Laboratory tests included appraisal of the precision of soil moisture and salinity measurements carried out with the soil probe (comparison with the results obtained by laboratory methods). Operational tests were conducted in field trials. In these trials, assessment of the possibility of practical control of irrigation and monitoring soil salinity was performed in an apple orchard. The conducted analyses have shown the usefulness of the system, not only for automatic control of irrigation but also for making decisions about the necessity to fertilize plants. The system enables continuous monitoring of changes in soil moisture and salinity, including the migration of minerals across the soil profile (using a probe with several measuring elements) as a result of the applied irrigation or rainfall. The system allows for automatic application of irrigation or fertigation depending on the adopted soil moisture and salinity thresholds. However, the tests showed that a salinity index calculated by the system does not directly correspond to the salinity values determined by laboratory methods. For this reason individual interpretation and determination of optimal ranges for plants is required

    The impact of phytosanitary treatments in the soil with signs of fatigue on the growth of apple seedlings and populations of bacteria and fungi

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    The object of research was the soil from an orchard after 27 years of apple cultivation, showing signs of fatigue re-sulting in weaker growth of apple seedlings planted into it, and the soil sampled on the same farm, but not used for growing fruit trees. The physicochemical properties of both soils did not differ significantly. In sick soil, no pathogens of fungal or fungi-like origin were found, and the number of nematodes was below the threshold of economic threat. There is a suspicion that abiotic fac-tors could be responsible for soil fatigue. It has been demonstra-ted that the cultivation of spring and winter wheat, triticale and white mustard before planting apple ‘Antonovka’ seedlings, had a positive impact on their growth. The best effect was obtained after the cultivation of white mustard or after the introduction of mustard seed meal into the soil, which was also confirmed by measurements of the intensity of apple seedlings photosynthesis. The cultivation of these phytosanitary plants or the addition of mustard seed meal positively influenced the biological potential of the soil expressed by a significant increase in the population of bacteria from the genera Pseudomonas and Bacillus. There was also a very large increase in the number of Trichoderma spp. fun-gi after the addition of mustard seed meal into the soil and winter wheat cultivation

    Salt stress vs. salt shock - the case of sugar beet and its halophytic ancestor

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    Abstract Background Sugar beet is a highly salt-tolerant crop. However, its ability to withstand high salinity is reduced compared to sea beet, a wild ancestor of all beet crops. The aim of this study was to investigate transcriptional patterns associated with physiological, cytological and biochemical mechanisms involved in salt response in these closely related subspecies. Salt acclimation strategies were assessed in plants subjected to either gradually increasing salt levels (salt-stress) or in excised leaves, exposed instantly to salinity (salt-shock). Result The majority of DEGs was down-regulated under stress, which may lead to certain aspects of metabolism being reduced in this treatment, as exemplified by lowered transpiration and photosynthesis. This effect was more pronounced in sugar beet. Additionally, sugar beet, but not sea beet, growth was restricted. Silencing of genes encoding numerous transcription factors and signaling proteins was observed, concomitantly with the up-regulation of lipid transfer protein-encoding genes and those coding for NRTs. Bark storage protein genes were up-regulated in sugar beet to the level observed in unstressed sea beet. Osmotic adjustment, manifested by increased water and proline content, occurred in salt-shocked leaves of both genotypes, due to the concerted activation of genes encoding aquaporins, ion channels and osmoprotectants synthesizing enzymes. bHLH137 was the only TF-encoding gene induced by salt in a dose-dependent manner irrespective of the mode of salt treatment. Moreover, the incidence of bHLH-binding motives in promoter regions of salinity-regulated genes was significantly greater than in non-regulated ones. Conclusions Maintaining homeostasis under salt stress requires deeper transcriptomic changes in the sugar beet than in the sea beet. In both genotypes salt shock elicits greater transcriptomic changes than stress and it results in greater number of up-regulated genes compared to the latter. NRTs and bark storage protein may play a yet undefined role in salt stress-acclimation in beet. bHLH is a putative regulator of salt response in beet leaves and a promising candidate for further studies

    The influence of biofertilization on the vegetative growth, yielding and nutritional status of 'Sampion' apple trees in first years after planting

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    The effects of biofertilizers on the growth, yielding, and nutritional status of apple trees (in comparison with the standard mineral fertilization) was evaluated in 3-years experiment (2018-2020). The experiment included the following treatments: (i) Super Fos Dar, (ii) Polifoska 6, (iii) Super Fos Dar + fungi (Aspergillus niger, Purpureocillium lilacinum), (iv) Urea enriched with fungi, (v) Urea dose reduced to 60% enriched with fungi, (vi) Super Fos Dar + bacteria applied on their own to the soil (Bacillus sp., Bacillus amyloliquefaciens, Paenibacillus polymyxa), (vii) Super Fos Dar enriched with bacteria, (viii) Super Fos Dar 60% enriched with bacteria, (ix) Polifoska 6 enriched with bacteria, (x) Polifoska 6 60% enriched with bacteria. The application of mineral fertilizers (even in reduced doses) enriched with beneficial microorganisms enhanced the growth of apple trees. The most abundant flowering was recorded when fertilization (with Super Fos Dar) was supplemented with beneficial microorganisms applied to the soil. No significant differences in plant yielding were noted (due to damages caused by spring frosts), but the highest fruit weight was recorded in the case of the trees fertilized with microbiologically enriched Super Fos Dar
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