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A column experiment with five different pore densities (0, 1, 2, 3, and 4 pores column−1) and two varying moisture regimes (comparatively dry and comparatively moist regime) in the subsoil part of the columns was established. In each pore, Lumbricus terrestris was introduced for 28 days before sowing wheat plants. After 40 days of plant growth, watering was stopped to induce progressive topsoil drying. Parameters describing the shoot hydration, mineral uptake, and aboveground biomass were quantified. Root biomass and root length densities (RLD) were measured separately for six soil layers. Under dry subsoil conditions, plants grown under increasing biopore density showed an increase of the RLD and an improved shoot hydration but the aboveground biomass was unaffected. Since RLD but not root biomass was enhanced, it is assumed that roots were able to explore a larger volume of soil with the same amount of root biomass. Thereby, subsoil water likely was used more efficiently leading to an improved hydration. Under moist subsoil conditions, plants grown with increasing biopore density revealed enhanced shoot biomasses and nutrient uptake while the belowground biomass was unaffected. The improved nutrient uptake can be ascribed to, first, the higher subsoil water availability favoring mass flow driven nutrient uptake, and second, to direct and indirect effects of earthworms on the availability of soil nutrients. It is concluded that high biopore abundancies have the potential to improve not only the belowground but also the aboveground biomass. This, however, largely depends on subsoil moisture. [ABSTRACT FROM AUTHOR]

Tissue culture approaches are widely used in crop plants for the purposes of micropropagation, regeneration of plants through organogenesis, obtaining pathogen-free plantlets from meristem culture, and developing genetically modified plants. In this research, we evaluated variables that can influence the success of shoot growth and plantlet production in tissue cultures of drug-type Cannabis sativa L. (marijuana). Various sterilization methods were tested to ensure shoot development from nodal explants by limiting the frequency of contaminating endophytes, which otherwise caused the death of explants. Seven commercially grown tetrahydrocannabinol (THC)-containing cannabis genotypes (strains) showed significant differences in response to shoot growth from meristems and nodal explants on Murashige and Skoog (MS) medium containing thidiazuron (1 μM) and naphthaleneacetic acid (0.5 μM) plus 1% activated charcoal. The effect of Driver and Kuniyuki Walnut (DKW) or MS basal salts in media on shoot length and leaf numbers from nodal explants was compared and showed genotype dependency with regard to the growth response. To obtain rooted plantlets, shoots from meristems and nodal explants of genotype Moby Dick were evaluated for rooting, following the addition of sodium metasilicate, silver nitrate, indole-3-butyric acid (IBA), kinetin, or 2,4-D. Sodium metasilicate improved the visual appearance of the foliage and improved the rate of rooting. Silver nitrate also promoted rooting. Following acclimatization, plantlet survival in hydroponic culture, peat plugs, and rockwool substrate was 57, 76, and 83%, respectively. The development of plantlets from meristems is described for the first time in C. sativa and has potential for obtaining pathogen-free plants. The callogenesis response of leaf explants of 11 genotypes on MS medium without activated charcoal was 35% to 100%, depending on the genotype; organogenesis was not observed. The success in recovery of plantlets from meristems and nodal explants is influenced by cannabis genotype, degree of endophytic contamination of the explants, and frequency of rooting. The procedures described here have potential applications for research and commercial utility to obtain plantlets in stage 1 tissue cultures of C. sativa.

Brassinosteroid-insensitive-1 (BRI1) plays important roles in various signalling pathways controlling plant growth and development. However, the regulatory mechanism of BRI1 in brassinosteroid (BR)-mediated signalling for shoot growth and wood formation in woody plants is largely unknown. In this study, PtBRI1.2 , a brassinosteroid-insensitive-1 gene, was overexpressed in poplar. Shoot growth and wood formation of transgenic plants were examined and the regulatory genes involved were verified. PtBRI1.2 was localized to the plasma membrane, with a predominant expression in leaves. Ectopic expression of PtBRI1.2 in Arabidopsis bri1-201 and bri1-5 mutants rescued their retarded-growth phenotype. Overexpression of PtBRI1.2 in poplar promoted shoot growth and wood formation in transgenic plants. Further studies revealed that overexpression of PtBRI1.2 promoted the accumulation of PtBZR1 (BRASSINAZOLE RESISTANT1) in the nucleus, which subsequently activated PtWND s (WOOD-ASSOCIATED NAC DOMAIN transcription factors) to up-regulate expression of secondary cell wall biosynthesis genes involved in wood formation. Our results suggest that PtBRI1.2 plays a crucial role in regulating shoot growth and wood formation by activating BR signalling. [ABSTRACT FROM AUTHOR]

Tissue culture approaches are widely used in crop plants for the purposes of micropropagation, regeneration of plants through organogenesis, obtaining pathogen-free plantlets from meristem culture, and developing genetically modified plants. In this research, we evaluated variables that can influence the success of shoot growth and plantlet production in tissue cultures of drug-type Cannabis sativa L. (marijuana). Various sterilization methods were tested to ensure shoot development from nodal explants by limiting the frequency of contaminating endophytes, which otherwise caused the death of explants. Seven commercially grown tetrahydrocannabinol (THC)-containing cannabis genotypes (strains) showed significant differences in response to shoot growth from meristems and nodal explants on Murashige and Skoog (MS) medium containing thidiazuron (1 μM) and naphthaleneacetic acid (0.5 μM) plus 1% activated charcoal. The effect of Driver and Kuniyuki Walnut (DKW) or MS basal salts in media on shoot length and leaf numbers from nodal explants was compared and showed genotype dependency with regard to the growth response. To obtain rooted plantlets, shoots from meristems and nodal explants of genotype Moby Dick were evaluated for rooting, following the addition of sodium metasilicate, silver nitrate, indole-3-butyric acid (IBA), kinetin, or 2,4-D. Sodium metasilicate improved the visual appearance of the foliage and improved the rate of rooting. Silver nitrate also promoted rooting. Following acclimatization, plantlet survival in hydroponic culture, peat plugs, and rockwool substrate was 57, 76, and 83%, respectively. The development of plantlets from meristems is described for the first time in C. sativa and has potential for obtaining pathogen-free plants. The callogenesis response of leaf explants of 11 genotypes on MS medium without activated charcoal was 35% to 100%, depending on the genotype; organogenesis was not observed. The success in recovery of plantlets from meristems and nodal explants is influenced by cannabis genotype, degree of endophytic contamination of the explants, and frequency of rooting. The procedures described here have potential applications for research and commercial utility to obtain plantlets in stage 1 tissue cultures of C. sativa. [ABSTRACT FROM AUTHOR]

Transcription factors (TFs) such as ethylene-responsive factors (ERFs) are important for regulating plant growth, development, and responses to abiotic stress. Notably, more than half of the rice ERF-X group members, including ethylene-responsive factor 106 (OsERF106), are abiotic stress-responsive genes. However, their regulatory roles in abiotic stress responses remain poorly understood. OsERF106, a salinity-induced gene of unknown function, is annotated differently in RAP-DB and MSU RGAP. In this study, we isolated a novel (i.e., previously unannotated) OsERF106 gene, designated OsERF106MZ (GenBank accession No. MZ561461), and investigated its role in regulating growth and the response to salinity stress in rice. OsERF106MZ is expressed in germinating seeds, primary roots, and developing flowers. Overexpression of OsERF106MZ led to retardation of growth, relatively high levels of both malondialdehyde (MDA) and reactive oxygen species (ROS), reduced catalase (CAT) activity, and overaccumulation of both sodium (Na+) and potassium (K+) ions in transgenic rice shoots. Additionally, the expression of OsHKT1.3 was downregulated in the shoots of transgenic seedlings grown under both normal and NaCl-treated conditions, while the expression of OsAKT1 was upregulated in the same tissues grown under NaCl-treated conditions. Further microarray and qPCR analyses indicated that the expression of several abiotic stress-responsive genes such as OsABI5 and OsSRO1c was also altered in the shoots of transgenic rice grown under either normal or NaCl-treated conditions. The novel transcription factor OsERF106MZ negatively regulates shoot growth and salinity tolerance in rice through the disruption of ion homeostasis and modulation of stress-responsive gene expression. [ABSTRACT FROM AUTHOR]

(1) Background: Cold-hardy interspecific hybrid grapes (CIHG) are well adapted to the Annapolis Valley edaphoclimatic conditions. The main characteristics of CIHG are the high bud hardiness tolerance to winter frost, the short growing cycle, and the good tolerance to cryptogamic diseases. Based on local experience, the Vitis vinifera varieties should be grown in the warmest areas of the Annapolis Valley (Nova Scotia, Canada). Despite this, there is little scientific evidence that shows the viticultural behavior of these varieties under the edaphoclimatic conditions of this valley. (2) Methods: Thus, the aim of this research was to evaluate the viticultural behavior of two CIHG (L’Acadie and New York Muscat) and three V. vinifera varieties (Chardonnay, Riesling, and Pinot Noir) growing in the Annapolis Valley over three consecutive seasons. (3) Results: The coldest season (2019) produced a delay in grapevine phenology of at least 18 days for budburst compared to the warm seasons (2017 and 2018). In addition, in the coldest season from budburst to bloom the duration decreased compared to the rest of the seasons. The main phenological stages started earlier in L’Acadie than in the V. vinifera varieties. L’Acadie presented lower N petiole content than the V. vinifera varieties, which conditioned shoot growth in the studied seasons. CIHG presented low B petiole levels and produced musts with low malic acid content, while V. vinifera varieties produced musts with high N content. L’Acadie was the only variety that could bud out, and differentially produced fruit after the spring frost of −2 to −3 °C for 2 h in 2018 in this trial. (4) Conclusions: L’Acadie, and to a lesser extent, Riesling, hold an interesting adaptation to the edaphoclimatic conditions of the Annapolis Valley [ABSTRACT FROM AUTHOR]

Copyright of Atatürk University Journal of Agricultural Faculty is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Time of planting is a normal part of any agricultural operation. It has a particularly importance in water-challenged areas where soil moisture is an issue. During the winter months in these areas, there is usually sufficient precipitation to maintain adequate water content levels in freshly planted trees. However, during the summer and early autumn, there is very little precipitation. This can adversely affect young trees. In this study, measurements were taken to determine root growth and variations in the upper parts of apple trees that were planted in the winter, compared to those planted in the spring when planting usually takes place. To do so, one-year-old 'Miyabi Fuji', grafted onto Marubakaido (Ma) (Malus prunifolia 'Ringo') and M.9 rootstocks, were examined from January through May. The results showed dramatic changes in root growth from March (average root length less than two cm before March) to May (average root length longer than 10 cm) for both rootstocks. Furthermore, trunk moisture content increased over time (51.8% in January and 56.1% in May on M.9). Although root growth in the young apple trees occurred, it is unknown if root water absorption began before or at the same time of the root growth. Root growth developed favorably because of the soil moisture generated by the winter precipitation. We found satisfactory root growth and tree moisture content changes in the trees used in the study, leading us to recommend winter planting in areas where water resources are limited in the non-winter months. [ABSTRACT FROM AUTHOR]

Background and aimsShoot characteristics differ depending on the meristem tissue that they originate from and environmental conditions during their development. This study focused on the effects of plant water status on axillary meristem fate and flowering patterns along proleptic and epicormic shoots, as well as on shoot growth rates on 'Nonpareil' almond trees (Prunus dulcis). The aims were (1) to characterize the structural differences between proleptic and epicormic shoots, (2) to determine whether water deficits modify shoot structures differently depending on shoot type, and (3) to determine whether shoot structures are related to shoot growth rates.MethodsA hidden semi-Markov model of the axillary meristem fate and number of flower buds per node was built for two shoot types growing on trees exposed to three plant water status treatments. The models segmented observed shoots into successive homogeneous zones, which were compared between treatments. Shoot growth rates were calculated from shoot extension measurements made during the growing season.Key resultsProleptic shoots had seven successive homogeneous zones while epicormic shoots had five zones. Shoot structures were associated with changes in growth rate over the season. Water deficit (1) affected the occurrence and lengths of the first zones of proleptic shoots, but only the occurrence of the third zone was reduced in epicormic shoots; (2) had a minor effect on zone flowering patterns and did not modify shoot or zone composition of axillary meristem fates; and (3) reduced growth rates, although patterns over the season were similar among treatments.ConclusionsTwo meristem types, with different latency durations, produced shoots with different growth rates and distinct structures. Differences between shoot type structure responses to water deficit appeared to reflect their ontogenetic characteristics and/or resource availability for their development. Tree water deficit appeared to stimulate a more rapid progression through ontogenetic states.

Water is essential for crops and plays a vital role in olive (Olea europaea) growth. Three irrigation treatments, rain-fed (CK), flood irrigation (FI), and drip irrigation (DI), were applied from late November to late May in a 2-year study (Nov. 2015 to Oct. 2017) on two olive cultivars, Coratina and Koroneiki. Shoot growth, flower and fruit characteristics, and olive and oil yields were measured. Compared with CK, FI had significantly higher values of vegetative growth, olive and oil yields, moisture content, and oil content. Although the fruit weight, pulp rate, and oil content with DI were the lowest, our results support that DI had the greatest positive effects on olive vegetative growth, flowers, fruit set, and olive and oil yields. It is suggested that DI in winter and spring is the best irrigation strategy for olive productivity in southwest China.

Tomato INDOLE-3-ACETIC ACID9 (SlIAA9) is a transcriptional repressor in auxin signal transduction, and SlIAA9 knockout tomato plants develop parthenocarpic fruits without fertilization. We generated sliaa9 mutants with parthenocarpy in several commercial tomato cultivars (Moneymaker, Rio Grande, and Ailsa Craig) using CRISPR-Cas9, and null-segregant lines in the T1 generation were isolated by self-pollination, which was confirmed by PCR and Southern blot analysis. We then estimated shoot growth phenotypes of the mutant plants under different light (low and normal) conditions. The shoot length of sliaa9 plants in Moneymaker and Rio Grande was smaller than those of wild-type cultivars in low light conditions, whereas there was not clear difference between the mutant of Ailsa Craig and the wild-type under both light conditions. Furthermore, young seedlings in Rio Grande exhibited shade avoidance response in hypocotyl growth, in which the hypocotyl lengths were increased in low light conditions, and sliaa9 mutant seedlings of Ailsa Craig exhibited enhanced responses in this phenotype. Fruit production and growth rates were similar among the sliaa9 mutant tomato cultivars. These results suggest that control mechanisms involved in the interaction of AUX/IAA9 and lights condition in elongation growth differ among commercial tomato cultivars.

As a new specialty crop with high market value, microgreens are vegetable or herb seedlings consumed at a young age, 7–21 days after germination. They are known as functional food with high concentrations of mineral nutrients and health beneficial phytochemicals. Microgreen industry lacks standardized recommendations on cultural practices including species/variety selection, substrate choice, and fertilization management. This study evaluated shoot growth and mineral nutrient concentrations in five microgreens including four Brassica and one Raphanus microgreens as affected by four hydroponic pad types and post-emergent fertilization in two experiments in January and February 2020. The five microgreens varied in their shoot height, fresh, dry shoot weights, and mineral nutrient concentrations with radish producing the highest fresh and dry shoot weights. Radish had the highest nitrogen (N) concentration and mustard had the highest phosphorus (P) concentrations when grown with three hydroponic pads except for hemp mat. Hydroponic pad type altered fresh, dry shoot weights, and mineral nutrients in tested microgreens. Microgreens in hemp mat showed the highest shoot height, fresh, dry shoot weights, and potassium (K) concentration, but the lowest N concentration in one or two experiments. One time post-emergent fertilization generally increased shoot height, fresh, dry shoot weights, and macronutrient concentrations in microgreens. [ABSTRACT FROM AUTHOR]

Tomato INDOLE-3-ACETIC ACID9 (SlIAA9) is a transcriptional repressor in auxin signal transduction, and SlIAA9 knockout tomato plants develop parthenocarpic fruits without fertilization. We generated sliaa9 mutants with parthenocarpy in several commercial tomato cultivars (Moneymaker, Rio Grande, and Ailsa Craig) using CRISPR-Cas9, and null-segregant lines in the T1 generation were isolated by self-pollination, which was confirmed by PCR and Southern blot analysis. We then estimated shoot growth phenotypes of the mutant plants under different light (low and normal) conditions. The shoot length of sliaa9 plants in Moneymaker and Rio Grande was smaller than those of wild-type cultivars in low light conditions, whereas there was not clear difference between the mutant of Ailsa Craig and the wild-type under both light conditions. Furthermore, young seedlings in Rio Grande exhibited shade avoidance response in hypocotyl growth, in which the hypocotyl lengths were increased in low light conditions, and sliaa9 mutant seedlings of Ailsa Craig exhibited enhanced responses in this phenotype. Fruit production and growth rates were similar among the sliaa9 mutant tomato cultivars. These results suggest that control mechanisms involved in the interaction of AUX/IAA9 and lights condition in elongation growth differ among commercial tomato cultivars. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This investigation was carried out through three successive seasons (2017, 2018, and 2019) on young pomegranate trees of the Wonderful cultivar to study the effect of four different irrigation treatments (100%, 75%, 50%, and 25% of crop evapotranspiration—ETc) on vegetative growth and the water–yield relationship. The study was conducted in Foggia (Apulia region, Southern Italy), an agricultural area characterized by strong wind speeds and scarce water resources. The results showed the effects of the different irrigation levels and seasons on the vegetative growth and fruit yield characteristics. The cumulative trunk diameter, the annual shoot growth, the number of fruits per tree, and the yield decreased from the full water restitution (100% ETc) to the severe water restriction (25% ETc). The weight and the size of fruits decreased significantly with the restriction of water volumes applied to the crop. A linear relationship between water consumption and yield (R = 1.00 in 2018 and 1.21 in 2019; n = 12) was found. The water use efficiency (WUE) gave no statistical differences among irrigation treatments. The yield response factors (Ky: 1.06 in 2018 and 0.99 in 2019) showed the sensitivity of pomegranates to water deficits. [ABSTRACT FROM AUTHOR]

The epidermal cell layer of plants has important functions in regulating plant growth and development. We have studied the impact of an altered epidermal cytokinin metabolism on Arabidopsis shoot development. Increased epidermal cytokinin synthesis or breakdown was achieved through expression of the cytokinin synthesis gene LOG4 and the cytokinin-degrading CKX1 gene, respectively, under the control of the epidermis-specific AtML1 promoter. During vegetative growth, increased epidermal cytokinin production caused an increased size of the shoot apical meristem and promoted earlier flowering. Leaves became larger and the shoots showed an earlier juvenile-to-adult transition. An increased cytokinin breakdown had the opposite effect on these phenotypic traits indicating that epidermal cytokinin metabolism can be a factor regulating these aspects of shoot development. The phenotypic consequences of abbreviated cytokinin signaling in the epidermis achieved through expression of the ARR1-SRDX repressor were generally milder or even absent indicating that the epidermal cytokinin acts, at least in part, cell non-autonomously. Enhanced epidermal cytokinin synthesis delayed cell differentiation during leaf development leading to an increased cell proliferation and leaf growth. Genetic analysis showed that this cytokinin activity was mediated mainly by the AHK3 receptor and the transcription factor ARR1. We also demonstrate that epidermal cytokinin promotes leaf growth in a largely cell-autonomous fashion. Increased cytokinin synthesis in the outer layer of reproductive tissues and in the placenta enhanced ovule formation by the placenta and caused the formation of larger siliques. This led to a higher number of seeds in larger pods resulting in an increased seed yield per plant. Collectively, the results provide evidence that the cytokinin metabolism in the epidermis is a relevant parameter determining vegetative and reproductive plant growth and development.

This study investiges the rooting ability and the growth performance of lower and upper shoot positions and type of the cuttings, i.e. soft and hard wood and leafy and non leafy, of Tecoma stans (L.) Kunth. The cuttings were collected from 4-year old plants growing in the Chauras Campus of H.N.B. Garhwal University Srinagar Garhwal, Uttarakhand, India. The rooting ability of cuttings was studied under the treatments of indole-3-butyric acid (IBA) and Indole 3-acidic acid (IAA) under 0.0%, 0.3%, 0.4%, 0.5% concentration in both hormones. The rooting response was significantly (p < 0.05) better in 0.4% IBA compared to other treatments and control (0% IBA and IAA). The ratio of number of roots to rooted cuttings and length of root to rooted cuttings in the different treatments showed significant differences (p < 0.05). The rooted cuttings were further transferred, into the polythene bags and shifted to open nursery conditions. Under such conditions, the rooted cuttings treated with 0.4% and 0.5% IBA demonstrated the highest (90% to 100%) survival capacity in the lower portion soft wood and leafy stem cuttings. Plantable plant and plant height was greater in the 0.4% IBA concentration treatment. The results of the study suggest that rooting of soft wood stem cuttings having lower position and leaves could be an effective mean of regenerating to T. stans. Furthermore, the application of 0.4% IBA concentration treatment is appropriate for rooting of juvenile leafy stem cuttings in a mist chamber.

Although boron (B) is an element that has long been assumed to be an essential plant micronutrient, this assumption has been recently questioned. Cumulative evidence has demonstrated that the players associated with B uptake and translocation by plant roots include a sophisticated set of proteins used to cope with B levels in the soil solution. Here, we summarize compelling evidence supporting the essential role of B in mediating plant developmental programs. Overall, most plant species studied to date have exhibited specific B transporters with tight genetic coordination in response to B levels in the soil. These transporters can uptake B from the soil, which is a highly uncommon occurrence for toxic elements. Moreover, the current tools available to determine B levels cannot precisely determine B translocation dynamics. We posit that B plays a key role in plant metabolic activities. Its importance in the regulation of development of the root and shoot meristem is associated with plant developmental phase transitions, which are crucial processes in the completion of their life cycle. We provide further evidence that plants need to acquire sufficient amounts of B while protecting themselves from its toxic effects. Thus, the development of in vitro and in vivo approaches is required to accurately determine B levels, and subsequently, to define unambiguously the function of B in terrestrial plants.

Catechins are the major compounds in tea (Camellia sinenesis L.) and are responsible for its sensory qualities and health benefits. The study investigated the response of catechins biosynthesis to temperature changes in the controlled conditions and the possible mechanisms. The low-temperature treatment inhibited the growth of young shoots, suppressed the expression of catechins biosynthesis-related genes (except CsCHS3, CsDFR2, CsLAR2), and decreased the content of total esterified catechins but increased the content of total non-esterified catechins in tea plants. When the temperature increased from 15°C to 30°C, the young shoots grew faster, and the contents of total catechins, total esterified catechins and epigallocatechin gallate in tea plants increased by 87.7%, 92.5% and 53.6%, respectively. Meanwhile, the expression of growth-related genes was upregulated in the higher temperature treatment and was consistent with the response of catechins biosynthesis-related genes to temperature. The positive correlation and the cubic function (R2 > 90%) were noted between the growth of young shoots and catechins content. In brief, the response of catechins biosynthesis to temperature changes coordinately regulated by shoot growth and catechins genes expression of tea plants. Our findings provide the reference for improving tea quality by increasing its catechin contents. [ABSTRACT FROM AUTHOR]

The epidermal cell layer of plants has important functions in regulating plant growth and development. We have studied the impact of an altered epidermal cytokinin metabolism on Arabidopsis shoot development. Increased epidermal cytokinin synthesis or breakdown was achieved through expression of the cytokinin synthesis gene LOG4 and the cytokinin-degrading CKX1 gene, respectively, under the control of the epidermis-specific AtML1 promoter. During vegetative growth, increased epidermal cytokinin production caused an increased size of the shoot apical meristem and promoted earlier flowering. Leaves became larger and the shoots showed an earlier juvenile-to-adult transition. An increased cytokinin breakdown had the opposite effect on these phenotypic traits indicating that epidermal cytokinin metabolism can be a factor regulating these aspects of shoot development. The phenotypic consequences of abbreviated cytokinin signaling in the epidermis achieved through expression of the ARR1-SRDX repressor were generally milder or even absent indicating that the epidermal cytokinin acts, at least in part, cell non-autonomously. Enhanced epidermal cytokinin synthesis delayed cell differentiation during leaf development leading to an increased cell proliferation and leaf growth. Genetic analysis showed that this cytokinin activity was mediated mainly by the AHK3 receptor and the transcription factor ARR1. We also demonstrate that epidermal cytokinin promotes leaf growth in a largely cell-autonomous fashion. Increased cytokinin synthesis in the outer layer of reproductive tissues and in the placenta enhanced ovule formation by the placenta and caused the formation of larger siliques. This led to a higher number of seeds in larger pods resulting in an increased seed yield per plant. Collectively, the results provide evidence that the cytokinin metabolism in the epidermis is a relevant parameter determining vegetative and reproductive plant growth and development. [ABSTRACT FROM AUTHOR]

Although boron (B) is an element that has long been assumed to be an essential plant micronutrient, this assumption has been recently questioned. Cumulative evidence has demonstrated that the players associated with B uptake and translocation by plant roots include a sophisticated set of proteins used to cope with B levels in the soil solution. Here, we summarize compelling evidence supporting the essential role of B in mediating plant developmental programs. Overall, most plant species studied to date have exhibited specific B transporters with tight genetic coordination in response to B levels in the soil. These transporters can uptake B from the soil, which is a highly uncommon occurrence for toxic elements. Moreover, the current tools available to determine B levels cannot precisely determine B translocation dynamics. We posit that B plays a key role in plant metabolic activities. Its importance in the regulation of development of the root and shoot meristem is associated with plant developmental phase transitions, which are crucial processes in the completion of their life cycle. We provide further evidence that plants need to acquire sufficient amounts of B while protecting themselves from its toxic effects. Thus, the development of in vitro and in vivo approaches is required to accurately determine B levels, and subsequently, to define unambiguously the function of B in terrestrial plants. [ABSTRACT FROM AUTHOR]

This study evaluates the effect of container structures on the growth and root architecture of rubber (Hevea brasiliensis) rootstock seedlings .The container structures and planting materials used were cylindrical plastic tubes, size 7.5 cm x 35 cm without plastic rods, and with two or four plastic rods glued inside, filled with a mixed medium of topsoil : coir dust :rice husk ash (1:1:1), and polybags, size 7.5 cm x 35 cm, filled with topsoil alone (control). The rubber seedlings' growth were measured above-ground and below-ground at 4, 6 and 8 months .The results showed that the rubber seedlings reached a suitable size for budding at 6 months with optimum seedling growth. The cylindrical plastic tubes with two and four plastic rods glued inside produced a good root architecture characterised by a high number of strong vertically oriented roots, an increase in the distributed root percentage in the upper root zone and also a decrease in branch roots based on both the root dry weight and root spiralling in the lower root zone, resulting in fewer circling roots . [ABSTRACT FROM AUTHOR]

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study was conducted to know a damage progress of soil sickness of fig trees and effect of initial planting conditions on it. Shoot growth of 10liter potted ‘Masui Dauphine’ figs was inhibited with sick soil from the 1st year of planting, and a stable dwarfish growth was maintained form the 2nd to 9th years, with only a few trees dying. The sick soil affected trees planted in 25-­liter pots in June worse than those planted in February, and trees with roots enclosed by non-­woven fabric worse than without it. However, these differences had faded by the 3rd year. The sick soil affected trees in 60­-liter pots in the 1st year of planting worse in smaller rooted cuttings than in larger ones. However, in subsequent years, growth inhibition was not affected by the rooted cutting size. These results suggest that the initial conditions, such as planting timing, physical barriers to rooting, and rooted cutting size, all affect potted fig tree growth in the early growing period, and influence the observed damage caused by sick soil. However in subsequent years, dwarfish growth in sick soil may attain a stable level, which is maintained for many years with very low mortality.

Humic substances (HS, fulvic and humic acids) are widely used as fertilizers or plant growth stimulants, although their mechanism of action still remains partially unknown. Humic substances may be applied either directly to the soil or as foliar sprays. Despite both kind of application are commonly used in agricultural practices, most of the studies regarding the elicited response in plants induced by HS are based on the root-application of these substances. The present work aimed at discriminating between the mechanisms of action of foliar application versus root application of a sedimentary humic acid (SHA) on plant development. For this purpose, six markers related to plant phenotype, plant morphology, hormonal balance and root-plasma membrane H+-ATPase were selected. Both application strategies improved the shoot and root growth. Foliar applied- and root applied-SHA shared the capacity to increase the concentration of indole-3-acetic acid in roots and cytokinins in shoots. However, foliar application did not lead to short-term increases in either abscisic acid root-concentration or root-plasma membrane H+-ATPase activity which are, however, two crucial effects triggered by SHA root-application. Both application modes increased the root concentrations of jasmonic acid and jasmonoyl-isoleucine. These hormonal changes caused by foliar application could be a stress-related symptom and connected to the loss of leaves trichomes and the diminution of chloroplasts size seen by scanning electron microscopy. These results support the hypothesis that the beneficial effects of SHA applied to roots or leaves may result from plant adaptation to a mild transient stress caused by SHA application.

Tawangmangu tangerine (Citrus reticulate Blanco subsp. tawangmangu) is one of prime local fruit from Tawangmangu region, Karanganyar, Central Java. This tangerine have good appearance, easy to peeled, sweet flavored fruit, and high production rate. However at 1984 Tawangmangu tangerine run into depreciation of population caused by CVPD (Citrus Vein Phloem Degeneration). As a result, this variety listed as endangeredThe effort of consevation by culture tissue technique can order to obtain prime seeds that free from virus or disease. This study was aimed to understand the effect of IBA and BAP in culture medium on growth of apical and lateral shoot of Tawangmangu tangerine. The treatment provided were IBA (0 ppm, 0.5 ppm, and 1 ppm) and BAP (0 ppm, 1 ppm and 2 ppm). The treatment in this research was using complete randomized factorial design in 9 different treatment. This research resulted that added combination of IBA and BAP affecting growth of Tawangmangu tangerine but the interaction of IBA and BAP did not happen. The highest shoot length occurs on treatment IBA 1 ppm+BAP 2 ppm while when the fastest shoot appears occurs on treatment IBA 0 ppm+ BAP 2 ppm and the highest shoot formed on treatment IBA 0.5 ppm+BAP 2 ppm. Benefit of the research Efforts to conserve Tawangmangu orange plants need to be done to maintain the diversity of germplasm and support the cultivation in a manner. One technique that can support the conservation of plants is by tissue culture techniques.

Influence of plant growth regulators chlormequat chloride, chlormequat chloride + ethephon, ethephon, and mepiquat chloride + prohexadione-Ca + pyraclostrobin + ammonium sulphate (BAS67800F + BAS00800D) on decreasing sunflower height was evaluated. It was determined that sunflower height can be reduced by as much as 30 cm. In the case of BAS67800F + ammonium sulphate, there was a slight difference between application at BBCH 31-33 and BBCH 50-51, whereas for ethephon better application time was at BBCH 50-51. For chlormequat chloride, application at BBCH 31-33 was better, but height reduction did not endure until harvest. Flower head diameter shortly before harvest was not affected at any tested regulator. Flowering was delayed primarily at applications at BBCH 50-51.

Salinity stress is among the major abiotic stresses prevailing in arid and semiarid areas such as the southern high plains of the United States. In these areas, both declining quality of groundwater and cultivation practices have resulted in increased accumulation of salts in the root zone. The occurrence of excessive salts in the root zone is detrimental for plant growth and economic yield. Recently, biochar has received a great consideration as a soil amendment to mitigate the detrimental impacts of salinity stress. However, the effectiveness of biochar to mitigate the salinity stress depends on the feedstock type, pyrolysis temperature and time, soil type and properties, and plant species. Therefore, a pot experiment in a greenhouse was conducted to 1) examine the effects of salinity stress on physiology, shoot and root growth, and yield of eggplant (Solanum melongena L.), and 2) evaluate the potential of hardwood biochar and softwood biochar to mitigate the damaging effects of salinity stress on eggplant. The experiment was conducted in a split-plot design with three salinity levels of irrigation water [S0 (control, 0.04 dS·m-1), S1 (2 dS·m-1), and S2 (4 dS·m-1)] as main-plot factor and three biochar treatments [B0 (control, non-biochar), Bh (hardwood biochar), and Bs (softwood biochar)] as subplot factor with four replications. Results showed that stomatal conductance (gs) and photosynthesis rate decreased significantly, while leaf temperature and electrolyte leakage increased significantly with increase in irrigation water salinity levels. Root growth (root length density and root surface area density), shoot growth (plant height, stem diameter, and leaf area), and yield of eggplant declined with increase in levels of salinity stress. Biochar application helped to enhance gs and photosynthesis rate, and to decrease leaf temperature and electrolyte leakage in leaf tissues of plants. This resulted in better root growth, shoot growth, and fruit yield of eggplant in treatments amended with biochar than non-biochar (control) treatment. There was no significant difference in the effect of two types of biochars (hardwood and softwood biochar) on physiology, root growth, shoot growth, and yield of eggplant. Therefore, it can be concluded that softwood and hardwood biochars could be used to minimize the detrimental impacts of salinity stress in eggplant. [ABSTRACT FROM AUTHOR]

The study was conducted to know a damage progress of soil sickness of fig trees and effect of initial planting conditions on it. Shoot growth of 10liter potted 'Masui Dauphine' figs was inhibited with sick soil from the 1st year of planting, and a stable dwarfish growth was maintained form the 2nd to 9th years, with only a few trees dying. The sick soil affected trees planted in 25liter pots in June worse than those planted in February, and trees with roots enclosed by nonwoven fabric worse than without it. However, these differences had faded by the 3rd year. The sick soil affected trees in 60liter pots in the 1st year of planting worse in smaller rooted cuttings than in larger ones. However, in subsequent years, growth inhibition was not affected by the rooted cutting size. These results suggest that the initial conditions, such as planting timing, physical barriers to rooting, and rooted cutting size, all affect potted fig tree growth in the early growing period, and influence the observed damage caused by sick soil. However in subsequent years, dwarfish growth in sick soil may attain a stable level, which is maintained for many years with very low mortality. [ABSTRACT FROM AUTHOR]

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Many modern rice varieties have been intensively selected for high‐yielding performance under irrigated conditions, reducing their genetic diversity and potentially increasing their susceptibility to abiotic stresses such as drought. In this study, we tested benefits for stress tolerance of introducing DNA segments from wild ancestor Oryza rufipogon to the modern cultivar O. sativa cv Curinga (CUR) by applying a gradient of osmotic stress to both parents and seven introgressed lines. Shoot growth of O. rufipogon had a high tolerance to osmotic stress, and the number of total root tips increased under mild osmotic stress. One introgression line showed greater shoot growth, root growth, and higher number of total root tips than the parent line CUR under osmotic stress. Abscisic acid (ABA) is a key hormone mediating plant responses to abiotic stresses. Both root and shoot growth of O. rufipogon were much more sensitive to ABA than CUR. Introgression lines varied in the extent to which the sensitivity of their growth responses to ABA and some lines correlated with their sensitivity to osmotic stress. Our results suggest that rice responses to ABA and osmotic stress are genotype dependent, and growth responses of rice to ABA are not a consistent indicator of resilience to abiotic stress in introgression lines. [ABSTRACT FROM AUTHOR]

Many strains of the Pseudomonas fluorescens have been characterized as plant growth promoting rhizobacteria (PGPR) and they enhance the growth and yield of economical important paddy crops. The effect of bio-priming on paddy paddy seed growth was assessed at Crop Research Centre S.V.B.P.A.&T Meerut India by studying the effect of fluorescent Pseudomonas strains for their growth stimulatory effect on paddy plants in Randomized Block Design (RBD) in pot conditions. A total of nineteen isolates of the rhizobacteria Pseudomonas fluorescens were selected from the fields of paddy, wheat, mustard, chilli, sorghum and pearlmillet and these strains were used as bio-priming agents for paddy paddy seed. The highest increase in shoot dry weight was seen in the isolate Pseudomonas fluorescens SVP 12 followed by SVP 11 and SVP 13 with 93.33, 86.67 and 80 per cent enhancement in shoot dry weight. All isolates of P. fluorecens, when applied as seed biopriming of paddy paddy seed, had some stimulatory effect on growth and physiological parameters of treated plants indicating that such strains could be use for enhancing the yield and quality of paddy paddy crop. [ABSTRACT FROM AUTHOR]

Drought cycling and soil re‐watering trends due to intermittent rainfall patterns are key stress factors that influence rice growth and yield under upland cultivation conditions. However, upland rice adaptation responses to fluctuating soil moisture conditions remain poorly understood. This study investigated root and shoot responses of upland New Rice for Africa (NERICA) varieties to episodic drought and re‐watering during growth. We examined root and shoot growth of NERICA 1 and NERICA 4 compared with those of IR72, an improved lowland variety, and Dular, a traditional drought‐tolerant variety, in terms of soil moisture fluctuations with different levels of nitrogen fertilization under field conditions that impeded deep root development. During soil moisture fluctuation, all varieties reduced shoot dry weight compared with well‐watered plants, regardless of nitrogen fertilization levels. However, total root length for the three upland varieties was enhanced by soil moisture fluctuations at moderate and high nitrogen fertilization, while that of the lowland variety was reduced. Comparing root development during water fluctuations revealed that NERICA 1 had a greater root system than NERICA 4, which was attributed to lateral root development. Furthermore, we found that NERICA varieties increase lateral root mass during soil desiccation under adequate nitrogen fertilization, while Dular and IR72 reduced their root growth rate during drought and increased it after re‐watering. Both root growth patterns developed, from around maximum tillering to heading. The analysis of regression between root elongation and shoot growth with fluctuating soil moisture indicated that an enhanced root system during drought, on adequate nitrogen fertilization, can contribute to shoot growth when sufficient water becomes available, specifically around the maximum tillering to the heading growth stage of rice. [ABSTRACT FROM AUTHOR]

In this study, selenite ions were reduced to selenium nanoparticles using a leaf extract of barley (Hordeum vulgare L.) plants. Characterization of synthesized nanoparticles using Scanning Electron Microscopy (SEM) and UV-visible spectrophotometry indicated the formation of variable size of selenium nanoparticles, suggesting that leaf extract could form polydispersed nanoparticles. Then we used these synthesized selenium nanoparticles to mitigate salt stress in barley plants under hydroponic conditions. Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) analyses suggested that the hydroponically nano-Se application resulted in direct accumulation of Se in the leaves of barley. Shoot growth was negatively affected by salinity levels up to 100 mM, whereas this reduction was mitigated by application of exogenous Se nanoparticles. Our results indicated that high salinity stress decreased the activity of superoxide dismutase (SOD), and enhanced the levels of malondialdehyde (MDA) in the leaves of barley seedlings, whereas application of Se nanoparticles increased total phenolic levels, and also resulted in a significant reduction of MDA (a marker for the ROS-mediated cell membrane damage) contents, which could influence the metabolism and be responsible for the increasing shoot dry weight. These results provided the first evidence that the green Se nanoparticles promote the growth of barley seedlings under salt stress. [ABSTRACT FROM AUTHOR]

Humic substances (HS, fulvic and humic acids) are widely used as fertilizers or plant growth stimulants, although their mechanism of action still remains partially unknown. Humic substances may be applied either directly to the soil or as foliar sprays. Despite both kind of application are commonly used in agricultural practices, most of the studies regarding the elicited response in plants induced by HS are based on the root-application of these substances. The present work aimed at discriminating between the mechanisms of action of foliar application versus root application of a sedimentary humic acid (SHA) on plant development. For this purpose, six markers related to plant phenotype, plant morphology, hormonal balance and root-plasma membrane H+-ATPase were selected. Both application strategies improved the shoot and root growth. Foliar applied- and root applied-SHA shared the capacity to increase the concentration of indole-3-acetic acid in roots and cytokinins in shoots. However, foliar application did not lead to short-term increases in either abscisic acid root-concentration or root-plasma membrane H+-ATPase activity which are, however, two crucial effects triggered by SHA root-application. Both application modes increased the root concentrations of jasmonic acid and jasmonoyl-isoleucine. These hormonal changes caused by foliar application could be a stress-related symptom and connected to the loss of leaves trichomes and the diminution of chloroplasts size seen by scanning electron microscopy. These results support the hypothesis that the beneficial effects of SHA applied to roots or leaves may result from plant adaptation to a mild transient stress caused by SHA application. [ABSTRACT FROM AUTHOR]

Arrowleaf balsamroot (Balsamorhiza sagittata (Pursh) Nutt. [Asteraceae]) and silverleaf phacelia (Phacelia hastata Douglas ex Lehm. var. hastata [Hydrophyllaceae]) are Intermountain West native plants with potential horticultural uses in native and low-water-use landscapes; however, information is lacking on greenhouse production. This research focuses on the container type and fertilizer rate necessary for greenhouse production. Seedlings were transplanted into 10-cm (4-in) square pots or cone-shaped containers and fertilized at 5 rates, once a week. For arrowleaf, rates of 200 and 400 mg/l of nitrogen (N) resulted in the highest shoot dry weight, leaf width, and leaf length measurements, whereas the root-to-shoot ratio declined when more than 100 mg/l N was applied. Cone-shaped containers proved to be a more effective container type for arrowleaf balsamroot production, based on root morphology, root dry weight, and leaf width response. For silverleaf phacelia, shoot dry weight, plant height, and canopy diameter increased as fertilizer rate increased from 50 to 200 mg/l N, whereas the root-to-shoot ratio declined if more than 50 mg/l N was applied. The 10-cm square pot was superior to the coneshaped container for silverleaf phacelia, based on much higher shoot and root dry weights and on plant height and spread. [ABSTRACT FROM AUTHOR]

Approximately 30% of harvested yams are used in subsequent plantings as seed tubers, which reduces the harvest size; however, planting tuber pieces (setts) potentially represents a viable alternative. To determine how sett size affects yam production, different sett sizes were compared for sprouting, shoot growth, and tuber yield. Larger setts exhibited faster sprouting with greater shoot biomass due to larger shoot growth rates during the early growth period. Tuber yield from 200 g setts was higher than that from 50 g setts; however, this yield advantage was not enough to compensate for the cost of larger sett size. Thus, planting 50 g setts might be the most cost-effective. Even the 50 g setts yielded higher than 1 kg tuber per plant which were available for selling in markets. Thus, planting with smaller setts can be promising method for efficiently improving yam production. [ABSTRACT FROM AUTHOR]

Jasmonic acid (JA) is involved in plant adaptations to biotic and abiotic stresses and accumulates transiently in response to osmotic/salt stress. Effects of 100 mM NaCl (osmotic stress) on shoot growth and biosynthesis of JA in two maize genotypes (Zea mays L.), salt-sensitive Across 8023 and resistant hybrid SR 03 were investigated. Plants were grown in aerated nutrient solution under controlled conditions. The analysis of jasmonic acid in root and shoot tissues was carried out by means of gas chromatography-tandem mass spectrometry (GC-MS/MS). Salt stress-induced reduction in shoot growth was more pronounced in the salt-sensitive genotype (30%) than the salt-resistant one (17%). Endogenous concentration of JA was not affected in both roots and shoots of SR 03, but it was increased in the roots of Across 8023 during the first phase of salt stress. In the second experiment, 6 d old maize seedlings were grown with or without 30 µM JA in the root medium. Exogenous treatment of JA, significantly reduced the maize seedling growth in terms of shoot extension, root length and root and shoot fresh weights. The differences in JA biosynthesis in genotypes of contrasting salt resistance indicate that jasmonic acid may have a role in plant adaptation to osmotic stress and increased JA in roots of the salt-sensitive genotype may be responsible for shoot growth inhibition.

(1) Background: Cold-hardy interspecific hybrid grapes (CIHG) are well adapted to the Annapolis Valley edaphoclimatic conditions. The main characteristics of CIHG are the high bud hardiness tolerance to winter frost, the short growing cycle, and the good tolerance to cryptogamic diseases. Based on local experience, the Vitis vinifera varieties should be grown in the warmest areas of the Annapolis Valley (Nova Scotia, Canada). Despite this, there is little scientific evidence that shows the viticultural behavior of these varieties under the edaphoclimatic conditions of this valley. (2) Methods: Thus, the aim of this research was to evaluate the viticultural behavior of two CIHG (L’Acadie and New York Muscat) and three V. vinifera varieties (Chardonnay, Riesling, and Pinot Noir) growing in the Annapolis Valley over three consecutive seasons. (3) Results: The coldest season (2019) produced a delay in grapevine phenology of at least 18 days for budburst compared to the warm seasons (2017 and 2018). In addition, in the coldest season from budburst to bloom the duration decreased compared to the rest of the seasons. The main phenological stages started earlier in L’Acadie than in the V. vinifera varieties. L’Acadie presented lower N petiole content than the V. vinifera varieties, which conditioned shoot growth in the studied seasons. CIHG presented low B petiole levels and produced musts with low malic acid content, while V. vinifera varieties produced musts with high N content. L’Acadie was the only variety that could bud out, and differentially produced fruit after the spring frost of −2 to −3 °C for 2 h in 2018 in this trial. (4) Conclusions: L’Acadie, and to a lesser extent, Riesling, hold an interesting adaptation to the edaphoclimatic conditions of the Annapolis Valley.

Irrigation is a key factor for different physiological aspects of fruit trees. Therefore, such irrigation protocols that can save water consumption during irrigation and maintain fruit trees productivity are an essential goal especially under semiarid climate conditions. The aim of this 3-year apricot study was to investigate the effect of four deficit irrigation (DI) treatments (control, moderate regulated deficit irrigation: RDIm, severe RDI: RDIs and continuous DI: CDI) on 15 tree physiological properties (chilling requirement—CR, heat requirement—HR, days from end—dormancy until fruit harvest—DEDFH, sum of growing degree days—sGDD, total number of buds—TNB, number of flower buds—NFB, number of vegetative buds—NVB, starting date of flowering—SDF, number of opened flower buds—NOFB, flower bud abscission—FBA, fruit set—FS, seasonal vegetative growth—SVG, fruit number per tree—FNT, fruit weight—FW, fruit yield—FY), and on two tree chemical properties (total soluble carbohydrates—TSC and total proline content—TPC) on apricot cultivars ‘Ninfa’ and ‘Canino’ in Egypt. Results showed that both DI treatments and cultivars significantly influenced the values of CR, HR, TNB, SDF, NOFB, FS, SVG, FNT, FY, TSC, and TPC. Values of FBA were significantly affected by years and DI treatments, while sGDD by years and cultivars. Values of DEDFH, NFB, and FW were significantly influenced only by cultivars, while NVB only by DI treatments. The RDIm treatment gave the most acceptable values for most measured properties compared to the fully irrigated control treatment. Prediction based model analysis demonstrated that generalized linear models (GLMs) can be predictors for the measured tree properties in the DI treatments. The best goodness-of-fit of the predicted GLMs was reached for HR, NOFB, FS, SVG, FNT, TSC, and TPC. In all the four DI treatments, 22 pair-variables (TNB versus (vs.) NFB, TNB vs. NOFB, TNB vs. NOFB, NFB vs. NOFB, NFB vs. FNT, NFB vs. FY, NFB vs. FW, NOFB vs. SVG, NOFB vs. FNT, NOFB vs. FY, FS vs. FNT, FS vs. FY, SVG vs. FNT, SVG vs. FY, SVG vs. TSC, FNT vs. FY, FY vs. FW, CR vs. TSC, HR vs. TNB, HR vs. NFB, HR vs. FNT, HR vs. FY, and NOFB vs. FBA) correlated significantly in Pearson correlation and regression analyses. Principal component analyses explained 82% of the total variance and PC1, PC2, and PC3 explained 23, 21, and 15% of the total variance and correlated with the HR, TNB, FS, FNT and FY; FBA, SVG, TSC, and TPC; and NFB, NVB and NOFB, respectively, indicating strong connections among tree physiological and chemical properties. In conclusion, DI techniques using moderate water deficits can be managed successfully in apricot production under semiarid Mediterranean climate conditions such as the one in Egypt.

Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis) on reproductive and vegetative growth, return bloom, fruit set, and also fruit quality in ‘Golden Delicious’ apple grafted on M.9 rootstock, an experiment was performed during 2010-2012. The applications of 125 mg dm-3 Pro-Ca on the same trees in each year resulted in a 40-43% shoot length reducing. Internodes length decreased with Pro-Ca at about 30%, while total node number was unaffected. Results indicate that Pro-Ca applications have no effects on tree trunk growth, flowering, yield, fruit set and development. Pro-Ca also didn’t have any negative impact on fruit quality during the three consecutive years. Moreover, Pro-Ca resulted in higher fruit size compared to control in the third year of trial. The results of this experiment clearly suggest that fruit growers can use Pro- Ca for the control of vegetative growth without having any negative effects on fruit quality and yield parameters. Once a full canopy has been achieved, annual shoot growth can be suppressed in the range of 20 to 30 cm with 125 mg dm-3 Pro-Ca treatment in ‘Golden Delicious’ apple trees.

This investigation was carried out through three successive seasons (2017, 2018, and 2019) on young pomegranate trees of the Wonderful cultivar to study the effect of four different irrigation treatments (100%, 75%, 50%, and 25% of crop evapotranspiration—ETc) on vegetative growth and the water–yield relationship. The study was conducted in Foggia (Apulia region, Southern Italy), an agricultural area characterized by strong wind speeds and scarce water resources. The results showed the effects of the different irrigation levels and seasons on the vegetative growth and fruit yield characteristics. The cumulative trunk diameter, the annual shoot growth, the number of fruits per tree, and the yield decreased from the full water restitution (100% ETc) to the severe water restriction (25% ETc). The weight and the size of fruits decreased significantly with the restriction of water volumes applied to the crop. A linear relationship between water consumption and yield (R = 1.00 in 2018 and 1.21 in 2019; n = 12) was found. The water use efficiency (WUE) gave no statistical differences among irrigation treatments. The yield response factors (Ky: 1.06 in 2018 and 0.99 in 2019) showed the sensitivity of pomegranates to water deficits.

Boron (B) is an essential nutrient for plant growth and development, exhibiting extremely narrow margins between deficiency and toxicity. B toxicity is devastating for productivity and apparent for a continuously increasing part of agricultural land, under the influence of on-going climate change. In this study, the effects of increased B supply (by using H3BO3) were addressed by examining critical physiological responses of young and mature leaves, which were devoid of toxicity symptoms, in two melon varieties (Armenian cucumbers, cantaloupes). B was primarily translocated through the transpiration stream, and secondarily via the active cell membrane transport system. The B distribution pattern was independent of leaf age, and remained rather unchanged under increased B supply. Armenian cucumbers, exhibiting higher leaf B levels, underwent an enhanced adverse impact on (root and shoot) growth, photosynthetic pigment content, cellular membrane integrity, and also exhibited attenuated antioxidant defense stimulation. Notably, and unlike other abiotic stressors, no evidence of B toxicity-induced systemic reaction was apparent. B toxicity greatly enhanced the transcription of the genes coding for borate influx and efflux channels, an effect that was mostly evident in mature leaves. In conclusion, shoot physiological responses to B toxicity are highly localized. Moreover, the obstruction of the diffusion and the B translocation to the aerial organs under increased B supply is genotype-dependent, governing plant physiological responses.