Plant Vigor Research Articles

Effect of Spraying with Different Concentration of Pyridoxine (Vit B6) and Planting Dates on Growth and Yield of Sesame (Sesamum indicum L.)

A field experiment was carried out to study the response of sesame (Sesamum indicum L.) cultivar (Local Red) to planting dates, and pyridoxine concentration (Vit B6) levels on growth, yield and its components characters and its interactions. 1. It could be concluded from this study that sowing dates had a significant effect on all yield and components characters. The highest values of all yield and its components characters were obtained from planting date (20 July). The results showed a plant length of 163.66 and 167.27 cm, number of pods plant of 69.16 and 71.97 pod.plant-1, plant vigor index of 65.60 and 73.43 cm, 1000-grain weight of 4.497 and 5.155 g’grains yield of 1.046 and 1.155 t.ha-1, for 10 July and 20 July’respectively2.. Increasing pyridoxine concentration (Vit B6) levels up to (150 B6mg.l-1) significantly increased all yield and components characters, were recorded 170.23 cm, 72.17 pod.plant-1, 72.02 cm, 5.162 g and 1.265 t.ha-1 respectively, under the same conditions for 0 and 100 B6mg.l-1. 3. Increasing seed oil content % and seed crude protein content %, when planting date (20 July) and pyridoxine concentration (Vit B6) levels up to (150 B6mg.l-1).

Optimizing the Droplet-Vitrification Procedure by Balancing the Cryoprotection and Cytotoxicity of Alternative Plant Vitrification Solutions Based on the Nature of Donor Plant Vigor

Over 30 years of plant vitrification, droplet vitrification (DV) of in vitro propagules and slow freezing of dormant buds are typical methods of large-scale cryobanking worldwide. One-step sucrose preculture and Plant Vitrification Solution 2 (PVS2) cryoprotection in solution-based vitrification often face unacceptably low regeneration, and the results are on a case-by-case basis depending on the plant species, like a blind test. The absence of a universal protocol applicable across all plant diversity is considered one of the limiting factors. For wild flora, limits of source material available and difficulties in in vitro propagation make it worse to re-optimize the protocol steps for new species. Since cryoprotectant toxicity is the most crucial barrier to the vitrification of organized explants, selecting alternative plant vitrification solutions (PVS) based on the cytotoxicity of cryoprotectants is vital. This review proposes the concept of donor plant vigor (DPV), which refers to the donor plant properties that determine the potential to regenerate normal plantlets under various cryopreservation procedures. DV is a multi-stage procedure with many factors from stage (1) material preparation to (2) pre-liquid nitrogen (pre-LN) (preculture, osmoprotection, cryoprotection), (3) LN (cooling), (4) warming conditions (rewarming, unloading), and (5) regrowth. Since the cytotoxicity of PVS is a primary limiting factor in DV approaches, DPV is crucial for coping with the toxicity of PVS. The DPV is innate and can be maximized with appropriate material preparations, i.e., vigorously growing in subcultures aided by a liquid overlay on top of the gelled medium, selecting proper explants, optimizing the two-step preculture conditions, and media supplements. Developing the DV protocol starts with testing the material with a tentative standard protocol, which includes a two-step preculture (10% sucrose for 31 h and 17.5% sucrose for 16 h), osmoprotection with C4-35%, cryoprotection with A3-80% (60 min at 0 °C), cooling, and rewarming using aluminum foil strips. Using a three-step regrowth initially with ammonium-free regrowth medium, regrowth of shoot tips in one plate following the successive stages of the tentative standard protocol for shoot tips, i.e., fresh, PC, OP, CP (LNC), and LN, is a valuable tool to characterize the sensitivity of the material and to standardize the procedure by tuning the cryoprotection and cytotoxicity of cryoprotectants. A-series PVS (A3-90%, A3-80%, A3-70%) and B-series PVS (PVS3, B5-85%) can be tested based on the DPV. These alternative PVSs have been applied in over 30 pieces of literature with an 8.5~67.3% increase in LN regeneration compared to PVS2 and Plant Vitrification Solution 3 (PVS3) treatments. Using this approach as an alternative to blind condition screening would be influential in broadening the cryopreservation of diverse wild species and problem materials.

Brevundimonas vesicularis (S1T13) Mitigates Drought-Stress-Associated Damage in Arabidopsis thaliana

Drought stress is a significant threat to agricultural productivity and poses challenges to plant survival and growth. Research into microbial plant biostimulants faces difficulties in understanding complicated ecological dynamics, molecular mechanisms, and specificity; to address these knowledge gaps, collaborative efforts and innovative strategies are needed. In the present study, we investigated the potential role of Brevundimonas vesicularis (S1T13) as a microbial plant biostimulant to enhance drought tolerance in Arabidopsis thaliana. We assessed the impact of S1T13 on Col-0 wild-type (WT) and atnced3 mutant plants under drought conditions. Our results revealed that the inoculation of S1T13 significantly contributed to plant vigor, with notable improvements observed in both genotypes. To elucidate the underlying mechanisms, we studied the role of ROS and their regulation by antioxidant genes and enzymes in plants inoculated with S1T13. Interestingly, the inoculation of S1T13 enhanced the activities of GSH, SOD, POD, and PPO by 33, 35, 41, and 44% in WT and 24, 22, 26, and 33% in atnced3, respectively. In addition, S1T13 upregulated the expression of antioxidant genes. This enhanced antioxidant machinery played a crucial role in neutralizing ROS and protecting plant cells from oxidative damage during drought stress. Furthermore, we investigated the impact of S1T13 on ABA and drought-stress-responsive genes. Similarly, S1T13 modulated the production of ABA and expression of AO3, ABA3, DREB1A, and DREB2A by 31, 42, 37, 41, and 42% in WT and 20, 29, 27, 38, and 29% in atnced3. The improvement in plant vigor, coupled with the induction of the antioxidant system and modulation of ABA, indicates the pivotal role of S1T13 in enhancing the drought stress tolerance of the plants. Conclusively, the current study provides valuable insights for the application of multitrait S1T13 as a novel strain to improve drought stress tolerance in plants and could be added to the consortium of biofertilizers.

Industrial Scale Gene Editing in Brassica napus

In plants, an increasing number of traits and new characteristics are being developed using gene editing. Simple traits represented by a single gene can be managed through backcross breeding, but this is typically not the case for more complex traits which may result from the function of a large number of genes. Here, we demonstrate two case studies of improving oleic oil content and developing pod shatter reduction in Brassica napus by using gene editing tools on an industrial scale. There are four BnaFAD2 genes involved in oleic oil content and eight BnaSHP genes involved in pod shatter tolerance. In order to develop these two traits, we delivered nuclease ribonucleoproteins with Gene Repair OligoNucleotides (GRONs) into protoplasts, with subsequent regeneration into plants on an industrial scale, which encompassed robust tissue culture protocols, efficient gene editing, robotics sampling, and molecular screening, vigorous plant regeneration, growth, and phenotyping. We can produce precise loss-of-function-edited plants with two improved agronomically important complex traits, high oleic oil or pod shatter reduction, in elite canola varieties within 1–3 years, depending on the trait complexity. In the edited plants carrying loss of function of four BnaFAD2 genes, the seed fatty acid oleic acid content reached 89% compared to 61% in the non-edited wildtype control. The plants carrying eight edited BnaSHP genes achieved 51% pod shatter reduction in multiple year field testing in the target environment compared to the wildtype control.

First report of feeding injury of Proba fraudulenta Stäl (Hemiptera: Miridae) to Cynara cardunculus (L.) Fiori (Asterales: Asteraceae) in Brazil

An outbreak of Proba fraudulenta Stäl (Hemiptera: Miridae) causing feeding injury to leaves and inflorescences, and leading to economic damage of artichoke, Cynara cardunculus var. scolymus (L.) Fiori (Asterales: Asteraceae), was observed for the first time in plantations located in the municipalities of Piedade (23°43′S, 47°25′W) and Ibiúna (23°39′29.88″S, 47°12′40.68″W), São Paulo state, Brazil. This is the first formal record of the mirid bug P. fraudulenta as an insect pest of artichoke. This scientific note aims to describe the feeding injury and economic importance of P. fraudulenta for artichoke production. Nymphs and adults of P. fraudulenta were manually collected from inflorescences of artichoke plants at “Sítio Osako”, a property located in the municipality of Piedade. The second author, a taxonomist specialist in Miridae, identified the species based on morphological diagnostic characteristics. Feeding by P. fraudulenta on artichoke was observed to cause yellowing and drying of leaves, reduction of plant vigor and inflorescence size and quality, and plant death, which directly affects yield. This report is a relevant finding because the state of São Paulo is the biggest artichoke-producing region in Brazil, and this insect could pose a threat to artichoke production if it were to invade other producing regions including Europe and the United States.

Deep incorporation of organic amendments into soils of a 'Calardis Musqué' vineyard: effects on greenhouse gas emissions, vine vigor, and grape quality.

Traditional wine growing regions are increasingly endangered by climatic alterations. One promising approach to mitigate advancing climate change could be an increase of soil organic matter. Here, especially subsoils are of interest as they provide higher carbon storage potential than topsoils. In this context, vineyard subsoils could be particularly suitable since they are deeply cultivated once before planting and afterwards, left at rest for several decades due to the perennial nature of grapevines. For this purpose, a biochar compost substrate and greenwaste compost were incorporated in up to 0.6 m depth before planting a new experimental vineyard with the fungus-resistant grapevine cultivar 'Calardis Musqué'. The influence of this deep incorporation on greenhouse gas emissions and grapevine performance was evaluated and compared to a non-amended control using sensor-based analyses. Increased CO2 emissions and lower N2O emissions were found for the incorporation treatments compared to the control, but these differences were not statistically significant due to high spatial variability. Only few plant traits like chlorophyll content or berry cuticle characteristics were significantly affected in some of the experimental years. Over the course of the study, annual climatic conditions had a much stronger influence on plant vigor and grape quality than the incorporated organic amendments. In summary, organic soil amendments and their deep incorporation did not have any significant effect on greenhouse gas emissions and no measurable or only negligible effect on grapevine vigor, and grape quality parameters. Thus, according to our study the deposition of organic amendments in vineyard subsoils seems to be an option for viticulture to contribute to carbon storage in soils in order to mitigate climate change.

Agronomic strategies to enhance the early vigor and yield of maize part II: the role of seed applied biostimulant, hybrid, and starter fertilization on crop performance.

Maize cropping systems need to be re-designed, within a sustainable intensification context, by focusing on the application of high-use efficiency crop practices, such as those that are able to enhance an early plant vigor in the first critical growth stages; such practices could lead to significant agronomic and yield benefits. The aim of this study has been to evaluate the effects of the cultivation of hybrids with superior early vigor, of the distribution of starter fertilizers at sowing, and of the seed application of biostimulants on promoting plant growth and grain yield in full factorial experiments carried out in both a growth chamber and in open fields. The greatest benefits, in terms of plant growth enhancement (plant height, biomass, leaf area) and cold stress mitigation, were detected for the starter fertilization, followed by the use of an early vigor hybrid and a biostimulant seed treatment. The starter fertilization and the early vigor hybrid led to earlier flowering dates, that is, of 2.1 and 2.8 days, respectively, and significantly reduced grain moisture at harvest. Moreover, the early vigor hybrid, the starter NP fertilization, and the biostimulant treatment increased grain yield by 8.5%, 6.0%, and 5.1%, respectively, compared to the standard hybrid and the untreated controls. The combination of all the considered factors resulted in the maximum benefits, compared to the control cropping system, with an increase in the plant growth of 124%, a reduction of the sowing-flowering period of 5 days, and a gain in grain yield of 14%. When choosing the most suitable crop practice, the diversity of each cropping system should be considered, according to the pedo-climatic conditions, the agronomic background, the yield potential, and the supply chain requirements.

Effect of ethylene pretreatment on tomato plant responses to salt, drought, and waterlogging stress.

Salinity, drought, and waterlogging are common environmental stresses that negatively impact plant growth, development, and productivity. One of the responses to abiotic stresses is the production of the phytohormone ethylene, which induces different coping mechanisms that help plants resist or tolerate stress. In this study, we investigated if an ethylene pretreatment can aid plants in activating stress-coping responses prior to the onset of salt, drought, and waterlogging stress. Therefore, we measured real-time transpiration and CO2 assimilation rates and the impact on biomass during and after 3days of abiotic stress. Our results showed that an ethylene pretreatment of 1ppm for 4h did not significantly influence the negative effects of waterlogging stress, while plants were more sensitive to salt stress as reflected by enhanced water losses due to a higher transpiration rate. However, when exposed to drought stress, an ethylene pretreatment resulted in reduced transpiration rates, reducing water loss during drought stress. Overall, our findings indicate that pretreating tomato plants with ethylene can potentially regulate their responses during the forthcoming stress period, but optimization of the ethylene pre-treatment duration, timing, and dose is needed. Furthermore, it remains tested if the effect is related to the stress duration and severity and whether an ethylene pretreatment has a net positive or negative effect on plant vigor during stress recovery. Further investigations are needed to elucidate the mode of action of how ethylene priming impacts subsequent stress responses.

ВЛИЯНИЕ УСЛОВИЙ ПРОИЗРАСТАНИЯ И НОРМЫ НАГРУЗКИ ПОБЕГАМИ НА РОСТ И РАЗВИТИЕ ВИНОГРАДА СОРТА СИБИРЬКОВЫЙ

The paper presents research data on the colle-ration of vineyards’ yield and quality of grapes on the shoot load. The research was conducted at the All-Russian Research Institute of Viticul-ture and Winemaking named after Ya.I. Potapenko, Novocherkassk, Rostov region. On grafted vineyards of Sibirkoviy variety, load norms were studied: 25; 30; 35; 40 shoots per bush. In different conditions (Pukhlyakov exper-imental field department and Novocherkassk experimental field department), the influence of growth place on development, fruiting and vigor of the grape plant was studied. The conducted studies revealed: the maximum yield was ob-tained in plantings with a load of 40 shoots per plant and amounted to 12.9 t/ha with the best grape conditions in the experiment: the mass concentration of sugars in berry juice was 19.6 g/100 cm3, and titrated acids 6.3 g/dm3. In Novocherkassk experimental field department, the yield was higher relative to Pukhlyakovsky experimental field department by 2.9 t/ha, but with lower conditions.

Boosting wheat yield, profitability and NUE with prilled and nano urea in conservation tillage

Rice–wheat production in the Indo-gangetic plains (IGPs) of India faces major concerns such as depleting resources, rice residue burning, excessive fertilizer use, and decreasing nitrogen use efficiency. These issues threaten sustainable crop production in the future. Therefore, a field study was conducted during the winter seasons of 2020–21 and 2021–22 to evaluate the effect of combined conventional and nano fertilizers on nitrogen application just before or after irrigation to improve wheat productivity, profitability and NUE under conservation tillage. The study evaluated eight treatment combinations of nitrogen application through conventionally applied urea (46% N) and foliar applied nano urea (4% N) under zero tillage with rice residue retention. Results revealed that growth, physiological indices, yield, and quality parameters were enhanced with the application of 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation alone (T2) or along with a spray of nano urea (T5) compared to other treatments. T5 recorded 7.2%, 8.5%, and 7.8% more plant dry matter, number of tillers, and grain yield, respectively, over the conventional practice of applying 150 kg N/ha in three equal splits as basal and 7–10 days after 1st and 2nd irrigation (T3, farmers practice). Although, T2 showed similar results to T5, T5 recorded significantly higher gross ($2542/ha) and net returns ($1279/ha) than the other treatments. However, the benefit–cost ratio of T2 and T5 was same (2.01). A significant and positive correlation coefficient between grain yield and physiological parameters such as CCI and NDVI confirmed that increasing the nitrogen dose enhanced the chlorophyll content, greenness, and plant vigor. Based on the results, it can be concluded that applying 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation under conservation agriculture, along with a single spray of nano urea (4% N) at 60–65 days after sowing, can improve growth, yield attributes, wheat yield, and NUE compared to farmers practice (T3) in India.

Ameliorating effect of nanoparticles and seeds’ heat pre-treatment on soybean plants exposed to sea water salinity

Impairing plant growth and reducing crop production, salinity is considered as major problem in modern agriculture. The current study aimed to investigate the role of seeds' heat pretreatment at 45 °C as well as application of two different nanoparticles nanosilica (N1) and nanoselenium (N2) in reducing salinity stress in three genotypes of Egyptian commercial soybeans (Glycine max L.). Two levels of salt stress using diluted sea water (1/12 and 1/6) were tested either alone or in combination with protective treatments. Obtained results revealed that salinity caused a significant reduction in all tested physiological parameters such as germination rate and membrane stability in soybean plants. A significant reduction in mitotic index and arrest in metaphase were recorded under both tested levels of salinity. It was also revealed that chromosomal abnormalities in soybean plants were positively correlated with the applied salinity concentrations. The fragmentation effect of salinity on the nuclear DNA was investigated and confirmed using Comet assay analysis. Seeds heat pre-treatment (45 °C) and both types of nanoparticles' treatments yielded positive effects on both the salt-stressed and unstressed plants. Quantitative real-time reverse transcription PCR (qRT-PCR) analysis for salt stress responsive marker genes revealed that most studied genes (CAT, APX, DHN2, CAB3, GMPIPL6 and GMSALT3) responded favorably to protective treatments. The modulation in gene expression pattern was associated with improving growth vigor and salinity tolerance in soybean plants. Our results suggest that seeds’ heat pretreatment and nanoparticle applications support the recovery against oxidative stresses and represent a promising strategy for alleviating salt stress in soybean genotypes.

Seaweed polysaccharides on seed germination of Brassica napus L.

Seaweed polysaccharides, when compared to synthetic commercial fertilizers, have been proven to achieve excellent results in plant growth parameters. When applied to the soil directly or sprayed on the foliage, seaweed poly- and oligosaccharides can improve seed germination and plant vigor, increase the uptake of soil nutrients, and protect plants against several abiotic and biotic stresses, by stimulating a plant to produce secondary metabolites and manage its defense pathways. In this study, three different polysaccharides (alginate, agar and carrageenan) were extracted from one brown seaweed, Saccorhiza polyschides, and two red seaweeds, Gracilaria gracilis and Chondrus crispus, respectively, with aim to analyse their impact on Brassica napus L. seed germination. The polysaccharides' chemical structure, mineral profile and other physicochemical properties were assessed. Carrageenan exhibited the best results in seedling growth and germination percentage when compared to alginate and agar. The carrageenan extracted from the tetrasporophyte, non-fructified thalli and female gametophyte of Chondrus crispus exhibited 94.67, 92 and 98.67 % seed germination, respectively. Carrageenan's bioactivities appear to be related with their sulphation level, plus the pH and the conductivity of its solution. The optimum concentration for germination of each polysaccharides' solution was assigned to propose further experiments in turnip greens.

Is the Direct Soil Application of Two-Phase Olive Mill Waste (Alperujo) Compatible with Soil Quality Protection?

In Spain and other Mediterranean countries, significant quantities of semi-solid olive mill waste are generated, which should be preferentially applied to agricultural soils to close nutrient cycles. However, two-phase olive mill waste (termed alperujo in Spanish) is known to pose risks to soil quality and plant production when applied to soil in large quantities. Alperujo has high contents of polyphenol substances, which can inhibit microbial growth and are also phytotoxic in nature. However, when applied in appropriate quantities and following specific methods, it is possible that the practice may not pose any risks, and this requires evaluation. As a waste management option, direct application of alperujo can supply plant nutrients and organic matter to degradation-prone Mediterranean soils. In order to validate this circular economy fertilization and soil protection strategy, an 18-month field experiment was undertaken, applying moderate quantities of alperujo on permanent crop groves throughout the Spanish region of Valencia. Eleven experimental parcels with permanent crops managed by farmers were identified to test two scenarios: a single application of 10 t/ha, and a second application of 10 t/ha after 10 months. Soil chemical parameters were assessed at 0, 6, 10, and 18 months. Soil organic carbon, total Kjeldahl nitrogen, pH, electrical conductivity, nitrates, and polyphenol contents were modified by alperujo application, but these effects were highly transient in nature, with generally no lasting effects after 4–6 months for either application scenario. Also, qualitative evaluations carried out by farmers revealed few effects, although some reductions in erosive processes and improvements in plant vigor were noted. As such, based on the measured parameters, it is concluded that the direct soil application of alperujo olive mill wastes at low application rates did not lead to any lasting detrimental effects on soil quality or compromise the productivity of permanent crops in this Mediterranean region.

Macadamia Breeding for Reduced Plant Vigor: Progress and Prospects for Profitable and Sustainable Orchard Systems

Vigor control in tree crops plays an important role in increasing orchard efficiency and sustainability. It has enabled high-density plantations to maximize yield efficiency while reducing production costs. Although traditional methods such as frequent hedging and pruning are still used, dwarfing rootstocks and low-vigor cultivars are the most effective and sustainable means of vigor control, as these methods reduce labor and management costs while maintaining yield efficiency. Considerable variation among cultivars and rootstocks for vigor has been identified; however, mechanisms by which rootstocks affect scion vigor in slow-maturing tree crops remain unclear. With the lack of adequate information required for early and rapid selection, breeding programs in tree crops such as macadamia still utilize manual phenotyping, which is laborious, time-consuming, and expensive. Providing insights on emerging technologies that enhance breeding programs via rapid selection, this review summarizes the current state of vigor management and underlying mechanisms of vigor control in tree crops. It provides further understanding of the prospects of applying those techniques in rootstock and scion breeding for low-vigor and yield-efficient cultivars in tree crops, with specific reference to macadamia.

History of chicken grazing stunts tomato seedling growth and influences bacterial endophytes isolated from tomato.

Abstract Integrated crop-livestock production systems promote resource interchange on the farm. Although crop-livestock integration can increase soil quality and fertility, information on their impact on plant vigor and endophytic bacterial communities is sparce. We aimed to address the impact of chicken-grazed soil (CGS) on tomato ( Solanum lycopersicum ) seedling growth and stem endophytes. We hypothesized that as planting substrate contains higher amounts of CGS, tomato seedlings will have higher biomass and greater bacterial endophyte diversity. Furthermore, endophytes recovered from tomato seedlings grown in planting substrate containing CGS will be similar to those commonly found in plants, and possibly to those associated with animal sources, including chicken manure. To test this hypothesis, two greenhouse trials were conducted where tomato seedlings grew for six weeks in substrates containing different dilutions of CGS. We observed that the greater the amount of CGS, the greater seedling stunting. Bacterial endophytes recovered in these experiments differed by CGS dilution. Bacillus and Paenibacillus were the dominant genera, Bacillus being the only genus present across all treatments. Most recovered isolates were found to be close matches to formerly cultured plant endophytes and soil bacteria. Future directions should focus on identifying mechanisms to ameliorate seedling stunting when grown in CGS.

Endophytic bacteria, from the desert spurge (Euphorbia antiquorum) enhance nutrients uptake and suppress root rot in the common bean

Global agriculture has long been concerned with the management of soil-borne diseases. Owing to their occurrence under the ground surface, coupled to the soil long-lasting anatomic structures such as conidia and chlamydospores formed by their causative agents, the latter are especially tricky to diagnose, identify and effectively manage. In this study, we evaluated the fungitoxic effects and nutrient mobilising abilities of 36 endophytic bacteria derived from the "desert spurge" (Euphorbia antiquorum L.) against Fusarium solani, Fusarium oxysporum, and Macrophomina phaseolina, the principal causative agents of common bean root rot in Cameroon. The antagonistic potentials of the biocontrol agents (BCAs) were assessed using conventional direct and indirect antagonism tests. The shortlisted candidates were thereafter evaluated for their in planta suppressive effects in a climate-controlled greenhouse in a completely randomised block design layout. Bacillus amyloliquefaciens BFL2, Bacillus velezensis BE1, and Pseudomnas aeruginosa RR4 produced wide spectrum hydro-soluble antifungal metabolites, with inhibitory percentages culminating at 80.79% vis-a-vis Fusarium solani Fs4. Likewise, with reference to Fusarium oxysporum NG22, the BCAs; Unidentified LPR3+ (84.25%) and Lyncinibacillus fusiformis RR7 (90.75%) released the most harmful volatile organic metabolites (VOM). Root rot incidence (75.4%) and severity (60.54%) were dramatically reduced after seed bacterization with B. amyloliquefaciens RA37, a far better outcome compared to Carbendazin (47.29%), a synthetic fungicide. Ultimately, N, P, K, Cu, Zn, Fe, and Mn contents, as well as overall plant vigour, were fostered by some BCAs. These findings demonstrate the remarkable biocontrol abilities of B. amyloliquefaciens RA37, opening a path to a biological solution to bean root rot.

Effect of seed size and pod position of clove (Syzigium aromaticum) to seed viability

Cloves are commonly propagated generatively using true seed. One of the factors causing the lack of qualified clove seeds is farmers^ low awareness of using high-quality seeds. Farmers usually do not produce seeds- in particular, they obtain seeds from their trees without exclusively separating trees for making seeds and flowers. The seeds are randomly harvested from all the flowers without considering the pod position and size. This study aimed to evaluate the effect of pod position and size on clove seed viability. The research was conducted at the Glass House of Indonesian Spices and Medicinal Crops Research Institute, Indonesia, from August to December 2018. The study was arranged in a completely randomized design with two factors. The first factor was the seed size: large (≥ 0.9 g) and small (< 0.9 g). The second factor was pod position : (a) the pods exposed to the morning sun, (b) the pods exposed to the afternoon sun, and (c) the pods’ unexposed sun (hidden). The pods originated from selected mother trees from Kayu Aro, West Sumatra. The results showed that seed size ≥ 0.9 g and pods exposed to the morning sun had higher viability, as indicated by the high seed growth rate, vigor, and better plant growth than other treatments.

Host-parasite Interactions between Solanum aethiopicum, Meloidogyne incognita, and Fusarium oxysporum f.sp. melongenae as Portrayed by Disease Traits and Crop Yield

Solanum aethiopicum L. cultivation is highly constrained by wilt disease induced by Fusarium oxysporum f.sp melongenae and Meloidogyne incognita. The effects of initial population densities of these pathogens on the crop were investigated to enhance knowledge of the host-parasite interactions. The 4 x 4 factorial set of treatments were laid out in the field using the randomized complete block design with three replications. Data were collected on plant vigour, vascular discoloration, fruit weight, shoot weight, root-gall index, final nematode population, disease incidence, and disease severity. The different initial population densities of Fusarium and/or Meloidogyne spp. had detrimental effects on the crop compared to the Control. The main effects of the pathogens on the crop/wilt showed the existence of cross-over interactions for all the disease parameters. The effects of the pathogens on yield (fruit weight and shoot weight) were partially directly proportional to population densities even though the effects were significantly different (P≤0.05) compared to the Control. All the disease parameters were positively correlated. Each of the pathogens was capable of causing severe damage to the crop in either single or concomitant infection.

In Vitro Micropropagation, Rooting and Acclimatization of Two Agastache Species (A. aurantiaca and A. mexicana)

Agastache aurantiaca ‘Sunset Yellow’ and A. mexicana ‘Sangria’ are aromatic plants with edible flowers characterized with good flavors, nutritional values and pleasant aromas. The aim of this study was to establish a successful protocol to ensure fast shoot propagation, rooting and in vivo acclimatization to obtain many vigorous plants for edible flower production. Micropropagation was tested with an agarized Murashige and Skoog (MS) medium enriched with different 6-benzylamino purine (BAP) levels. In vitro rooting trials were carried out using a half-strength MS medium comparing the traditional jar method with an agarized medium and the temporary immersion system (TIS) bioreactor with a liquid medium. After acclimatization in a greenhouse, the survival of plants and their development were recorded. Microscopical analyses were performed on both in-jar and in-TIS leaves at rooting stages and compared with in vivo leaves. In both species, the greatest number of new shoots was noted at 2.22 µM and 3.33 µM of BAP. In TIS, rooting started earlier, resulting in larger plants with more roots and longer roots than in the jar substrate. Any anatomical difference was observed in leaves collected from the jar and TIS during the rooting stage. The best acclimatization performances were recorded in plants coming from the TIS bioreactor.

How soil and climate variability within a vineyard can affect the heterogeneity of grapevine vigour and production

This study aimed to determine how within-plot soil heterogeneity combined with yearly climate variability can promote the heterogeneity of vine growth at plot level, and which soil-climate parameters influence final yield and berry composition the most. An 8-year experiment was conducted on grapevine in two zones of a vineyard (1 ha) differentiated according to grapevine vigour as determined by NDVI: high vigour (HV) and low vigour (LV). The heterogeneity of the soil properties (depth, texture and composition), plant growth (shoots and roots) and plant production (yield components and berry composition) were determined at plot level. Compared to the LV zone, the HV zone was associated with deeper soils, higher soil water and nitrogen availability, CEC and montmorillonite/illite ratio. More extended root systems, higher vegetative growth and higher yield were observed in the HV zone compared to the LV zone. Drier and warmer vintages increased the difference in heterogeneity of vine growth and yield between the two zones. Berry composition (primary and secondary metabolites) also differed between HV and LV zones but seemed unconnected to vigour and mainly depended on soil-climate-plant interactions over the years. The heterogeneity of plant vigour within the vineyard mainly resulted from differences in root exploration, soil profile and composition (notably montmorillonite/illite ratio). The present study identified soil and crop factors that, depending on weather conditions, can be drivers for reducing the heterogeneity of plant development and improving productivity at vineyard level.