Plant Dry Matter Research Articles

Rice Response to Struvite and Other Phosphorus Fertilizers in a Phosphorus-Deficient Soil Under Simulated Furrow-irrigation

AbstractWastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was grown in tubs in controlled environmental conditions in a greenhouse for a full growing season in a P-deficient, silt-loam soil (Typic Glossaqualfs). Plant nutrients (i.e., N. P. K. Mg, Zn) were determined at the end of the growing season through Mehlich-3 extraction. Below- and aboveground rice dry matter (DM), root-P concentration and uptake, aboveground tissue-P uptake, total aboveground and total plant DM, grain yield, and grain P uptake from CPST and ECST did not differ from DAP or TSP. However, aboveground tissue-P concentration was greater (P < 0.05) from TSP (0.05%) than from ECST, CPST, and the unamended control (UC). Total aboveground (i.e., vegetative plus grain) tissue-P uptake was largest (P < 0.05) from TSP (4.8 g m− 2), which did not differ from DAP or CPST, and was at least 1.1 times greater than from ECST and the UC. Despite only a few differences from the UC, the many similar rice responses among struvite and other common fertilizer-P sources suggest that struvite, especially ECST, is a potential alternative fertilizer-P source that warrants further research into struvite’s role in food production.

Formulating efficient P-rich biobased starter fertilizers: Effects of acidification and pelletizing on fertilizer properties

Animal-derived biowastes can be alternatives to mineral phosphorus fertilizers, although they typically have lower efficiency and higher transport costs because of their bulk. Pelletizing can reduce their volume and facilitate their use as placement fertilizers but may also decrease phosphorus availability. This study examined how acidification and pelletizing affect phosphorus availability in biowastes. Digestate solid fraction and meat and bone meal were treated in four ways: (1) untreated (U), (2) acidified (A), (3) untreated pelletized (UP), and (4) acidified pelletized (AP). These treatments were tested in soil incubation and pea growth experiments, with fertilizers placed 5 cm beneath the seeds to evaluate their effectiveness as placement fertilizers. Acidification significantly enhanced the phosphorus solubility of DSF and MBM by approximately 5 and 7 times respectively, while pelletizing acidified materials reduced it. In the incubation experiment, acidified materials in the powdery form showed the highest soil water-extractable phosphorus, with no significant differences among U, UP, and AP ways. In the rhizobox experiment, pelletizing untreated digestate significantly reduced plant dry matter compared to the untreated fibrous form (from 2.0 g to 1.35 g). Acidified and acidified pelletized digestate treatments resulted in the highest shoot dry matter (2.8 g and 2.95 g, respectively), surpassing even triple the amount of superphosphate (2.53 g). For meat and bone meal, the acidified powder led to the highest plant growth (2.0 g), while untreated powder resulted in the lowest amount of plant growth (0.4 g), which was lower than that of the negative control (0.6 g). No significant differences were noted between untreated and acidified pellets. These findings indicate that acidification enhances phosphorus availability in biowastes, while pelletizing reduces it. The acidified pelletized digestate solid fraction has lower volume and higher P use efficiency than its untreated material, showing higher plant growth when compared to mineral P fertilizer.

Potential of novel Rhizobium strains as biofertilizer for improved groundnut (Arachis hypogaea L.) cultivation in Eastern India

ABSTRACT Comprehensive assessments were conducted on eight fast growing, novel Rhizobium isolates, short listed from a preliminary selection of 68 isolates obtained from root nodules of groundnut plants grown in diverse agro-climatic regions of eastern India. Additionally, two conventional rhizobia strains, viz. IGR6 and GN2, (collected from the Nodule Research Center, BCKV), were utilized for comparative analysis. Cluster analysis, based on carbon utilization and biochemical parameters, grouped all the test isolates with an average similarity level of 73%. The ability of the isolates to utilize a wide range of carbon sources, including hexoses, pentoses, and disaccharides, confirms their fast-growing nature. Further analysis through 16S rDNA extraction and nucleotide sequencing revealed that the promising fresh isolates exhibited 95–99% similarity to known Rhizobium species in public databases. When evaluated in pot culture experiments using new alluvial soil from the Gangetic Plains in eastern India, the native fresh isolate NRA1(PP355674) outperformed other isolates and conventional strains in terms of nodulation efficiency, plant dry matter production, and plant nitrogen uptake. This study highlights the significant potential of native Rhizobium isolates to surpass conventionally used strains in biological nitrogen fixation, supporting the development of sustainable, environmentally-friendly, and cost-effective agricultural practices.

Monitoring and Optimization of Potato Growth Dynamics under Different Nitrogen Forms and Rates Using UAV RGB Imagery

The temporal dynamics of canopy growth are closely related to the accumulation and distribution of plant dry matter. Recently, unmanned aerial vehicles (UAVs) equipped with various sensors have been increasingly adopted in crop growth monitoring. In this study, two potato varieties were used as materials, and treated with different combinations of nitrogen forms (nitrate and ammonium) and application rates (0, 150, and 300 kg ha−1). A canopy development model was then constructed using low-cost time-series RGB imagery acquired by UAV. The objectives of this study were to quantify the variation in canopy development parameters under different nitrogen treatments and to explore the model parameters that represent the dynamics of plant dry matter accumulation, as well as those that contribute significantly to yield. The results showed that, except for the thermal time to canopy senescence (t2), other parameters of the potato canopy development model exhibited varying degrees of variation under different nitrogen treatments. The model parameters were more sensitive to nitrogen forms, such as ammonium and nitrate, than to application rates. The integral area (At) under the canopy development curve had a direct effect on plant dry matter accumulation (path coefficient of 0.78), and the two were significantly positively correlated (Pearson correlation coefficient of 0.93). Integral area at peak flowering (AtII) was significantly correlated with yield for both single and mixed potato varieties, having the greatest effect on yield (total effect of 1.717). In conclusion, UAV-acquired time-series RGB imagery could effectively quantify the variation of potato canopy development parameters under different nitrogen treatments and monitor the dynamic changes in plant dry matter accumulation. The regulation of canopy development parameters is of great importance and practical value for optimizing nitrogen management strategies and improving yield.

Comparative Analysis of Water Stress Regimes in Avocado Plants during the Early Development Stage.

The avocado cv. Hass requires a suitable rootstock for optimal development under water stress. This study evaluated the performance of two avocado rootstocks (ANRR88 and ANGI52) grafted onto cv. Hass under four water stress conditions, 50% and 25% deficit, and 50% and 25% excess during the nursery stage. Plant height, leaf area (LA), dry matter (DM), and Carbon (OC) content in the roots, stems, and leaves were measured. Root traits were evaluated using digital imaging, and three vegetation indices (NDVI, CIRE, and MTCI) were used to quantify stress. The results showed that genotype significantly influenced the response to water stress. ANRR88 exhibited adaptation to moderate to high water deficits. ANGI52 adapted better to both water deficit and excess, and showed greater root exploration. LA and DM reductions of up to 60% were observed in ANRR88, suggesting a higher sensitivity to extreme changes in water availability. More than 90% of the total OC accumulation was observed in the stem and roots. The NDVI and the MTCI quantified the presence and levels of stress applied, and the 720 nm band provided high precision and speed for detecting stress. These insights are crucial for selecting rootstocks that ensure optimal performance under varying water availability, enhancing productivity and sustainability.

Effect of adding fish emulsion and vermicompost on the growth of Tarragon (Artemisia dracunculus L.)

The experiment was carried out in the canopy of the Horticulture and Landscape Department - College of Agriculture - University of Kerbala during the spring semester of 2023. The study was implemented as a factorial experiment with a randomized complete block design (R.C.B.D.) with three replications. The experiment included two factors: fish emulsion (F), which was added at four concentrations: 0, 1, 2, 3% and added five times every two weeks, while the second factor was vermicompost (V), which was added before transferring the seedlings to the planting pots, at four levels: 0, 25, 50. 100 g pot-1. The results showed that adding fish emulsion had a significant effect on most vegetative growth traits, except for plant height and dry matter percentage, while adding Vermicompost had no significant effect on plant height and chlorophyll content of leaves, while it had a significant effect on the rest of the vegetative growth traits. The results of the intervention treatments between the study factors varied in their influence on the studied traits. The F4V4 intervention treatment gave the highest rate of plant height and number of branches, as it gave 85.16 cm and 32.50 branch plant-1, respectively, while the F2V3 treatment gave the highest rate of stem diameter of 3.127 mm, and F1V3 gave the highest rate of dry matter perce32wesaz2ntage, which gave 20.57%, and F3V3 the highest rate of leaf chlorophyll content, which gave 46.91 mg g-1 fresh weight. It can be concluded from this study that fertilizers resulting from organic waste can be used as fertilization sources for plants and combined with them to reduce the use of chemical fertilizers, reduce environmental damage, follow a sustainable agriculture system, and increase the efficiency of fertilizer use.

Evaluation of the Effect of Urea and Nanourea on Growth Pattern of Rainfed Bt Cotton (Gossypium hirsutum L.)

A field experiment was conducted to evaluate the effect of different levels of nitrogen through Nanourea and commercial urea with different time of nitrogen application on Bt Cotton (Gossypium hirsutum L.) Fifteen treatment combinations consisting of five different levels of nitrogen through nano urea and commercial urea such as (125% of RDN through nano urea, 100% of through nano urea, 75% RDN through nano urea, 100% RDN through commercial urea and control plot (No nitrogen)) were applied in three split applications of nitrogen at 30,60,90 DAS (40%,40%,20%), 30,60,90,120 DAS (25%,25%,25%,25%), 30,60,90,120 DAS (30%, 30%,20%,20%) were evaluated in split plot design with three replications. The highest absolute growth rates (AGR) for both plant height and dry matter in the context of application of nitrogen through commercial urea were observed during specific growth intervals: 61-90 days after sowing (DAS) for plant height (1.350 cm day-1 plant-1) and 91-120 DAS for dry matter (2.374 g day-1 plant-1). Similarly, when considering split application of nitrogen, the application of nitrogen at 30,60,90 DAS (40%,40%,20%) showed the highest AGR for plant height (1.054 cm day-1 plant-1) during 61-90 DAS and for dry matter (2.158 g day-1 plant-1) during 91-120 DAS. Furthermore, various growth parameters such as CGR, RGR, NAR, and LAI also exhibited their maximum values under both different levels of nitrogen and the mentioned split application of nitrogen.

Herbicidal and Nitrogen Efficacy on Weed Management in Wheat Fields of Eastern Uttar Pradesh, India

Weeds can significantly affect crop yield and nutrient uptake, making effective management crucial in wheat fields. This study, conducted during the winter (Rabi) season of 2018-19 at the Agricultural Research Farm of Banaras Hindu University in Varanasi, aimed to assess the combined impact of different nitrogen levels and herbicide treatments on weed control and wheat production. The objective was to determine the best practices for reducing weed competition and improving crop performance. The experiment was set up using a split plot design with three replications. The treatments comprised of 3 nitrogen levels and 5 weed control methods. The study identified nine prevalent weed species in wheat fields, including Phalaris minor, Anagallis arvensis, Cynodon dactylon, Chenopodium album, Melilotus indicus, Vicia sativa, Medicago denticulata, Solanum nigrum, and Cyperus rotundus, with Anagallis arvensis, Chenopodium album and Vicia sativa being the most dominant. The application of Sulfosulfuron (25 g ha-1) combined with 2, 4-D (750 ml ha-1) resulted in the lowest weed density and biomass and the highest weed control efficiency. Additionally, performing hand weeding twice (30 and 60 days after sowing) in conjunction with 180 kg N ha-1, followed by the application of Sulfosulfuron (25 g ha-1) + 2, 4-D (750 ml ha-1), significantly reduced Anagallis arvensis, Chenopodium album and Vicia sativa population and biomass and improved weed control effectiveness. Higher weed dry weight and population results in lower plant nutrient uptake and lower dry matter of crop plant and yield.

Impact of Crop Establishment Methods on the Growth and Yield Performance of Maize Varieties in the Kharif Season

A field trial was carried out in Pantnagar, Uttarakhand, India, during the Kharif season to evaluate the performance of maize varieties using various planting methods. The study included five distinct planting techniques: Flat, Bed, Ridgetop, Ridge mid-slope and Broad Ridge mid-slope both sides. Two maize varieties were tested: the composite PSM-1 and the hybrid DKC 9144. Results showed that the Broad Ridge mid-slope on both sides method led to the highest growth parameters, including; plant height, stem girth and dry matter accumulation per plant. During both the years, the Broad Ridge mid-slope planting method led to notable increase in plant height (7% and 6.1%), stem girth (5.25 & 4.67 cm) and dry matter accumulation (13.6% & 20.7%) respectively when compared to the flat planting method. Among the varieties, the hybrid DKC 9144 exhibited greater height, stem girth, more dry matter accumulation, grain and stover yields compared to the composite PSM-1. The findings suggest that the broad ridge mid-slope planting method, and hybrid variety DKC 9144, was the most effective and viable strategy for Kharif maize production in tarai region.

The Effects of Soil Acidity and Aluminium on the Root Systems and Shoot Growth of Lotus pedunculatus and Lupinus polyphyllus.

Lotus pedunculatus (lotus) and Lupinus polyphyllus (Russell lupin) persist in the upland grasslands of New Zealand, where soil acidity and associated aluminium (Al) toxicity impede conventional pasture legumes. This experiment investigated the response of lotus and Russell lupin to soil acidity and Al. The species were sown in 20 cm tall 1.2 L pots of acidic upland soil. A mass of 4.5 or 6.7 g lime (CaCO3)/L was added to either the top or bottom or both soil horizons (0-9 cm and 9-18 cm), resulting in six treatments across six randomised blocks in a glasshouse. The soil pH was 4.4, 4.9, and 5.4; the exchangeable Al concentrations were 24, 2.5, and 1.5 mg/kg for 0, 4.5, and 6.7 g lime/L. At 16 weeks post-sowing, the plants were divided into shoots and roots at 0-9 cm and 9-18 cm. Root morphology, shoot and root dry matter (DM), shoot nitrogen (N), and nodulation were measured. The total plant DM and shoot-to-root DM ratio were higher, and the shoot %N was lower for the lotus plants than the Russell lupin plants for the various lime rates (13.2 vs. 2.9 g plant-1, 5.6 vs. 1.6, and 2.4 vs. 3.3%, p < 0.05). No response to lime in terms of total DM or total root morphology parameters was exhibited in either species (p > 0.05). Root morphology adjustments in response to acidity between soil horizons were not observed. The results indicated that lotus and Russell lupin are tolerant to high soil acidity (pH 4.4-5.4) and exchangeable Al (1.5-24 mg kg-1), highlighting their considerable adaptation to grasslands with acidic soils.

Effect of Liquid Nano Urea Fertilizer on Periodical Growth and Yield of Sugarcane

A field experiment was carried out during rabi of 2021-22 as plant crop and 2022-23 as ratoon crop, at Navsari, Gujarat. The experiment was laid out in randomized block design including treatment comprising of nitrogen levels for soil application with foliar spray of nano urea and urea in both plant-ratoon system of sugarcane. The results recorded in respect to the periodical plant height and dry matter yield (DMY) from 90 to 180 days after planting (DAP) of plant crop and days after ratooning (DAR) of ratoon crop were significantly higher with the application of 100 % RDN (T2) which was at par with treatments T3 and T4. However, at 210 DAP of plant crop and DAR of ratoon crop as well as at harvest plant height and DMY were recorded significantly higher with the application of 75% RDN + 2 spray of liquid nano urea at 90 and 180 DAP which was at par with T2 and T4. In case of No. of tillers/hill at 180 DAP of plant and DAR of ratoon crop was significantly higher when with 75% RDN + 2 spray of liquid nano urea at 90 and 180 DAP which was at par with T2 and T4. In plant crop and ratoon crop of sugarcane, millable cane yield and green top yield were found to be significant highest with the application of 75% RDN + 2 spray of liquid nano urea at 90 and 180 DAP which was at par with T2 and T4. Based on the results, it concluded that for achieving higher growth and yield in sugarcane plant-ratoon cultivation should be fertilized with 100 % of recommended P2O5 and K2O + 75 % RDN + two sprays of either liquid nano urea @ 4 ml/L or 2 % urea at 90 and 180 DAP of plant crop and DAR of ratoon crop. This application effectively replaces the 25% of recommended dose of nitrogen while matching the performance of the 100% RDN treatment.

Drought Stress Tolerance in Rice: Physiological and Biochemical Insights

Rice (Oryza sativa L.), an important food crop, necessitates more water to complete its life cycle than other crops. Therefore, there is a serious risk to rice output due to water-related stress. Drought stress results in morphological changes, including the inhibition of seed germination, reduced seeding growth, leaf area index, flag leaf area, increased leaf rolling, as well as the decrement of yield traits, such as plant height, plant biomass, number of tillers, and 1000-grain yield. Stress also causes the formation of reactive oxygen species (ROS) such as O2−, H2O2, and OH−, which promote oxidative stress in plants and cause oxidative damage. The process of oxidative degradation owing to water stress produces cell damage and a reduction in nutrient intake, photosynthetic rate, leaf area, RWC, WUE, and stomatal closure, which may be responsible for the decrement of the transpiration rate and plant dry matter under decreasing soil moisture. Plants have the ability to produce antioxidant species that can either be enzymatic (SOD, POD, CAT, GPX, APX) or non-enzymatic (AsA, GSH) in nature to overcome oxidative stress. During drought, several biochemical osmoprotectants, like proline, polyamines, and sugars, can be accumulated, which can enhance drought tolerance in rice. To meet the demands of an ever-growing population with diminishing water resources, it is necessary to have crop varieties that are highly adapted to dry environments, and it may also involve adopting some mitigation strategies. This study aims to assess the varying morphological, physiological, and biochemical responses of the rice plant to drought, and the various methods for alleviating drought stress.

Foliar application of agrochemicals enhance growth, productivity, quality and biochemical traits of soybean

Flower drop, senescence of flowers and inadequate pod filling pose significant challenges in soybean cultivation as rapid nutrient extraction from leaves during the reproductive stage accelerates leaf aging. The present study assessed the effect of foliar application of agrochemicals on growth, productivity, quality and biochemical traits of soybean at two locations during kharif (rainy) season of 2021 and 2022. The experiment comprised of ten treatments of foliar application of agrochemicals [absolute control, water spray, potassium nitrate (KNO3) 1.5%, NPK (19:19:19) 1.5%, boron 0.3%, ammonium molybdate (AM) 0.5%, thiourea 750 parts per million (ppm), urea 2.0%, muriate of potash (MOP) 0.5% and salicylic acid (SA) 100 ppm] at flower and pod initiation stages along with the recommended dose of fertilizer (RDF) in a randomized complete block design replicated thrice. Results revealed that foliar application of boron 0.3%, urea 2.0% and MOP 0.5% at Ludhiana and MOP 0.5%, potassium nitrate 1.5% and urea 2.0% at Ballowal Saunkhri increased growth (plant height and dry matter accumulation), yield attributes (number of pods plant−1, number of filled pods plant−1 and 100-seed weight) and seed yield. These agrochemicals showed positive effects on the biochemical parameters with increased levels of proline and total phenol content as well as improvements in total soluble sugars, starch and protein content. The findings suggest that foliar application of agrochemicals (boron 0.3%, urea 2.0%, MOP 0.5% and potassium nitrate 1.5%) along with RDF can improve soybean growth and seed yield by mitigating the nutrient stress at reproductive stages.

Effect of Varieties and Nutrient Management on Growth and Yield of Wheat Crop under Irrigated Condition (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is the third most crucial staple food globally, providing essential nutrients and being widely utilized in various applications. A field experiment was conducted during the rabi season of 2022–2023 at Lovely Professional University's Agriculture Research Farm in Jalandhar, Punjab, to investigate the impact of different wheat varieties and nutrient treatments on growth and grain yield. The study utilized a factorial randomized block design with three replications and eight treatment combinations involving two wheat varieties: V1 (Unnat PBW 550) V2 (WH 1105) and four nutritional levels: N1 (control), N2 (100% RDF Recommended dose of fertilizer), N3 &amp; 15% VC (Vermicompost), and N4 (70% RDF &amp; 30% VC). The results showed that the N3 treatment significantly enhanced growth parameters, including plant height, number of leaves, tiller count, and dry matter accumulation. V2 (WH 1105) exhibited superior growth, with greater plant height (93.6 cm), leaf count (24.1 leaves/plant), and dry matter accumulation (54.57 g at 90 DAS).Yield attributes such as the number of effective tillers per plant, grains per spike, and 1000-grain weight were highest in the N3 treatment, with V2 (WH 1105) against outperforming V1 (Unnat PBW 550). Specifically, N3 treatment resulted in the highest number of effective tillers (6.0), grains per spike (58.16), and 1000-grain weight (39.40 g). Grain yield was maximized with the N3 treatment (57.15 q/ha), with V2 (WH 1105) producing a significantly higher grain yield (50.5 q/ha) compared to V1 (Unnat PBW 550). Additionally, the N3 treatment led to the highest straw yield (78.96 q/ha) and biological yield (136.11 q/ha). The harvest index was highest with the N2 treatment (42.35%), while V2 (WH 1105) showed a higher harvest index (41.97%) than V1 (Unnat PBW 550). These findings underscore the importance of nutrient management and variety selection in optimizing wheat growth and yield.

Effect of pruning height and organic fertilization on the morphological and productive characteristics of Moringa oleifera Lam. in the Peruvian dry tropics

Abstract The objective of the study was to evaluate the effect of pruning height (PH) and organic fertilization dose (FD) on the morphology and productive characteristics of Moringa oleifera Lam. We germinated seeds collected from 10-year-old shrubs, and 2-month-old seedlings were transplanted in the final field. We used a two-factor design of PH (PH1:0.4, PH2:0.8, and PH3:1.2 m from the ground) and FD (FD0:0, FD1:500, FD2:750, and FD3:1,000 g of decomposing goat manure). We carried out an initial pruning 4 months after transplanting and the harvests every 45 days. After three consecutive harvests, PH3 improved N° branches (12.53 ± 3.09) and dry matter (21.98 ± 1.30%), but PH1 showed greater stem lengths (1.65 ± 0.24 m) (p &lt; 0.01). There was no difference in the stems and leaf weights between PH2 and PH3, and no trait varied according to FD (p &gt; 0.05). The PH × FD interaction can improve the plant diameter (p &lt; 0.01) and dry matter (p &lt; 0.05) with PH2 (56.79 ± 3.71 mm) and PH3 (23.20 ± 1.04%) from FD1. We found an increasing trend in N° branches, plant diameter (p &lt; 0.01), and the leaf–stem ratio. However, in the third harvest, the biomass production trend was downward for a short period for an adequate replacement of nutrients from the incorporated organic fertilizer. It is recommended to prune M. oleifera at 1.2 m from the ground to stimulate greater biomass and maintain the leaf–stem ratio throughout the evaluated harvests and apply more than 500 g of goat manure after each harvest to restore the nutrients extracted from the soil.

The role of red and white light in optimizing growth and accumulation of plant specialized metabolites at two light intensities in medical cannabis (Cannabis sativa L.).

The cultivation of medical cannabis (Cannabis sativa L.) is expanding in controlled environments, driven by evolving governmental regulations for healthcare supply. Increasing inflorescence weight and plant specialized metabolite (PSM) concentrations is critical, alongside maintaining product consistency. Medical cannabis is grown under different spectra and photosynthetic photon flux densities (PPFD), the interaction between spectrum and PPFD on inflorescence weight and PSM attracts attention by both industrialists and scientists. Plants were grown in climate-controlled rooms without solar light, where four spectra were applied: two low-white spectra (7B-20G-73R/Narrow and 6B-19G-75R/2Peaks), and two high-white (15B-42G-43R/Narrow and 17B-40G-43R/Broad) spectra. The low-white spectra differed in red wavelength peaks (100% 660 nm, versus 50:50% of 640:660 nm), the high-white spectra differed in spectrum broadness. All four spectra were applied at 600 and 1200 μmol m-2 s-1. Irrespective of PPFD, white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased inflorescence weight, compared to white light with a single red peak of 660 nm (7B-20G-73R/Narrow) (tested at P = 0.1); this was associated with higher total plant dry matter production and a more open plant architecture, which likely enhanced light capture. At high PPFD, increasing white fraction and spectrum broadness (17B-40G-43R/Broad) produced similar inflorescence weights compared to white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks). This was caused by an increase of both plant dry matter production and dry matter partitioning to the inflorescences. No spectrum or PPFD effects on cannabinoid concentrations were observed, although at high PPFD white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased terpenoid concentrations compared to the other spectra. At low PPFD, the combination of white light with 640 and 660 nm increased photosynthetic efficiency compared with white light with a single red peak of 660nm, indicating potential benefits in light use efficiency and promoting plant dry matter production. These results indicate that the interaction between spectrum and PPFD influences plant dry matter production. Dividing the light energy in the red waveband over both 640 and 660 nm equally shows potential in enhancing photosynthesis and plant dry matter production.

Productive and Qualitative Traits of Sorghum Genotypes Used for Silage under Tropical Conditions

The aim of this study was to evaluate the productive potential, chemical composition, and fermentation profile of 24 genotypes of forage sorghum after ensiling. For this agronomic evaluation, a completely randomized block design with six replicates and twenty-four treatments was employed. Genotype 5 had the highest dry matter (DM) yield of 22.24 t/ha. The plant DM content ranged (p &lt; 0.001) from 271.8 g/kg of fresh matter (FM) in genotype 9 to 330.0 g/kg FM in genotype 3, averaging 302.9 g/kg FM. The crude protein and non-fibrous carbohydrates differed significantly (p &lt; 0.001) in the evaluated silages, with mean values of 61.0 and 275.3 g/kg DM, respectively. The pH of the sorghum silages also differed (p &lt; 0.001), despite having an average of 3.94, with values ranging from 3.68 to 4.27. No changes were observed (p &gt; 0.05) for the dry matter recovery of the sorghum genotype silages, which averaged at 853.9 g/kg FM. In the present study, genotype 5 resulted in being the most recommended genotype because it demonstrated a higher yield and higher nutritional value in both its fresh form and its ensiled form; had the lowest losses; and showed an ideal dry matter recovery after ensiling of 880 g/kg.

Evaluación de parámetros relacionados con el crecimiento de plantas de café (Coffea arabica L.) en respuesta al déficit hídrico del suelo

Contextualization: Water is indispensable for plant development, and its response to water deficit varies according to the species and their growth stages. Knowledge gap: The magnitude of the effect of soil water deficit on the growth of young coffee (Coffea arabica L.) plants evaluated over time is unknown. Purpose: Research was carried out to identify the effect of soil water deficit and, therefore, the sensitivity to drought in young coffee plants. Methodology: The deficit irrigation method was used. Coffee plants of the Cenicafé 1 variety were planted at three months old in cylindrical pots and conditioned for four months in mesh houses at Cenicafé - Planalto. After conditioning, the effect on plants' growth and dry matter subjected to five ranges of soil matric potential was evaluated over 140 days. Potentials ranged from -20±10 kPa (control) to -1600±100 kPa. Results and conclusions: The results showed that soil water deficit affects the growth of young coffee (C. arabica) plants, which could define C. arabica at this stage as drought sensitive. Plants subjected to the least stress and the extreme drought showed a 30% and 57% decrease in dry matter, respectively. For growth variables, the effect of water deficit was evident in the evaluations at 77, 113, and 140 days of treatment application. In all cases, the results showed differences between the extreme drought and the control of up to 30cm in height and equatorial diameter, 0.9 m2 of leaf area, 132 leaves, 3 branches, and 66 nodes. The mathematical models that explained the effect of drought on dry mass were of the logarithmic type. It was identified that for weather and soil conditions similar to those in the study, young coffee plants begin to deteriorate after 40 days of drought. With a soil matric potential close to -40 kPa, for a time of 120 days, coffee plants can lose 10% of dry mass, and when the potential exceeds -90 kPa there can be further losses in dry matter and decreases in the number of branches between the 77 and 113 days.

Impacts of soil type and drought stress on growth and cesium accumulation in Napier grass.

In our previous study, the decontamination efficiency of cesium-137 (137Cs) by Napier grass (Pennisetum purpureum Schum.) in the field was shown to be variable and often influenced by natural environmental factors. To elucidate the factors influencing this variable 137Cs-decontamination efficiency, we investigated the influences of soil type and drought stress on Cs accumulation using cesium-133 (133Cs) in Napier grass grown in plastic containers. The experiment was performed using two soil types (Soil A and B) and three different soil moisture conditions: well-watered control (CL), slight drought stress (SD), and moderate drought stress (MD). Overall, our results indicate that soil type and drought have a significant impact on plant growth and 133Cs accumulation in Napier grass. Plant height (PH), tiller number (TN), leaf width (Wleaf), and dry matter weight of aboveground parts (DWabove) and root parts (DWroot) in Soil B were greater than those in Soil A. Drought stress negatively affected chlorophyll fluorescence parameters (maximal quantum efficiency of photosystem (PS) II photochemistry and potential activity of PS II), PH, TN, Wleaf, DWabove, DWroot, and total 133Cs content (TCs), but it had a positive effect on 133Cs concentration. The 133Cs concentration in the aboveground parts (Csabove) was increased by MD approximately 1.62-fold in Soil A and 1.11-fold in Soil B compared to each CL counterpart. The TCs in the aboveground parts (TCsabove) decreased due to drought by approximately 19.9%-39.0% in Soil A and 49.9%-62.7% in Soil B; however, there was no significant effect on TCsabove due to soil type. The results of this study indicate that soil moisture is a key factor in maintaining Napier grass 137Cs-decontamination efficiency.

Nitrogen Fixation and Growth of Potted Olive Plants through Foliar Application of a Nitrogen-Fixing Microorganism

Given the importance of biological nitrogen (N) fixation in agroecosystems, using inoculants with phyllosphere N fixers effective across various crops would revolutionize agriculture. In this study, the application of an inoculant prepared from Methylobacterium symbioticum was tested on young olive trees. The pot experiment was arranged in a factorial design, with inoculant (Yes and No) and mineral N applied to the soil [0 (N0), 25 (N25), 50 (N50), and 100 (N100) kg ha−1], and four replicates. The inoculant application did not increase plant dry matter yield (DMY), whereas the application of mineral N had a significant and pronounced effect. The inoculant also did not significantly increase N concentration in tissues, unlike the strong increase observed with N applied to the soil. The inoculant significantly increased plant N recovery, a cumulative effect resulting from small increases in DMY and N concentration in tissues. This increase represented 5.2% more N in plants receiving the inoculant compared to untreated ones. However, only treatments receiving mineral N recorded positive values of fixed N, with the highest value observed in the N50 treatment (12.4%), whereas a negative value (−7.7%) was observed in the N0 treatment. Overall, these low values of fixed N question the economic rationale of using this inoculant by farmers and especially render it unsuitable for organic farming systems, where plants tend to have lower N levels in tissues.