Total Dry Mass Research Articles

Do Stimulate® and Ascophyllum nodosum seaweed promote the morphophysiological characteristics of Cordia alliodora seedlings?

Biostimulants in native forest seedlings, when absorbed and assimilated by plants, can function as activators or inhibitors of their metabolic and physiological processes. In view of the above, the present study establishes the following research problem: Can doses of Ascophyllum nodosum seaweed extract and Stimulate® be effective in the promotion of initial growth and morphophysiological indices of Cordia alliodora seedlings? The experimental design used was completely randomized, in a 4 x 2 factorial scheme, corresponding to four doses (0, 0.2, 0.4 and 0.6 ml L-1) and two hormones (Ascophyllum nodosum and Stimulate®), with five replicates, each of which composed of five seedlings (one in each container). The morphological variables evaluated were shoot height (H), stem diameter (SD), increments in stem diameter (ΔSD) and shoot height (ΔH), shoot dry mass (SDM, g plant-1), root dry mass (RDM, g plant-1), total dry mass (TDM, g plant-1), and Dickson Quality Index (DQI). Physiological variables were: net assimilation rate (EA, g.m-2.day-1), leaf relative growth rate (RA, g.m-2.day-1), leaf area ratio (FA, m2.g-1), specific leaf area (SA, cm2.g-1) and leaf mass ratio (Fw, g.g-1). The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 promotes increments in height (ΔH) and stem diameter (ΔSD) of Cordia alliodora seedlings. Ascophyllum nodosum at dose of 0.2 ml L-1 has positive influence on the physiological indices studied in Cordia alliodora seedlings at 120 days after transplanting. The bioregulator Stimulate® at dose of 0.6 ml L-1 is not indicated to obtain Cordia alliodora seedlings with better quality and sturdiness and shorter nursery time. The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 is recommended to obtain increments in height (ΔH) and stem diameter (ΔSD) in Cordia alliodora seedlings

Growth and development patterns in Mustard (Brassica spp.) as influenced by sowing time

Mustard is Bangladesh's leading oil crop, produced only during the winter (rabi) season. The sowing date is a key factor determining mustard's optimum growth and development. Because of global warming, gradual changes in season and weather parameters over time is creating a challenge in mustard cultivation. Thus, the present investigation assessed the role of different planting dates on several modern mustard varieties to disclose the optimum growth indicators necessary for elevated biological yield (BY) and harvest index (HI). Three planting times, viz. 31st October (D1), 10th November (D2), 20th November (D3) and six varieties viz. Binasarisha-4 (V1), Binasarisha-9 (V2), Binasarisha-10 (V3), BARI Sarisha-14 (V4), BARI Sarisha-16 (V5), BARI Sarisha-17 (V6) were put on a replicated factorial randomized complete block design (RCBD) during rabi 2019 at BINA Sub-station farm, Magura. At the final harvest stage, outcomes depicted that highest and lowest total dry mass (g/plant) was produced by treatment D3× V5 (64.03) and D1× V1 (15.34), maximum and minimum absolute growth rate (mg/plant/day) by D1× V5 (2389.10) and D2× V1 (184.50), most and least relative growth rate (mg/g/day) in D1× V4 (53.34) and D2× V1 (3.55), maximum and least crop growth rate (g/m2/day) with D1× V3 (55.60) and D3× V4 (20.04). BY was the peak (8.13, 8.71, 8.77 t/ha) under all plantings (D1, D2, D3) with V5 variety, but HI (44.96%) was most in variety V4 with D2 sowing. Therefore, correlation studies showed a significant positive relationship between biological yield and harvest index. Overall, BARI Sarisha-16 performed well in all three sowing times, and remarkably, BY was rising with delayed planting in the case of Binasarisha-9, Binasarisha-10, and BARI Sarisha-14. This implies that delayed planting might not hamper yield but boost yield to some extent.

Metabolic, Nutritional and Morphophysiological Behavior of Eucalypt Genotypes Differing in Dieback Resistance in Field When Submitted to PEG-Induced Water Deficit

Dieback is a physiological disorder that has caused losses on eucalyptus plantations. Thinking that water stress is one of the triggers for the physiological disorder and aiming at the early identification of tolerant genotypes, we evaluated plantlets of four commercial clones with divergent behavior in field conditions. The plantlets were grown in a greenhouse where the drought conditions were provided by the application of polyethylene glycol 6000 solutions at 100 and 300 g L−1. After water deficit treatments, the morphological, physiological, nutritional and metabolic analyses were performed. SuzT maintained the carbon fixation and the instantaneous water use efficiency, even under water deficit, while sustaining growth. This resulted in higher leaf area and total dry mass in SuzT. Despite higher photosynthetic rate, SuzS exhibited reduced dry biomass accumulation, implying less efficient carbon use. SuzT revealed a higher level of calcium that supports cell structure and homeostasis and indicates higher capacity to manage specific resources and survival under water deficit. SuzT suffered reduction in some free amino acids; however, there was no significant variation for total amino acid content. The principal component and cluster analyses indicated that SuzMT and SuzTP genotypes behave similarly to SuzT under water deficit, while SuzS clustered in isolation. Our results support that there are common trends in water deficit responses for contrasting eucalypt genotypes. The existence of other strategies coping with water deficit resistance is not discarded and should be further evaluated.

Initial development of maize plants grown with different combinations of nitrate and ammonium

Corn is one of the main commodities of Brazilian agribusiness, due to its wide use, whether for human or animal consumption or in the chemical and biofuel industries. Thus, this work was carried out to evaluate the influence of different proportions of nitrate and ammonium in the initial development of corn plants. The experiment took place in a greenhouse, by direct sowing, where the seeds were placed at a depth of 1 cm in plastic pots with a capacity of 6 dm3 containing a mixture of previously sieved and washed with vermiculite, in a 2:1 ratio. Five proportions of nitrate and ammonium ions (NO3- :NH4+) were used: T1=100:0, T2=75:25, T3=50:50, T4=25:75 and T5=0:100, through nutrient solutions. After 35 days of cultivation, the following were evaluated: plant height, number of leaves, culm diameter, chlorophyll a, b, total and a/b ratio, root length, leaf fresh matter mass, dry matter mass of leaves, culm, roots, total dry mass, and root dry mass/shoot dry mass ratio, leaf area, specific leaf area, leaf area ratio, and leaf mass ratio. Nitrate as the only source of nitrogen provided a smaller increase in the chlorophyll a index of maize plants, which is the most important chlorophyll in the capture of light in the antenna complex. It is not recommended to cultivate corn plants with only nitrate or ammonium; however, it was observed that high doses of nitrate combined with low doses of ammonium in the culture medium provided satisfactory performance for most variables.

CHEMICAL CONTROL OF Colletotrichum gloeosporioides ON SEEDLINGS OF SINGLE ASSAI PALM

Anthracnose (Colletotrichum gloeosporioides) is the main disease affecting single assai palm seedlings and, therefore, a limiting factor to the production of quality seedlings. So far, there are no fungicide recommendations for the control of C. gloeosporioides in Euterpe precatoria. Thus, this study aimed to investigate the action of fungicides, such as pyraclostrobin + fluxapyroxad, as a possible alternative for controlling anthracnose in single assai palm seedlings. The experiment was installed in the nursery at Embrapa Acre, in a randomized block design, with seven treatments (0 – 0.155 – 0.187 – 0.218 – 0.250 – 0.281 – 0.312 μl of fungicide), with four replications of five plants. Evaluations were conducted for ten months regarding seedling height, stem diameter, number of leaves, shoot dry mass, root dry mass, total dry mass, and Dickson Quality Index. A visual scale ranging from 1 to 9 was used to assess the severity of the disease. The data were submitted to analysis of variance and regression analysis. Under the study conditions, the application of the active ingredient pyraclostrobin + fluxapyroxad reduced anthracnose severity by an average of 36.94% in single assai palm, providing better quality seedlings in the nursery.

Growth and development of Paspalum virgatum L.

The objective of the work was to evaluate the growth and development of the razor-blade grass (Paspalum virgatum L.). The experimental design was a randomized complete block design with 17 treatments, and the growth evaluations were performed at 20, 27, 34, 41, 48, 55, 62, 69, 76, 83, 90, 97, 104, 111, 118, 125, 132 days after sowing (DAS) and five replications, considering as sowing date the day the seeds were placed in the plastic boxes. The evaluated characteristics were: total dry mass (Mt), shoot dry mass (Ma) and dry mass of roots (Mr), number of leaves and number of tillers per plant. The quantitative variables related to plant growth were analyzed by applying the F test on the analysis of variance followed by non-linear log-logistic regressions, with the objective of modeling the data in the form of equations. The razor-blade grass (Paspalum virgatum L.) is a weed with slow initial development and growth, but with high dry mass production at the end of the cycle.

LANZA® Tedera Is Strongly Suppressed by Competition from Lolium multiflorum and Is Best Adapted to Light-Textured Soils

Bituminaria bituminosa var. albomarginata, known as Tedera, is a promising forage for Mediterranean climates. An improved variety named LANZA® has been developed. Previous research suggests that soil water saturation in heavy-textured soils might affect its initial development. Competition from grasses could also compromise its successful establishment and persistence. We investigated the effects of soils with contrasting textures (loamy sand vs. clay) with a high soil water content and the competition from Lolium multiflorum on the development of LANZA® in a pot experiment. Dry mass (DM) production of LANZA® was strongly reduced (86%) when grown with L. multiflorum. LANZA® shoot DM was 60% higher than the total shoot DM production of the mixture of LANZA® and L. multiflorum. Soil type did not significantly affect the shoot and total root DM. However, a 44% reduction of the DM of thin roots and slower development was observed in clay soils, which may indicate a preference for light-textured soils. This study provides further information on the factors limiting the establishment and persistence of LANZA®. Future research should confirm these results at field scale and investigate measures aimed at reducing early competition in monocultures and functional complementarity with partner species in mixtures to successfully establish LANZA®.

Homeopatic for treatment of cucumber seeds contaminated with auxinic herbicide

The aim of the present study was to investigate the use of homeopathic preparations to reduce the harmful effects caused by auxin herbicide residues on seed germination and early development of cucumber seedlings. The statistical design was completely randomized (DIC) in a 3x5+2 factorial scheme, with four replications. The treatments were the combination of three homeopathic preparations (Nux vomica, Carbo vegetabilis and Arsenicum album), in five centesimal dynamizations (6CH; 12CH; 18CH; 24CH and 30CH), plus two controls (T0= distilled water and TH = herbicide (Artys™) without homeopathic treatment). Each experimental unit consisted of transparent acrylic boxes (Gerbox™) with 25 cucumber seeds, distributed over two sheets of paper for germination and moistened with homeopathic treatments. The experimental units were kept in a BOD germination chamber (in a controlled environment at 25 ºC and 12 ho of light). On the tenth day after the installation of the experiment, the following variables were evaluated: percentage of germination, shoot length, root length, phytointoxication, percentage of dead seedlings and total dry mass. The homeopathic treatment of cucumber seeds contaminated with picloram + 2,4-D herbicide (Artys™) causes positive changes, causing interesting effects on seed germination, but it is not efficient for the total neutralization of the effect caused by the herbicide 2 picloram + 2,4-D and development of early cucumber seedlings. However, for some variables, the results are inconclusive with the preparations (Nux vomica, Carbo vegetabilis and Arsenicum album), and their ultradilutions (6CH, 12CH, 18CH, 24CH and 30CH), requiring more research to evaluate and describe the complexity of properties inherent to homeopathic treatment.

TOLERANCE OF MARANDU GRASS TO EXCESS IRON AND MANGANESE

In soaked soils there is an increase in the availability of iron and manganese. Thus, it becomes important to investigate the tolerance levels of plants to excess of these nutrients. The objective was to evaluate the tolerance of Urochloa brizantha cv. Marandu cultivated in nutrient solution with different levels of iron and manganese. The experimental design was completely randomized with seven treatments and four replications. The treatments consisted of a nutrient solution and consisted of: 1- adequate concentration of Fe (8.22 mM) and Mn (2.05 mM); 2– Fe, four times the adequate concentration; 3– Fe, eight times the adequate concentration; 4– Mn, four times the adequate concentration; 5– Mn, eight times the adequate concentration; 6– Fe and Mn, four times the appropriate concentration, and; 7– Fe and Mn, eight times the appropriate concentration. The variables evaluated were visual diagnosis (symptomatology), shoot height, root volume, Fe and Mn content in shoots and dry mass production. Grass plants were not tolerant to excess Fe and Mn. The excess of nutrients promoted less development of the root system, with a reduction in volume and dry mass, and the treatment with the highest dose of nutrients resulted in the lowest values. Grass plants were sensitive to the increase in nutrient concentrations, showing reductions in total dry mass production of 55% for treatment with the application of the highest concentration of nutrients in relation to the adequate dose of Fe and Mn.

Tratamentos pré-germinativos em sementes de pitaya (Hylocereus spp.) para atenuação do estresse hídrico

ABSTRACT The use of mitigating agents to minimize the deleterious effects of water stress is a promising alternative for plant species, especially during germination and initial seedling development. Thus, the objective was to evaluate the effect of different pre-germination treatments as mitigating agents of water stress during germination and initial development of pitaya seedlings of the species Hylocereus undatus and H. costaricensis. The experiment was carried out in a completely randomized design, in a 2 x 6 factorial scheme, corresponding to two pitaya species and six pre-germination treatments (T1 = 0.0 MPa (control), T2 = -0.2 MPa (water stress); T3 = hydropriming + water stress; T4 = gibberellic acid + water stress; T5 = salicylic acid + water stress and T6 = thiamethoxan + water stress) with four replicates of 50 seeds. The variables analyzed were germination, germination speed index, shoot and primary root lengths, total dry mass, total soluble sugars and total free amino acids. The water potential of -0.2 MPa is limiting for germination and initial growth of H. costaricensis and H. undatus, with H. undatus being more tolerant to water stress in the germination phase. Pre-germination treatments with hydropriming, gibberellic acid, salicylic acid and thiamethoxan improve the physiological performance of H. costaricensis seeds, with gibberellic acid being the best attenuator of water stress. Gibberellic acid improves the physiological performance of H. undatus seeds under water deficit conditions.

Potential of Desmodesmus abundans as biofertilizer in common bean (Phaseolus vulgaris L.)

Microalgae are source of macro- and micronutrients, phytohormones, lipids and carbohydrates, in addition to having an excellent adaptive capacity to the most diverse environments. Due to this, they have gained prominence in the biofertilizer industry. In this work, we evaluated the potential Desmodesmus abundans L2B Bold biofertilizer in bean cultivar “Pérola”. Microalgal biomass (107 cells mL−1) was applied to bean plants by manual irrigation starting at 15 days after sowing (DAS) and then every 10 days thereafter. The total number of pods and seeds, leaf fresh and dry mass, root dry mass, and total fresh and dry mass were positively influenced by microalgae biofertilizer. The leaf pigments were significantly (p < 0.05) increased with the use of D. abundans L2B Bold. This increase was of approximately 30% in chlorophyll a and b content with the application of biofertilizer 17 DAS and 7% in the middle of the crop cycle (37 DAS). The biofertilizer also significantly (p < 0.05) impacted foliar enzymatic activity with superoxide dismutase (SOD) being increased during all the crop cycle. Phenylalanine ammonia-lyase (PAL) presented higher activity under microalgae use, being increased approximately 120%–1500% in biofertilized plants in the middle and at the end of the crop cycle, respectively. There were significant(p < 0.05) increases in K and Ca of seed beans contents with the application of biofertilizer. Based on our results, we conclude that D. abundans L2B Bold has great potential for use as a biofertilizer in bean crop.

Forage Mass Estimation in Silvopastoral and Full Sun Systems: Evaluation through Proximal Remote Sensing Applied to the SAFER Model

The operational slowness in the execution of direct methods for estimating forage mass, an important variable for defining the animal stocking rate, gave rise to the need for methods with faster responses and greater territorial coverage. In this context, the aim of this study was to evaluate a method to estimate the mass of Urochloa brizantha cv. BRS Piatã in shaded and full sun systems, through proximal sensing applied to the Simple Algorithm for Evapotranspiration Retrieving (SAFER) model, applied with the Monteith Radiation Use Efficiency (RUE) model. The study was carried out in the experimental area of Fazenda Canchim, a research center of Embrapa Pecuária Sudeste, São Carlos, SP, Brazil (21°57′S, 47°50′W, 860 m), with collections of forage mass and reflectance in the silvopastoral systems animal production and full sun. Reflectance data, as well as meteorological data obtained by a weather station installed in the study area, were used as input for the SAFER model and, later, for the radiation use efficiency model to calculate the fresh mass of forage. The forage collected in the field was sent to the laboratory, separated, weighed and dried, generating the variables of pasture total dry mass), total leaf dry mass, leaf and stalk dry mass and leaf area index. With the variables of pasture, in situ, and fresh mass, obtained from SAFER, the training regression model, in which 80% were used for training and 20% for testing the models. The SAFER was able to promisingly express the behavior of forage variables, with a significant correlation with all of them. The variables that obtained the best estimation performance model were the dry mass of leaves and stems and the dry mass of leaves in silvopastoral and full sun systems, respectively. It was concluded that the association of the SAFER model with the proximal sensor allowed us to obtain a fast, precise and accurate forage estimation method.

Kin and Non-Kin Connected Plants Benefit More Than Disconnected Kin and Non-Kin Plants under Nutrient-Competitive Environments.

In the natural environment, plants grow and interact with both conspecific and heterospecific neighbours under different environmental conditions. In this study, we tested whether Chenopodium quinoa Willd genotypes differ in growth performance when grown with kin and non-kin under nutrient limitation in pot partitioning treatments. Biomass accumulation, allocation, organ efficiency, and specific leaf area were measured at the end of the experiment. Response variables were differentially impacted by kinship, fertility, and barrier. Total dry mass, shoot dry mass, and root and stem allocation were greater for plants grown with kin in connected pots than with non-kin in connected pots across the nutrient treatments. Kin connected and disconnected plants had a greater specific root length, specific stem length, and average leaf mass than non-kin connected and disconnected plants. Non-kin connected and disconnected plants had greater LAR and SLA than kin connected and disconnected plants under low- and high-nutrient treatments. Plants always grew better in the presence of their kin than non-kin. These results conclude that quinoa plant production benefits from planting closely related individuals under both high- and low-nutrient conditions.

Partição de fotoassimilados em plantas de quiabo submetidas a doses de nitrogênio

ABSTRACT Nitrogen (N) is the third nutrient more absorbed by okra. Therefore, an adequate supply of this element is essential for okra growth through the accumulation of dry matter in the leaves, stem, root and fruit. The objective was to evaluate the influence of N doses on growth, photoassimilates partition and yield of okra. The experiment was carried out in a Red-Yellow Argisol. A randomized complete block design with four replicates was used. The treatments consisted of N doses applied as topdressing (0, 60, 120, 240, 360 kg/ha). Samples of plants were held at 60, 75, 90, 105, 120, 135, 150 and 165 DAS for determination of the plant’s dry weight. The plant showed slow growth until 70 days, and after that time, intensified its growth until the end of the cycle. Total dry mass and absolute plant growth rate increased with increasing N availability, reaching the maximum marketable fruit yield of 10,665 kg/ha with 346 kg/ha N. The growth and partition of photoassimilates among the organs of the okra plant ‘Santa Cruz’ are altered with increasing nitrogen availability applied in topdressing.

Produção de mudas pré-brotadas de cana-de-açúcar utilizando-se bagana de carnaúba como substrato

ABSTRACT Sugarcane seedling quality is strongly influenced by the substrate used. Currently, alternative substrate sources from the sugarcane industry itself have been used; however, there is no specific substrate to produce pre-sprouted seedlings. This study aimed to evaluate the quality of pre-sprouted sugarcane using substrates with different proportions of carnauba bagana (0, 20, 40, 60, 80 and 100 %) plus soil. The experimental design was completely randomized, with six treatments and five replicates. Pre-sprouted seedlings cultivated using substrate composed by 80 % of carnauba bagana showed the best response for number of leaves, diameter, shoot length, shoot, root and total dry mass, and Dickson Quality Index, owing to the improvement in the substrate physical and chemical characteristics.

Electrical Conductivity and Nitrogen:Potassium Ratios from Nutrigation in the Quality of Zucchini Fruits

HIGHLIGHTS Electrical conductivity (EC) and N:K ratios modify zucchini fruit size. Organoleptic characteristics of zucchini fruits increase with EC. Total dry mass production of plants showed interaction between N:K ratio and EC.

Effect of using repeated and siderate crops on soil fertility, yield of cotton varieties, and technological quality indicators of cotton fiber in short rotation cropping systems

In the 1:1 (cotton:grain) system of short-rotation, soybean, bean, mung bean crops were harvested as a repeat crop after winter wheat. Their stem crop and mixed siderate crops (perco, oats, green peas) were planted in the second half of August, and the blue mass crop grown in October-November was harvested for livestock. The lower 15-20 cm part of the stem was plowed under the plow as a blue manure, at the end of one rotation, the amount of organic carbon in the soil increased by 0.041-0.073%, and the total nitrogen content by 0.012-0.016% compared to the initial values. The highest rate of dry mass accumulation of cotton was observed when using short-row rotation 1:1, winter wheat + mixed siderate crops (perco, oat, green pea):cotton system. The dry mass of the leaves of the Navroz variety of cotton was 22.6 g, the dry mass of the stem was 33.4 g, the dry mass of the bolls was 18.5 g, and the dry mass of the cotton was 48.0 g. The total dry mass of 1 plant was equal to 122.5 g. In the 1:1 (cotton:grain) system of short-rotation, when cotton was grown as a repeat crop after legume-cereal (soybean, mung bean) and mixed siderate (perco, oat, green pea) crops, it provided a higher and better quality cotton yield. Cotton yield was 3.2-5.8 tons/ha, fiber output was 1.0-1.5 percent, and 1000 seed mass was 9.0-11.0 g/ha. Besides, the length of the fiber was found to be higher by 1.4-2.0 mm.

Arbuscular mycorrhizal fungi activity in the rhizosphere of tree seedlings subjected to residual herbicides.

Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.

Response of Strawberry to the Substitution of Blue Light by Green Light in an Indoor Vertical Farming System

Indoor production systems with light emitting diode (LED) lamps are a feasible alternative for increasing strawberry productivity by reducing the incidence of pests and diseases and the damage caused by extreme weather events. Blue (BL) and red (RL) LED light are considered the most important light spectra for photosynthesis and crop yield; however, recent studies have demonstrated that the beneficial effects of green light (GL) have been underestimated. This information would be of particular importance for strawberry production in controlled-environments/vertical farming systems as it may lower input costs and enhance production efficiency and quality and marketability. The present study aimed to define the effect of GL in combination with BL in strawberry. A proportion of 20% GL (20% BL + 60% RL) of total photosynthetic photon flux density was beneficial for plant growth and productivity; however, a 27% GL (12% BL + 61% RL) proportion was detrimental or comparable to that with 6% GL (36% BL + 58% RF). Total dry mass increased 51% when plants were illuminated with 20% GL lamps compared to those with 6% GL; the most impacted plant part was the root as it increased by 155%. The higher yield was observed with GL at 20%, but further increasing GL to 27% resulted in reduced yield. GL at 20% and 27% exhibited higher photosynthesis but reduced transpiration, stomatic conductance, and internal CO2, which in turn increased instantaneous and intrinsic water-use efficiency. Plants with the highest yield (20% GL) exhibited lower total soluble solids in fruits but still the values obtained were acceptable (8.25 °Brix); these fruits contained a high total sugars and phenolics concentration but a reduced antioxidant scavenging capacity. High proportions of GL were associated with a higher leaf and fruit Ca and a higher leaf P and K, which may be due to the increased allocation of biomass to the roots. In conclusion, GL at 20% and BL at 20% resulted in the best growth and yield parameters, enhanced net photosynthesis rate, water-use efficiency and fruit quality attributes. The effects of GL observed in this study may also be important for other high-value horticultural crops suitable for indoor vertical farming.

Wheat Straw Burial Enhances the Root Physiology, Productivity, and Water Utilization Efficiency of Rice under Alternative Wetting and Drying Irrigation

This study evaluated whether the straw burial and alternative wetting and drying (AWD) irrigation could improve the root activity, yield, and water utilization efficiency (WUE) of rice. Accordingly, we conducted a field experiment with three straw burial levels, i.e., with no straw burial (NSB), low straw burial 300 kg.ha−1 (LSB), and dense straw burial 800 kg.ha−1 (DSB), and three irrigation regimes, i.e., alternate wetting/moderate drying (AWMD), alternate wetting/severe drying (AWSD), and alternate wetting/critical drying (AWCD). Results showed that straw burial improved the root activity, rice yield, and WUE under AWD regimes. The combination AWMD×DSB resulted in the greatest values of total dry mass (1764.7 g/m2) and water use (853.1 mm). Conversely, the treatment AWCD × NSB led to the lowest values of total biomass (583.3 g/m2) and water use (321.8 mm). Root dry weight density (1.11 g cm−3) and root active absorption area (31.6 m2 plant−1) were higher in the treatment AWMD × DSB than root dry weight density (0.41 g cm−3) and root active absorption area (21.2 m2 plant−1) were in the treatment AWCD×NSB. The former combined treatment increased root oxidation ability (55.5 mg g−1 FWh−1), the root surface phosphatase activity (1.67 mg g−1 FWh−1) and nitrate reductase activity of root (14.4 μg g−1 h−1) while the latter considerably reduced the values of root oxidation ability (21.4 mg g−1 FWh−1), the root surface phosphatase activity (0.87 mg g−1 FWh−1) and nitrate reductase activity of root (5.8 μg g−1 h−1). The following conclusions can be drawn with regard to water use and biomass yield. (i) The reduction in water consumption was greater than the reduction in yield in the case of AWSD. (ii) The decline in water consumption was less than the decline in biomass yield in the case of AWCD. (iii) The increase in in water consumption was greater than the increase in biomass yield in the case of AWMD. Therefore, the indicators of WUE were recorded in the following order: AWSD &gt; AWMD &gt; AWCD. This study recommends AWD irrigation to improve the root growth traits that contribute to the greater biomass yield of rice. It also suggests that farmers should implement AWD irrigation after leaving wheat straw residues in the field, and followed by deep tillage, to mitigate the negative effect of drought stress caused by AWD irrigation, preserving plant growth without large biomass losses, and thus, addressing the constrains of straw residues and sustaining rice production under limited freshwater resources.