Days Of Treatment Application Research Articles

Deciphering the effect of salinity and boron stress on broccoli plants reveals that membranes phytosterols and PIP aquaporins facilitate stress adaptation

Abiotic stresses, such as salinity and boron toxicity/deficiency, are prevalent in arid and semi-arid regions where broccoli is largely cultivated. This study aimed to investigate the physiological response of broccoli leaves to these stresses, focusing on parameters such as growth, relative water content, stomatal conductance, and mineral concentration after 15 days of treatment application. The effects of individual and combined stresses of salinity and boron (deficiency and toxicity) were examined. Additionally, the study explored the molecular aspects of PIP aquaporins in relation to their presence in the plasma membrane and their interaction with the lipid environment. The results showed that the combined stress of salinity and boron deficiency resulted in a significant reduction in plant biomass, suggesting a specific adaptation to this stress combination. Changes in stomatal conductance and mineral nutrient levels indicated that the adaptation mechanisms were associated with water and boron concentration in the leaves. The expression patterns of PIP aquaporins varied among the different stress treatments, either individually or in combination. Furthermore, the presence of aquaporins in the plasma membrane and microsomal fraction highlighted the potential regulatory roles of trafficking along with the membrane composition, particularly the concentration of phytosterols. The results underscore the importance of water transport by aquaporins and their interaction with the sterol composition in the membranes, in facilitating salinity-boron stress adaptation mechanisms.

DIURNAL CIRCADIAN VARIATION IN PHOTOSYNTHESIS IN Dracaena sanderiana UNDER CONTRASTING TEMPERATURE AND LIGHT

Dracaena sanderiana is prominent and in-demand cut foliage in the global ornamental industry. This study was conducted to examine the stress responses of Dracaena sanderiana under contrasting temperature and light conditions by using chlorophyll fluorescence (ChlF) transient analysis technique. D. sanderiana cuttings were held in distilled water and subjected to two different light levels, i.e., 22,500±2,000 lux and 750±200 lux allowing two distinct temperature levels. The chlorophyll fluorescence data were collected through OJIP analysis using a portable fluorometer (FluorPen, FP 110). The measurements were recorded four times a day (9 am, 12 pm, 3 pm, and 6 pm) and the data were collected continuously for four days commencing from the first day of treatment application. The major parameters derived from the OJIP analysis, including specific energy fluxes per reaction center (ABS/RC, TR/RC, ET/RC, and DI/RC), flux ratios (maximum quantum yield of primary photochemistry-φPo, electron transport efficiency -ψo, and quantum yield of electron transport –φEo and maximum quantum yield of non-photochemical de-excitation- φDo), and performance index (PI) were recorded. ChlF data showed a clear unimodal diurnal variation in plant performances of D. sanderiana at 22,500±2,000 lux. The circadian variation was reported for all measured ChlF parameters except the ψo, TR/RC, and ET/RC. Based on these circadian variations of ChlF, it can be concluded that D. sanderiana displays a facultative CAM pathway as an adaptation to the stressed conditions.

Eco-friendly management of rice weevil, [(Sitophilus oryzae L.) Coleoptera; Curculionidae] in Rupandehi, Nepal

An experiment to manage rice weevil (Sitophilus oryzae L. Coleoptera, Curculionidae) in wheat (Triticum aestivum L. Gramineae) was carried out at Institute of Agriculture and Animal Science (IAAS), Paklihawa Campus, Nepal. The experiment was conducted under completely randomized design with seven treatments viz. neem (Azadirachta indica A. Juss) @ 15 g/kg, tobacco (Nicotiana tabacum L)@ 10g/kg, ginger (Zingiber officinale Roscoe) @20g/kg, garlic (Allium sativum L.)@20g/kg, sichuwan pepper(Xanthoxylum alatum Roxb.)@10g/kg, sweet flag (Acorus calamus L.) @5g/kg, and control and replicated three times. The highest weevil mortality of weevils was observed in the wheat treated with A. calamus (98.33%,), followed by N. tabacum (85.67%), A. sativum (73.34%), A. indica (70.67%), Z. alatum (70.34%)and Z. officinale (58.34%). Similarly, the lowest percent weight loss (3.32 %) and seed damage (4.0%) was observed in wheat treated with A. calamus. Moreover, germination (89%) was observed in seeds treated with A. calamus when tested after 90 days of treatment application. Based on weevil mortality and germination test in this experiment, it is found that sweet flag is the best treatment against rice weevil followed by tobacco and garlic respectively. Therefore, these botanicals could be one of the effective alternatives for the management of weevil especially to the farmers who do not use chemical insecticides in rural area of Nepal.

Determination of nitrogen mineralization in an open dumpsite soil treated with poultry manure in Anyigba, Nigeria.

Nitrogen mineralization is the process of conversion of organic nitrogen to a useful form for plant use. A pot experiment was conducted at Soil and Environmental Management Department of Kogi State University Anyigba to determine nitrogen's mineralization rate in an open dumpsite soil treated with organic manure. About 1.6kg of soil sample was collected from Fallow land where no fertilizer history has been recorded and at three different dumpsite soil (Ate-Iji dumpsite (DS1), Ijebu-Ode dumpsite (DS2) and Iyale road dumpsite (DS3) ) in Anyigba at a depth of 0-15cm and was put inside a pot, which was replicated three times. The spacing between pots was 8m×5m range in completely randomized design (CRD). The soil's physicochemical properties were determined, 20g of poultry manure was added to each pot at a constant rate excluding the control pots (fallow land soil). The soil was stirred, and water was added at regular interval. The mineralization rate of nitrogen was determined after 14days, 28days and 56 days of treatment application. Nitrate (NO3-N), ammonium (NH4+–N) and nitrite (NO2-N) was calculated from total nitrogen. The data was analyzed, and treatments mean separated using Least Significant Difference (LSD). Poultry manure had a significant influence on the mineralization rate of nitrogen. DS3 soil gave the highest mineralization values for all the nitrogen forms. Highest values of 184.5mg/kg of NH4+ was recorded after 14days of mineralization in DS3 soil, while the highest value of 470.8mg/kg of NO2 -was recorded after 14days of mineralization in DS3 soil and the highest value of 634.5mg/kg of NO3- was recorded after 14days of mineralization compared to other dumpsite soil. The fallow land which serves as control gave the lowest mineralization values for all the nitrogen forms, and this indicated that organic manure has a greater impact in nitrogen mineralization in soil when applied to the soil within 28 days

Interactive Effect of Biochar and Silicon on Improving Morpho-Physiological and Biochemical Attributes of Maize by Reducing Drought Hazards

Maize (Zea mays L.) is one of the most important food and feed cereals of the world, but its production is threatened by sudden climate change especially drought. While, low organic matter in soils increases the drought severity. Therefore, study was planned to investigate the interactive effect of biochar and silicon (Si) nutrition on morpho-physiological and biochemical traits under water-deficit environment. Drought stress was applied subsequent 15 days of seedlings development. Experimental treatments comprised of CK (controlled soil no drought stress nor amended), only drought (40% water holding capacity (WHC)), drought + Si (40% WHC with 100 mg Si kg−1 soil), drought + biochar (40% WHC with 4 t ha−1), and drought + Si + biochar (40% WHC + 100 mg Si kg−1 soil +4 t ha−1). Data were collected after 15 days of treatment application. Drought reduced the growth of maize seedlings by reducing shoot biomass (38%), seedling weight (37%), photosynthetic rate (29%), transpiration rate (28.7%), and relative water contents (23.8%) and increased the activities CAT (30%), SOD (38.5%), and POD (33%). The positive effect of sole application of biochar and silicon was observed in improving physio-biochemical traits. In addition, better results were obtained with combined application of biochar and Si in enhancing maize growth such as shoots (25%), roots (40%), and seedlings (27%) as compared with drought. Combined application of biochar and Si may be a viable option to alleviate adversities of drought stress for maize growth and development.

English

Wheat production is dependent on costly insecticides that generate social and environmental issues. The growing demand for a rate reduction of spray applications and increased spray efficiency make essential the research for more adequate crop management. Therefore, this study aimed to evaluate technologies of imidacloprid application on wheat aphid, Schizaphis graminum and its natural enemies, Chrysoperla externa and Orius insidiosus. A set of experiments were performed to evaluate the effectiveness of S. graminum control and the toxicity to natural enemies using imidacloprid plus adjuvants sprayed with different nozzles and application rates. Improved S. graminum control was observed in the association between the adjuvant lauryl ether sodium sulfate and the hollow cone nozzle for both application rates (75 and 150 L ha-1), and the adjuvant copolymer of polyester + silicone + d-limonene with the asymmetric twin flat-fan nozzle at a low rate (75 L ha-1), since these treatments eliminate the wheat aphid after the fifth day of treatment application. The reduction of spray volume to wheat aphid control is possible with no loss of insecticide effectiveness. Imidacloprid associated with any one of the adjuvants tested is harmful to C. externa and O. insidiosus, even at the fifth day after application the insecticide continues being harmful to the natural enemies, regardless of the technology used.   Key words: Triticum aestivum, Schizaphis graminum, ecological disturbance, insecticide impacts, natural control, neonicotinoid.

Resin tapping transcriptome in adult slash pine (Pinus elliottii var. elliottii)

To better understand the bases of resin production, a major source of terpenes for industry, the transcriptome of adult Pinus elliottii var. elliottii (slash pine) trees under field commercial resinosis was obtained. Samples were collected from cambium after 5 and 15 days of treatment application, which included tapping followed by application of commercial resin stimulant paste or control wounding without paste. Overall mean number of reads of all 16 libraries (2 treatments x 2 times x 4 replicated trees) was 34,582,048. Of these, 89% were mapped against the reference sequence, with a mismatch of 0.58%. Using the Blast2Go, 570 candidate genes were detected based on sequence annotation. By comparing the expression profile between paste and control, 310 differentially expressed genes (DEGs) were identified at 5 days, and 190 at 15 days with a significant fold change of log2 > 1.2. Regarding changes in time comparisons within each treatment, 210 and 105 DEGs were identified within control and paste treatment, respectively. Genes with different expression patterns in the times and treatments examined included ethylene responsive transcription factors, geranylgeranyl diphosphate synthase, diterpene synthase, cytochrome P450 and ABC transporters, all of which may play important roles in resin production. RT-qPCR analysis correlated well with the data obtained by RNAseq. Resin composition changed over time. This is the first transcriptomic investigation of resinosis of the main species used in the bioresin industry and of molecular analyses of resinosis under field operations, with implications for stand management, stimulant paste development, genotype selection and breeding for high resinosis.

English

Dosage rates of 0.625, 1.25 and 2.5% of the leaves powder of Calpurnia aurea and Milletia ferruginea, and red and white inert dusts that were admixed with the 100 g of three resistance maize varieties were tested as protectant against maize weevils under laboratory condition. Significantly (p < 0.05) higher parental adult weevil’s mortality were recorded in all treatments of integration than untreated check at almost all days (except first day) after treatment. Mortality effects of the tested integrated components were also increased both with increased dosage and days after treatment. The mortality also became 100% in all treatments of integration applied at all rates, following 12 days of treatment application likewise the positive control. All treatments of integration applied at all rates also induced significantly (P < 0.05) higher (≥ 60.31%) protection of maize grains against F1 progeny emergence, grain damage (≤ 6.67) and weight loss (≤ 1.12) by S. zeamais than negative control. Besides, 100% inhibition of F1 progeny emergence, no percent grain damage and weight loss of maize grains were also observed in all of the three treatments of integration applied at dosage of 10% likewise also for that of the positive control. Therefore, integration of the aforementioned botanicals and inert dusts with resistant varieties applied at 2.5% and above (5 and 10%) rates were potent in preventing maize grains against maize weevils attack and could be used in the management of maize weevils as ecologically sound, safe and cheap weevil’s management alternatives under farmer’s storage conditions. Key words: Calpurnia aurea, Milletia ferruginea, red inert dust, white inert dust, Sitophilus zeamais,, resistant varieties.

Interaction Effects of 6-Benzylaminopurine (BAP) and Indole-3-Butyric Acid (IBA) on Ex Vitro Propagation of Sugarcane

Ex vitro propagation of micropropagated sugarcane plantlets of three selected sugarcane genotypes was carried out with the objective of evaluating their propagation responses to the interaction effects of BAP and IBA. Accordingly, six levels of IBA (0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mg L-1) and eight levels of BAP (0.0, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 and 2.25 mg L-1) with three sugarcane genotypes, each replicated three times were tested. The treatments were arranged in a factorial completely randomized design. Data on the number of tillers per shoot, average shoot length (cm) and number of active leaves per shoot were collected twice every 30th day after 30 days of treatment application. Analysis of variance revealed that the interaction effects of BAP, IBA and the sugarcane genotypes was very highly significant (P<0.0001) on the number of tillers per shoot, average shoot length and number of active leaves per shoot. The optimum number of tillers per shoot (5.67), average shoot length (40.77 cm) and number of active leaves per shoot (6.97) were obtained at 0.1 mg/l IBA+0.75 mg/l BAP in C132-81. In C86-56, the optimum number of tillers per shoot (4.50) was obtained at 0.1 mg/l IBA+1.5 mg/l BAP while the maximum average shoot length (48.33 cm) and maximum number of active leaves per shoot (7.67) were obtained at 0.2 mg/l IBA+0.75 mg/l BAP. In SP70-1284, the optimum number of tillers per shoot (6.43) was obtained at 0.3 mg/l+1 mg/l BAP with 16.05 cm average shoot length and 4.87 active leaves per shoot. Thus, it can be deduced that production of an average of 5.5 plantlets per shoot within a month can be possible.

Combate de malezas, en monocultivo de maní forrajero (Arachis pintoi).

We evaluated four chemical treatments (herbicides) used to fight weeds, as compared to manual weed picking and using a witness treatment. All treatments had a rotational handling with 6.5 animal units (12 animals of 250 kg per five haurs). We used a proteid bank or monoculture of forage peanut, in an arca of 1080 sq.mt., with a 30 days break. In order to evaluate the many variables, we used an experimen-tal design of complete random blocks, with six treatments and tree repetitions per treatment. In order to determine the coverage of the culture, its tolerance to the active ingredient and the level of treatment control, we carried out four evaluations: 0, 30, 60, and 90 days of treatment application. We found differences (P&lt;0.01) between treatments related to the degree of coverage of the forage peanut plants. With Gliphosate and manual weeding, we obtained a dominant coverage of forage peanut, while with the witness treatment the degree of coverage was inferior. The production of dry matter from the weeds, as well as their percentage in the pasture, decreased in a significant way (P&lt;0.01), through the sampling process. With the witness treatment we obtained the largest amount of dry matter in the weeds, and also the highest percentage of weeds in the pasture.

Fluoride Exposure Compromises Gas Exchange of Plants

Fluorine (F-) stands out for its phytotoxic potential, because it accumulates in plants, changes enzymes activity, reduces chlorophyll content and, consequently, affects growth and yield of crop plants. An experiment was conducted to evaluate the effects of F- on leaf gas exchange in coffee and sweet orange plants, compared to sensitive (gladiolus) and tolerant (ryegrass) reference species. Plants grown in pots were exposed to F- in a semi-open mist chamber. The experimental design was completely randomized with treatments defined by the combination of plant species and two intensities of exposure to atmospheric F, with nebulization of HF solutions (low = 0.065 mmol·m-3 and high = 0.260 mmol·m-3) in a mist chamber, as well as with non-exposed control samples. CO2 assimilation (A), transpiration (E), stomatal conductance (gs) and chlorophyll fluorescence rates were measured after 27 days of treatment application. The leaf gas exchange variables in ryegrass and orange plants did not vary in response to the increase in atmospheric F, while an increase in gs and E values was observed in gladiolus and coffee plants. A decrease in A and potential quantum efficiency of photosystem II (Fv/Fm) was found for gladiolus plants. On the contrary, an increase of A for coffee plants was associated with the apparent effect previously reported about the loss of leaf stomatal regulation related to the short assessment period of plants in this experiment. Damages caused to the photosynthetic system were reflected in the susceptibility of the evaluated species to the contamination by the element.

Growth, photosynthetic activity, and potassium and sodium concentration in rice plants under salt stress

Salt stress affects crop growth and productivity. In this study, we determined the growth, yield of photosystem II (PSII), and K+ and Na+ concentration in root, stem, old leaves, and young leaves of two Mexican varieties of rice, Tres Ríos and Cotaxtla. In addition, the K+/Na+ ratio in stem and root of both varieties was determined. The experiment was conducted in a growth chamber under controlled conditions, under a completely randomized distribution, with a 2 x 2 (Variety x Salinity) factorial arrangement and 12 replications. Plants were grown in a hydroponic solution for 15 days and then some of them were treated with 100 mM NaCl; control plants (without NaCI treatment) were grown in parallel. Salt stress caused 20 and 15% reductions in stem and root length, respectively, in the variety Tres Ríos, while in the variety Cotaxtla no significant differences were observed in these variables compared to the control. Dry matter weight decreased by 24% in the variety Tres Ríos. The quantum yield of PSII decreased by 30% the third day of treatment application, in both varieties. Na+ concentration was significantly (p ≤ 0.05) higher in NaCI-treated plants. In the variety Tres Ríos, the yield of PSII was completely eradicated six days after treatment implementation, while the K+ concentration in stem and older leaves also decreased and the lowest K+/ Na+ ratio in stem was recorded, which could indicate that it is more susceptible to salinity than the variety Cotaxtla.

Mycoremediation—a prospective environmental friendly technique of bioseparation and dewatering of domestic wastewater sludge

Environmental safe and friendly management and disposal of wastewater sludge is a problem of every treatment plant throughout the world. Bioseparation and dewaterability of raw domestic wastewater sludge were evaluated for proper management and disposal by mycoremediation, i.e., using prior grown 2% (v/v) spore suspension of filamentous fungal (Mucor hiemalis Wehmer) broth inoculation, which were grown in 2% (w/v) solution of malt extract and wheat flour for 48-60 h in orbital shaker. Within 2-3 days of treatment application, encouraging results were achieved in total dry solids (TDS), total suspended solid (TSS), turbidity, chemical oxygen demand (COD), specific resistance to filtration (SRF), and pH due to fungal treatment in recognition of bioseparation and dewaterability of wastewater sludge compared to control. The significant reduction of TDS was remarked at fungal biomass (FB) in wheat flour (WF) treatment. The removal of TSS, turbidity, COD, and SRF were observed 96.0%, 99.4%, 92.6%, and 97.6%, respectively, in supernatant at 5 days by FB in WF. The SRF measuring the dewaterability was decreased with maximum (0.26 × 10(-12) mg/kg) equivalent to 95.5% at 2 days in FB in WF also. FB in WF broth is a potential, environmental friendly, comparatively low-cost biological technique which might play the significant role for bioremediation and bioseparation of domestic wastewater sludge. The present technique may bring a dynamic change in treatment of wastewater in future.

Urea hydrolysis and lateral and vertical movement in the soil: effects of urease inhibitor and irrigation

A glasshouse-based study was conducted to investigate the effect of urease inhibitor N-(n-butyl) thiophosphoric triamide (‘Agrotain’) and irrigation on urea hydrolysis and its movement in a Typic Haplustept silt loam soil (in 72 repacked soil cores). Half (36) of these cores were adjusted to soil moisture contents of 80% field capacity (FC) and the remaining 36 cores to 50% FC. Granular urea with or without Agrotain was applied at a rate equivalent to 100 kg N ha−1. There were three replicates to these two sets of soil cores. After 1 day of treatment application, soil cores of the 50% FC were adjusted to 80% FC by applying surface irrigation. Twelve pots were destructively sampled at each day after 1, 2, 3, 4, 7 and 10 days of treatment application to determine urea hydrolysis and its lateral and vertical movement in different soil layers. Agrotain-treated urea delayed urea hydrolysis during the first 7 days after its application. This delay in urea hydrolysis caused by Agrotain enabled added urea, which is uncharged, to move away from the surface soil layer to the sub-surface soil layer both vertically and laterally. In contrast, most urea hydrolysed to soil NH4+ within 2 days of its application. Irrigation after 1 day resulted in further urea movement both laterally and vertically from the surface soil layer (0–10 mm) to the sub-soil layer (30–50 mm) in Agrotain-treated urea. These results suggest that Agrotain delayed urea hydrolysis and allowed more time for rainfall or irrigation to move added urea from the surface layer to sub-soil layers where it is likely to make good contact with plant roots. This distribution of urea in the rooting zone has the potential to enhance N use efficiency and minimize N losses associated with ammonia volatilization from surface-applied urea.

Antagonism of Nutrient-Activated Conidia of Trichoderma harzianum (atroviride) P1 Against Botrytis cinerea

ABSTRACT The effect of preliminary nutrient activation on the ability of conidia of the antagonist Trichoderma harzianum (atroviride) P1 to suppress Botrytis cinerea was investigated in laboratory, greenhouse, and field trials. Preliminary nutrient activation at 21 degrees C accelerated subsequent germination of the antagonist at temperatures from 9 to 21 degrees C; at >/=18 degrees C, the germination time of preactivated T. harzianum P1 conidia did not differ significantly from that of B. cinerea. When coinoculated with B. cinerea, concentrated inocula of preactivated but ungerminated T. harzianum P1 conidia reduced in vitro germination of the pathogen by >/=87% at 12 to 25 degrees C; initially quiescent conidia achieved this level of suppression only at 25 degrees C. Application of quiescent T. harzianum P1 conidia to detached strawberry flowers in moist chambers reduced infection by B. cinerea by >/=85% at 24 degrees C, but only by 35% at 12 degrees C. Preactivated conidia reduced infection by >/=60% at 12 degrees C. Both quiescent and preactivated conidia significantly reduced latent infection in greenhouse-grown strawberries at a mean temperature of 19 degrees C, whereas only preactivated conidia were effective in the field at a mean temperature of 14 degrees C on the day of treatment application. An antagonistic mechanism based on initiation of germination in sufficiently concentrated inocula suggests that at suboptimal temperatures the efficacy of Trichoderma antagonists might be improved by conidia activation prior to application.

High CO2 Storage Improves the Shelf Life of `Arapaho' and `Navaho' Blackberries

Application of modified-atmosphere storage (MA) (high carbon dioxide and/or low oxygen) extends the shelf life of several fruits. This study was done to determine the effects of MA on quality and flavor of blackberries. `Navaho' and `Arapaho' blackberries were harvested in 1998 and 1999, precooled overnight at 2 °C, and placed in 0.5-L treatment jars. Treatments of 15% CO2/10% O2 or of air (0.03% CO2/21% O2) were applied at 2 °C for 3, 7, or 14 days. After treatment application, jars were held at 2 °C for an additional 11, 7, or 0 days, respectively. Seven and 14 days of application of CO2 reduced the incidence of decayed and leaky berries by 10% to 20% for both `Arapaho' and `Navaho', but firm berries decreased 10% after 14 days of treatment. Titratable acidity was slightly lower, and pH higher, in control fruit but soluble solids content was not affected by treatment. Anthocyanin content was not affected by treatment in `Arapaho' berries but was lower in `Navaho' berries after 7 and 14 days of treatment. Samples taken for taste tests after 3 and 7 days of treatment had no off-odors or off-flavors. `Arapaho' and `Navaho' blackberries benefitted from high CO2 storage, with a minimum of 7 days of treatment application needed to increase marketable berries by 10%.

Effects of Milsana and Benzothiadiazole on the Ultrastructure of Powdery Mildew Haustoria on Cucumber

ABSTRACT Disease assessments and cytological investigations provided valuable information on the modes of action and efficacies of two prophylactic compounds, Milsana and benzothiadiazole (BTH), against powdery mildew development on long English cucumber. Milsana application significantly reduced disease incidence relative to inoculated controls through induction of localized resistance. Microscopic observations showed most haustoria had collapsed in the localized Milsana treatment and were encapsulated by an amorphous material impregnated by electron-opaque substances. The rapidity of haustorial collapse (within 4 days of treatment application) together with the encasement by electron-dense substances stained blue by toluidine blue O suggest that phenolics are possibly involved in the Milsana defense response. Cytochemical labeling of chitin with a wheat germ agglutinin/ovomucoid-gold complex showed that complete cellular disorganization of the fungus had occurred without disturbance to chitin in the walls of mycelia and haustoria. This may indicate that chitinolytic activity is not important in the Milsana-activated defense response. Application of high doses of BTH induced occasional cell wall thickening and accumulation of a compound that stained purple by toluidine blue O, but the defense response was weak, sporadic, and insufficient to reduce powdery mildew infection on cucumber. Responses to BTH could not be differentiated in terms of timing of the initial application or systemicity.