Plant Dry Matter Accumulation Research Articles

Comparação das distribuições Normal, Logística, Laplace e t de Student para o erro experimental na descrição bayesiana do acúmulo de matéria seca de Allium sativum

ABSTRACT: This study assessed distributions associated with Bayesian nonlinear modeling error in the description of total plant dry matteraccumulation (TDMA) of Allium sativumas a function of days after planting (DAP). According to the DIC criterion, Logistic and Gompertzmodels that use student’s t distribution error exhibited the highest DIC with logistic error distribution. In general, the difference of DIC in all the scenarios was not more than 5.The Bayes factor (BF) criterion showed no difference in the Logistic and Gompertzmodel fit when four distributions are used for the errors, where BF values do not exceed 2. Posterior distributions and the usual estimators of Logistic and Gompertz model parameters were similar even forvaried error distribution. In summary, there was no difference in the use of 4 distributions associated with the modeling error of garlic plant growth by the Bayes factor, whereby the results showed that alternating between error distributions significantly changes the number of Markov Chain Monte Carlo (MCMC) iterations.

Aeration Alleviated the Adverse Effects of Nitrogen Topdressing Reduction on Tomato Root Vigor, Photosynthetic Performance, and Fruit Development.

To explore the compensation effect of aeration on tomato vegetative and reproductive growth in arid and semi-arid areas, a two-year field experiment was conducted with four micro-nano aeration ratios (0%, 5%, 10%, and 15%) and three nitrogen topdressing levels (80, 60, and 40 kg·ha-1) during the tomato growth period in Ningxia, China. The results showed that increasing the aeration ratio in the range of 0-15% was conducive to the enhancement of tomato root vigor (the ability of triphenyltetrazolium chloride to be reduced, 3-104%) and the leaf net photosynthetic rate (14-63%), favorable to the facilitation of plant dry matter accumulation (3-59%) and plant nitrogen accumulation (2-70%), and beneficial to the improvement of tomato yield (12-44%) and fruit quality. Interestingly, since the aeration ratio exceeded 10%, the increase in the aeration ratio showed no significant effects on the single-fruit weight, tomato yield, and fruit quality. Moreover, with aerated underground drip irrigation, properly reducing the traditional nitrogen topdressing level (80 kg·ha-1) by 25% was favorable for enhancing tomato root vigor (5-31%), increasing tomato yield (0.5-9%), and improving fruit soluble solid accumulation (2-5%) and soluble sugar formation (4-9%). Importantly, increasing the aeration ratio by 5% could compensate for the adverse effects of reducing the nitrogen topdressing level by 25% by improving the leaf photosynthetic rate, promoting plant dry matter accumulation, increasing tomato yield, and enhancing the soluble solid and soluble sugar accumulation in tomato fruits. Synthetically considering the decrease in the nitrogen topdressing amount, leading to plant growth promotion, a tomato yield increase, and fruit quality improvement, a favorable nitrogen topdressing level of 60 kg·ha-1 and the corresponding proper aeration ratio of 10% were suggested for tomato underground drip irrigation in the Yinbei Irrigation District of Ningxia.

Response of Fertility Levels and Biofertilizers on Growth and Yield Attributes Quality of Chickpea (Cicer arietinum L.) Crop

The experiment was conducted on agricultural research form with split plot design in four main treatments: F1 (control), F2 (100% recommended dose of fertilizer-RDF), F3 (75% RDF), and F4 (50% RDF), and three sub-plot treatments: B1 (Rhizobium + PSB), B2 (Rhizobium + PGPR), and B3 (Rhizobium + PSB + PGPR), each replicated three times. Growth parameters such as plant height and dry matter accumulation were significantly influenced by both fertility levels and biofertilizers. Chickpea plants showed higher growth parameter values and root parameter when treated with 100% RDF (F2). Similarly, biofertilizer treatments, particularly Rhizobium + PSB + PGPR (B3), followed by 75% RDF (F3). Root dry weight per plant was significantly affected by both fertility levels and biofertilizers across all growth stages except at 30 days after sowing (DAS). The number of pods per plant and the number of seeds per pod were significantly influenced by both fertility levels and biofertilizers at all growth stages except at 30 DAS and in the case of 100 seed weight. Chickpea plants treated with 100% RDF (F2) exhibited higher values for both the number of pods per plant and the number of seeds per pod.

Effect of Foxtail Millet Cultivars on Yield and Yield Attributes under Different Sowing Windows

The investigation conducted at the Agronomy Farm, College of Agriculture, Pune, during the Kharif season of 2022 focused on the "Effect of foxtail millet cultivars on yield and yield attributes under different sowing windows." The study employed a split-plot design with sixteen treatments and three replications, involving four sowing dates (26 MW, 28 MW, 30 MW, and 32 MW) and four foxtail millet varieties (SiA 3156, SiA 3085, Suryanandi, and Renadu). The soil, a clay loam with slightly alkaline pH, low nitrogen, medium phosphorus, and high potassium levels, received RDF 60:30:30 N: P2O5: K2O kg ha-1 at sowing. The investigation monitored various growth parameters, including plant height, number of tillers, number of functional leaves, and dry matter accumulation, at different growth stages. The study revealed that early sowing at 26 MW significantly influenced plant height, number of tillers, and dry matter production, favoring greater vegetative growth. The Renadu variety consistently exhibited superior performance in plant height, tiller count, and dry matter accumulation compared to other varieties. Days to 50% flowering and maturity were significantly affected by both sowing dates and varieties, with early-sown crops taking more days to reach these stages. Grain yield, straw yield, and harvest index were influenced by sowing dates and varieties, with the combination of the Renadu variety and 26 MW sowing exhibiting the highest grain yield and straw yield. Renadu also displayed a superior harvest index, emphasizing its suitability for optimal growth and yield. The study recommends sowing foxtail millet on 26 MW or 28 MW, particularly with the Renadu variety, for achieving maximum growth and yield during the Kharif season. The findings highlight the significance of considering both sowing windows and foxtail millet varieties to optimize production in the given agro-climatic conditions of Pune, Maharashtra.

Metabolic Adaptations in Rapeseed: Hemin-Induced Resilience to NaCl Stress by Enhancing Growth, Photosynthesis, and Cellular Defense Ability.

This study aimed to investigate whether presoaking with hemin (5 μmol·L-1) could alleviate NaCl stress during rapeseed seedlings' growth and its role in the regulation of photosynthesis. In this experiment, 'HUAYOUZA 62 (HYZ 62)' and 'HUAYOUZA 158R (158R)' were used as materials for pot experiments to study the morphology, photosynthetic characteristics, antioxidant activity, and osmoregulatory factors of seedlings under different salt concentrations, as well as the regulatory effects of hemin-presoaked seeds. Our findings revealed that, compared the control, NaCl stress inhibited the growth of two rapeseed varieties, decreased the seedling emergence rate, and increased the content of malondialdehyde (MDA), the electrolyte leakage rate (EL) and antioxidant enzyme activity. Hemin soaking alleviated the adverse effects of salt stress and increased plant height, root elongation and dry matter accumulation. Compared with all NaCl treatments, hemin significantly enhanced photosynthetic indexes, including a percent increase of 12.99-24.36% and 5.39-16.52% in net photosynthetic rate (Pn), 17.86-48.08% and 8.6-23.44% in stomatal conductivity (Gs), and 15.42-37.94% and 11.09-19.08% in transpiration rate (Tr) for HYZ62 and 158R, respectively. Moreover, hemin soaking also increased antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), reducing the malondialdehyde, and thus resulting in the alleviation of oxidative damage caused by NaCl stress. Furthermore, hemin stimulated the formation of soluble protein, which effectively regulated the osmo-protective qualities. The current findings strongly elucidate that hemin soaking could effectively alleviate the negative impacts of NaCl stress by regulating the morphological, photosynthetic, and antioxidant traits. This study provides a new idea regarding the effect of Hemin on the salt tolerance of rapeseed, and provides a basis for the practical application of Hemin in saline-alkali soil to improve the salt tolerance of cultivated rapeseed.

Effect of salinity and drip fertigation on maize (<i>Zea mays</i>) and water use efficiency

Climatic variability is immensely pressurised on freshwater availability in arid and semi-arid ecosystems, leading to poor quality water for crop production not becoming uncommon, especially in coastal ecosystems. A field experiment was conducted during winter (rabi) season of 2022–23 at the Saline Water Scheme at Agricultural College Farm, Acharya N. G. Ranga Agricultural University, Bapatla, Andhra Pradesh to assess the impact of saline water on maize growth, yield and water use efficiency under drip fertigation. The experiment consisted 8 treatments laid in randomized block design (RBD) with 4 replications. The utilization of the BAW irrigation method, together with the application of a prescribed quantity of fertilizer, resulted in the highest plant height and dry matter accumulation during all phases of crop growth. These outcomes were comparable to those achieved by using a combination of fresh water and saline water with an electrical conductivity of 2 dS/m. The maximum values for the number of kernels per cob (451), cob length (17.2 cm), cob weight (164.4 g), kernel yield (7.38 t/ha), stover yield (9.61 t/ha) and water use efficiency (18.5 kg/ha mm) of maize were observed under the irrigation treatment T4. The parameters exhibited their minimum values when irrigation was conducted using water with a salt level of 4 dS/m and no fertilizers were used. However, there was no statistically significant difference observed in the number of cobs per plant and harvest index of maize when saline water was used in conjunction with drip fertigation. In the context of maize cultivation, employing a cyclic irrigation technique that alternates between salty (EC 2–4 dS/m) and freshwater sources, in conjunction with recommended dose of fertiliser (RDF) has the potential to deliver comparable crop development, productivity, and economic benefits when compared to the use of freshwater sources alone.

Influence of Natural Farming, Organic and Inorganic Systems of Nutrition on Wheat (Triticum aestivum L.)

A field experiment entitled “influence of natural farming, organic and inorganic systems of nutrition on wheat (Triticum aestivum L.)” was conducted at Research Farm of School of Agriculture, Abhilashi University, Mandi (H.P.) during Rabi season (2021-2022). The experiment was laid out in randomized block design with three replications, consisting of six nutrient management treatments. Results of study revealed that inorganic and integrated nutrient management (FYM @ 5 ton ha-1 + 50 percent recommended dose of fertilizers) treatments behaving alike resulted in better crop growth (plant height, shoot number and dry matter accumulation), yield attributes (number of effective tillers, spike length, number of grains per spike and 1000-grain weight) and higher yield (grain and straw) compared to treatments comprised of farmer’s practice (FYM @ 2.5 ton ha-1 + 50 percent recommended dose of fertilizers), organic (FYM @ 10 ton ha-1 + Jeevamrit) and natural farming (Beejamrit +Jeevamrit + mulching) systems of nutrition.

Examining the Impact of Integrated Nutrient Management and Vermicompost on Mustard Growth and Nutrient Composition

This study examines the impact of Integrated Nutrient Management (INM) on the growth attributes and nutrient composition of Indian mustard (Brassica juncea L.), a vital rabi season oilseed crop in India. Nine different treatment combinations were evaluated in a Randomized Block Design at Agronomy Research Farm. The treatments included various combinations of chemical fertilizers, vermicompost, sulfur, and zinc. The results indicate that the application of INM significantly influenced various growth parameters, including plant height and dry matter accumulation. Treatment T4 (75% RDF +Vermicompost@ 4t ha-1 + S @ 20kg ha-1) demonstrated the highest plant height and dry matter accumulation at different stages of growth. Additionally, seed yield, stover yield, and biological yield were positively impacted by INM, with T4 exhibiting the highest seed yield. Furthermore, the study highlights the importance of INM in enhancing the overall quality of Indian mustard. The application of these nutrient management practices not only led to increased seed yield but also improved the nutrient composition of the crop. The findings underscore the potential of INM as a sustainable approach to optimize crop productivity and improve food security in India. Overall, this research provides valuable insights for farmers, agricultural practitioners, and policymakers, offering a promising strategy for enhancing oilseed production and contributing to the agricultural economy of India. The positive outcomes of this study support the adoption of INM practices to ensure sustainable and productive mustard cultivation in the region.

Effect of Foliar Application of Plant Growth Regulators on Quality and Economics of Broccoli Production under Walk-In-Tunnel

An experiment was conducted at “Center of Excellence on Protected Cultivation, College of Agriculture, IGKV, Raipur (CG)” to find out the possible effect of foliar application of plant growth regulators with different concentration levels on yield of broccoli. The experiment was laid out in randomized block design (RBD) with three replications. It was consisted of ten treatments including T0: Control (without spray of PGRs), T1: GA3 @ 40 ppm, T2: GA3 @ 60 ppm, T3: GA3 @ 80 ppm, T4: NAA @ 60 ppm, T5: NAA @ 120 ppm, T6: NAA @ 180 ppm, T7: GA3 @ 40 ppm + NAA @ 60 ppm, T8: GA3 @ 60 ppm + NAA @ 120 ppm and T9: GA3 @ 80 ppm + NAA @ 180 ppm”. Two foliar applications were performed at 20 days after transplanting and 40 days after transplanting. The important parameters encompassed in the study were gurd diameter (cm), primary curd weight (g), secondary curd weight (g), curd yield per plant, curd yield per plot and curd yield per hectare. Data was recorded three times during investigation that is 30 DAT, 60 DAT and at the time of harvest. Although all treatments showed a positive effect on yield among all the treatments, T9 was showed better performance which may be due to the elongation of cells and cell division, increased dry matter accumulation in plants. Therefore, foliar application of GA3 80 ppm + NAA 180 was optimum among all treatments for getting higher yield in broccoli crop.

Residual effect of nitrogen management on succeeding summer moong (Vigna radiata) under maize-wheat-moong rotation

Nitrogen management in crop/cropping system plays a significant role to enhance crop growth and productivity in sustainable manner. To ensure sustained soil fertility, optimal crop growth and productivity in subsequent growing seasons, it is necessary to consider the residual effect of N management on moong (Vigna radiata L.). Therefore, a field experiment was conducted for two consecutive years (2019–20 and 2020–21) to evaluate the effect of organic and inorganic sources of nutrition with/without residue retention applied to preceding crops on growth and productivity of succeeding moong. Fourteen treatments applied to preceding crops were, T1, 100% N through FYM without residue; T2, 100% N through FYM with residue; T3, 75% N through FYM + 25% RDF without residue; T4, 75% N through FYM + 25% RDF with residue; T5, 50% N through FYM + 50% RDF without residue; T6, 50% N through FYM + 50% RDF with residue; T7, 25% N through FYM + 75% RDF without residue; T8, 25% N through FYM + 75% RDF with residue; T9, 100% RDF + 25% N extra through FYM without residue; T10, 100% RDF + 25% N extra through FYM with residue; T11, 100% RDF without residue; T12, 100% RDF with residue; T13, Cowpea intercropping without fertilizer in maize and residue retention in wheat and; T14, Control. The data revealed that treatment T6 recorded significantly higher growth parameters [plant height (59.7 cm) and dry matter accumulation (469.8 g/m2)] and yield attributes (number of pod/plant (27.4), pod length (8.8 cm) and number of seeds/pod (10.2)] of moong over other treatments but was found at par with T2, T3, T4 and T5 in 2020 and during 2021. Treatment T2 recorded significantly higher growth parameters [plant height (61.3 cm) and dry matter accumulation (478.9 g/m2)] and yield attributes (number of pod/ plant (30.2), pod length (8.9) and number of seeds/pod (10.3)] being at par with T1, T3, T4, T5 and T6 of moong over other treatments. Moreover, due to significant increase in yield attributes, treatment T6 and T2 exhibited significant increase in grain yield of about 62.32 and 62.96%, respectively over control in year 2020 and 2021, respectively.

Influence of Cow Based Liquid Manures and Spraying Frequency on Growth and Yield of Green Gram (Vigna radiata L.) Under Natural Farming

A field experiment was conducted at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P) during Kharif, 2022. The soil of the experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.1), organic carbon (0.75%), available N (269.96 kg/ha), available P (33.10 kg/ha), and available K (336 kg/ha). The treatments applied were of Panchagavya (3%), Jeevamrutha (500 lit/ha), cow urine (2500 lit/ha), and spraying schedule on every 7, 10 and 14 different days. The experiment was laid out in Randomized Block Design with nine treatments each replicated thrice. Based on the objectives taken maximum plant height (88.07 cm), number of total branches (5.02), number of nodules (40.87), plant dry matter accumulation (20.66 g/plant), number of pods/plant (25.67), number of seeds/pod (11.60), seed yield (1.65 t/ha), stover yield (3.89 t/ha), biological yield (5.54 t/ha) were recorded significantly higher in treatment combination of Panchagavya spraying interval at 10 days interval.

Effect of Combined Application of Herbicides on the Growth, Yield Attributes, Yield and Profitability of Kharif Groundnut [Arachis hypogaea (L.)

Groundnut (Arachis hypogaea L.) is a significant oilseed crop extensively cultivated throughout India. Despite the availability of high-yielding varieties and modern agricultural practices, the productivity of groundnut remains relatively low. Weed infestation is identified as one of the primary factors contributing to reduced productivity among various unstable factors. During the early stages of growth, groundnut exhibits slow initial growth, making it a poor competitor against weeds. To enhance growth and yield, effective weed management strategies are crucial. To address this, a field experiment was conducted during the kharif season of 2019 at Agricultural Research Station, Mandor, Agriculture University, Jodhpur, Rajasthan. The experiment consisted of thirteen treatments involving pre- and post-emergence herbicides, including weedy check and weed-free check, with three replications in a randomized block design. Results revealed that weed-free treatment recorded significantly lower weed density, weed dry matter and higher weed control efficacy, ultimately leading to improved growth, yield attributes, and overall yield of groundnut as compared to weedy check. Among weed control measures, Pendimethalin + imazethapyr @ 1.0 kg /ha (PE) + one manual weeding at 30 DAS (Days After Sowing) recorded significantly lower weed density, weeds dry matter and increased weed control efficiency, growth parameters (plant height and dry matter accumulation), yield attributes (number of pods /plant, pod yield /plant, number of kernels /pod and seed index) and yield (pod yield, kernel yield, haulm yield, biological yield, harvest index, and shelling out-turn), followed by pendimethalin @ 1.0 kg /ha (PE) + imazethapyr @ 75 g /ha at 20 DAS. Economically, these treatments recorded significantly higher gross returns, net returns and B: C ratio, proving to be more profitable than other herbicide applications used in the groundnut crop.

Improving the monitoring of root zone soil salinity under vegetation cover conditions by combining canopy spectral information and crop growth parameters.

Soil salinization is one of the main causes of land degradation in arid and semi-arid areas. Timely and accurate monitoring of soil salinity in different areas is a prerequisite for amelioration. Hyperspectral technology has been widely used in soil salinity monitoring due to its high efficiency and rapidity. However, vegetation cover is an inevitable interference in the direct acquisition of soil spectra during crop growth period, which greatly limits the monitoring of soil salinity by remote sensing. Due to high soil salinity could lead to difficulty in plants' water absorption, and inhibit plant dry matter accumulation, a method for monitoring root zone soil salinity by combining vegetation canopy spectral information and crop aboveground growth parameters was proposed in this study. The canopy spectral information was acquired by a spectroradiometer, and then variable importance in projection (VIP), competitive adaptive reweighted sampling (CARS), and random frog algorithm (RFA) were used to extract the salinity spectral features in cotton canopy spectrum. The extracted features were then used to estimate root zone soil salinity in cotton field by combining with cotton plant height, aboveground biomass, and shoot water content. The results showed that there was a negative correlation between plant height/aboveground biomass/shoot water content and soil salinity in 0-20, 0-40, and 0-60 cm soil layers at different growth stages of cotton. Spectral feature selection by the three methods all improved the prediction accuracy of soil salinity, especially CARS. The prediction accuracy based on the combination of spectral features and cotton growth parameters was significantly higher than that based on only spectral features, with R2 increasing by 10.01%, 18.35%, and 29.90% for the 0-20, 0-40, and 0-60 cm soil layer, respectively. The model constructed based on the first derivative spectral preprocessing, spectral feature selection by CARS, cotton plant height, and shoot water content had the highest accuracy for each soil layer, with R2 of 0.715,0.769, and 0.742 for the 0-20, 0-40, 0-60 cm soil layer, respectively. Therefore, the method by combining cotton canopy hyperspectral data and plant growth parameters could significantly improve the prediction accuracy of root zone soil salinity under vegetation cover conditions. This is of great significance for the amelioration of saline soil in salinized farmlands arid areas.

Efficacy of Liquid Organics on Growth and Yield of Cowpea under Natural Farming

A field experiment was conducted at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P) during Zaid, 2022. The soil of the experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.1), organic carbon (0.75%), available N (269.96 kg/ha), available P (33.10 kg/ha), and available K (336 kg/ha). The treatments applied were of Panchagavya (2, 4 and 6 %) and Jeevamrutha 500 and 1000 l/ha. The experiment was laid out in Randomized Block Design with nine treatments each replicated thrice. Based on the objectives taken maximum plant height (84.34 cm), number of total branches (5.34), number of nodules (40.87), plant dry matter accumulation (17.96 g/plant), number of pods per plant (25.47), number of seeds per pods (11.78), seed yield (1.78 t/ha), stover yield (3.99 t/ha) and biological yield (5.77 t/ha) were recorded significantly higher in treatment combination of Panchagavya (6 %) + Jeevamrutha 1000 l/ha. Further, the maximum gross returns (₹ 71200.00/ha) and net returns (₹ 31300.00/ha) were recorded higher in treatment combination of Panchagavya (6 %) + Jeevamrutha 1000 l/ha. However, B:C ratio was highest in 1.78 Panchagavya (2 %) + control.

Effects of exogenous strigolactone on growth, dry matter accumulation, and yield of tissue-cultured ginger

ABSTRACT Ginger tissue culture seedlings can reduce the incidence of soil-borne diseases. However, they have several branches, small ginger bulbs, and slow seed recovery. Strigolactone can inhibit the growth of lateral buds, adjust plant types, and increase crop yield. This study used exogenous strigolactone to treat tissue-cultured ginger and assess its effects on growth, dry matter accumulation, and yield. The results showed that the number of branches and ginger bulbs per plant decreased significantly with the application of exogenous GR24 (Synthetic analog of strigolactone, rac-GR24), and higher concentrations led to a greater decrease. Plant height, stem diameter, root, rhizome, stem sheath, leaf and plant dry matter accumulation, average ginger bulb weight, and yield increased significantly, increasing initially and then decreasing with increasing concentration. Depending on the concentrations, exogenous strigolactone can inhibit the branching of tissue-cultured ginger, reduce the number of branches, increase plant height and stem diameter, optimize the aboveground plant type, increase dry matter accumulation and root-shoot ratio, decrease the number of ginger bulbs per plant, increase the average ginger ball weight, and increase yield. When the GR24 concentration was further increased, the number of branches, the plant height, stem diameter, dry matter accumulation, root shoot ratio, ginger bulbs per plant, average weight of ginger bulbs, and ginger yield decreased. Treatment with 7.5 um L−1 of exogenous GR24 could optimize the plant type of tissue-cultured ginger and increase yield.

Polyethylene glycol-induced drought stress screening of selected Philippine high-yielding sugarcane varieties

A greenhouse study was conducted to characterize the drought response of eight high-yielding sugarcane varieties at tillering stage using polyethylene glycol 6000 (PEG6000) induced drought conditions. Plant height, stalk diameter, dry matter accumulation, root characteristics, stomatal conductance, chlorophyll fluorescence, SPAD, normalized difference vegetation index (NDVI), and canopy temperature were evaluated at 2.5 months after planting after four weeks of induced drought conditions. The study aimed to determine whether 1.0% PEG treatment would be able to produce significant differences among test genotypes and use it as a basis to determine drought-tolerant and susceptible varieties. Significant differences were observed among genotypes in PEG stress treatments. PEG stress resulted in significant reductions relative to non-PEG treatment in plant height (32.1%), leaf dry matter (31.6%), and stalk dry matter (49.5%) while total root length (11.8%), root surface area (7.8%) and root volume (19.6%) have generally increased. Reduced plant height, stalk diameter, and dry matter accumulation were observed in susceptible genotypes, while potential tolerant lines maintained or exhibited less reduction in these traits. Moreover, principal component analysis suggests that stalk dry matter, stomatal conductance, chlorophyll fluorescence plant height, SPAD, canopy temperature, and NDVI, highly contributed to the overall variation in the data (41.5%). With this, vars. 2289, 1011, 2569, and 1899 were identified to be potential drought-tolerant varieties while vars. 1763 and 2155 were potential drought susceptible varieties. Screening for drought tolerance under controlled conditions using PEG-induced drought stress offers a promising approach for sugarcane breeding especially when focusing on specific drought responses during important formative stages such as tillering stage. Being able to select genotypes of interest as early as the tillering stage would significantly hasten breeding cycles and will highly benefit the efforts towards drought stress tolerance in sugarcane.

Relay intercropping cover crop combined with reduced nitrogen application improves subsequent cotton agronomic traits while maintaining yield and quality

AbstractApplying cover crops to reduce nitrogen (N) fertilizer application while ensuring crop productivity is a major challenge for sustainable agricultural production. However, few studies have quantified N fertilizer application reduction through the use of February orchid (Orychophragmus violaceus) cover crops with the goal of ensuring cotton productivity. We conducted field experiments in the Yellow River basin on two cropping systems, monoculture cotton (Gossypium hirsutum L) and cotton/February orchid under four levels of N application (0 [N0], 112.5 [N1], 168.75 [N2], and 225 [N3] kg N·ha−1), to evaluate the impacts of cover cropping on cotton growth parameters, yield, and quality under different N application levels. The results indicated that replacing winter fallow with February orchid prolonged the cotton growth period and increased plant height, leaf area index (LAI), and dry matter accumulation but did not improve cotton yield or fiber quality. The Cotton/February orchid system under a 168.75 kg ha−1 N application rate improved cotton growth, and achieved yield and quality equivalent to those of monoculture cotton under a 225 kg ha−1 N application. Further analysis revealed that February orchid cover crop and N application positively affected lint yield, whereas plant height, LAI, and dry matter accumulation (positively) and phenology (negatively) predicted lint yield and fiber quality. In conclusion, cotton relay intercropping with February orchid in combination with 168.75 kg ha−1 N application is recommended as a suitable cropping system to reduce fallow fields and ensuring cotton productivity in the Yellow River basin and other areas with similar ecological conditions.

Plant Photosynthesis and Dry Matter Accumulation Response of Sweet Pepper to Water–Nitrogen Coupling in Cold and Arid Environment

In order to optimize the water and nitrogen management mode and realize the efficient scale production of sweet pepper, from 2021 to 2022, field experiments on sweet pepper cultivation with different water and nitrogen coupling modes were conducted in the Hexi Oasis irrigation areas. The regulation effects of the water–nitrogen coupling mode on the dry matter accumulation characteristics, photosynthesis, yield, and water–nitrogen utilization efficiency of sweet pepper were further discussed. Irrigation was set for full irrigation (W1, 75–85% FC [field capacity]), mild (W2, 65–75% FC), and moderate (W3, 55–65% FC) water deficit levels. Three levels of nitrogen were applied, high (N1, 300 kg·ha−1), medium (N2, 225 kg·ha−1) and low (N3, 150 kg·ha−1), with full irrigation and no nitrogen application used as the control (CK). The results showed that the appropriate water–nitrogen coupling mode could enhance the photosynthetic rate, increase dry matter accumulation and the accumulation rate, advance the days of a maximum rate of dry matter accumulation, and improve yield and water–nitrogen utilization efficiency. N1W1 had the greatest dry matter accumulation, the mean rate and the maximum increase rate of dry matter accumulation in sweet pepper, which was not a significant difference from N2W2, but significantly increased by 19.61%, 19.67%, and 23.45%, respectively, compared with CK. Water deficit significantly advanced the days of a maximum rate of dry matter accumulation. The days of a maximum rate of dry matter accumulation appeared 1.18–5.79 days earlier at W3 than at W2 and W1, and the maximum rate appeared gradually later with increasing irrigation. The net photosynthetic rate, the transpiration rate, and stomatal conductance of N2W2 sweet pepper showed the best performance at all growth stages, significantly increasing by 23.87%, 27.71%, and 27.39%, respectively, compared with CK. Moreover, the Intercellular CO2 concentration was significantly reduced by 14.77% in N2W2 compared to CK. The N2W2 had the highest yield, water use efficiency, and irrigation water use efficiency of sweet pepper, significantly increasing 26.89%, 33.74%, and 31.22% compared to CK. Excessive water and nitrogen dosage reduced nitrogen partial factor productivity, while an appropriate increase in irrigation under reduced nitrogen conditions facilitated the water nitrogen potential. Passage path analysis further showed that water–nitrogen coupling promotes plant biomass formation and distribution by increasing photosynthetic assimilation capacity, ultimately increasing yield. Therefore, the N2W2 treatment (65–75% FC, 225 kg·ha−1) is the ideal water and nitrogen mode for obtaining higher yields and water and nitrogen use efficiency of sweet pepper in a cold and arid environment.

Effects of drip irrigation frequency on the yield and nutrient utilization efficiency of tomato under long-season cultivation in solar greenhouse.

To improve the utilization efficiency of nutrients and water and determine the best drip irrigation frequency for long-season tomato cultivation in solar greenhouses, we cultivated tomato grafted seedlings in soil using an integrated water and fertilizer technology: drip irrigation under mulch. Seedlings drip-irrigated with balanced fertilizer (containing 20% N, 20% P2O5, and 20% K2O) and high-K fertilizer (containing 17% N, 8% P2O5, and 30% K2O) once every 12 days were set as control (CK) and that with water once every 12 days as CK1, while other seedling groups, drip-irrigated with a nutrient solution of Yamazaki (1978) formula for tomato, were set as treatments (T1-T4). There were four drip-irrigation frequencies, i.e., once every 2 days (T1), 4 days (T2), 6 days (T3), or 12 days (T4), who received the same total amounts of fertilizer and water over the 12 experimental days. The results showed that, with the decreases of drip irrigation frequency, tomato yield, the accumulation of N, P and K in plant dry matter, the fertilizer partial productivity, and the nutrient utilization rate first increased and then decreased, peaking at the T2 treatment. Compared with CK, under the T2 treatment, plant dry matter accumulation and the accumulation of N, P and K increased by 4.9%, 8.0%, 8.0%, 16.8%, the partial productivity of fertilizer and the utilization efficiency of water increased by 142.8% and 12.2%, the use efficiency of N, P and K was better than CK by 241.4%, 466.6% and 235.9%, respectively, and the tomato yield increased by 12.2%. Under the experimental conditions, drip irrigation with the Yamazaki nutrient solution at a frequency of 4 days could increase the tomato yield, as well as the use efficiency of nutrients and water. Under long-season cultivation, these trends would result in considerable saving of water and fertilizer. Overall, our findings provided a basis for improving the scientific management of water and fertilizers under long-season tomato cultivation in protected facilities.

Ciclos de seca/reidratação no crescimento vegetativo de mudas de citros

Abstract The objective of this work was to evaluate the effect of three dehydration/rehydration cycles on the vegetative growth and shoot dry matter of citrus seedlings, as well as seedling acclimatization to this environmental stress. The five following water regimes were evaluated: WR1 (control), WR2, and WR3, with plants kept at 100, 75, and 50% of pot capacity during the three cycles, respectively; and WR4 and WR5, with plants kept at 75, 100, and 75% and 50, 100, and 50% of pot capacity during the first, second, and third cycles, respectively. Relative water content, plant height, length and diameter of the main and secondary branches, angle of leaf insertion in the branch, specific leaf area, leaf chlorophyll content, and dry matter were evaluated. Rehydration after a cycle with 50% of pot capacity did not improve plant growth or dry matter accumulation in relation to the well-hydrated plants of the control. However, after a cycle with 75% of pot capacity, rehydration restores water content, the diameter of the secondary branches, and the angle of leaf insertion. The exposure to successive events of dehydration/rehydration makes the citrus seedlings more resistant to future exposures to water stress.