Crop Stages Research Articles

Mineral and Labile Organic Nitrogen Fractions in Soil Profile and Their Response to FYM and Inorganic Fertilization in Different Growth Stages of Rice Crop

Nitrogen is the key element among the major nutrients in crop production. The mineralizable soil organic nitrogen is the main contributors of soil N supply. A better understanding of soil organic nitrogen dynamics in agro-ecosystems is needed to improve N management. The present investigation was conducted in Regional Agricultural Research Station (RARS), Assam Agricultural University, Titabar, Jorhat during 2017-18. In this study, the impact of Farmyard Manure (FYM) and inorganic fertilization on soil mineral nitrogen (NO3−-N and NH4+-N) dynamics and labile organic nitrogen fractions viz. microbial biomass N (MBN), particulate organic N (PON) and water-extractable organic N (WEON) at three growth stages of rice viz. active tillering, flowering and physiological maturity stages and nitrogen stock were assessed. Six treatments viz. control (no fertilization), 100% NPK, 100% NPK + FYM 5 t ha-1, 50% NPK, 50% NPK + 50% N through FYM and FYM 10 t ha-1 were tested in randomized block design with four replications. The results showed that NO3−-N and NH4+-N were found to be significantly higher in 100% NPK+FYM 5 t ha-1 at the three growth stages of rice. The labile organic nitrogen fractions were significantly higher in FYM 10 t ha-1. All these variables were decreased with increase in crop growth stages. Integrated use of inorganic fertilizer and FYM recorded the highest nitrogen stock. Stepwise regression analysis indicated that NH4+-N was the main contributor to nitrogen stocks at the three growth stages of rice of the studied soils.

Mulching effects on soil evaporation, crop evapotranspiration and crop coefficients: a review aimed at improved irrigation management

AbstractMulching is a widely adopted agronomic practice, often used as a water-saving strategy due to its effectiveness in reducing soil evaporation. However, effects vary depending on the materials used and the extent of mulch soil coverage. Consequently, the impacts of mulching may differ considerably across production systems, preventing the establishment of reliable guidelines for irrigation water management. The objective of this study is to comprehensively review existing literature that compares mulching versus no-mulching management, aiming to gain a deeper understanding of the effects of mulching on soil evaporation (Es), crop coefficients (Kc), and actual crop evapotranspiration (ETc act). 58 studies were selected. The impact of mulching was particularly notable in the early crop stages, when the soil is not fully covered. Data in literature shows that plastic films were more effective in reducing Kc than organic materials. However, this effect, while evident during the early crop stages, diminished throughout the rest of the season. Black plastic films were more effective during the early crop stages compared to other colored plastics, particularly relative to the decrease of Kc, but this effect also diminishes during the rest of the season. Building upon these findings, the study provides guidelines for expected reductions in Kc values based on the type of crop, crop stage, and the mulching material most used in each cropping system.

Towards the development of cover crop - reduced tillage systems without herbicides and synthetic fertilizers in onion cultivation: Promising but challenges remain

Cover crops with reduced tillage technology (CC-RT) can foster soil health and functioning, a crucial agroecological principle in any transition strategy to more sustainable agricultural systems. However, CC-RT commonly strongly relies on herbicides and synthetic fertilizers, and vegetable crop yields are variable and often low. We assessed the effects of two tillage systems (RT and conventional tillage) and the application of native effective microorganisms (NEM) on onion crop growth and development, yield, N-status, weed pressure, and soil physico-chemical and biological quality after a summer CC, without using herbicides or synthetic fertilizers. Using a participatory research strategy, we conducted a two-year experiment at an experimental station and a one-year trial on two commercial farms. Onion yields were generally low (between 10 and 16 Mg ha−1) and lower in 2019 than in 2020, and lower in RT than in CT in 2020. The relatively low yields in 2019 and RT were associated with poor crop growth and development and leaf-N concentrations below the critical threshold in the early stages of crop development. Soil bulk density was not limiting crop growth in any treatment. Soil mineral N was lower in 2019 than in 2020 and did not significantly differ between treatments. Soil biological activity was higher in RT than in CT. Although the CC residue soil cover in the early stages of the onion crop in RT was more than 50%, RT had a higher weed pressure than CT, which was reversed later in the growing season. The NEM application did not significantly affect most crop, weed, and soil variables. In conclusion, a reduced tillage system for onions without herbicides and synthetic fertilizers is within reach. However, further research is needed to manage weeds and soil N supply dynamics to make CC-RT feasible for no or low agrochemical input systems.

Biological and Chemical Vicissitudes in Soil Rhizosphere Arbitrated under Different Tillage, Residues Recycling and Oilseed Brassica-Based Cropping Systems

In this study, the impacts of long-term soil and crop management practices on crop productivity and soil health in oilseed brassica-based production systems were examined. Different tillage, crop residue recycling and cropping systems (fallow–mustard, cluster bean–mustard, green gram–mustard, maize–mustard, pearl millet–mustard and sesame–mustard) were studied for 5 years at two soil depths (0–15 and 15–30 cm) in a split-plot design with three replications. No-till permanent beds with crop residue (PB + R) noticeably improved soil organic carbon (SOC), microbial biomass carbon (MBC), enzymes (dehydrogenase (DHA) and alkaline phosphatase (AlP)), nitrogen fractions (available and total nitrate) and available phosphorus and potassium content in both soil layers compared to conventional tillage without crop residues. However, the plough soil layer (0–15 cm) showed higher concentrations of soil carbon, enzymes, N fractions and available P than in the subsoil (15–30 cm). The dynamic soil biological and chemical properties also varied with the crop stage, and higher MBC at 30 days, SOC and enzymatic activities at 60 days, and N fractions and available P and K during the harvesting of mustard crop were recorded. Green gram–mustard rotation showed higher values in terms of biological and chemical parameters. Thus, the legume-based mustard crop rotation following no-till permanent beds and residue recycling was found to be holistic in terms of improving soil health and nutrient cycling.

The effectiveness of intercropping and agri-environmental schemes on ecosystem service of biological pest control: a meta-analysis

Plant diversification contributes to the ecological intensification of agroecosystems through pest biocontrol services provision. However, the existing evidence for the effectiveness of plant diversification in enhancing pest biocontrol services is highly uncertain across features of plant diversity and biodiversity characteristics. We undertook a comparative meta-analysis focusing on three essential crops (wheat, maize, and soybean) to investigate how diversification schemes in-field (intercropping) and Agri-environmental scheme (AES) around the field (flower strip, hedgerow and field margin) affect arthropod abundance. A random effects analysis was used to determine the role of 10 key factors underlying the effectiveness of plant diversification including biodiversity level and habitat, main and companion plant species, intercropping arrangement, the growth stage of the main crops, type of AES planting scheme, AES planting width, distance from AES plantings and geographical latitude. The overall results revealed that intercropping reduced herbivore and boosted predators and parasitoids abundance significantly, while AES successfully increased predators but not herbivores. Maize intercropping with legume and non-legume plants and row intercropping allowed for effective pest management. The abundance of predators increased in wheat fields immediately adjacent to planting around the field (AES), but this effect declined beyond 5 m from the flower strips. Our results suggest that the response of arthropod abundance to plant diversification is a compromise between spatial management scale, ecological characteristics of arthropod and plant diversification features. These results offer promising pathways for optimizing plant diversification schemes that include functional farm biodiversity across spatial and temporal scales and designing multi-functional landscapes.

Modeling canopy water content in the assessment for rainfall induced surface and groundwater nitrate contamination: The Bilate cropland sub watershed

Nitrate contamination in surface and groundwater remains a widespread problem in agricultural watersheds is primarily associated to high levels of percolation or leakage from fertilized soil, which allows easy infiltration from soil into groundwater. This study was aimed to predict canopy water content to determine the nitrate contamination index resulting from nitrogen fertilizer loss in surface and groundwater. The study used Geographically Weighted Regression (GWR) model using MODIS 006 MOD13Q1-EVI Earth observation data, crop information and rainfall data. Satellite data collection was synchronized with regional crop calendars and calibrated to plant biomass. The average plant biomass during observed plant growth stages was between 0.19 kg/m2 at the minimum and 0.57 kg/m2 at the maximum. These values are based on the growth stages of crops and provide a solid basis for monitoring and validating crop water productivity data. The simulation results were validated with a high correlation coefficient (R2 = 0.996, P < 0.0005) for the observed rainfall in the growing zone compared to the predicted canopy water content. The nitrate contamination index assessment was conducted in 2004, 2008, 2009, 2010, 2011, 2013, 2014, 2015, 2018 and 2020. Canopy water content and root zone seasonal water content were measured in (%) per portion as indicators of the NO−3-N-nitrate contamination index in these years (0.391, 0.316, 0.298, 0.389, 0.380, 0.339, 0.242, 0.342 and 0.356).

The effect of dataset construction and data pre-processing on the eXtreme Gradient Boosting algorithm applied to head rice yield prediction in Australia

Dataset quality heavily impacts the predictive performance of data-driven modelling. This issue can be exacerbated in the prediction of agricultural production due to the complex interactions between the climate, the environment and the way the plant is affected by these conditions during the season. This study aims to create an empirical model to predict Head Rice Yield (HRY), the primary quality metric for rice growers and millers globally. Model development focused on an industry-level dataset made available by SunRice, Australia's most prominent rice trading company. Using the SunRice data, two dataset construction methods were implemented to evaluate the effect of dataset construction and data pre-processing on model accuracy. The first dataset construction method was based on aggregating meteorological conditions using estimates of phenology, while the second method used aggregations based on defined lengths of time. Deviations of each construction method were generated to explore the impact of varying levels in aggregation stages and stage lengths. Each constructed dataset underwent feature selection prior to model training using the XGBoost algorithm with Leave-One-Year-Out Cross-Validation. The time-based dataset construction method proved to be the most accurate dataset construction method, producing the highest mean model accuracy scores across all pre-processing and model training configurations. The single most accurate model came from the two-week aggregation dataset, which yielded a 125% increase in Lin’s Concordance Correlation Coefficient compared to the worst-performing model produced in this study. Developing a highly accurate model that allows for crop stage knowledge discovery is critical for uncovering actionable insights to improve the management of future rice crops for HRY. The knowledge discovered in this study provides actionable insights to improve the management of future rice crops for HRY. The developed model demonstrates the potential for SunRice to predict HRY at the receival point to optimise post-harvest handling and milling. When matched to region-specific data, the dataset construction methods explored can be replicated in other rice-growing regions globally.

Topdressing nitrogen applied at different phenological stages and growth regulator on wheat in subtropical regions in southern Brazil

There are doubts about nitrogen (N) management and the use of growth regulator in wheat. Thus, the objective was to evaluate the wheat performance as a function of topdressing N applied at different phenological stages of crop, and the use of trinexapac-ethyl (TE) growth regulator associated with N fertilization in subtropical regions in southern Brazil. In each environment, two experiments were carried out, all with an experimental design in 2 × 4 factorial scheme. The factors in experiment 1 were topdressing N application at seedling emergence and tillering stages and N rates (0, 40, 80, and 120 kg N ha−1); and in experiment 2: use of TE (with and without) and N rates (0, 40, 80, and 120 kg N ha−1) applied at tillering. The augment of N in topdressing increases the lodging. The use of TE minimizes the lodging. In environment with irrigation, the application of intermediate N rates at crop emergence reduces lodging. The yield components are altered by the rates and stages of N application, with variable responses according to the cultivation environment. The stage of application does not affect grain yield. N fertilization increases the yield, being that in Ponta Grossa the wheat is more responsive to higher N input. In certain environments, TE reduces the number of spikes m−2 and increases the number of grains per spike. TE impairs yield when associated with N non-application in topdressing. On the other hand, it maximizes the effect of N fertilization on yield, when using higher N rates in topdressing.

Plant Growth Promoting Rhizobacteria for Sustainable Production of Sugarcane and Rice

Sugarcane (Sacchraum officinarum L.) and rice (Oryza sativa L.) are important cash and staple crop in the world respectively. In today’s population explosion the lots of pressure on cropping land to mitigate the feed need of consumers with judicious use of chemical fertilizers without considering the health of soil and its sustainability. The rhizobacteria live region around roots (2-80 mm) of crop with divers, dynamic and complex microflora having capacity with direct and indirect beneficial effects on crop health by availability of different nutrient, siderophores, rhizo deposits, auxins and role with bioremediation. There are different types of bacteria is isolated from rhizosphere of sugarcane and rice having Bacillus, Rhizobium, comamonas, cyanaobacteria, Nodosilinea, Levinella and Pseudomonas genera with most efficient nitrogen producer, solubilizers of inorganic phosphate, potash and other macro and micronutrient. In rice microbiome as Levinella, Psudomonas Anaeromyxobacter, Arenimonas, Arthrobacter, Bacillus, Bellilinea Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria and cyanobacteria with strains of Nitrosomonas and Nitrobacter are further divided in vegetative and reproductive growth stage of rice crop. The article give brief idea about the large arena of them.

The Co-occurrence Matrix and the Correlation Network of Phytophagous Insects Are Driven by Abiotic and Biotic Variables: the Case of Canola.

Co-occurrence a correlation profiles are driven by different factors (exogenous and endogenous) and drawing a profile of association between species based on co-occurrence, without assessing how these species vary in terms of ecological niche can lead to wrong conclusions. The objective was to determine the co-occurrence and correlation patterns of phytophagous insects in canola crop and to evaluate how these patterns varied according to the crop stage (phenology-biotic) and sowing times (agricultural practice-abiotic). We found that the patterns of co-occurrence and correlation between species were reflections of population variations due to the phenology and sowing times of canola. Variations in the multi-species abundance matrix were influenced by mean air temperature and accumulated rainfall. The main species associated with canola in southern Brazil, in terms of abundance, were P. xylostella, D. speciosa, and N. viridula. These species were mostly negatively associated. When evaluating their population variations, we found that they explore different temporal niches, whether in terms of phenology or sowing times. Finally, we demonstrate empirically that despite being important, association patterns based on co-occurrence and correlation should be interpreted in light of the understanding of patterns of niche exploitation and temporal variation of species.

Emulsifiable oil-formulated Beauveria bassiana competes with imidacloprid for seasonal control of cereal aphids in Zhejiang, China.

Alternatives to neonicotinoids against cereal aphids are needed to mitigate aphid resistance and non-target effects. The emulsifiable oil formulations of two Beauveria bassiana strains, namely Bb registered as a mycoinsecticide and TBb overexpressing an endogenous virulence factor, were tested for seasonal control of cereal aphids at the elongating (April 7) to milk ripening (May 12) stages of winter wheat crop in Yuhang, Zhejiang. Each of three field trials consisted of blank control and the treatments (three randomized 100-m2 plots per capita) of each fungal strain sprayed biweekly at rates of 1.0 × 1013 and 1.5 × 1013 conidia ha-1 and 10% imidacloprid WP sprayed biweekly at a label rate. Tiller infestation percentage and aphid density in the 5-week field trials after the first spray were reduced to 18.7-22.4% and 9.1-12.4 aphids per tiller in the fungal treatments, and 12.8-25.3% and 2.8-20.9 aphids per tiller in the chemical treatment, contrasting with 49.2-60.3% and 37.1-108.5 aphids per tiller in the control. Percent control efficacies (±SD) computed with weekly aphid densities over the period averaged 84.0 ± 1.6 and 85.3 ± 1.8 versus 78.0 ± 4.0 and 79.9 ± 3.2 in the high-rate versus low-rate treatments of Bb and TBb, respectively, and 84.5 ± 7.8 in the chemical treatment. Imidacloprid showed faster kill action but more variable efficacy than the fungal treatments throughout the trials. Either Bb or TBb formulation competes with imidacloprid in reducing percent infestation and aphid density. The overall efficacy was significantly higher in the treatments of TBb than of Bb. © 2024 Society of Chemical Industry.

Insect Pest Complex of Field Pea Crop

A study on diverse insect pest complex of field pea was made in both the years of experimentation i.e. during Rabi, 2021-22 and 2022-23 at Crop Research Centre, College of Agriculture, SVPUA&amp;T, Meerut. As many as 15 insect species were recorded during the study period which belongs to different orders viz. Orthoptera (one species), Hemiptera (four species), Lepidoptera (seven species), Isoptera (one species) and Diptera (two species). All the major parts of this legume plant viz., pod/seed, leaf, root and stem were found to be infested by the insect pests. Sucking insect pests appear during the seedling and vegetative stage of crop i.e. 1st week of December to 2nd week of January. Gram pod borer, pea pod borer and blue butterfly are the pod borer complex that appeared from flowering to maturity stage i.e. 1st week of January to 2nd week of February. Among all the fifteen insect pests, only two pod borers, Etiella zinckenella (Treitschke) and Helicoverpa armigera (Hübner) were found as major pests of field pea with severe economic status to this area during successive Rabi, seasons.

Influence of season and crop stage on incidence of banana pseudostem weevil, Odoiporus longicollis

Influence of season and crop stage on incidence of banana pseudostem weevil, Odoiporus longicollis

Effect of liming in plinthic and petroplinthic soils for soybean cultivation in the Brazilian Savanna

Agricultural expansion is advancing on marginal soils (Plinthic soils), but the liming recommendation for this soil, especially for soybean cultivation, remains unknown. This study aimed to evaluate soybean (Glycine max) responses to limestone doses in concretionary soils (plinthic and/or petroplinthic). The experiment was carried out in the greenhouse, in randomized blocks, with four soil types and six limestone doses (4x6 factorial scheme), with four replicates. Soils were: RYO: Red-Yellow Oxisols; CPP-29, CPP-72, CPP-82 corresponds to the Concretionary Petric Plinthosol with 29, 72, and 82% concretions, respectively. Limestone doses varied from 0 to 4 times for each soil, based on the recommendation of regional bulletins. Soil temperature, crop emergence, development, and soybean yield characteristics were evaluated. Results were evaluated by ANOVA, followed by the LSD test or polynomial regression adjustment (p ≤ 0.05). Soybean response to liming varied with soil types. Seedlings showed lower vigor in Plinthic soils with plinthite contents ≥72%. These soils showed higher thermal accumulation (°C), and this increase showed a strong negative correlation with soybean development and reproductive characteristics. Evidence of liming response was observed after crop stage V5. Limestone substantially improved soybean growth and development in Plinthic soils with high plinthite levels, although they had lower yield potential than low plinthite levels and Oxisol. In general, the maximum response of the crop occurred at doses ~2 times higher than that practiced in the Brazilian Savanna region, especially in Plinthic soils

Foliar application of natural zeolites affects the growth and productivity of processing tomato

The foliar application of zeolites has been proven to positively affect plant physiology suggesting that it could improve plant growth, however, this topic has been little studied. Two field trials were carried out (in 2021 and 2022) to study the potential beneficial effect of natural zeolite particle films on processing tomato crops. Natural zeolites i) clinoptinolite + and mordenite (CubZeo) and ii) micronized clinoptinolite (BigZeo) were sprayed onto the plants six times in the central crop cycles. In both trials, BigZeo promoted leaf and fruit dry mass (DM) accumulation, and leaf area from the early crop stage compared to the water-sprayed plants (Control). The final aerial DM of BigZeo plants enhanced more in the year with favourable (+39.2%) (2022) than in that with more stressing thermal conditions (2021) (+12.1%). Concurrently, the marketable yield was improved by + 36% in both years with positive effects also on fruit total soluble solids. Under heat stress, the CubZeo crop showed even lower aerial DM than the Control, however, the marketable yield remained similar due to higher fruit DM and higher incidence of blossom-end-rot (BER) in untreated plants. In 2022, CubZeo promoted DM accumulation, leaf expansion and yield even if to a lesser extent than the BigZeo treatment. In the fruits the concentrations of K, Ca, and Mg rose in zeolite-treated plants. The improved Ca level in the fruits can explain the lower occurrence of BER in the zeolite-treated plants, particularly with CubZeo. Si was observed at the highest level in fruits and stems of BigZeo-treated plants, followed by CubZeo and Control ones. The accumulation of Si could explain the best crop responses elicited by BigZeo, whereas the observed responses did not appear to involve changes in the photosynthetic machinery. However, further and comprehensive investigations are needed to define the zeolite film particle characteristics and the related physiological and nutritional changes in the plants.

Optimizing water use and crop yield with deficit irrigation techniques: A comprehensive overview and case study from Morocco

Water scarcity is a global challenge that threatens agricultural productivity and food security. Irrigation agriculture consumes most of the world’s freshwater resources and often suffers from low water use efficiency. To address water shortages, deficit irrigation techniques have been developed to minimize water inputs while sustaining or enhancing crop yields and quality. Deficit irrigation consists of allocating a minimum amount of water to the crop. It can be applied either for the entire growing season (sustained deficit irrigation) or for specific crop stages (regulated deficit irrigation). Another technique is partial root zone drying, which involves alternately irrigating different parts of the root system. This causes partial water stress and increases the water uptake efficiency. These techniques aim to maximize net water use efficiency by exploiting the physiological responses of crops to water stress. This paper provides a theoretical background on deficit irrigation, a review of recent studies on its effects on different crops and environments, and a case study in Morocco where sustained deficit irrigation was applied to peach trees in a semiarid region. The findings showed that sustained deficit irrigation reduced water use by 20% without affecting fruit yield or quality and increased water productivity by 33%. This paper also discusses the challenges and opportunities for implementing deficit irrigation in different contexts and provides some recommendations for future research and development.

Weather Variables for Within-Vineyard Awareness of Botrytis Risk

Background and Aims. Botrytis bunch rot (BBR) in cool temperate climates is a key constraint to the consistent supply of grapes to winery specifications. BBR severities have been correlated with specific environmental conditions; however, data-driven applications intended to support crop protection decisions are restricted in access and/or of unknown commercial value. The aims of this study were to evaluate variables providing within-vineyard awareness of BBR risk in Riesling vines. Methods and Results. Descriptors of BBR epidemics from eight site years, 2009–2014, were developed for vine areas of ∼0.5 ha within two regions of Tasmania with different climates. Two variables using the daily Bacchus index, from crop stage E-L 19 to E-L 31 or 34, accounted for &gt;80% of the variance in the final mean BBR severity. A BBR risk index (BBR-I), incorporating the mean daily Bacchus index from E-L 19 to E-L 31 and the median daily vapour pressure deficit of air at 15 : 00 during the late-season interval, accounted for up to 99.5% of the variance in the final mean BBR severity. The late-season interval (days) or median daily RH (%) at 15:00 in the same period accounted for 86.4 or 83.3% of the variance. Spatial variability of BBR severity mapped in 4.8 ha of Sauvignon Blanc in 2018-19 confirmed the need to apply BBR risk indicators at an appropriate spatial scale. Conclusions. Environmental variables with biological relevance served as indicators of BBR risk at the study sites and have the potential to discriminate BBR risk among production regions in Tasmania. Significance of the Study. Study findings are expected to support the development of applications that raise awareness of BBR risk at an appropriate spatial scale for in-season adaption of crop protection, diagnosis of crop protection efficacy, and/or site selection decisions. Accompanying formulae with sample data in Microsoft® Excel will support transitions to automated data analyses.

Farmstead-Specific Weather Risk Prediction Technique Based on High-Resolution Weather Grid Distribution

In recent years, the importance and severity of weather-related disasters have escalated, attributed to rising temperatures and the occurrence of extreme weather events due to global warming. The focus of disaster management has shifted from crisis management (e.g., repairing and recovering from damage caused by natural disasters) to risk management (e.g., prediction and preparation) while concentrating on early warning, thanks to the development of media and communication conditions. The Rural Development Administration (Korea) has developed the “early warning service for weather risk management in the agricultural sector” that detects weather risks for crops from high-resolution weather information in advance and provides customized information to respond to possible disaster risks in advance in response to the increasing number of extreme weather events. The core technology of this service is damage prediction technology that determines the overall agricultural weather risk level by quantifying the current growth stage of cultivated crops and the probability of possible weather disasters according to the weather conditions of the farm. Agrometeorological disasters are damages caused by weather conditions that can affect crops and can be predicted by estimating the probability of damage that may occur from the interaction between hazardous weather and crop characteristics. This review introduces the classification of possible weather risks by their occurrence mechanisms, based on the developmental stage of crops and prediction techniques that have been developed or applied to date. The accumulated crop growth and weather risk information is expected to be utilized as support material for farming decision-making, which helps farmers proactively respond to crop damage due to extreme weather events by providing highly reliable disaster forecasts through the advancement of prediction technology.

Mitigation of rice blast disease by using biocontrol agents and new molecular fungicides

Rice blast is one of the most devastating diseases which is caused by Pyricularia grisea. The disease infects the all growth stages of rice crop and causes severe yield loss. Biocontrol agents and new molecular fungicides were tested against blast disease of rice. Among the nine treatments tested, Seed treatment with Bacillus subtilis + Foliar spray of Tebuconazole 50% + Trifloxystrobin 25% WG @ 1g/l (T7) recorded the maximum (67.88 %) reduction of the blast disease followed by Seed treatment with Bacillus subtilis @10g/kg + Foliar spray of Picoxystrobin 6.78% + Tricyclazole 20.33% SC @1ml/l (T8) which recorded 58.67 % reduction of the blast disease. Combined application of biocontrol agents having ability to reduce rice blast disease and increase the yield significantly.

Response of Matching Degree between Precipitation and Maize Water Requirement to Climate Change in China

The synchronicity of rain and heat in the summer of China’s monsoon region provides sufficient water and heat resources for maize growth. However, the intra-annual distribution of precipitation and the probability of extreme precipitation have been inevitably altered by the ongoing climate change, thus affecting the matching degree between precipitation and crop water requirements (MDPCWR). Evaluating the extent to which the MDPCWR will change in the future is of great importance for food security and the sustainable management of water resources. In this study, considering that different growth stages of crops have different sensitivities to water stress, the AquaCrop model was used to calculate the MDPCWR more accurately. In addition, a cumulative distribution function-transform (CDF-t) method was used to remove the bias of 11 global climate models (GCMs) under two typical emission scenarios (SSP2-4.5 and SSP5-8.5) from phase six of the Coupled Model Intercomparison Project (CMIP6). A comprehensive investigation was conducted on how maize growth, water consumption, and the MDPCWR will respond to future climate change with CO2 concentration enrichment in the Huang–Huai–Hai (3H) region in China by driving a well-tested AquaCrop model with the bias-corrected GCMs outputs. The results indicate the following: (1) The CDF-t method can effectively remove seasonal bias, and it also performs well in eliminating the bias of extreme climate events. (2) Under the SSP2-4.5 scenario, the average maximum temperature will increase by 1.31 °C and 2.44 °C in 2021–2050 and 2051–2080, respectively. The average annual precipitation will increase up to 96.8 mm/year, but it will mainly occur in the form of heavy rain. (3) The increased maize evapotranspiration rate does not compensate for the decreased crop water requirement (up to −32 mm/year), due to a shorter growth cycle. (4) The farmland cultivation layer is not able to hold a significant amount of precipitation, due to the increased frequency of heavy rains, resulting in increased irrigation water requirements for maize over the next two periods, with the maximum value of 12 mm/year. (5) Under different scenarios, the projected future MDPCWR will decrease by 9.3–11.6% due to changes in precipitation patterns and crop water requirements, indicating that it will be more difficult for precipitation to meet the water demand of maize growing in the 3H region. The results can provide comprehensive information to understand the impact of climate change on the agricultural water balance and improve the regional strategy for water resource utilization in the 3H region.