Crop Production Research Articles

Subsoil testing required to detect the rundown of soil potassium to deficient levels for wheat production on loam-textured soils

Context Long-term negative potassium (K) balances in crop production have depleted soil K levels in Western Australia (WA). Previous research has focussed on sand-textured soils, but recently, monitoring of crops grown on loam-textured soils has shown deficient or marginal shoot K concentrations where Colwell K 0–10 cm is above current critical levels. Aims The aims were to examine whether grain yield responses to fertiliser K can be detected on loam-textured soils and if soil test calibration curves can be identified for these soils. Methods Eight field trials were conducted with wheat on loam-textured soils. The same experimental design was used at all sites; six levels of K applied at sowing, from 0 to 200 kg K ha−1 with one treatment including a split application. Soil and plant test calibration curves were modelled using measurements from the trials. Key results Grain yield responses of 0.69 to 1.37 t ha−1 to fertiliser K (P < 0.05) occurred in 4 of 8 trials. Relative yield was closely related to soil exchangeable K and the goodness of fit of the soil test calibration curves increased as the depth of sampling increased. The best soil test calibration curve was for sampling 0–40 cm. Conclusions This research confirms that on some loam-textured soils, yield loss is occurring to K deficiency if no K fertiliser is applied. Implications As soil K reserves are run down, soil sampling at 0–40 cm on loam-textured soils will provide the most accurate monitoring of soil K deficiency for wheat production.

The impact of weather patterns on inter-annual crop yield variability

Inter-annual variations in crop production have significant implications for global food security, economic stability, and environmental sustainability. Existing crop yield prediction models primarily using meteorological variables may not adequately encapsulate the full breadth of weather influences on crop development processes, such as compound or extreme events. Incorporating weather patterns into crop models could provide a more comprehensive understanding of the environmental conditions affecting growth, enabling more accurate and earlier yield predictions.Our study examines 30 distinct UK Met Office weather patterns (MO30) based on mean sea level pressure. We investigate their association with weather conditions that limit winter wheat yield in the UK (1990–2020). Blocked, negative North Atlantic Oscillation (NAO) patterns create the highest risk of temperatures that are below optimal for crop yield. However, the connection between weather patterns and yield is complex, with differing effects at a regional scale and even at which point in the growth cycle they appear. It was found that anticyclonic weather patterns during sowing, emergence, vernalisation, anthesis, and grain filling exhibit a relationship with good crop yields with a Spearman correlation coefficient of up to 0.55 for a single weather pattern (WP3 during vernalisation in South East England), whilst cyclonic patterns can help during the terminal spikelet phenological phase. The strongest positive correlations were during sowing, emergence, and vernalisation, whilst the largest negatives were observed in anthesis and grain filling.The potential of combining weather patterns with existing crop simulation models to produce earlier and more accurate yield predictions is shown. This would enable effective crop management and climate mitigation strategies, critical to strengthening food security. Projected changes in weather pattern occurrences in the late 21st century will likely reduce crop yields. This is due to increased cyclonic weather patterns, which bring warmer, wetter conditions during the wheat's vernalisation stage, followed by warmer, drier conditions during the anthesis and grain-filling phases.

TaWRKY55-TaPLATZ2 module negatively regulate saline-alkali stress tolerance in wheat.

Saline-alkaline soils are a major environmental problem that limit plant growth and crop productivity. Plasma membrane H+-ATPases and the salt overly sensitive (SOS) signaling pathway play important roles in plant responses to saline-alkali stress. However, little is known about the functional genes and mechanisms regulating the transcription of H+-ATPases and SOS pathway genes under saline-alkali stress. In the present study, we identified that the plant AT-rich sequence and zinc-binding (TaPLATZ2) transcription factor are involved in wheat response to saline-alkali stress by directly suppressing the expression of TaHA2/TaSOS3. The knockdown of TaPLATZ2 enhances salt and alkali stress tolerance, while overexpression of TaPLATZ2 leads to salt and alkali stress sensitivity in wheat. In addition, TaWRKY55 directly upregulated the expression of TaPLATZ2 during saline-alkali stress. Through knockdown and overexpression of TaWRKY55 in wheat, TaWRKY55 was shown to negatively modulate salt and alkali stress tolerance. Genetic analyses confirmed that TaPLATZ2 functions downstream of TaWRKY55 in response to salt and alkaline stresses. These findings provide a TaWRKY55-TaPLATZ2-TaHA2/TaSOS3 regulatory module that regulates wheat responses to saline-alkali stress.

Mapping predicted biomass in cereal rye using 3D imaging and geostatistics

Abstract Cover crops are becoming an increasingly important tool for weed suppression. Biomass production in cover crops is one of the most important predictors of weed suppressive ability. A significant challenge for growers is that cover crop growth can be patchy within fields, making biomass estimation difficult. This study tested ground-based structure-from-motion (SfM) for estimating and mapping cereal rye (Secale cereale L.) biomass. SfM generated 3D point clouds from red, green, and blue (RGB) videos collected by a handheld GoPro camera over five fields in North Carolina during the 2022 to 2023 winter season. A model for predicting biomass was generated by relating measured biomass at termination using a density–height index (DH) from point cloud pixel density multiplied by crop height. Overall biomass ranged from 320 to 9,200 kg ha−1, and crop height ranged from 10 to 120 cm. Measured biomass at termination was linearly related to DH (r2 = 0.813) through levels of 9,000 kg ha−1. Based on independent data validation, predicted biomass and measured biomass were linearly related (r2 = 0.713). In the field maps generated by kriging, measured biomass data were autocorrelated at a range of 5.4 to 42.2 m, and predicted biomass data were autocorrelated at a range of 3.4 to 12.0 m. However, the spatial arrangement of high- and low-performing areas was similar for predicted and measured biomass, particularly in fields with greatest patchiness and spatial correlation in biomass values. This study provides proof-of-concept that ground-based SfM can potentially be used to nondestructively estimate and map cover crop biomass production and identify low-performing areas at higher risk for weed pressure and escapes.

Impacts of adaptation to climate change on farmers’ food security and level of sesame production in Western Ethiopia

The existence of multiple stresses and poor adaptive capacity make Africa most susceptible to climate change. In Ethiopia the potential adverse effects of climate change on the agricultural sector, the main stay of the country’s economy, are major concerns. To ensure food security, reducing the vulnerability of agricultural systems through different feasible adaptation strategies is one of the policy options in response to climate change impact This study is a first of its kind in examining the relative effectiveness of various adaptation strategies in ensuring farmers’ food security and enhancing level of sesame production in rural area of Western Ethiopia. In addition to data obtained from meteorological stations, cross-sectional data were collected interviewing 400 farm households. Descriptive statistics, two-stage least square (2SLS) and double-hurdle (D-H) models were used to analyze the data. The results of the study indicate that households are adapting using various strategies to the looming climate change in the area. The study also indicated that, though sesame production was negatively impacted by the climate hazards, smallholders have continued its production at minimum level due mainly to its high value crop character. 2SLS estimation results revealed that rainfall and temperature variability have negative impact on household’s food security. Moreover, the result indicates effectiveness of climate adaptation strategies namely agronomic practices, irrigation and soil and water conservation in reducing climatic risks and ensuring household food security. The result also implicitly indicated that farmers continued to adapt sesame production under risk climate and it is contributing to farmers’ food security. Further, the result revealed that climate change adaptation strategies have positively impacted the level of sesame production. Consequently, policy that augments households’ climate awareness and promotes adaptation decision and strategies could help reducing risks pertaining to climate and thereby improves farmers’ food security status and production of high value export potential crop—sesame.

Identifying and modeling the impact of neonicotinoid exposure on honey bee colony profit

Abstract Pollination by the European honey bee, Apis mellifera, is essential for the production of many crops, including highbush blueberries (Vaccinum corymbosum). To understand the impact of agrochemicals (specifically, neonicotinoids, a class of synthetic, neurotoxic insecticides) on these pollinators, we conducted a field study during the blueberry blooms of 2020 and 2021 in British Columbia (B.C.). Forty experimental honey bee colonies were placed in the Fraser Valley: half of the colonies were located within 1.5 km of highbush blueberry fields (“near” colonies) and half were located more than 1.5 km away (“far” colonies). We calculated risk quotients for these compounds using their chronic lethal dietary dose (LDD50) and median lethal concentration (LC50). Pesticide risk was similar between colonies located near and far from blueberry forage, suggesting that toxicity risks are regionally ubiquitous. Two systemic neonicotinoid insecticides, clothianidin and thiamethoxam, were found at quantities that exceeded chronic international levels of concern. We developed a profit model for a pollinating beekeeper in B.C. that was parameterized by: detected pesticide levels; lethal and sublethal bee health; and economic data. For colonies exposed to neonicotinoid pesticides in and out of the blueberry forage radii, there were economic consequences from colony mortality and sublethal effects such as a loss of honey production and compromised colony health. Further, replacing dead colonies with local bees was more profitable than replacing them with imported packages, illustrating that beekeeping management selection of local options can have a positive effect on overall profit.

Right to Food Policies, Justice and Sovereignty in Nigeria

This study assessed the right to food policies, justice and sovereignty in Nigeria. The main areas of concentration were: introduction, meaning of food policy, some food policies in Nigeria, types of policies, audit of right to food policies in Nigeria, past policy articulations (1900 – 1999), food policy articulation and policy thrust in 2003, food policy legislations, sovereignty of food and agricultural development among many others. The study indicated that food policy is a public declaration that conveys the decisions to pursue a specific course of action aimed at improving food production practices, ensuring output growth and the overall development of the food sector. Some food policies in Nigeria are; food crop production policy, livestock production policy, food commodity storage policy among others. The study identified three types of polices namely; position declaration, policy statements and discussion papers. Past policy articulations are: Timber/non timber policy 1937, food policy 1946 and food policy for the western region 1952. Some policy legislations were identified, namely: adulteration of produce ordinance No.67 of 1917; 29 of 1920, 8th November 1917, Weight and measurements Act No. 32 of 1974 to June 1975 and River Basin Development Authorities Act No.35 of 1st October, 1986. Some inventory of right to food sovereignty strategies in Nigeria includes: Sovereignty strategy formulations, commodity boards, National Accelerated Food Production Project (NAFPP), National Livestock Development Project (NLDP), Operation Feed the Nation (OFN) and Green Revolution among very many others. One major problem of food policy implementation is lack of a well-defined programme. In conclusion, Right to Food Policy, Justice and Sovereignty Implementation means money spent, laws enforced, employees hired, plan of action formulated and carried out successfully for the development of the Nigerian food sub-sector. But the problem with Nigerian food policies is the structure among which is the absence of central coordinating members. Also, the study recommended that there is the need for government to set institutions that will monitor the planning and execution of food polices projects. Key words: Agricultural Development, Food, Justice, Legislations, Nigeria, Policies, Rights, Sovereignty

Predicting Subsurface Drainage Requirement for Different Soil Desalinization Goals in Coastal Reclamation Areas

ABSTRACTBuilding subsurface drainage systems for more efficient salt leaching with the natural rainfall or artificial irrigation is a widely accepted practice for saline soils reclamation, but the high initial cost of the system construction often limits its adoption, and the uncertainty in drainage intensity requirement to meet desired desalinization goals for field crop production challenges the system design. In this paper, we proposed a soil desalinization model based on the field hydrology model‐DRAINMOD, predicted number of years required to lower soil salinity to a threshold level under different subsurface drainage conditions, and estimated the net return from different subsurface drainage system layout based on a case study in a coastal reclamation area in eastern China. The results showed that, DRAINMOD accurately predicted water table fluctuations in artificially drained fields: the root mean square error to standard deviation ratio (RSR) was 0.4 and 0.54, and the Nash Sutcliffe efficiency (NSE) was 0.84 and 0.68, respectively, during the model calibration and validation periods. The DRAINMOD based soil desalinization model predicted a negative relationship between subsurface drainage intensity and the soil desalinization period, that is, improving drainage condition shortened the time requirement for soil desalinization. For the study area, the model's predictions showed that installing subsurface drainage at 20 m spacing and 1.2 m deep lowered soil salinity to the slightly saline level in less than 7 years under the rainfall leaching only, and such system layout produced the maximum economic return based on the local agricultural practice. The results indicate that, early investment in adequate subsurface drainage systems is beneficial for field crop production in the salt impacted farmland areas. Findings from this research may provide technical references for saline soil reclamation or land improvement in both rain fed and irrigated agricultural areas.

Enhancing Iron and Zinc Uptake in Spring Wheat Through Commercial Arbuscular Mycorrhizal Fungi Inoculation under Different Soil Phosphorus Addition Levels

Improving the concentrations and bioavailability of micronutrients, especially iron (Fe) and zinc (Zn), in crop grains is important to alleviate their deficiencies in humans. Inoculating crops with arbuscular mycorrhizal fungi (AMF) can potentially enhance soil nutrient supply and crop yield, but the effectiveness is influenced by soil factors, particularly soil phosphorus (P) availability. A greenhouse pot experiment was conducted to evaluate the effect of a commercial AMF product on spring wheat (Triticum aestivum L.) yield and grain concentrations of Zn and Fe under different soil P addition levels (0, 5 and 20 mg P kg-1 dry soil). Results showed that AMF inoculation significantly increased root colonization rate of wheat across all P addition levels. Wheat growth, as evidenced by dry weights of shoot and grain, was significantly enhanced by AMF and high P addition treatments. AMF inoculation did not affect grain Zn concentration, but significantly increased grain Fe concentration compared to the un-inoculated control. As expected, P addition resulted in a significant reduction in grain concentrations of Fe and Zn, primarily due to a growth dilution effect. An integrated analysis using the radar plot concludes that AMF inoculation is most effective in increasing crop yield and grain micronutrient concentrations when soil P levels are low. Importantly, while adequate P supply is crucial for maintaining crop productivity, it may decrease grain micronutrient availability without complementary strategies.

Determining food intake, the requirement, and weighing the relative risk between food secure and insecure households in rural areas of Ethiopia: The case of West Hararghe zone

The severity of food insecurity in Ethiopia is among the worst globally, with record-breaking food assistance needs by various factors. This study tries to uncover various aspects of food security related to food availability, food access, food utilization and food stability dimensions of food security. The study was executed in the west Hararghe zone of the Oromia region of Ethiopia. Its main objective was to determine the food security status of households, with specific objectives aiming at computing individual daily kilo calorie intake, determining the average food requirement, comparing the relative risk between food secure and insecure households and identifying factors that affect household food security status. A multi-stage sampling procedure, involving the purposive selection of; the Zone and Woreda, and a simple random selection of households, to draw the required number of representative sample respondents, was adopted. Hence, from 4163 total households, 134 were selected for collecting primary data. Data were analyzed using descriptive statistics, relative risk analysis using Cohorts and independent tests using ANOVA. Food security status was measured using the Household Food Balance Model (HFBM). Using this model, the study obtained 1973 kilo calories per individual per day intake and 2108 kilo calorie as their requirement, which indicated households were energy deficient by 135 kilo calorie with 2-sided-value < 0.1 critical level (t= -1.747, df =133 & sig2-sided. 0.083). Independent test results showed that farm income (at p-value < 0.1), gross product (at p-value < 0.05), age of household head (at p-value < 0.1), years of owning land (at p < 0.1) and family size (at p-value < 0.1) contributed significantly to food security status. Cross-tabulation showed a linear relationship between food security and higher education level (at p-value < 0.05), which urges a concern in improving farming societies’ literacy to the desired level. In the study areas, about 91.8% of the population produces crops depending on the seasonal rainfall and their daily kilo calorie consumed depends on it; this is statistically correlated with the food insecurity problem at p-value < 0.1 critical level (lambada = 1.75 & sig. = 0.08). Therefore, to tackle the food insecurity problem, alternative method of crop production should be devised such as the establishment of irrigation schemes, water harvesting structures, and water conservation practices, among others. Key words: food security, calorie requirement, food availability, relative risk

The LTAR Cropland Common Experiment at Platte River/High Plains Aquifer.

The Platte River/High Plains Aquifer (PR/HPA) region is characterized by cropland, pastures, and grasslands that are faced with changing climatic conditions and agricultural intensification. The PR/HPA Long-Term Agroecosystem Research (LTAR) site is located in Eastern Nebraska with the goal of improving resilience, sustainability, and profitability of agroecosystems through enhancing ecosystem services and environmental quality, developing strategies for efficient agricultural production, and mitigating and adapting to climate change. To meet this goal, a common experiment and five ancillary experiments have been developed to evaluate prevailing regional practices in grain crop production systems compared to alternative practices in rainfed and irrigated systems. These experiments reflect different geographic regions and cropping systems within PR/HPA. The common experiment is at a plot scale under sub-drip irrigation. The prevailing practice is a corn-soybean rotation with a fixed N fertilizer rate. The alternative practice is a corn-winter wheat-relay cropped soybean rotation with temporally variable N rates using fertigation. There is also an auxiliary alternative practice, a corn-soybean rotation with temporally variable N rates using fertigation with fall manure application after soybean harvest. This document describes the regional characteristics, cropland LTAR experiments, stakeholder engagement, and future plans for the PR/HPA cropland experiments.

Model for estimating red mulberry leaf area using a genetic algorithm

The success of sericulture depends directly on the quality and quantity of mulberry leaves, as it is essential for the feeding and development of silkworm caterpillars and, consequently, influences the quality of the silk thread manufactured. The estimation of mulberry leaf area is important to have plant development and growth indicators, such as transpiration intensity, net assimilation rate, leaf area ratio, specific leaf area and leaf area index, which allow predicting crop productivity. Thus, the objective of this study was to develop and test a model capable of estimating the red mulberry leaf area using a genetic algorithm. The model was adjusted with the proposed stochastic optimization method. The mean error found for the tested dataset was approximately 228.17 mm2 in sample space with mean leaf area of 6515.55 mm2. The information generated allows applying the model to estimate red mulberry leaf area in future studies.

Evaluating the effects of rice husk derived nanosilica on growth, photosynthesis, and antioxidant activity in hybrid maize

Drought stress was exacerbated by changing climatic conditions and impact the plant water relations from the cellular to whole plant level, thereby reducing the crop productivity and causing economic losses in agriculture. The present study was aimed to explore the potentials of nanosilica synthesized from rice husk in improving growth and drought stress tolerance in maize. Synthesized nanosilica from rice husk has spherical morphology, amorphous structure, siloxane bonding and higher purity (99.1 %). Soil application of varied levels of synthesized nanosilica (0, 5, 10, 15, 20, 30 and 40 mg kg−1) was tested with hybrid maize plants grown under irrigated and drought stress (100 and 50 % field capacity, respectively). The results of the study revealed that, drought stress has adverse effect on plant growth, biomass production and physiological parameters. However soil application of nanosilica has significantly improved growth, physiological and biochemical attributes of both irrigated and drought stressed plants. Nanosilica application at 20 mg kg−1 for irrigated and 30 mg kg−1 for drought stressed hybrid maize plants has recorded higher plant height, biomass, chlorophyll a, chlorophyll b, superoxide dismutase, peroxidase, phenols, soluble proteins and considerably decreased the proline, electrolyte leakage and melondialdehyde content in hybrid maize. In contrary, higher doses of nanosilica (>30 mg kg−1) caused a slight reduction in plant growth and antioxidant activity under both the water regimes. Hence, we conclude that, soil application of 20 and 30 mg kg−1 nanosilica synthesized from rice husk had a positive effect on plant growth and development besides aided in mitigating drought stress.

OsAAH confers salt tolerance in rice seedlings.

Soil salinization is becoming a great threat that reduces crop productivity worldwide. In this study, we found that rice allantoate amidohydrolase (OsAAH) expression was significantly upregulated by salt stress, and its overexpression conferred salt tolerance at the seedling stage. Compared to wild type (WT), the contents of ureides (allantoin and allantoate) were significantly increased in Osaah mutants and reduced in OsAAH overexpression lines both before and after salt treatments. Exogenous allantoin significantly promoted salt tolerance in OsAAH overexpression, but not in Osaah mutants. Subcellular localization showed that OsAAH was also localized to the peroxisomes in addition to the previously reported endoplasmic reticulum (ER). The differential expression of peroxisome-related genes was identified between Osaah mutants and WT. Furthermore, the contents of H2O2 and malondialdehyde (MDA) were significantly accumulated in Osaah mutants and reduced in OsAAH overexpression lines. The activities of antioxidant enzymes were significantly reduced in Osaah mutants and enhanced in OsAAH overexpression under NaCl treatment. The transcription factor OsABI5 could directly bind to OsAAH promoter and activate OsAAH expression. Our findings reveal that OsAAH could be induced by salt stress through the activation of OsABI5 and then confer salt tolerance by enhancing the scavenging capacity of reactive oxygen species (ROS), which contributes to rice breeding in salt tolerance.

Investigating the influence of selenium and epibrassinolide on antioxidant activity, proline accumulation, and protein expression profiles in wheat plants experiencing heat and drought stress.

In the current investigation, the combination of selenium (Se) and epibrassinolide (EBL) exhibited a promising alleviative response against the concurrent stress of heat and drought in wheat plants. The compromised growth and photosynthetic performance of wheat plants under the combined stress of heat and drought were substantially improved with the treatment involving Se and EBL. This improvement was facilitated through the expression of Q9FIE3 and O04939 proteins, along with enhanced antioxidant activities. The heightened levels of antioxidant enzymes and the accumulation of osmoprotectant proline helped mitigate the overaccumulation of reactive oxygen species (ROS), including electrolyte leakage, H2O2 accumulation, and lipid peroxidation, thus conferring tolerance against the combined stress of heat and drought. Studies have demonstrated that Se and EBL can assist wheat plants in recuperating from the adverse effects of heat and drought. As such, they are essential components of sustainable farming methods that aim to increase crop productivity.

Resistance of barley cultivars and accessions to pathotypes of the spot blotch causative agent

Background. The spot blotch disease caused by the hemibiotrophic fungus Bipolaris sorokiniana has become a serious problem for barley. Utilization of resistant or tolerant barley cultivars ensures sustainable diversity conservation and environmentfriendly crop production. Thus, supplying barley breeders with sources of resistance to harmful diseases is an urgent task. Materials and methods. A set of 100 barley accessions, earlier selected for different levels of resistance to B. sorokiniana, served as the material for this study. Eleven isolates of B. sorokiniana of various geographic origin, belonging to 4 pathotypes, were used for testing. The resistance of barley seedlings was assessed under controlled laboratory conditions, and that of adult plants under artificial infection pressure in the field. Responses to B. sorokiniana were scored using the 0–9 rating scale.Results and conclusions. Barley genotypes with race-specific resistance to the spot blotch causative agent were identified. The percentage of barley genotypes resistant to five isolates of B. sorokiniana pathotype 1 averaged 24.2%; two isolates of pathotype 3, 29.5%; three isolates of pathotype 7, 18.3%; and one isolate of pathotype 0, 37%. Barley accessions manifesting resistance in their seedlings, but susceptible in the phase of milk-wax ripeness, and vice versa, with seedling susceptibility and adult resistance, were identified. Six (6) barley genotypes showed seedling and adult resistance to pathotype 1, nine (9) to pathotype 3, and two (2) to pathotype 7. No barley accessions resistant to all isolates of the pathogen were found.

Magnetized Irrigation and its Potential in Sustainable Agriculture: A Review

Magnetisation in agriculture is not a conventional method. It has tremendous implications in the crop production as well as mitigating the poor quality soil and water conditions. This reviews looks into the changes that occur in the properties of water on magnetization and the changes in the physico-chemical of soil that are affected by magnetic water. The practical application of magnetic irrigation in agriculture are reviewed based on recent researches. Magnetisaton positively influences the seed germination, seedling establishment, vegetative growth and yield of treated plants. Magnetic irrigation boosts the anti-oxidant and enzyme activity, enhances the plant metabolism and synthesis of plant pigments for coping up the adverse growth conditions. The remediation of poor quality irrigation water and waste water management are another fields where magnetization can be effectively utilized. Magnetic water can be used to alleviate abiotic stresses such as salinity and drought stresses. Magnetised irrigation is a suitable alternative for reduced water requirement and improved water use efficiency. Hence magnetised irrigation is a promising scientific method to boost crop production, while being sustainable and environmentally safe.

Efficacy of Pre and Post Emergence Herbicides against Complex Weed Flora, Yield and Economics of Blackgram under High Hills Wet Temperate Zone of Himachal Pradesh

Background: Implementing integrated strategies for weed management is essential in maximizing blackgram yield. Unchecked weed proliferation leads to substantial decrease in crop productivity. Methods: The current field experiment was conducted at Salooni, Himachal Pradesh, to evaluate the efficacy of different integrated weed management practices during Kharif 2022 and 2023. Eleven treatments targeting weed control were evaluated both at pre and post - emergence stages. Result: The predominant weeds were Echinochloa colona, Galinsoga parviflora, Cyperus species and other broad leaf weeds were Plantago lanceolata, Trifolium repens, Trianthema species, Ageratum conyzoides. Data on weed dynamics revealed that; after weed-free treatment, the application of Imazethapyr 75 g/ha as PE fb HW at 30 DAS; Pendimethalin 1.0 kg/ha as PE fb HW at 30 DAS and Pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE) recorded a significantly lower total weed count as compared to other treatments. Parameters related to blackgram growth and yield, including plant height, number of branches per plant, pods per plant, grain yield and haulm yield were significantly higher with weed-free treatment followed by application of imazethapyr 75 g/ha as PE fb HW at 30 DAS, remaining at par with application of pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE) and pendimethalin 1.0 kg/ha as PE fb HW at 30 DAS. The most economically efficient weed control method was the combination of pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE), as it resulted in the highest net returns and marginal benefit-cost ratio.

Assessment of Groundwater Quality for Irrigation in Jhagadia, Netrang and Valia Taluka of Bharuch District in South Gujarat, India

Bharuch, a heavily industrialized district on the west coast, faces challenges like over-extraction and contamination, which threaten its groundwater quality. In response, a post-monsoon 2023 assessment was conducted in the Jhagadia, Netrang, and Valia talukas, where water samples from 78 locations were collected and analyzed. These locations were identified using landforms developed through GIS. The study found that around 40% of the TGA in these blocks is used for agriculture, with 52,106 hectares for single crops and 7,843 hectares for double crops, making up 15.05% of the total cultivated area. Eastern part of Jhagadia and Netrang recorded deep water levels (10–20 m), while other areas had moderately shallow levels (5–10 m). Tube wells were mainly found in Valia, northern Jhagadia, and western Netrang, whereas dug wells dominated eastern Netrang and southeastern Jhagadia. Irrigation water pH ranged from 6.31 to 8.82, averaging 6.97, with higher pH in Jhagadia. Electrical conductivity (EC) was highest in Valia (0.66–2.94 dSm⁻¹), and medium salinity was noted in Jhagadia (1.03 dSm⁻¹) and Netrang (0.71 dSm⁻¹), affecting irrigation suitability. All samples had a SAR classification of S1 (<10). Most water samples were "Suitable" based on RSC, except some in Valia with RSC >1.25 meL⁻¹. Chloride levels varied from 0.50 mg/L-1 to 25.48 mg/L-1. The specific soil management practices, such as gypsum application, improving drainage and the growing of salt-tolerant crop varieties can help mitigate potential negative impacts on crop productivity.

Thermal Stress as a Critical Factor in the Viability and Duration of Spittlebug Eggs

The spittlebug Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) is an important pest that causes significant losses in the production of forage crops for cattle feed. Information on the thermal requirements of this insect during the egg stage is crucial in assessing the interaction between insects and forage. The aim of this research was to evaluate the effects of constant and oscillating (diurnal/nocturnal) temperatures on the viability of M. spectabilis eggs and the duration of the egg stage. Temperatures of 20 °C to 30 °C were ideal for the development of this insect pest, resulting in greater viability and faster development of the embryos. In addition, it should be noted that a variation of up to 8 days is feasible for synchronizing the phenological stages of the forage plants and the eggs to be laid on these plants when subjected to 30 °C (16.6 days) or 20 °C (25.7 days) without significantly altering the viability of the eggs. Notably, a temperature oscillation of 25 °C during the day and 15 °C at night increased the viability of the eggs after exiting diapause. These results are essential for the rearing of M. spectabilis in the laboratory, allowing for the supply of eggs for experiments and contributing to advances in studies aimed at developing effective integrated management strategies for this pest.