Effects of Climate Change on Nine Rainfed Zea mays Races in Chiapas, Mexico

Maize cultivation (Zea mays) is essential for Mexico from a nutritional, cultural and economic perspective. Scientific literature ignores the impact of anthropogenic causes of climate change on rainfed cultivation of Z. mays in Chiapas, Mexico, one of the poorest states in the country. Therefore, we modeled the feasibility of rainfed cultivation for nine races of rainfed maize for the years 2060 and 2100. The MaxEnt 4.4.4 algorithm modeled maize cultivation under two scenarios (4.5 and 8.5) for 2060 and 2100. Model inputs were 12 bioclimatic variables, 3 climatic variables, and 1 elevation variable. All layers were obtained from the WorldClim 2.1 project. By 2060, the suitable area for rainfed cultivation of the nine Z. mays races would drastically decrease under both modeled scenarios. By 2100, this area will decrease for seven races, and disappear for the Olotillo and Olotón races. To the best of our knowledge, this is the first study providing fundamental information on how climate change will negatively impact the nine Z. mays races in Chiapas, Mexico. This enables the development of sustainable management protocols or conservation strategies. Highlights: The MaxEnt algorithm proved very useful in modeling the effect of climate change on Zea mays. By the year 2060, the viable rainfed cultivation area of the nine mays races will drastically decrease under climate change scenarios 4.5 and 8.5 in Chiapas, México. By the year 2100, the viable rainfed cultivation area of seven mays races will drastically decrease under climate change scenarios 4.5 and 8.5, while Olotillo and Olotón maize races will completely disappear in Chiapas, México. “Maximum temperature of the warmest month” (Bio 5) was the variable with more contribution in 2060 (74% and 92.6%, for 4.5 and 8.5 scenarios, respectively) and in 2100 (59.3% and 89.1%, for 4.5 and 8.5 scenarios, respectively).Maize cultivation (Zea mays) is essential for Mexico from a nutritional, cultural and economic perspective. Scientific literature ignores the impact of anthropogenic causes of climate change on rainfed cultivation of Z. mays in Chiapas, Mexico, one of the poorest states in the country. Therefore, we modeled the feasibility of rainfed cultivation for nine races of rainfed maize for the years 2060 and 2100. The MaxEnt 4.4.4 algorithm modeled maize cultivation under two scenarios (4.5 and 8.5) for 2060 and 2100. Model inputs were 12 bioclimatic variables, 3 climatic variables, and 1 elevation variable. All layers were obtained from the WorldClim 2.1 project. By 2060, the suitable area for rainfed cultivation of the nine Z. mays races would drastically decrease under both modeled scenarios. By 2100, this area will decrease for seven races, and disappear for the Olotillo and Olotón races. To the best of our knowledge, this is the first study providing fundamental information on how climate change will negatively impact the nine Z. mays races in Chiapas, Mexico. This enables the development of sustainable management protocols or conservation strategies. Highlights: The MaxEnt algorithm proved very useful in modeling the effect of climate change on Zea mays. By the year 2060, the viable rainfed cultivation area of the nine mays races will drastically decrease under climate change scenarios 4.5 and 8.5 in Chiapas, México. By the year 2100, the viable rainfed cultivation area of seven mays races will drastically decrease under climate change scenarios 4.5 and 8.5, while Olotillo and Olotón maize races will completely disappear in Chiapas, México. “Maximum temperature of the warmest month” (Bio 5) was the variable with more contribution in 2060 (74% and 92.6%, for 4.5 and 8.5 scenarios, respectively) and in 2100 (59.3% and 89.1%, for 4.5 and 8.5 scenarios, respectively)

Transition Management and Dairy Cow Performance: Insights from Dairy Farms in Argentina

This study aims to describe nutritional strategies, management practices, and health events in transitioning cows on 28 commercial dairy farms in Argentina, selected based on their association with graduate students. During 2022, we surveyed herd management, feeding, health events, and milk yield, based on local research and validated recommendations. Most cows were housed in dry lots, with 97% of farms having far-off and close-up groups, but only half had a fresh group. The average dry period was 59±11.4 days. The mortality and culling rate were 1.2% and 1.4%, respectively. The herd incidence rates were 1.8% for milk fever, 0.3% for clinical mastitis, 2.7% for metritis, and 1.4% for retained placenta. All farms used anionic diets and monitored urinary pH, with corn silage included in all diets, and soybean meal/expeller as the main protein source. Lactating cows produced an average of 33.8±10.43 kg of milk on the first test day and 38.2±10.05 kg at peak. Primiparous cows produced 75% of the milk of mature cows. Bulk tank milk averaged 3.9±0.19% fat and 3.5±0.07% CP. This report highlights strengths and areas for improvement in Argentina’s dairy transition programs. Highlights: Surveyed transition cow management and performance on 28 Argentine dairy farms, providing novel regional data. Strengths: Routine far-off and close-up grouping, widespread use of negative DCAD diets, and frequent bunk monitoring contributed to low incidence of health disorders, culling, and mortality. Milk composition showed above-average fat and protein content, reflecting effective nutritional strategies. Challenges: Lack of fresh groups, grouping primiparous with multiparous cows, limited shade, and extended dry periods (>50 d) increased risks of social stress and overconditioning. Opportunities: Improve forage sampling frequency, refine energy balance prepartum, and enhance cow comfort to optimize productivity and sustainability.This study aims to describe nutritional strategies, management practices, and health events in transitioning cows on 28 commercial dairy farms in Argentina, selected based on their association with graduate students. During 2022, we surveyed herd management, feeding, health events, and milk yield, based on local research and validated recommendations. Most cows were housed in dry lots, with 97% of farms having far-off and close-up groups, but only half had a fresh group. The average dry period was 59±11.4 days. The mortality and culling rate were 1.2% and 1.4%, respectively. The herd incidence rates were 1.8% for milk fever, 0.3% for clinical mastitis, 2.7% for metritis, and 1.4% for retained placenta. All farms used anionic diets and monitored urinary pH, with corn silage included in all diets, and soybean meal/expeller as the main protein source. Lactating cows produced an average of 33.8±10.43 kg of milk on the first test day and 38.2±10.05 kg at peak. Primiparous cows produced 75% of the milk of mature cows. Bulk tank milk averaged 3.9±0.19% fat and 3.5±0.07% CP. This report highlights strengths and areas for improvement in Argentina’s dairy transition programs. Highlights: Surveyed transition cow management and performance on 28 Argentine dairy farms, providing novel regional data. Strengths: Routine far-off and close-up grouping, widespread use of negative DCAD diets, and frequent bunk monitoring contributed to low incidence of health disorders, culling, and mortality. Milk composition showed above-average fat and protein content, reflecting effective nutritional strategies. Challenges: Lack of fresh groups, grouping primiparous with multiparous cows, limited shade, and extended dry periods (>50 d) increased risks of social stress and overconditioning. Opportunities: Improve forage sampling frequency, refine energy balance prepartum, and enhance cow comfort to optimize productivity and sustainability

Social Welfare Effects of Water Security Improvements in Arid Regions: The Case of Mendoza, Argentina

Water security is a critical challenge in Mendoza, Argentina, an arid region that faces rising water demand and uncertainty caused by climate change. Agriculture consumes 90% of the fresh water in the region, while vineyards occupy just over 60% of the cultivated area. This study estimates the social welfare effects of an improvement in water security achieved by reallocating water from vineyards to other uses. We used a multidisciplinary approach, applying benefit transfer to estimate social welfare changes and water footprint to quantify shifts in water availability. Our findings suggest that a water security policy in the Mendocinian Northern Oasis can result in an average 21-percentage-point increase in annual water availability for other uses. This equals an average household welfare gain of 17.43 US dollars per year (95% CI: 8.40-35.64) at 2024 prices over the next 30 years. This study offers a framework for regions worldwide facing similar challenges of water scarcity, increasing water demand, and climate change. Moreover, it can support the design of more informed water management strategies to ensure long-term water security. Highlights: A framework is proposed for evaluating water security improvements in arid regions. Aligning water distribution with crop water needs enables efficient water allocation. Water security improvement policies increase social welfare for Mendocinian citizens. A multidisciplinary approach is developed using benefit transfer and water footprint. Water security improvement equals an annual welfare gain of 17.43 US dollars per household.Water security is a critical challenge in Mendoza, Argentina, an arid region that faces rising water demand and uncertainty caused by climate change. Agriculture consumes 90% of the fresh water in the region, while vineyards occupy just over 60% of the cultivated area. This study estimates the social welfare effects of an improvement in water security achieved by reallocating water from vineyards to other uses. We used a multidisciplinary approach, applying benefit transfer to estimate social welfare changes and water footprint to quantify shifts in water availability. Our findings suggest that a water security policy in the Mendocinian Northern Oasis can result in an average 21-percentage-point increase in annual water availability for other uses. This equals an average household welfare gain of 17.43 US dollars per year (95% CI: 8.40-35.64) at 2024 prices over the next 30 years. This study offers a framework for regions worldwide facing similar challenges of water scarcity, increasing water demand, and climate change. Moreover, it can support the design of more informed water management strategies to ensure long-term water security. Highlights: A framework is proposed for evaluating water security improvements in arid regions. Aligning water distribution with crop water needs enables efficient water allocation. Water security improvement policies increase social welfare for Mendocinian citizens. A multidisciplinary approach is developed using benefit transfer and water footprint. Water security improvement equals an annual welfare gain of 17.43 US dollars per household

Epiphytic Microorganisms Associated with Banana Phyllosphere with Potential Antagonism to Black Sigatoka (Pseudocercospora fijiensis) in Los Ríos, Ecuador

Black Sigatoka (Pseudocercospora fijiensis) is the most important leaf spot disease of bananas worldwide, particularly affecting Cavendish banana, the most exported variety. Additionally, this pathogen has developed resistance to some effective fungicides, making its management increasingly difficult. Epiphytic microorganisms with potential antagonism to P. fijiensis were identified in conventional banana farms in the province of Los Ríos. Sampling areas were determined through zoning processes and selecting the cantons of Mocache, Valencia, Baba and Pueblo Viejo. Leaf tissue samples were collected from three farms per zone. Microorganisms were isolated and morphologically and molecularly characterised in nine farms in the cantons of Valencia (63 bacteria), Baba (39 bacteria), Pueblo Viejo (8 bacteria) and 8 genera of fungi including 15 species. The isolated bacteria presented macroscopic and microscopic characteristics with different shapes, elevations, edges, consistencies and pigmentations. Taxonomically, they belonged to the genera Bacillus and Cocos, 81% Gram-negative and 19% Gram-positive. The analysis conducted for sampling-site selection allowed the identification of different microbial behaviours. Highlights: Biological control offers a viable strategy to reduce reliance on agrochemicals in agricultural practices. The isolation and characterization of microorganisms are essential for researching and developing biological solutions applicable to banana cultivation. The data obtained provide crucial insights for formulating and developing bioinoculants.Black Sigatoka (Pseudocercospora fijiensis) is the most important leaf spot disease of bananas worldwide, particularly affecting Cavendish banana, the most exported variety. Additionally, this pathogen has developed resistance to some effective fungicides, making its management increasingly difficult. Epiphytic microorganisms with potential antagonism to P. fijiensis were identified in conventional banana farms in the province of Los Ríos. Sampling areas were determined through zoning processes and selecting the cantons of Mocache, Valencia, Baba and Pueblo Viejo. Leaf tissue samples were collected from three farms per zone. Microorganisms were isolated and morphologically and molecularly characterised in nine farms in the cantons of Valencia (63 bacteria), Baba (39 bacteria), Pueblo Viejo (8 bacteria) and 8 genera of fungi including 15 species. The isolated bacteria presented macroscopic and microscopic characteristics with different shapes, elevations, edges, consistencies and pigmentations. Taxonomically, they belonged to the genera Bacillus and Cocos, 81% Gram-negative and 19% Gram-positive. The analysis conducted for sampling-site selection allowed the identification of different microbial behaviours. Highlights: Biological control offers a viable strategy to reduce reliance on agrochemicals in agricultural practices. The isolation and characterization of microorganisms are essential for researching and developing biological solutions applicable to banana cultivation. The data obtained provide crucial insights for formulating and developing bioinoculants

First Record of Spintherophyta aurichalcea (Germar, 1824) (Coleoptera: Chrysomelidae) Damaging Ilex paraguariensis (St. Hil.) Crops in Argentina

Ilex paraguariensis (St. Hil.), commonly known as yerba mate, is a native plant to South America and cultivated in Argentina, Brazil and Paraguay. In Argentina, yerba mate is produced and cultivated throughout the province of Misiones and northeastern Corrientes. Yerba mate is a major crop in this region, providing raw material for beverages and active compounds for the pharmaceutical industry. Yerba mate crops are attacked by different phytophagous insects that can cause significant damage. This study reports the first confirmed record of Spintherophyta aurichalcea (Germar, 1824) as a phytophagous insect damaging commercial Ilex paraguariensis plantations in Misiones and Corrientes provinces, Argentina. Highligths: First confirmed record of Spintherophyta aurichalcea damaging Ilex paraguariensis crops in Argentina. The beetle was detected in commercial yerba mate plantations in Misiones and Corrientes provinces. Adults feed on young shoots and mature leaves, causing necrotic and perforated damage. Findings provide baseline information for future monitoring and pest management strategies.Ilex paraguariensis (St. Hil.), commonly known as yerba mate, is a native plant to South America and cultivated in Argentina, Brazil and Paraguay. In Argentina, yerba mate is produced and cultivated throughout the province of Misiones and northeastern Corrientes. Yerba mate is a major crop in this region, providing raw material for beverages and active compounds for the pharmaceutical industry. Yerba mate crops are attacked by different phytophagous insects that can cause significant damage. This study reports the first confirmed record of Spintherophyta aurichalcea (Germar, 1824) as a phytophagous insect damaging commercial Ilex paraguariensis plantations in Misiones and Corrientes provinces, Argentina. Highligths: First confirmed record of Spintherophyta aurichalcea damaging Ilex paraguariensis crops in Argentina. The beetle was detected in commercial yerba mate plantations in Misiones and Corrientes provinces. Adults feed on young shoots and mature leaves, causing necrotic and perforated damage. Findings provide baseline information for future monitoring and pest management strategies

Yield and Development of Winter and Spring Rapeseed (Brassica napus L.) at Different Sowing Dates in Temperate Environments

Optimal sowing dates should match the crop-critical period with favorable conditions. In rapeseed, growth stages change among spring and winter cultivars. This study characterized changes in rapeseed phenology with varying sowing dates to determine critical periods in both winter and spring cultivars. The trial took place in Balcarce, Argentina, where a winter-type variety and a spring-type were sown on eight different dates in a randomized complete block design with three replicates. Phenology was monitored weekly, and yield was evaluated at the end of the season. Changes in sowing dates and cultivars led to variations in the timing of critical periods. Considering the experimental conditions, the optimal sowing window was between April and July for sowing either rapeseed cultivar. However, the winter variety did not bloom for sowing dates after July, while the spring variety showed yield reductions due to frosts for sowing dates before the end of April. Changes in sowing date resulted in differences in timing and duration of vegetative and reproductive stages, generally leading to shorter crop cycles. However, in late sowing, winter cultivars lengthened their life cycle to the point of not reaching flowering during the growing season. Highlights: Adjustments in sowing dates and cultivar types changed the timing and duration of vegetative and reproductive stages. Late sowing extended winter cultivar cycles, occasionally preventing flowering within the season. Winter cultivars failed to flower after July sowing, while spring cultivars faced yield reductions from frosts in early sowing.Optimal sowing dates should match the crop-critical period with favorable conditions. In rapeseed, growth stages change among spring and winter cultivars. This study characterized changes in rapeseed phenology with varying sowing dates to determine critical periods in both winter and spring cultivars. The trial took place in Balcarce, Argentina, where a winter-type variety and a spring-type were sown on eight different dates in a randomized complete block design with three replicates. Phenology was monitored weekly, and yield was evaluated at the end of the season. Changes in sowing dates and cultivars led to variations in the timing of critical periods. Considering the experimental conditions, the optimal sowing window was between April and July for sowing either rapeseed cultivar. However, the winter variety did not bloom for sowing dates after July, while the spring variety showed yield reductions due to frosts for sowing dates before the end of April. Changes in sowing date resulted in differences in timing and duration of vegetative and reproductive stages, generally leading to shorter crop cycles. However, in late sowing, winter cultivars lengthened their life cycle to the point of not reaching flowering during the growing season. Highlights: Adjustments in sowing dates and cultivar types changed the timing and duration of vegetative and reproductive stages. Late sowing extended winter cultivar cycles, occasionally preventing flowering within the season. Winter cultivars failed to flower after July sowing, while spring cultivars faced yield reductions from frosts in early sowing

Beef Quality of Braford Young Intact Males and Steers Grazing Pastures and Supplemented with Energy-Protein Sources During Growing and Fattening

In this study, the quality parameters of the carcass and meat of Braford young intact males (YIM) and steers (STR) aged 17 and 20 months were evaluated and compared under Rhodes grass grazing with supplementation systems. YIM and STR (n = 60) were assigned to the grazing period and finished concentration. The carcass quality parameters studied were conformation, fat content, tissue composition, carcass weight, dressing, longissimus thoracis area (LTA) and subcutaneous fat thickness (SFT). Meat quality parameters such as pH, color, water holding capacity and texture were studied in the longissimus thoracis (LT) and semitendinosus (ST) muscles at two aging times, 3 and 15 days. YIM exhibited significantly higher body weight (BW), lower subcutaneous fat thickness (SFT), and larger longissimus thoracis area (LTA) postmortem compared to STR. Significant differences (p <0.05) were found between the two slaughter ages for LTA. Among texture parameters, only the elasticity of LT varied with the age of animals, and this parameter decreased as the age of animals increased (p <0.05). Results show that YIM generate a good quality product (carcasses and meat), which justifies the implementation of this new category for productive advantages, demonstrating superiority in the meat industry. Highlights: Relative to steers, Braford young intact males (YIM) finished on Rhodes‑grass with energy–protein supplementation showed higher final body weight, larger Longissimus thoracis area, higher carcass yield, and lower subcutaneous fat thickness. YIM carcasses contained more lean tissue and less subcutaneous and intermuscular fat, yielding a higher muscle‑to‑fat ratio than steers. Meat pH trajectory and water‑holding capacity did not differ by category; however, 20‑month animals produced redder meat (higher a*), and YIM showed lower yellowness (b*). Texture profile analysis indicated LT elasticity decreased with slaughter age, and ageing the ST muscle from 3 to 15 days reduced hardness and gumminess.In this study, the quality parameters of the carcass and meat of Braford young intact males (YIM) and steers (STR) aged 17 and 20 months were evaluated and compared under Rhodes grass grazing with supplementation systems. YIM and STR (n = 60) were assigned to the grazing period and finished concentration. The carcass quality parameters studied were conformation, fat content, tissue composition, carcass weight, dressing, longissimus thoracis area (LTA) and subcutaneous fat thickness (SFT). Meat quality parameters such as pH, color, water holding capacity and texture were studied in the longissimus thoracis (LT) and semitendinosus (ST) muscles at two aging times, 3 and 15 days. YIM exhibited significantly higher body weight (BW), lower subcutaneous fat thickness (SFT), and larger longissimus thoracis area (LTA) postmortem compared to STR. Significant differences (p <0.05) were found between the two slaughter ages for LTA. Among texture parameters, only the elasticity of LT varied with the age of animals, and this parameter decreased as the age of animals increased (p <0.05). Results show that YIM generate a good quality product (carcasses and meat), which justifies the implementation of this new category for productive advantages, demonstrating superiority in the meat industry. Highlights: Relative to steers, Braford young intact males (YIM) finished on Rhodes‑grass with energy–protein supplementation showed higher final body weight, larger Longissimus thoracis area, higher carcass yield, and lower subcutaneous fat thickness. YIM carcasses contained more lean tissue and less subcutaneous and intermuscular fat, yielding a higher muscle‑to‑fat ratio than steers. Meat pH trajectory and water‑holding capacity did not differ by category; however, 20‑month animals produced redder meat (higher a*), and YIM showed lower yellowness (b*). Texture profile analysis indicated LT elasticity decreased with slaughter age, and ageing the ST muscle from 3 to 15 days reduced hardness and gumminess

Determinants of Agricultural Land Prices in the Mendoza River Basin: A Spatial Hedonic Analysis with Emphasis on Irrigation Water

This research examines the determinants of agricultural land prices in the Mendoza River Basin, with emphasis on the marginal contribution of irrigation water as a strategic resource in an arid context. An original georeferenced database of 297 cultivated rural properties (2003-2024) was compiled, using advertised asking prices expressed in 2024 constant US dollars. A mixed spatial hedonic model with a log-log functional form was applied, incorporating hierarchical random effects (district nested within department), exponential spatial correlation, and heterogeneous variance across districts. The results indicate that properties with definitive surface irrigation rights command prices approximately 21% higher than comparable properties that rely exclusively on groundwater, confirming surface irrigation water as a pivotal economic asset. Soil quality and productive improvements increase land values by approximately 20% and 21%, respectively. In contrast, land size and distance to urban centres have significant negative effects (elasticities of -0.39 and -0.47). These findings highlight the central role of surface irrigation water as an economic asset and indicate a territorially segmented land market. The proposed methodology provides empirical evidence to support the design and implementation of water management and land-use planning policies in irrigated agricultural regions.  Highlights:   A spatial mixed log–log hedonic model is estimated for 297 agricultural properties in an arid irrigated basin. Secure surface or mixed irrigation water increases farmland prices by approximately 21% relative to groundwater-only properties. Soil quality and productive improvements generate land value premiums of approximately 20% and 21%, respectively. Larger farms and greater distance to urban centres significantly reduce land values. Accounting for spatial dependence and territorial hierarchy improves inference and policy relevance.This research examines the determinants of agricultural land prices in the Mendoza River Basin, with emphasis on the marginal contribution of irrigation water as a strategic resource in an arid context. An original georeferenced database of 297 cultivated rural properties (2003-2024) was compiled, using advertised asking prices expressed in 2024 constant US dollars. A mixed spatial hedonic model with a log-log functional form was applied, incorporating hierarchical random effects (district nested within department), exponential spatial correlation, and heterogeneous variance across districts. The results indicate that properties with definitive surface irrigation rights command prices approximately 21% higher than comparable properties that rely exclusively on groundwater, confirming surface irrigation water as a pivotal economic asset. Soil quality and productive improvements increase land values by approximately 20% and 21%, respectively. In contrast, land size and distance to urban centres have significant negative effects (elasticities of -0.39 and -0.47). These findings highlight the central role of surface irrigation water as an economic asset and indicate a territorially segmented land market. The proposed methodology provides empirical evidence to support the design and implementation of water management and land-use planning policies in irrigated agricultural regions.  Highlights:   A spatial mixed log–log hedonic model is estimated for 297 agricultural properties in an arid irrigated basin. Secure surface or mixed irrigation water increases farmland prices by approximately 21% relative to groundwater-only properties. Soil quality and productive improvements generate land value premiums of approximately 20% and 21%, respectively. Larger farms and greater distance to urban centres significantly reduce land values. Accounting for spatial dependence and territorial hierarchy improves inference and policy relevance

Monitoring of the Community of Scandent Weeds in Yerba Mate (Ilex paraguariensis A. St. Hil., Aquifoliaceae) Cultivated in North-Eastern Argentina

Perennial crops account for 10% of the world’s cultivated area. In Argentina, yerba mate is grown within complex plant communities where scandent weeds are major challenges. We conducted bimonthly vegetation censuses to evaluate plant communities in yerba mate fields. These data were used to compare species presence-absence across the four seasons from 2018 to 2023. We grouped the censused species into scandent and non-scandent. The relative frequencies of the species analysed showed minor seasonal variation (chi-square = 2.0802, df = 3, p-value = 0.5559). These results indicated that frequency patterns remained stable throughout the observation period. Consequently, information on species richness and frequency may inform integrated management strategies for these challenges. Although this work focused on yerba mate, the monitoring methodology can be adapted and applied to other perennial crops of agronomic interest. Highligths: The cultivation of yerba mate is accompanied by a rich and complex plant community in North-Eastern Argentina. Bimonthly vegetatiion censuces conducted between 2018 and 2023 allowed a seasonal comparison of plant species presence-absense in yerba mate fields. Weed flora was classified into scandent and non scandent species to evaluate their relative frequencies within the crop system. Species aptterns showed no significant seasonal variation, remaining stable throughout the study period (χ² = 2.08; p = 0.56). Species richness and frequency data provide a robust basis for integrated Weed management strategies and can be applied to other perennial cropping systems.Perennial crops account for 10% of the world’s cultivated area. In Argentina, yerba mate is grown within complex plant communities where scandent weeds are major challenges. We conducted bimonthly vegetation censuses to evaluate plant communities in yerba mate fields. These data were used to compare species presence-absence across the four seasons from 2018 to 2023. We grouped the censused species into scandent and non-scandent. The relative frequencies of the species analysed showed minor seasonal variation (chi-square = 2.0802, df = 3, p-value = 0.5559). These results indicated that frequency patterns remained stable throughout the observation period. Consequently, information on species richness and frequency may inform integrated management strategies for these challenges. Although this work focused on yerba mate, the monitoring methodology can be adapted and applied to other perennial crops of agronomic interest. Highligths: The cultivation of yerba mate is accompanied by a rich and complex plant community in North-Eastern Argentina. Bimonthly vegetatiion censuces conducted between 2018 and 2023 allowed a seasonal comparison of plant species presence-absense in yerba mate fields. Weed flora was classified into scandent and non scandent species to evaluate their relative frequencies within the crop system. Species aptterns showed no significant seasonal variation, remaining stable throughout the study period (χ² = 2.08; p = 0.56). Species richness and frequency data provide a robust basis for integrated Weed management strategies and can be applied to other perennial cropping systems

Physiological and Biochemical Responses of Neltuma ruscifolia under Na2SO4 Stress

Salt stress limits plant production in arid and semi-arid zones. Although Na2SO4 is frequent in saline soils, most studies on plant physiological responses to salt stress were conducted using NaCl. This study aimed to determine the effect of Na2SO4 salt stress on physiological and biochemical responses in Neltuma ruscifolia. Increasing concentrations of Na2SO4 were added to 6-month-old plants grown hydroponically in 25% Hoagland nutrient solution. After 60 days of saline treatments, biomass, cysteine concentration, gas exchange, mineral composition, abscisic acid and salicylic acid concentrations, and antioxidant enzyme activity were determined. It is concluded that 200 mmol L-1 Na2SO4 is the threshold for N. ruscifolia seedling growth. Growth inhibition can be attributed to altered ionic homeostasis and photosynthesis inhibition after stomatal closure. Nevertheless, the species shows adaptive responses to this salt. Stomatal closure and increased foliar concentrations of abscisic acid contribute to water economy, while cysteine synthesis reduces sulfate toxicity. In parallel, salt stress induces salicylic acid accumulation in leaves, increasing the activity of antioxidant enzymes that prevent oxidative stress. Highlights: The threshold for growth of Neltuma ruscifolia is 200 mmol L-1 Na2SO4. Salt stress altered ionic homeostasis. Sodium sulfate inhibited photosynthesis due to stomatal closure. Salt stress increased concentrations of abscisic acid and salicylic acid. Salt stress triggers the species' antioxidant response.Salt stress limits plant production in arid and semi-arid zones. Although Na2SO4 is frequent in saline soils, most studies on plant physiological responses to salt stress were conducted using NaCl. This study aimed to determine the effect of Na2SO4 salt stress on physiological and biochemical responses in Neltuma ruscifolia. Increasing concentrations of Na2SO4 were added to 6-month-old plants grown hydroponically in 25% Hoagland nutrient solution. After 60 days of saline treatments, biomass, cysteine concentration, gas exchange, mineral composition, abscisic acid and salicylic acid concentrations, and antioxidant enzyme activity were determined. It is concluded that 200 mmol L-1 Na2SO4 is the threshold for N. ruscifolia seedling growth. Growth inhibition can be attributed to altered ionic homeostasis and photosynthesis inhibition after stomatal closure. Nevertheless, the species shows adaptive responses to this salt. Stomatal closure and increased foliar concentrations of abscisic acid contribute to water economy, while cysteine synthesis reduces sulfate toxicity. In parallel, salt stress induces salicylic acid accumulation in leaves, increasing the activity of antioxidant enzymes that prevent oxidative stress. Highlights: The threshold for growth of Neltuma ruscifolia is 200 mmol L-1 Na2SO4. Salt stress altered ionic homeostasis. Sodium sulfate inhibited photosynthesis due to stomatal closure. Salt stress increased concentrations of abscisic acid and salicylic acid. Salt stress triggers the species' antioxidant response.