Foliar Area Research Articles

Assessing Broccoli Cultivar Susceptibility to Alternaria brassicicola in Georgia

Alternaria leaf blight and head rot (causal agent: Alternaria brassicicola and other Alternaria species) in broccoli (Brassica oleracea L. var. italica) can lead to decreased yields, reduced head quality, and postharvest losses. While cultural practices and fungicides can decrease disease severity, further work is needed to determine resistance or susceptibility in commercial cultivars. This study evaluated susceptibility of 26 cultivars against A. brassicicola in Fall 2021 and 2022 at two locations in Georgia (Tifton and Watkinsville). Commonly used cultivars in the Eastern U.S. were selected and grown in a randomized complete block design. Approximately 20 days after transplant, plants were inoculated with a conidial suspension of A. brassicicola and monitored for disease development. Foliar disease severity, foliar area under disease progression curve (AUDPC), head disease severity, and yield were determined for each cultivar at each location. Significant differences existed among cultivars (year × location) for foliar AUPDC and head disease severity. Foliar AUPDC ranged from 299 to 1818 for both years and locations and head disease severity ranged from 1 to 81% across both years and locations. In this study, cultivars, ‘Eastern Crown’, ‘Emerald Jewel’, ‘Lieutenant’ and ‘Abrams’, had greater foliar and head disease severity and low marketable yields in both locations and years. The cultivars ‘Vallejo’, ‘Emerald Pride, ‘Burney’, ‘Belstar’ ‘Iron Man’, and ‘Marathon’ exhibited low disease severity across both locations and years and maintained greater marketable yields. Proper selection of commercially-available cultivars could help growers maintain yields in areas with high A. brassicicola pressure.

The ectomycorrhizal fungus Paxillus involutus positively modulates Castanea sativa Miller (var. Marsol) responses to heat and drought co-exposure

Castanea sativa Miller, a high-valuable crop for Mediterranean countries, is facing frequent and prolonged periods of heat and drought, severely affecting chestnut production. Aiming to tackle this problem, this study unraveled the influence of mycorrhizal association with the fungi Paxillus involutus (Batsch) on young chestnut plants' responses to combined heat (42 °C; 4 h/day) and drought (no irrigation until soil moisture reached 25%) over 21 days of stress exposure. Heat stress had no harmful effects on growth, photosynthesis, nor induced oxidative stress in either mycorrhizal (MR) or non-mycorrhizal (NMR) chestnut plants. However, drought (alone or combined) reduced the growth of NMR plants, affecting water content, leaf production, and foliar area, while also hampering net CO2 assimilation and carbon relations. The mycorrhizal association, however, mitigated the detrimental effects of both stresses, resulting in less susceptibility and fewer growth limitations in MR chestnut plants, which were capable of ensuring a proper carbon flow. Evaluation of the oxidative metabolism revealed increased lipid peroxidation and hydrogen peroxide levels in NMR plants under water scarcity, supporting their higher susceptibility to stress. Conversely, MR plants activated defense mechanisms by accumulating antioxidant metabolites (ascorbate, proline and glutathione), preventing oxidative damage, especially under the combined stress. Overall, drought was the most detrimental condition for chestnut growth, with heat exacerbating stress susceptibility. Moreover, mycorrhizal association with P. involutus substantially alleviated these effects by improving growth, water relations, photosynthesis, and activating defense mechanisms. Thus, this research highlights mycorrhization's potential to enhance C. sativa resilience against climate change, especially at early developmental stages.

Tamanhos de parcelas e amostras para variáveis biométricas em mudas de alface

ABSTRACT: In order to ensure reliable inferences in scientific experiments, sampling criteria should be determined and defined during the experimental design phase. Determining plot and sample sizes without scientific criteria could result in resource and labor inefficiencies with no gain in experimental precision. In this work we estimate plot and sample sizes for biometric variable analyses in lettuce seedlings. The seedlings were sown in four expanded polystyrene foam transplant trays with 128 and 200 cells. Foliar area, stem diameter, shoot height, root length, root volume, root area, fresh and dry shoot and root masses. The methods described by Paranaiba (PARANAIBA et al., 2009) and Cochran (COCHRAN, 1977) were used for plot size and sample size estimations, respectively. Sample size varied according to the variables analysed and transplant tray cell number. Root variables required the highest number of samples. For a 10% margin of error, 12 seedlings were necessary for evaluations in a 128 cell tray, while 11 seedlings were required for analysis in 200 cell trays.

Implementation of a botanical bioscrubber for the treatment of indoor ambient air

This study explores the effectiveness of a botanical bioscrubber system using Golden Pothos (Epipremnum aureum) in hydroponic setups to mitigate common indoor atmospheric pollutants. Over a 100-day operation, levels of SO2, NO2, O3, TVOC, CO, CO2, PM10, and PM2.5 were monitored, with a significant reduction in carbon-based compounds and particulate matter-. Notably, CO2 and PM2.5 removal efficiencies were significantly correlated with the foliar area, suggesting that the interaction between pollutants and plant leaves plays a crucial role in the phytoremediation process. In contrast, CO, PM10, and TVOC exhibited varied removal efficiencies, hinting the involvement of mechanisms beyond leaf interaction, such as adsorption in irrigation water or root system capture. The absence of significant correlations for PM10 emphasized the need for further investigation into alternative removal processes, potentially mediated by the root system. Overall, our findings suggest that botanical bioscrubbers, particularly those utilizing Golden Pothos, hold promise for indoor air purification through plant-based systems.

Salinity stress mitigation by radicular and foliar humic substances application in lettuce plants

Salinity stress constitutes one of the main abiotic stresses that considerably reduces crop yield. An approach to enhance plant growth under salt stress involves the addition of humic substances (HS) to roots or leaves. Here, we evaluated the potential use of BLACKJAK®, an HS-based product, to enhance salt tolerance in lettuce (Lactuca sativa L.). For this aim, plants were exposed to salinity (100 mM NaCl), salinity + HS: radicular (R)-HS (0.40 mL/L and 0.60 mL/L) and foliar (F)-HS (7.50 mL/L and 10.00 mL/L), along with a control (without NaCl). Parameters related to plant growth, Na+ and K+ accumulation, photosynthetic activity, oxidative stress, enzymatic and non-enzymatic antioxidants, as well as proline levels were evaluated. Results showed that R and F-HS considerably enhanced salinity tolerance. In addition, F-HS offered a greater improvement of plant growth in relation to shoot fresh weight, shoot relative growth rate, and foliar area, being 10.00 mL/L the best dose. This tolerance could be associated with reduced Na+ translocation to the shoot and enhanced shoot K+ accumulation, decreasing Na+/K+ ratio. Furthermore, HS improved the net photosynthetic rate, Rubisco carboxylation efficiency, and photosystem II performance, and reduced ROS levels and lipid peroxidation. Hence, our data show the potential use of BLACKJAK® to improve lettuce tolerance to salinity, with foliar application slightly better than radicular to achieve this aim, especially at 10.00 mL/L dose.

Chemical treatments in maize seeds to improve germination in acidic soils

Objective: To evaluate the effect of different germination promoters on three maize genotypes grown in Dystric Cambisol soils, since germination problems are linked to latency and restrict agronomic management.
 Design/Methodology/Approach: We conducted an experiment at the Instituto Tecnológico Superior de Juan Rodríguez Clara using a split-plot design with a factorial treatment arrangement. The large plot contained genotypes (GEN) G1 = MS-405, G2 = Arlequin, and G3 = MS-404; while the small one comprised promoter (PROMO) HS = humic substance, CI = citrulline, and SA = salicylic acid. We evaluated the following variables: germination speed (GS), emergence percentage (EMERG), stem and leaf volume (S&LV), root volume (RV), chlorophyll (CHL), secondary roots (SECR), stem diameter (DMT), number of leaves (NL), foliar area (FA), root length (RL), and plant height (PH). Then, we conducted a variance analysis and Tukey’s tests (α£0.05).
 Results: For each promoter, we observed main effects in EMERG, CHL, and PH for CI; S&LV, NL, FA, and PH for HS; and RL for SA. In genotypes G2 and G3, variables GS, EMERG, NL, and PH were statistically equivalent, DMT varied only in G2, and there were no statistical differences for S&LV, RV, CHL, SECR, FA, and RL. We observed some simple effects in combinations with CI: GS and PH varied in G3, EMERG in G2 and G3, CHL in G1 and G3, DMT in G1 and G2, and S&LV in G2.
 Study limitations/Implications: Soaking corn for one hour in the solution and weighing the correct amount properly are required, since weighing too much may inhibit germination.
 Findings/Conclusions: Promoter CI at a dose of 1,000 ppm accelerates the emergence speed of genotypes G2 and G3 in acidic soils.

Scheduling Fungicide Applications for Cucurbit Downy Mildew Control on Pickling Cucumber in Michigan Using Disease Forecasters

Cucumber production is important to Michigan's economy and was valued at more than $45 million in 2019. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is an annual threat to Michigan's cucumber production, and fungicides must be applied frequently to prevent major yield losses. Our objective was to evaluate the disease forecasting models TOM-CAST, BLITE-CAST, and DM-CAST for their application in scheduling fungicide applications for CDM control. Field trials were conducted in 2021 and 2022 to evaluate each disease forecaster at different spray thresholds compared with 7- and 10-day programs and an untreated control. In 2021, all treatments received applications of cyazofamid alternated with oxathiapiprolin/chlorothalonil alternated with ametoctradin/dimethomorph plus chlorothalonil. The 2022 fungicide program was similar to that of 2021 except that cyazofamid was tank-mixed with chlorothalonil. Treatment plots were visually assessed for the foliar area (%) with CDM symptoms, and the relative area under the disease progress curve was determined at the end of each season. The results indicate that using DM-CAST or BLITE-CAST to schedule fungicide applications limited CDM and was similar to the 7-day program. The 7-day program received 7 (2021) and 6 (2022) applications, whereas DM-CAST and BLITE-CAST required 4 to 8 or 5 to 6 applications, respectively, depending on the threshold and year. This is the first study to evaluate these disease forecasters for scheduling fungicide application intervals for CDM.

Conventional and Biopesticide Fungicides for Cucurbit Downy Mildew Control on Cucumber in Michigan

Michigan ranks first in the nation in cucumber production for processing (pickling), contributing over $45 million to the state's economy in 2019. Cucurbit downy mildew, caused by the oomycete Pseudoperonospora cubensis, is the most important disease of cucumber and an annual threat to yields. Fungicides are the most important means to control P. cubensis. Our goal was to monitor currently labelled conventional fungicides and biopesticides for efficacy over the course of an entire cropping period under high pathogen pressure. Field trials were conducted at the Michigan State University Plant Pathology Research Farm in 2021 and 2022. Fungicides were applied weekly, and disease severity was evaluated by visually assessing the percentage of foliar area showing downy mildew symptoms. At the end of the season, the relative area under the disease progress curve (rAUDPC) was calculated using the disease severity data. Based on rAUDPC results, oxathiapiprolin premixed with chlorothalonil was the most effective fungicide at controlling P. cubensis and was significantly better than all other conventional fungicides in both years tested. In both years, all conventional treatments had a significantly lower rAUDPC than the untreated control except pyraclostrobin, dimethomorph, and fluopicolide. No biopesticide fungicide reduced the rAUDPC compared with the untreated control in either year evaluated.

Physiological Behavior of Native Avocado in Nursery

In the State of Guerrero, Mexico, there are several types of native avocados that grow in backyards which die mainly because of adverse environmental conditions and various harmful activities of farmers. This study is one of the pioneers in the area. The aim of this research was to follow the growth in nursery and the physiological behavior of 12 native avocados from the municipality of Ometepec, Guerrero, Mexico, in order to explore their possible use as rootstocks. Thus, 20 fruits per tree of each genotype were harvested, and they were sown on substrate (85% river lama, 5% peat moss and 10% agrolite), at one month of age. A randomized complete block design was used with 12 treatments (each genotype was considered as treatment) and four repetitions. An analysis of variance and Tukey's means tests were performed (P ≤ 0.01 and 0.05) and LSD (P ≤ 0.05). The most vigorous rootstock was OME-7, followed by OME-10. The OME-7 showed higher NO3- and Na+ content; while OME-8, was superior in K+ and Ca++. The length*width of the avocado leaves, multiplied by its conversion factor (0.991), estimated a foliar area very similar to that obtained by the leaf area integrator. It was concluded that the OME-7, OME-3 and OME-10 rootstocks, were the most vigorous and they meet all the characteristics to be used as rootstocks.

Backyard aerosol pollution monitors: foliar surfaces, dust enrichment, and factors influencing foliar retention.

Air pollution is one of the leading causes of death from noncommunicable diseases globally, and in Arizona, both mining activities and abandoned agriculture can generate erodible dust. This dust is transported via wind and can carry high amounts of toxic pollutants. Industry-adjacent communities, or "fenceline communities," are generally closer to the pollution sources and are disproportionally impacted by pollution, or in this case, dust. The dust transported from the mine settles into nearby rivers, gardens, and homes, and increases the concentrations of elements beyond their naturally occurring amounts (i.e., enriched). This study was built upon previous community science work in which plant leaves were observed to collect similar concentrations to an accepted dust collection method and illustrated promise for their use as low-cost air quality monitors in these communities. This work investigated the concentration of Na, Mg, Al, K, Ca, Mn, Co, Cu, Zn, Mo, and Ba in dust from the leaves of community-collected backyard and garden plants (foliar dust), as well as if certain variables affected collection efficacy. This assessment evaluated (1) foliar concentration versus surface area for 11 elements, (2) enrichment factor (EF) values and ratios, (3) comparisons of foliar, garden, and yard samples to US Geological Survey data, and (4) what variable significantly affected dust collection efficacy. The EF results indicate that many of the samples were enriched (anthropogenically contaminated) and that the foliar samples were generally more contaminated than the yard and garden soil samples. Leaf surface area was the most influential factor for leaf collection efficiency (p < 0.05) compared to plant family or sampling location. Further studies are needed that standardize the plant species and age and include multiple replicates of the same plant species across partnering communities. This study has demonstrated that foliar dust is enriched in the participating partnering communities and that plant leaf samples can serve as backyard aerosol pollution monitors. Therefore, foliar dust is a viable indicator of outdoor settled dust and aerosol contamination and this is an adoptable monitoring technique for "fenceline communities."

Evaluating Options to Increase the Efficacy of Biocontrol Agents for the Management of Pantoea spp. Under Field Conditions.

Center rot of onion is caused by a complex of plant pathogenic Pantoea species, which can lead to significant yield losses in the field and during storage. Conventional growers use foliar protectants such as a mixture of copper bactericides and an ethylene-bis-dithiocarbamate (EBDC) fungicide to manage the disease; however, organic growers have limited management options besides copper-protectants. Biocontrol agents (BCAs) provide an alternative; however, their efficacy could be compromised due in part to their inability to colonize the foliage. We hypothesized that pretreatment with peroxide (OxiDate 2.0: a.i., hydrogen peroxide and peroxyacetic acid) enhances the colonizing ability of the subsequently applied BCAs, leading to effective center rot management. Field trials were conducted in 2020 and 2021 to assess the efficacy of peroxide, BCAs (Serenade ASO: Bacillus subtilis and BlightBan: Pseudomonas fluorescens), and an insecticide program (tank mix of spinosad and neem oil) to manage center rot. We observed no significant difference in foliar area under the disease progress curve (AUDPC) between the peroxide pretreated P. fluorescens plots and only P. fluorescens-treated plots in 2020 and 2021. Peroxide pretreatment before B. subtilis application significantly reduced the foliar AUDPC as compared with the stand-alone B. subtilis treatment in 2020; however, no such difference was observed in 2021. Similarly, peroxide pretreatment before either of the BCAs did not seem to reduce the incidence of bulb rot as compared with the stand-alone BCA treatment in any of the trials (2020 and 2021). Additionally, our foliar microbiome study showed comparatively higher P. fluorescens retention on peroxide pretreated onion foliage; however, at the end of the growing season, P. fluorescens was drastically reduced and was virtually nonexistent (<0.002% of the total reads). Overall, the pretreatment with peroxide had a limited effect in improving the foliar colonizing ability of BCAs and consequently a limited effect in managing center rot.

Usos tradicionales y prácticas de manejo de &lt;em&gt;Piper auritum&lt;/em&gt; en comunidades maya rurales de Yucatán

Background: Plant domestication is a continuous, multidirectional process that is directed via plant selection and management. In the current study we use Piper auritum, an aromatic plant frequently used in Mexican cuisine and for medicinal purpose, to characterize the domestication level using information about its cultural relevance, management practices and leaf traits differentiation in managed and ruderal populations.&#x0D; Questions: What is the level of domestication of the aromatic plant Piper auritum? Are there any morphological or phytochemical differences between home garden and ruderal populations?&#x0D; Studied species: Piper auritum, Kunth&#x0D; Study site and dates: Ten communities in eastern Yucatan, México, from 2019 to 2021.&#x0D; Methods: Fifty-three Semi-structured interviews were applied (72 % women and 28 % men). Morphological and phytochemical leaf traits were measured to test management effects using home garden and ruderal populations.&#x0D; Results: People interviewed knew P. auritum and its uses. Five culinary and 12 medicinal uses were registered. P. auritum is grown in homegardens and the main management activity is irrigation. The selection occurs at the leaf level according to their size and resistance. Home garden plants registered greater foliar area and hardness and decreased safrole, compared to ruderal.&#x0D; Conclusions: Piper auritum is widely known in the communities and has a variety of culinary and medicinal uses. Management is vital for its survival in home gardens, but the species germinates spontaneously and is not usually planted. We found differences in leaf traits in managed and unmanaged populations. With this evidence we propose that P. auritumis under incipient domestication.

Effect of Viusid Agro® on the Growth of Banana (Musa Spp.) Seedlings Under Nursery Conditions

The commercial production of plantains and bananas (Musa spp.) involves several aspects to overcome, including those ones related to abiotic and biotic factors. Catalysis, S. L. Agroveterinary Division has developed the product VIUSID agro® as a plant growth promoter in agriculture. Research centers from several countries have shown field studies that reveal the product efficacy. Studies conducted on this topic support the importance of the use of this product in crops, such as cassava, papaya, pumpkin, cucumber, bean, chickpea, garlic, among others at the Research Institute of Tropical Roots and Tuber Crops (INIVIT). This research is carried out with the aim of determining the effect of VIUSID agro® on the growth of banana seedlings. The experimental design was conducted in February 2020, using banana Musa AAA seedlings, Cavendish subgroup, 'Gran enano' cultivar of six months of age from meristem cultures, transplanted to polyethylene bags with a mixture of red soil and organic matter (70:30%), located at the Center for Accelerated Seed Reproduction (CRAS). VIUSID agro® (0,2 mL L-1) was applied as foliar application during the first, third and fifth weeks after transplanting. The treated seedlings showed significant statistical differences in terms of: basal diameter (mm), height (cm), number of leaves, foliar area (cm2), radial length of emerged roots directly from the corm (cm), biomass of the foliar and belowground area with respect to the control treatment. VIUSID agro® is an excellent biostimulant, which allows the farmer to take to his farms more vigorous and better adapted seedlings to adverse conditions.

Foliar Supplementation of Recycled Phosphorus from Cattle Bone Meal Improves Soybean Growth Characteristics, Nutrient Content, and Chlorophyll Pigment Concentration

Plants can absorb only 30 to 40% of nutrients from the soil through the root system because the absorption process depends on soil properties, wheatear conditions, and the plant’s species. Therefore, foliar fertilization using macro- and micronutrients has proven to be an excellent alternative. Herein, we evaluated the foliar application of a neutralized sulfuric bone meal hydrolysate (NSBMH) on soybean growth parameters, pod yield, nitrogen, phosphorus, and chlorophyll pigment concentrations under greenhouse conditions. A complete randomized block design was performed, and each block contained three treatments: 1% NSBMH, commercial fertilizer, and negative control. After 90 days of growth, soybean plants foliar-sprayed with 1% NSBMH improved significantly (p &lt; 0.05) in terms of foliar area, plant fresh mass, plant dried mass, plant height, nitrogen, and chlorophyll a + b concentrations, while trifoliar leaf number, pod number, and pod fresh and dried masses were higher but not significant, and phosphorus concentration maintained suitable levels when compared to the negative control treatment. Additionally, the 1% NSBMH group presented similar and higher values, but not significant (p &gt; 0.05), on the evaluated traits versus the commercial fertilizer treatment. Consequently, cattle bone recycling for the obtainment of alternative phosphorus as neutralized sulfuric bone meal hydrolysate is an excellent choice because it encourages the reutilization of anthropogenic waste, such as cattle bone waste, which protects the environment and reduces the soil and foliar application of mineral phosphoric fertilizers and reduces dependency on the main unsustainable fertilizer suppliers.

Gone with the wind: Negative genetic and progeny fitness consequences of habitat fragmentation in the wind pollinated dioecious tree Brosimum alicastrum.

Habitat fragmentation negatively affects population size and mating patterns that directly impact progeny fitness and genetic diversity; however, little is known about the effects of habitat fragmentation on dioecious, wind pollinated trees. We assessed the effects of habitat fragmentation on population sex ratios, genetic diversity, gene flow, mating patterns and early progeny vigor in the tropical dioecious tree, Brosimum alicastrum. We conducted our study in three continuous and three fragmented forest sites in a Mexican tropical dry forest. We used eight microsatellite loci to characterize the genetic diversity, gene flow via pollen distances and mean relatedness of progeny. We compared early progeny vigor parameters of seedlings growing under greenhouse conditions. Sex ratios did not deviate from 1:1 between habitat conditions, except for one population in a fragmented habitat, which was female biased. The genetic diversity of adult trees and their offspring was similar in both habitat conditions. Pollen gene flow distances were similar across habitat types; however, paternity correlations were greater in fragmented than in continuous habitats. Germination rates did not differ between habitat conditions; however, progeny from fragmented habitats produced fewer leaves and had a lower foliar area, total height, and total dry biomass than progeny from continuous habitats. Changes in mating patterns, because of habitat fragmentation, have negative effects on early progeny vigor. We conclude that negative habitat fragmentation effects on mating patterns and early progeny vigor may be a serious threat to the long-term persistence of tropical dioecious trees. This article is protected by copyright. All rights reserved.

Surviving in a new host: Eight years of monitoring translocated aroids, bromeliads, and orchids in the Andean forests in Colombia

Vascular epiphytes are extraordinarily diverse in the tropical Andean region. Compared to trees and terrestrial herbs, epiphytes are more vulnerable to forest alteration due to their structural dependence on trees and environmental requirements. Based on experimental approaches for ecological purposes, monitoring air pollutants, and seeking propagation alternatives, the rescue and translocation of vascular epiphytes (mainly bromeliads and orchids) from a threatened forest to a safer forest has been recently conducted in Colombia. Preliminary assessments indicate that epiphytes benefit from such well-planned measures, and their mortality and survival might be associated with extrinsic and intrinsic factors, which remain to be understood. We evaluated the survival of 16 vascular epiphyte species after translocation into a secondary forest in Antioquia (Colombia) for 8 years. We assessed the role of intrinsic (foliar area, number of leaves, initial pseudobulbs, stems or rosettes, functional group, and epiphyte species) and extrinsic factors (host tree species, bark water-holding capacity, type of substrate, location on the host tree, nutrients, and hormone addition) and the effect of climatic variables on plant survival. The overall mortality rate in this study ranked 1–7% per year, and survival decreased annually, reaching 44% by the end of the 8th year. Host tree species and intrinsic factors such as the functional group and epiphyte species significantly affected the probability of survival. Bromeliads, in particular, exhibited high mortality, which their monocarpic growth form could explain. Another group of species showing high mortality were the miniature orchids, Masdevalia amanda and M. platyglossa, and are associated with short life cycles. Five host tree species appear to affect the survival of translocated epiphytes; however, the factors or characteristics involved remain unclear. A higher seasonality of precipitation was related to the percentage of overall mortality. This result indicates that extreme precipitation events or drought reduce epiphyte longevity. In conclusion, our study suggests that a wide range of epiphytes may be successfully translocated to secondary forests in the Colombian Andes and demonstrates that the effective introduction of epiphyte assemblages may be useful for ecological restoration efforts in Andean forests.

Classifiers based on artificial intelligence in the prediction of recently planted coffee cultivars using a Remotely Piloted Aircraft System.

The classification and prediction methods through artificial intelligence algorithms are applied in different sectors to assist and promote intelligent decision-making. In this sense, due to the great importance in the cultivation, consumption and export of coffee in Brazil and the technological application of the Remotely Piloted Aircraft System (RPAS) this study aimed to compare and select models based on different data classification techniques by different classification algorithms for the prediction of different coffee cultivars (Coffea arabica L.) recently planted. The attributes evaluated were height, crown diameter, total chlorophyll content, chlorophyll A and chlorophyll B, Foliar Area Index (LAI) and vegetation indexes NDVI, NDRE, MCARI1, GVI, and CI in six months. The data were prepared programming language Python using algorithms of Decision Trees, Random Forest, Support Vector Machine and Neural Networks. It was evaluated through cross-validation in all methods, the distribution by FreeViz, the hit rate, sensitivity, specificity, F1 score, and area under the ROC curve and percentage and predictive performance difference. All algorithms showed good hits and predictions for coffee cultivars (0.768% Decision Tree, 0.836% Random Forest, 0.886 Support Vector Machine and 0.899 Neural Networks) and the Neural Networks algorithm produced more accurate predictions than other tested algorithm models, with a higher percentage of hits for the classes considered.

Feeding injury of major lepidopteran soybean pests in South America.

Lepidopteran pests are major factors limiting soybean productivity in South America. In some cases, effective management of these species requires the use of foliar insecticides. For sustainable use of these insecticides, they should only be applied when insect population size exceeds an economic threshold. Since this estimation requires to determine the consumption of different species, this work aimed to integrate all these factors, studying the consumption of small (less than 1 cm long) and medium (1 to 1.5 cm long) size larvae of major lepidopteran pests to vegetative and reproductive tissues on Bt (M7739IPRO variety, containing the event MON87701 which expresses the Cry1Ac protein from Bacillus thuringiensis) and non-Bt (BMX Desafio RR variety) soybeans. The feeding injury to vegetative tissues was tested in detached-leaf assays in grow chambers, and for reproductive structures the study was conducted in greenhouse with infestations at early (flowering) and mid reproductive (mid grain filling) stages. Based on the feeding behavior of the species tested, they were cast in four groups: a) Anticarsia gemmatalis and Chrysodeixis includens, defoliating only the RR variety with the lowest consumption of foliar area; b) Spodoptera eridania, defoliating both RR and IPRO varieties, consuming twice than the species mentioned above; c) Helicoverpa armigera, defoliating and being the most damaging species to pods in the RR variety; and d) S. cosmioides and S. frugiperda, defoliating and damaging pods in both varieties. The species differed in their ability to feed on IPRO varieties, so a different economic threshold should be considered. Consequently, in cases where more than one species are found simultaneously, the species composition should be considered in estimating the economic threshold. Additionally, our findings may contribute to a better decision-making to control insect feeding injury in IPRO varieties, because a slower larval growth provides more time to ensure the need of control with insecticides. In summary, this clasification contributes to an improved recommendation of sustainable insecticide use, taking into account the behavior of each species that are major soybeans pests in South America.

Implementación y evaluación del sistema de riego por borbolleamiento en el cultivo de café (Coffea canephora) en la Estación Experimental de Sapecho

The present research work was developed in the Sapecho Experimental Station belonging to the Faculty of Agronomy - UMSA, located 239 km from the city of La Paz, it presents an average temperature of 26 ° C with an annual rainfall of 1500 mm, the objective was to implement and evaluate the sprinkling irrigation system in the coffee crop (Coffea canephora). For the implementation of the system, the agronomic and hydraulic design was carried out that allowed the calculation of the water needs of the crop as well as the components of the system, the installation was made on a surface of 720 m2, it consists of a 2300-liter tank that works as constant load device, a 38.1 mm diameter bypass line with a length of 21 m, four laterals of 19.5 mm in diameter and 28.5 m in length each and distribution hoses of 5 mm in diameter and 2.5 m in length, it was installed to irrigate 80 coffee plants of the robusta variety. Subsequently, the operation evaluation of the irrigation system was carried out in which it was found that the Christiansen uniformity coefficient (CUC) is 83% and the distribution coefficient (CD) is equal to 76%, these results indicate that the implemented system is between good and acceptable. The evaluation on the effect of irrigation showed us that the application of optimal irrigation is positive in vegetative growth, being 30% higher in the development of the foliar area, 30.1% in number of nodes, 38.4% in length of bandola and it was reduced by 17% in the loss of fruits compared to the control.

Qualidade de hastes florais de lisianthus (Eustoma grandiflorum Raf.) inoculadas com Bacillus subtilis e Glomus intraradices

Abstract Lisianthus (Eustoma grandiflorum) is an ornamental species used as a potted plant or cut flower, its popularity is due to the diversity of colors, number of flower buds, and shelf life. Nevertheless, during the first phases of development, problems such as foliar chlorosis and root diseases affects most cultivars, causing poor growth, thin stems, and few flowers. The use of plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) improved plant growth as these microbes colonize the plant system root. Therefore, in order to provide better conditions for the stem development, the aim of this work was to evaluate the individual and combined effect of Bacillus subtilis (PGPR) and Glomus intraradices (AMF) on the growth and postharvest quality of the stems of lisianthus cv. Mariachi. Then commercial product Alubión-X (Bacillus subtilis (PGPR) and mycorrhizal fungus (Glomus intraradices) were used. The variables evaluated were stem height and diameter, foliar area, leaves number and in postharvest, buds number, open and diameter of flowers and stem dry weight. The results showed a significant effect of the inoculation of G. intraradices on the size (66.92 cm) of the stem, as well as the combination of B. subtilis + G. intraradices (65.51 cm) compared to the control (36.9 cm). The number of buds and open flowers of the stems treated with G. intraradices were 33.35 and 23.9 respectively significantly higher than the control. G. intraradices alone is the best option for applying to lisianthus, when compared to applying with B. Subtilis.