Infrared Thermometry Studies for Estimation of Crop Water Stress Index

An IR thermometry enables non-contact temperature measurements of the crop canopy, capturing infrared radiation emitted by objects without physical contact, which is beneficial for accurate Crop Water Stress Index (CWSI) estimation as it minimizes interference and temperature reading alterations. In this study, handheld IRT was used to measure the canopy temperature of selected crops in 32 farms, 8 each in crop of Maize, chilly, groundnut and Black gram which were predominantly grown in Bapatla and Prakasm districts. Canopy temperature (Tc) and temperature of non-water stressed crop (Tnws) were measured 4 times during the Rabi season on clear sky days. The results concluded that at the initial stage, crops were grown with residual moisture of Kharif paddy hence at that stage CWSI values were low. The highest CWSI in the season was observed for the crop black gram about 0.524 and the lowest was observed for the crop chilly about 0.245. The seasonal average CWSI values for Maize, Chilly, Groundnut and Black gram were 0.382, 0.323, 0.358 and 0.399, respectively. CWSI determination helps to monitor the crop stress level, by knowing it, it is easy for irrigation scheduling by taking a threshold CWSI value to start irrigation. The average CWSI for each crop can be taken as a threshold value for irrigation scheduling.

Significance of Plant Canopy Maintenance in Crop Yield

The yield of any crop depends on the capacity of a plant canopy to intercept and efficiently use the sunlight, which is dependent on canopy architecture of a plant viz., leaf size, shape and angle, number of leaves and branches, and a crop geometry viz., row orientation, row spacing, plant geometry, plant density, etc. The amount and distribution of leaf area in a crop canopy determine the way, by which, the photosynthetic active radiation is intercepted and consequently it influences the canopy photosynthesis and yield. The balance between the source and sink significantly contributes towards the higher accumulation of photosybthates Cropping geometry of a plant/crop affects the radiation use efficiency, intercepted photosynthetic active radiation (IPAR) and thereby the biological and economical yield of a crop. Optimum plant population stand and its density and a planting pattern with adequate spatial arrangement are important cultural factors that increase radiation interception and yield production.

Impact of Different Irrigation Techniques on Wheat Crop Micro-climate

Aim of this experiment is to study the impact of irrigation techniques on microclimate of wheat crop in terms of temperature and humidity. Randomized block design is used on the wheat crop (Triticum aestivum L.) variety Karan Narendra (DBW 222) at research farm of ICAR-CSSRI, Karnal during the Rabi 2021-22. In conventional practice treatment, higher temperature fluctuation was observed and was 0.5-1°C cooler as compared to other plots. Drip irrigation treatment showed most stable crop microclimate in terms of canopy temperature and humidity dynamics. A sharp rise in temperature at maturity cause dryness in crop and leads to lower productivity. Except at physiological maturity, canopy was cooler than the ambient air, while relative humidity was higher both during morning and evening hour.

Microclimate: Diurnal Temperature Variation inside Crop Canopy of Pearl Millet under Different Sowing Environments

The microclimate was evaluated for the pearl millet [Pennisetum glaucum (L.) R. Br.] crop at different height inside the crop canopy. Field experiments were conducted during autumn seasons and temperature was measured at bottom, middle and top of the crop canopy at panicle initiation stage, boot stage, 50 per cent flowering, dough stage and physiological maturity stages from 09:00 in the morning to 05:00 in the evening. The temperature profiles indicates that lower temperature were recorded at the top of crop canopy as compare to bottom of crop canopy i.e. temperature inside the crop canopy was higher than at top of the crop canopy in all the treatments. Temperature profiles showed decreasing trend in temperature inside the crop canopy means temperature decrease with increase in height inside the crop canopy in all the treatments within the crop canopy in both the crop seasons. The maximum temperature was observed in afternoon hours and the minimum temperature was recorded in the morning hours.

Evaluating Urban Greening Scenarios on Urban Heat Islands Effects

An Urban Heat Islands (UHI) are one of the most common phenomena of the 21st century. Climate change, and the associated rising trend of urban temperature is exaggerating the creation and extension of urban heat islands (UHI). This paper investigates various urban greening scenarios in the line with developing the resilient Sydney strategical document. Two different cooling street strategies are investigated in this research including high reflective pavement and green canopy cover. ENVI-Met software has been applied for simulating and quantifying microclimate processes at the urban scale before and after introducing urban greening scenarios. The results of this study show that applying the light-coloured pavement instead of asphalt surface will decrease surface temperature by up to 20°C. Planting short to medium height trees in the side walks will decrease the air temperature by up to 3°C and surface temperature by up to 11°C.

Effect of Canopy Gaps on Growth and Water Use Efficiency of Seedling of Vulnerable Species, Hopea sangal Korth

Aims: Hopea sangal Korth. is listed as vulnerable species and recently its remnant habitat was rediscovered in the degraded forest near the springs area in East Java. In the forest, the regeneration of the seedling and saplings understory is affected by the heterogeneity in environmental factors especially various light levels due to the canopy gaps. H. sangal is considered a shade-tolerant species, hence the establishment of the seedling in its natural habitat occurs under the closed canopy. This study aimed to understand the Water Use Efficiency (WUE) and Relative Growth Rate (RGR) of Hopea sangal Korth seedling grown in two different levels of tree canopy shades. Study Design: This research was using a completely randomized design, with 9 replications. Place and Duration of Study: This study was conducted in the Purwodadi Botanic Garden, East Java, between March � July. Methodology: We used seedling of H. sangal collected from the field in Pasuruan which were planted in plastic pots and acclimatized to obtain seedling of a similar size. The microclimate was measured weekly using solarimetri and sling psychrometer at 08.00; 10:00; 12:00; 14:00 and 16:00. RGR was measured by harvesting the seedling and whole plant WUE was measured using the gravimetric method. Results: We observed the light level during the periodic opening of the canopy gap was significantly different at a specific time (8-12 am), with the highest light intensity at 10.00 of 333.57 祄ol photon m-2s-1. The canopy shades differences did not affect the WUE of seedling (P = 0.333), meanwhile, there was a significant difference in the seedling RGR (P = 0.025). The seedling that were grown under a higher gap and received higher light intensity periodically during a day had higher RGR than those under a closed canopy. The WUE has a positive relationship with the RGR of seedling (R2 = 0.5; P < 0.05). Conclusions: This study suggested that the H. sangal is one of the shade-tolerant species capable of responding to gap-opening sunlight. The study also showed RGR of the seedling positively correlated with the WUE of plants, indicating that the seedling could use the water supply efficiently to grow rapidly.

Tree structure and diversity of a Humid Mountain Forest in the protected natural area La Martinica, Veracruz, Mexico / Estructura y diversidad arbórea de un bosque húmedo de montaña en el Área Natural Protegida La Martinica, Veracruz, México

Abstract Introduction: The Humid Mountain Forest (HMF) has the highest number of plants per unit of surface, whose vegetation grows under heterogeneous environmental conditions and possess a high floristic variation. HMF conservation is important due to the biodiversity it harbors and the environmental services it provides. Objective: This work evaluated the effect of the terrain aspect and density of the forest canopy on the structure and tree diversity in La Martinica Protected Natural Area, Mexico. Methods: Stratified sampling was performed in four terrain aspects and two canopy density conditions. Twenty five sampling units of 20 x 25 m were considered, in which the normal diameter (ND), total height and the largest and smallest diameters of the crown of the individuals with a ND ≥ 10 cm were registered. The diversity was estimated by rarefaction curves and the structure was analyzed through the importance value index (IVI) and the forest value index (FVI). Results: 37 species belonging to 30 genera and 24 families were recorded. Greater diversity was observed in the north terrain aspect and in the closed canopy. Tree species with the highest structural values were different between terrain aspect and canopy types; Carpinus tropicalis presented the highest values in the zenithal terrain aspect, Lippia myriocephala in the east and south terrain aspect, and Liquidambar styraciflua in the north. In both canopy types Lippia myriocephala obtained the highest IVI values and FVI in the open canopy; Carpinus tropicalis reached a higher FVI in the closed canopy. Conclusions: Tree structure was different in the four terrain aspects and two canopy conditions studied. The greatest difference in species composition and diversity was observed between the north and east terrain aspects; the north presented the highest richness values, frequent and dominant species.

Resumen Introducción: El Bosque Húmedo de Montaña (BHM) posee el mayor número de especies vegetales por unidad de superficie, cuya vegetación se desarrolla en condiciones ambientales muy heterogéneas y presenta una alta variación florística. La conservación del BHM es importante debido a la biodiversidad que alberga y los servicios ambientales que proporciona. Objetivo: Este trabajo evaluó el efecto de la orientación del terreno y la densidad del dosel del bosque sobre la estructura y diversidad arbórea en el Área Natural Protegida La Martinica, México. Métodos: Se efectuó un muestreo estratificado en cuatro orientaciones del terreno y dos condiciones de densidad del dosel; se consideraron 25 unidades de muestreo de 20 x 25 m, en las que se registró: el diámetro normal (DN), la altura total y los diámetros mayor y menor de la copa de los individuos con un DN ≥10 cm. La diversidad se estimó por medio de curvas de rarefacción y la estructura se analizó con el índice de valor de importancia (IVI) y el índice de valor forestal (IVF). Resultados: Se registraron 37 especies pertenecientes a 30 géneros y 24 familias. Se observó una mayor diversidad en la orientación norte y en el dosel cerrado. Las especies arbóreas con valores estructurales más altos fueron diferentes entre orientaciones y tipos de dosel; Carpinus tropicalis presentó los valores más elevados en la orientación cenital, Lippia myriocephala en las orientaciones este y sur, y Liquidambar styraciflua en la norte. En ambos tipos de dosel Lippia myriocephala obtuvo los valores más altos del IVI e IVF en el dosel abierto; Carpinus tropicalis alcanzó un IVF más elevado en el dosel cerrado. Conclusiones: La estructura arbórea fue diferente en las cuatro orientaciones estudiadas y en las dos condiciones del dosel. La mayor diferencia en composición de especies y diversidad se observó entre las orientaciones norte y este, de ellas, la norte presentó los valores más altos de riqueza, especies frecuentes y dominantes.

Floristic composition, structure and environmental characterization of Cyathea costaricensis population in a remnant cloud forest in Mexico / Composición florística, estructura y caracterización ambiental de una población de Cyathea costaricensis en un relicto de bosque mesófilo de montaña en México

Abstract Introduction: Tree ferns are significant components of temperate, tropical and subtropical forests, contributing to shape complex forest stand structures. Objectives: 1) to describe the population structure of Cyathea costaricensis in a remnant cloud forest of West-central Mexico; 2) to characterize and relate the floristic composition and the structure of the most important tree species associated to the C. costaricensis population and; 3) to describe the environment where C. costaricensis occurs. Methods: We estimated the Importance Value Index (IVI) to select the most important canopy-dominant species associated to C. costaricensis; we constructed height and Diameter at Breast Height (DBH) frequency distributions for those selected species according to IVI as well as for C. costaricensis population; we computed the asymmetry of the frequency distributions through the coefficient of skewness and the probability density function via the Kernel density estimation. We tested for differences between canopy-dominant tree species and C. costaricensis population structure by the non-parametric Wilcoxon rank sum test. Results: C. costaricensis individuals presented the smallest heights and intermediate DBH sizes as compared with the canopy-dominant species, with statistically significant differences for height but not for DBH according to the Wilcoxon test. Most of the tree fern individuals were located in uneven terrains and over the base slope of the terrain; canopy openness and Total Radiation Under the Canopy values were similar to those reported for Cyathea species elsewhere. Conclusions: We confirm the hypothesis of comparable structure between the canopy-dominant species and the C. costaricensis population only for DBH; on the contrary, for trunk height, there were statistically significant differences; the small heights of C. costaricensis suggest their coexistence in the understory through sheltering from the taller canopy-dominants. Mostly all individuals of C. costaricensis were confined to local environmental conditions, particularly to physiography.

Resumen Introducción: Los helechos arborescentes son componentes importantes de los bosques templados, tropicales y subtropicales, que contribuyen a dar forma a rodales de estructuras complejas. Objetivos: 1) Describir la estructura poblacional de Cyathea costaricensis en un remanente de bosque nuboso del centro-oeste de México; 2) Caracterizar y relacionar la composición florística y la estructura de las especies arbóreas más importantes asociadas a la población de C. costaricensis y; 3) Describir el ambiente donde se encuentra C. costaricensis. Métodos: Estimamos el Índice de Valor de Importancia (IVI) para seleccionar las especies dominantes más importantes del dosel asociadas a C. costaricensis; para las especies seleccionadas según IVI, construimos distribuciones de frecuencia de alturas y diámetros a la altura del pecho (DAP), así como para la población de C. costaricensis. Calculamos la asimetría de las distribuciones de frecuencia a través del coeficiente de asimetría y la función de densidad de probabilidad mediante la estimación de densidad de Kernel. Probamos las diferencias entre las especies de árboles dominantes en el dosel y la estructura de la población de C. costaricensis mediante la prueba no paramétrica de suma de rangos de Wilcoxon. Resultados: los individuos de C. costaricensis presentaron las menores alturas y tamaños intermedios de DAP en comparación con las especies dominantes del dosel, con diferencias estadísticamente significativas para la altura, pero no para el DAP según la prueba de Wilcoxon. La mayoría de los individuos de helechos arborescentes se ubicaron en terrenos irregulares y sobre la pendiente baja del terreno. Los valores de apertura del dosel y Radiación total bajo el dosel fueron similares a los reportados para las especies de Cyathea en otros lugares. Conclusiones: Confirmamos la hipótesis de que hay una estructura similar entre las especies dominantes del dosel y la población de C. costaricensis solo para el DAP; por el contrario, para la altura del fuste, hubo diferencias estadísticamente significativas; las pequeñas alturas de C. costaricensis sugieren su coexistencia en el sotobosque a través de la cobertura árboles dominantes del dosel. La mayoría de los individuos de C. costaricensis fueron encontrados confinados a condiciones ambientales locales, en particular a la fisiografía.

Herbage intake by steers grazing in a natural grassland with predominance of Andropogon lateralis Nees managed under different canopy heights / Consumo de forragem por novilhos em área de pastagem natural com predomínio de Andropogon lateralis Ness manejada em diferentes alturas

ABSTRACT: The animal performance on pasture is directly correlated to canopy structure since this influences the herbage consumption. This study was evaluated the effects of four pre-grazing canopy heights (12, 20, 28 and 36 cm) of Andropogon lateralis Ness on herbage intake and feeding behavior of steers in a natural grassland under intermittent stocking management, using the same proportion of defoliation (40% reduction in pre-grazing height, i.e., post-grazing heights of 7.2, 12.0, 16.8 and 21.6 cm). The experiment was conducted on a total area of ​​14,000 m2, divided into sixteen paddocks of 875 m2. Thirty-two steers were used, divided into uniform pairs according to the live weight (LW) at the start of the experiment (244 ± 23.0 kg). Each paddock was subdivided into three plots of identical area; the first two plots were used for the adaptation period and the third for the assessment period. A randomized block design was used with four replicates and two assessment periods. Herbage mass and neutral detergent fiber content increased linearly (P < 0,001) with the increase of pre-grazing canopy heights. In contrast, was not affected by treatments, with mean values ​​of 75 g/kg of dry matter (DM) in the upper stratum and 83 g/kg of DM in lower stratum. The herbage intake was similar between treatments (P = 0.255), averaging 1.78% LW. Grazing time increased linearly in the upper stratum and decreased linearly in the lower stratum with increasing pre-grazing canopy heights. Total time spent grazing, ruminating, and idling did not differ between treatments, with means of 52.6%, 23.0%, and 24.2%, respectively. Pre-grazing canopy heights treatments, based on the predominant species A. lateralis, did not affect the daily herbage intake of steers.

RESUMO: O desempenho de animais em pastejo possui direta correlação com a estrutura do dossel forrageiro, uma vez que este influencia o consumo. Objetivou-se mensurar o consumo e o comportamento ingestivo de novilhos em pastagem natural "palha grossa", manejada sob lotação intermitente, com diferentes alturas de pré pastejo (12, 20, 28, 36 cm), aferidas na espécie predominante Andropogon lateralis Ness, com severidade de desfolha de 40%. O experimento foi conduzido em uma área total de 14.000 m2, dividida em dezesseis piquetes de 875 m2. Foram utilizados 32 novilhos, divididos em lotes uniformes conforme o peso vivo no início do experimento (244 ± 23,0 kg). Cada piquete foi subdividido em três parcelas de igual área, sendo utilizadas as duas primeiras para o período de adaptação e a terceira para o período de avaliação. O delineamento experimental foi de blocos ao acaso, com quatro repetições e dois períodos de avaliação. As metas de altura em pré-pastejo foram alcançadas em todos os tratamentos. A massa de forragem aumentou linearmente (P < 0,001) com o aumento das alturas de pré-pastejo. Os teores de fibra em detergente neutro aumentaram linearmente (P < 0,001) com o aumento das alturas de manejo, enquanto a proteína bruta foi semelhante (P=0,107) entre os tratamentos tendo valores médios de 75 g/kg de matéria seca (MS) no estrato superior e de 83 g/kg MS no estrato inferior. O consumo de forragem foi similar entre tratamentos (P=0,255), com média de 1,78% do peso vivo. A porcentagem de tempo que os animais pastejaram no estrato superior aumentou e a porcentagem no estrato inferior diminuiu linearmente (P < 0,001) com o aumento das alturas de manejo. As porcentagens do tempo total destinado ao pastejo, ruminação ou ócio não diferiram entre tratamentos (P > 0,05), com médias de 52,6%, 23,0% e 24,2%, respectivamente. Alturas de pré pastejo entre 12 e 36 cm, baseadas na espécie predominante Andropogon lateralis Ness, não interferiram no consumo diário de matéria seca de novilhos em pastejo.

Tall and short-sized elephant grass genotypes: morphophysiological aspects cut-and-carry, and grazing management / Capins-elefante de porte alto e baixo: aspectos morfofisiológicos, manejo do pastejo e de capineiras

ABSTRACT: Elephant grass (pennisetum purpureum schum.) has been grown only in cut-and-carry systems for a long time. However, interest in its grazing management has been increasing because of the selection of short-sized genotypes, which have gained new relevance since 1988 with the registration of 'mott' grass. in this sense, tall and short-sized genotypes present important differences in morphology, quality and productivity; although, environmental factors also exert influence on these aspects. This review aimed to approach how the elephant grass size can influence the morphophysiological characteristics, management decisions, and exploitation of this species. the morphophysiological aspects and the elephant grass sizes are important to direct their utilization in the different production systems. The research results from previous decades suggest that the particularities of the tall-sized genotypes, such as great forage accumulation, high organic reserves content, and stem elongation, favor their management in cut-and-carry systems and industrial sectors. Conversely, the short-sized elephant grass genotypes present aspects as higher leaf proportion in the harvested forage, leaf/stem ratio, and tillering. these factors facilitate their exploitation in grazing systems.

RESUMO: O capim-elefante (pennisetum purpureum schum.) foi durante muito tempo cultivado apenas em capineiras. porém, o interesse pelo seu manejo sob pastejo vem aumentando por conta da seleção de genótipos de porte baixo, que ganhou nova relevância a partir de 1988, com o registro do capim mott. Neste sentido, genótipos de porte alto e baixo apresentam diferenças morfológicas, produtivas e qualitativas importantes, mesmo que fatores ambientais também exerçam influência sob estes aspectos. o objetivo desta revisão foi abordar como o porte do capim-elefante pode influenciar características morfofisiológicas, decisões de manejo e formas de utilização da espécie. Os aspectos morfofisiológicos e o porte do capim-elefante são importantes para direcionar sua utilização nos diferentes sistemas de produção. os resultados de pesquisa das últimas décadas sugerem que as particularidades dos genótipos de porte alto, como elevado acúmulo de forragem, reservas orgânicas e alongamento dos colmos favorecem seu manejo sob corte e sua utilização em setores industriais. já o capim-elefante de porte baixo apresenta aspectos como elevada proporção de folhas na forragem colhida, alta relação folha: colmo e elevado perfilhamento. Estes fatores facilitam sua utilização em sistemas de produção a pasto.

Principal component analysis of steers performance and structural and nutritional characteristics of Mombasa grass / Análise de componentes principais entre o desempenho de novilhos de corte e as características estruturais e nutricionais do capim-mombaça

ABSTRACT: There is little information about whether the increased secondary productivity observed in pastures fertilized with high nitrogen rates is attributable to fluctuations in the nutritional value or pasture structural characteristics, or both. This study aimed to identify a set of factors (structural and nutritional characteristics) that best explain the performance of beef steers grazing Mombasa grass pastures under residual effects of nitrogen fertilizer. The data were collected in Mombasa grass pastures fertilized with increasing rates of nitrogen (N) (100, 200 and 300 kg ha-1) from 2015 to 2017. In 2018, nitrogen fertilization was not used in order to characterize a residual effect of the nutrient. Variables related to pasture structural characteristics such as forage accumulation rate (FAR), canopy height, forage mass (FM) and morphological components were evaluated. The study also evaluated the nutritional value of leaf blades and the performance of beef steers based on average daily gain (ADG) and stocking rate. Principal component analysis was performed using the dataset available. Most of the variance (99.6%) was explained by only two principal components (PCs), of which 90.0% corresponded to PC1. The most influential parameters for PC1, in order of priority, were: FAR, FM, leaf blade and stem masses. These variables were positively associated with stocking rate. Conversely, ADG was not associated with any variable. ADG was the most relevant variable for the second PC; however, this PC explained less variance (9.6%). The structural characteristics of the pasture (FAR, FM and morphological components mass) better explain the fluctuations in the performance of cattle on pastures of Mombasa grass under residual effects of nitrogen fertilizer. The stocking rate is an efficient parameter to support decision-making in managed pastures with variable stocking.

RESUMO: Há pouca informação sobre se o aumento da produtividade secundária observada em pastagens fertilizadas com altas taxas de nitrogênio é atribuível a flutuações no valor nutricional ou nas características estruturais das pastagens, ou em ambas. Objetivou-se identificar grupos de caraterísticas (estruturais e nutricionais) que melhor explicassem o desempenho de novilhos de corte em pastos de capim-mombaça sob efeito residual de doses de nitrogênio. Os dados foram coletados em pastos de capim-mombaça que receberam três doses anuais de nitrogênio (N) (100, 200 e 300 kg ha-1) de 2015 a 2017. No ano de 2018 não foi utilizada adubação nitrogenada, para caracterizar o efeito residual do nutriente. As variáveis avaliadas foram relacionadas às características estruturais, taxa de acúmulo de forragem (TAF), altura do dossel, massa de forragem (MF) e dos componentes morfológicos. Também foi avaliado o valor nutritivo da lâmina foliar e o desempenho dos novilhos através do ganho médio diário (GMD) e da taxa de lotação. A partir do banco de dados foi realizada a análise de componentes principais. Os resultados demonstraram que 99,6% da variação no conjunto de dados foram explicados por apenas dois componentes principais (CPs), e 90,0% desse valor corresponde ao CP1. As características de maior magnitude para a diferenciação dos tratamentos no CP1, em ordem de prioridade foram: TAF, MF, massas de lâmina foliar e de colmo. Essas variáveis estiveram positivamente associadas com a taxa de lotação. Já o GMD não se relacionou com nenhuma variável. O GMD foi a variável de maior importância para o segundo CP, entretanto, esse CP teve pouca contribuição (9,6%) para a elucidação do resultados. As características estruturais (TAF e MF e compondes morfológicos) do pasto explicam melhor as oscilações em pastos de capim-mombaça sob efeito residual de doses de nitrogênio. A taxa de lotação é um parâmetro eficiente para apoiar a tomada de decisão em pastos manejados com lotação variável.

Características estruturais e produção de forragem do capim-piatã submetido a regimes de desfolhação intermitente / [Structural characteristics and forage production of piata grass submitted to intermittent defoliation management]

Objetivou-se avaliar as características estruturais e a produção de forragem do capim-piatã submetido à combinação de duas frequências de corte (95% e máxima interceptação de luz pelo dossel forrageiro, ILmax) e duas alturas pós-corte (15 e 20cm), no período de janeiro de 2012 a março de 2013. O delineamento utilizado foi em blocos ao acaso, com três repetições, em esquema fatorial 2x2, totalizando 12 unidades experimentais de 14m2 cada. Foram avaliadas as seguintes variáveis-respostas: altura do dossel no pré-corte, intervalo de corte, índice de área foliar pré e pós-corte, taxa de produção de forragem e as percentagens de colmo, folha e forragem morta na forragem produzida. A altura pré-corte decresceu durante o experimento (de 65,81 para 34,03cm), sendo a menor altura observada no dossel sob alta frequência de desfolhação (95% de IL). A taxa de produção de forragem foi maior nas épocas favoráveis ao crescimento da gramínea forrageira. As percentagens de folha, colmo e forragem morta foram semelhantes entre as frequências de corte. Assim, o capim-piatã sob manejo de desfolhação intermitente pode ser colhido com qualquer combinação de frequências de corte de 95% e ou máxima interceptação de luz, e alturas pós-corte de 15 ou 20cm.(AU)

The objective of this study was to evaluate the structural characteristics and forage production of the piatã grass submitted to the combination of two cutting frequencies (95% and maximum interception of light by the forage canopy, ILmax) and two post cutting heights (15 and 20cm) in the period from January 2012 to March 2013. The design was a randomized complete block with three replications, in a 2x2 factorial scheme, totaling 12 experimental units of 14m2 each. The following variables were evaluated: pre-cut canopy height, cut interval, pre and post-cut leaf area index, forage yield rate, and percentage of stem, leaf and dead forage in the forage produced. The pre-cut height decreased during the experiment (from 65.81 to 34.03cm), with the lowest height observed in the canopy under high frequency of defoliation (95% IL). The rate of forage production was higher in the seasons favorable to forage grass growth. The percentages of leaf, stem and dead fodder were similar between cut-off frequencies. Thus, piatã grass under intermittent defoliation management can be harvested with any combination of 95% and maximum light interception cut frequencies, and post cutting heights of 15 or 20cm.(AU)

Sowing density and clipping management: effects on the architecture and yield of dual-purpose wheat / Densidade de semeadura e manejo da corte: efeitos na arquitetura e rendimento do trigo de duplicação

The dual-purpose wheat stands out as a complementary alternative for forage supply during the winter period. Therefore, this work had the objective of evaluate the performance characteristics in five genotypes of dual-purpose wheat submitted to different sowing densities and different clipping managements. The experiment was carried out during the 2016 and 2017 harvests. The experimental design was a randomized block design, organized in a factorial scheme, with five dual-purpose wheat genotypes (BRS Tarumã, BRS Umbu, BRS Figueira, BRS Guatambu and BRS 277) x five sowing densities (75, 150, 225, 300 and 375 seeds m²) x four clipping operations (zero, one, two and three clippings), arranged in three replicates. The measuring of characters were number of fertile tillers, seeds yield, angle of flag leaf, chlorophyll content and flowering. The genotype BRS Tarumâ is superior in number of fertile tillers and chlorophyll index for all the sowing densities, as well, the flowering is influenced direct by clipping managements. The sowing density of 75 seeds m-2 is not indicated for dual-purpose wheat independent of the clipping management. The seeds yield is amplified thought the increase in sowing density, however, advancing in clipping levels there is a decrease in forage yield.

O trigo de duplo propósito se destaca como uma alternativa complementar para o fornecimento de forragem durante o período de inverno. Portanto, este trabalho teve como objetivo avaliar as características de desempenho de cinco genótipos de trigo de duplo propósito submetidos a diferentes densidades de semeadura e diferentes manejos de corte. O experimento foi realizado durante as safras de 2016 e 2017. O delineamento experimental foi em blocos ao acaso, organizado em esquema fatorial, com cinco genótipos de trigo de duplo propósito (BRS Tarumã, BRS Umbu, BRS Figueira, BRS Guatambu e BRS 277) x cinco densidades de semeadura (75, 150, 225, 300 e 375 m² de sementes) x quatro operações de clipagem (zero, um, dois e três recortes), dispostos em três repetições. As medidas dos caracteres foram número de perfilhos férteis, rendimento de sementes, ângulo de folha de bandeira, teor de clorofila e floração. O genótipo BRS Tarumâ é superior em número de perfilhos férteis e índice de clorofila para todas as densidades de semeadura, assim como o florescimento é influenciado diretamente pelos manejos de corte. A densidade de semeadura de 75 sementes m-2 não é indicada para trigo de dupla finalidade independente do manejo de corte. O rendimento das sementes é amplificado pelo aumento da densidade de semeadura, entretanto, avançando nos níveis de recorte, há uma diminuição no rendimento de forragem.

Diversity and vertical distribution of psocids (Psocodea: Psocoptera) in two forests of the Colombian Amazon / Diversidad y distribución vertical de psócidos (Psocodea: Psocoptera) en dos bosques de la Amazonía colombiana

Introduction: The knowledge on the diversity of psocids in Colombia has increased, following the global trend, but the main interest of most of the studies has been oriented to solve taxonomic aspects, leaving aside other biological aspects, of which little is known, such as the ecological interactions of these organisms in tropical forests. Objective: To describe the psocid diversity in two Colombian Amazonian localities and provide the first data on their vertical distribution in tropical forests. Methods: Monthly samplings of Psocoptera were conducted during new moon periods, from July 2014 to May 2015. Surveys were carried out in two localities of the Putumayo department, Colombia (Puerto Asís and Mocoa), using LED light traps. Results: During the sampling period, 152 species, in 23 genera and nine families were collected. The richest family was Psocidae, followed by Epipsocidae and Lachesillidae. More than 80 % of the species found are still undescribed, and among the described ones, nine represent new records for Colombia, and are shared with neighboring countries in the Amazon basin. Fourteen (9.2 %) species are shared by the two localities surveyed. Puerto Asís is considerably richer than Mocoa. Vertical stratification of Psocoptera was found in both localities, with the canopy being the most species rich stratum. Conclusion: The relatively high diversity of psocidos found, as well as the high number of new species, is an indicator of the need to continue the exploration of these organisms in the rest of the Colombian territory and Andean countries, especially in the Amazon foothills. Stratification of the studied psocoptera community was evident, with the canopy stratum being the richest in species, a trend that continues throughout the year.

Introducción: El conocimiento que se tiene acerca de la diversidad de psócidos en Colombia ha ido en aumento, siguiendo la tendencia mundial, pero el interés principal de la mayoría de estudios se ha centrado en la resolución de aspectos taxonómicos dejando de lado otros aspectos de su biología tales como las interacciones ecológicas de estos organismos en bosques tropicales. Objetivo: Describir la diversidad de psócidos en dos localidades de la Amazonía colombiana y proporcionar los primeros datos sobre su distribución vertical en bosques tropicales. Métodos: Se realizaron muestreos mensuales de psócidos durante los periodos de luna nueva entre julio 2014 y mayo 2015, en dos localidades del departamento de Putumayo, Colombia, utilizando trampas de luz LED. Resultados: Durante el periodo de muestreo, se recolectaron 152 especies, 23 géneros y nueve familias. La familia más rica en especies fue Psocidae, seguida por Epipsocidae y Lachesillidae. Más del 80 % de las especies encontradas no están descritas y entre las descritas, nueve representan nuevos registros para Colombia y son compartidas con países vecinos de la cuenca del Amazonas. Catorce especies (9.2 %) son compartidas por las dos localidades de este estudio; Puerto Asís presentó mayores valores de diversidad que Mocoa. En ambas localidades se encontró una estratificación en la distribución vertical de Psocoptera, siendo el dosel el estrato más rico en especies. Conclusión: La relativamente alta diversidad de psócidos encontrada, así como el alto número de especies nuevas, es un indicador de la necesidad de continuar las exploraciones de estos organismos en el resto del territorio colombiano y países andinos, especialmente en el piedemonte amazónico. Fue evidente una estratificación de la comunidad de psocópteros estudiada, siendo el estrato dosel el más rico en especies, una tendencia que se mantiene a lo largo del año.

Effect of Microclimate on Yield and Quality Attributes of Cherry Tomato (Solanum lycopersicum L. var. cerasiforme) under Open Field and Polyhouse Conditions

Cherry tomatoes are usually cultivated under greenhouse which is out of the reach of the marginal farmers. Due to unavailability of microclimatic and biochemical data in cherry tomato, meagre yield is obtained at open field conditions. Since the microclimatic factors and growing environment have immense influence on yield and quality attributes of any crop, this experiment was aimed to study the correlation of microclimate with the yield and quality contributing traits of eighteen genetically diverse genotypes of cherry tomato at open field trained on trellis and under naturally ventilated polyhouse conditions. In the given study, under open conditions, mean canopy temperature in morning at 7 a.m. (15.3-19.4°C) showed highly significant positive correlation with total yield, whereas total yield possessed highly significant negative association with the mean mid-day (12 noon) canopy temperature and mean mid-day soil temperature above 25°C. In poly house condition, total yield reflected significant negative correlation with morning mean canopy temperature (24.6°C) and mid-day mean canopy temperature (25.8-26°C), whereas total yield was negatively correlated with morning and mid-day mean soil temperature when the temperature was above 20.7°C. Among biochemical parameters, lycopene and beta-carotene content increased with mean canopy temperature at 19.5°C and further decreased above 21.5°C, however TSS increased with increase in mean canopy temperature from 15 to 25°C and decreased beyond 30°C temperature.

Development of non-stress baseline of crop water stress index for wheat in humid sub-tropical climate in India

Aim: A study was conducted to develop a new approach of non-stress baseline and evaluate different approach of determining non stress baseline for Crop Water Stress Index (CWSI).Methodology: To observe maximum and minimum canopy temperature, two plots with three replications were maintained at fully stress (no irrigation) and no stress (fully irrigated) conditions, respectively. Portable weather station with data logger was installed at the middle of field to record continuous data at half an hour interval. Gypsum block soil moisture sensor were buried at 20 cm interval up to 100 cm and connected with data logger. Infrared radiometer was used to measure canopy temperature. Results: The evaluation was based on five statistical indicators; correlation coefficient (R2), root mean square error (RMSE), mean absolute error (MAE), mean bias error (MBE) and Wilmot index of agreement (d). It was found that new regression base line performed better than other existing approaches. The calculated value of RMSE, MAE, MBE, d and R2 were 0.65, 0.51, 0.02, 0.79 and 0.83, respectively, for new baseline approach. Interpretation: The newly developed multiple regression equation (incorporating three weather parameters (Rn, VPD and u) and two crop growth parameters (h and CC)) helped to reduce error in the calculation of non-stress baseline for wheat crop in humid subtropical climate

Microhabitat selection, and seasonal and daily activity of the snail Tikoconus costarricanus (Stylommatophora: Euconulidae) in tropical montane wet forest understory / Selección de microhábitat, y actividad diaria y estacional del caracol Tikoconus costarricanus (Stylommatophora: Euconulidae) en el sotobosque de bosques tropicales húmedos de montaña

Introduction: The integument of terrestrial mollusks is highly susceptible to dehydration; therefore, microhabitat selection, seasonality and behavior around the day are crucial to their survival. However, they are still poorly understood, especially for tropical montane wet forest species. Objetive: To analyze activity patterns and microhabitat selection on shrubs of the land snail Tikoconus costarricanus, according to season, daytime and weather. Methods: I conducted the study near "El llano" water dam in a tropical montane wet forest in Costa Rica. I observed daily activity of T. costarricanus, during the rainy and the dry season on a 2 km long trail. I observed 167 specimens and made 781 observations in total. I took note of: season, time, activity, weather, temperature and relative humidity inside the forest, and part of the leaf and height where snails were. Active snails had optical tentacles extended. I analysed daily rainfall data from a nearby meteorological station. Results: This species can be found mainly on understory leaves between 1.1 and 2 m above the floor. They are active the day around during the whole year. Only 24 % of the snails were on the upper side of leaves, but 92 % of them were active. The following behaviors were season dependent: activity peaks, leaf side selection according to daytime and weather, quantity of snails aestivating and vertical distribution. During the dry season, I found more active snails in rainy and cloudy days. During the rainy season I found more active snails in sunny days. During rainy season light hours, active snail percentage on the upper side of leaves decreased with rainfall increase, while in the dry season decreased with temperature increase and relative humidity decrease. During night hours of both seasons, the number of snails on the upper side of leaves decreased considerably in relation to active snails, especially in the rainy season. This snail aestivated on the underside of leaves during periods shorter than 21 h, mainly around noon and afternoons during the dry season. High humidity in this forest allowed snail activity around the day at any season. However, this species aestivated when moisture reached the lowest values, mainly, around noon and in the afternoons in the dry season. The rainfall pattern during the rainy season light hours explains the specimen decrease on the upper side of leaves, but in the dry season it is better explained by the temperature increase and the decrease in relative humidity. During dark hours, the almost complete snail absence on the upper side of leaves during the rainy season is explained if the effect of canopy drip produced by rain and dew condensed on leaves is added to the rain pattern. The situation is slightly different in dark hours of the dry season, in this case, snail decrease on the upper side of leaves is explained by canopy drip from dew and fog precipitation. Seasonal difference in vertical distribution may be a way to avoid rain and rain splash out on the soil. Conclusions: Moisture, temperature, rain, and canopy drip from dew, fog and rain, affect behavior and substrate selection of small terrestrial mollusks that inhabit shrubs in wet tropical rainforests.

Introducción: El integumento de los moluscos terrestres es susceptible a desecación, por eso la selección de microhábitats, la estacionalidad y el comportamiento a lo largo del día son cruciales para su sobrevivencia. No obstante, es poco lo que se ha investigado al respecto, en especial para moluscos tropicales de arbustos del sotobosque en bosques húmedos de montaña. Objetivo: Analizar los patrones de actividad y de la selección de microhábitats del caracol terrestre Tikoconus costarricanus según la estación del año, la hora del día y el clima. Métodos: El trabajo lo realicé en un bosque tropical húmedo de montaña cerca de la represa hidrológica "El Llano", Costa Rica. Analicé la actividad diaria de especímenes de T.costarricanus en un trayecto de 2 km: observé 167 especímenes e hice 781 observaciones. Tomé nota de: estación del año, hora, actividad, parte de la hoja donde estaba el caracol, altura en la planta, clima y humedad relativa y temperatura dentro del bosque. Consideré que un espécimen estaba activo cuando los tentáculos ópticos estaban extendidos. Analicé la precipitación pluvial por horas con datos de una estación meteorológica cercana. Resultados: Encontré caracoles principalmente en las hojas de arbustos entre 1.1 y 2 m sobre el suelo; encontré individuos activos a todas horas y en cualquier época del año. Solo el 24 % de los individuos estaban en el haz, de esos el 92 % estaban activos. Encontré variación estacional en el patrón de actividad, la selección del lado de la hoja de acuerdo a la hora del día y el clima, la cantidad de especímenes estivando, y la distribución vertical. En la época seca encontré más caracoles activos con clima húmedo, por el contrario, en la estación lluviosa encontré más caracoles activos con clima seco. Durante las horas de luz de la estación lluviosa, la cantidad de caracoles activos sobre el haz de las hojas disminuyó con el aumento de precipitación pluvial, en tanto que en la estación seca disminuyó con el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas nocturnas de ambas estaciones, la cantidad de caracoles sobre el haz de las hojas disminuyó considerablemente en relación a los caracoles activos, especialmente en la época lluviosa. Este caracol estivó principalmente a mediodía y en las tardes de la época seca en el envés de las hojas por periodos inferiores a 21 h seguidas. La elevada humedad del bosque tropical húmedo de montaña permite que estos caracoles estén activos en cualquier momento. Sin embargo, la estivación les permite protegerse de la desecación durante los periodos más secos. El patrón de lluvias durante las horas de luz de la época lluviosa explica la disminución de especímenes presentes en el haz de las hojas, pero en la época seca lo explica mejor el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas oscuras, la casi ausencia de caracoles en el haz de las hojas durante la estación lluviosa se explica si al patrón de lluvia se le agrega el efecto del goteo foliar producido por la lluvia y el rocío que se condensa sobre las hojas. La situación es un poco diferente en las horas oscuras de la estación seca, en este caso, la disminución de caracoles en el haz, se explica por el goteo foliar derivado del rocío y de la precipitación de neblina. Es posible que la diferencia en la preferencia vertical se deba a que evitan la lluvia y la salpicadura de la lluvia al caer en el suelo. Conclusiones: La humedad, la temperatura, la lluvia y el goteo foliar derivado de rocío, neblina y lluvia, afectan el comportamiento y la selección de sustrato de moluscos terrestres pequeños que habitan en arbustos de bosques tropicales húmedos de montaña.

Changes in Morpho-physiological and Yield Parameters of Rice (Oryza sativa L.) in Response to Ultraviolet-B (UV-B) Radiation

A rice variety Jyothi (PTB 39) is a red kernelled with bold grain, popular in the region of Kerala, India used in the study. Plants were grown in pots under three different conditions, natural solar UV-B conditions, UV-B excluded condition using UV-B filters and supplemental UV-B using UV-B lamps along with ambient solar radiation. During the study period, UV-B radiation was in the range of 1.30 to 3.58 Wm2 which affected the productivity of the crop under open solar condition. A decrease in morphological traits like plant height, number of tillers, flag leaf angle and increase in leaf thickness were observed. Physiological parameters, leaf gas exchange parameters and biochemical constituents such as chlorophyll content also recorded less value under high UV-B condition along with the high content of protective compounds such as flavonoid content, catalase and PAL activity. The phenophases of the crop were also delayed by 4-5 days under UV-B radiation exposed conditions. All these negative impacts of UV-B radiation on crop leads to restricted filling of grain, lesser harvest index and grain development leading to a decrease in yield and yield attributing characters.

Diversity and population dynamic of Tabanidae (Diptera) in the cerrado-pantanal ecotone / Diversidade e dinâmica populacional de tabanídeos (insecta: diptera) no ecótono cerrado-pantanal

Tabanid (Diptera) species are associated with the mechanical transmission of several pathogens to both domestic and wild animals around the world. The aim of this study was to evaluate the diversity, abundance, and seasonal dynamic of tabanids in the Cerrado-Pantanal ecotone in Miranda, state of Mato Grosso do Sul, Brazil. Tabanids were collected once a month, from June 2001 to May 2003, for seven consecutive days per collection, using canopy and nzi type traps baited with a chemical attractant (1-octen-3-ol). A total of 6,492 individuals from 39 species and 18 genera was collected, which increases from 25 to 34 the number of tabanid species reported for the studied region. Tabanus occidentalis Linnaeus, 1758 (62.21%) was the most abundant species throughout the collection period, followed by Lepiselaga crassipes (Fabricius, 1805) (7.19%) and Tabanus sorbillans Wiedemann, 1828 (5.68%). The peak of the tabanid population was reached during the rainy season, which is the period of the highest potential risk of mechanical transmission of pathogens by these insects in the studied region.

Tabanídeos (Diptera) são importantes vetores de patógenos a animais domésticos e silvestres no mundo. O objetivo foi estudar a diversidade, abundância e dinâmica sazonal de Tabanidae no ecótono Cerrado-Pantanal em Miranda, Mato Grosso do Sul, Brasil. Uma captura foi realizada por mês cada por sete dias consecutivos de junho 2001 a maio 2003 utilizando armadilhas modelo canopy e nzi. As armadilhas foram iscadas com o atrativo químico "1-octen-3-ol". Um total de 6.491 tabanídeos, de 39 espécies e 18 gêneros, foi capturado, ampliando a lista de espécies de tabanídeos relatados para o Mato Grosso do Sul de 25 para 34. Tabanus occidentalis Linnaeus, 1758 (62,21%) foi o mais abundante durante o período de coleta, seguido por Lepiselaga crassipes (Fabricius, 1805) (7,19%) e Tabanus sorbillans Wiedemann, 1828 (5,68%). A maioria das espécies de tabanídeos teve pico populacional durante o período chuvoso, considerado o de maior risco potencial de transmissão mecânica de patógenos por estes vetores na região estudada.

¿Refleja Formicidae el impacto de la degradación de los bosques ribereños en la Amazonía Oriental?

La creciente presión antropogénica sobre la Amazonia Oriental hace imperativo el diagnóstico de la degradación forestal y, particularmente, su efecto sobre las comunidades clave dentro de los ecosistemas ribereños, unos de los últimos bosques amazónicos remantes en el estado de Maranhão. La familia de hormigas Formicidae juega un papel fundamental en el suelo, refleja los cambios en el uso de la tierra y es un grupo abundante en los bosques estudiados. Este trabajo tuvo como objetivo determinar el efecto del gradiente sucesional en la riqueza, frecuencia y composición de esta familia. El muestreo fue realizado durante los periodos seco y lluvioso con el método TSBF. Los organismos recolectados se identificaron a nivel de morfoespecies y se crearon curvas de acumulación de especies. Fueron utilizados modelos lineales mixtos para evaluar los efectos del periodo de recolecta local y estado de sucesión en la riqueza y la frecuencia de las hormigas. Por otro lado, se utilizaron regresiones polinómicas para investigar la relación entre la riqueza y la frecuencia de los formícidos según la cobertura del dosel y la altura de la vegetación. La composición de especies fue representada a través del índice de similitud de Jaccard. En total, 1 940 individuos fueron separados en 86 morfoespecies. Se obtuvo más del 80 % de la riqueza de especies probables. La frecuencia y riqueza de hormigas aumentó significativamente siguiendo la sucesión con valores bajos en las áreas abiertas durante la estación seca. Asimismo, durante esta estación, la cobertura del dosel y la altura de la vegetación tuvieron un efecto parcial en la riqueza y frecuencia de Formicidae. Por su parte, las áreas de sucesión intermedia y avanzada presentaron una composición similar con 50 especies compartidas, seguidas de las áreas de sucesión temprana con 43 y el uso antrópico con 34. Concluimos que la eliminación de los bosques ribereños tiene un efecto considerable sobre la riqueza y frecuencia de Formicidae, con valores mínimos en áreas degradadas durante la estación seca. Por otro lado, las áreas de bosques transformadas en sistemas agrícolas sufrieron pérdidas de 41 y 56% en la riqueza y frecuencia respectivamente. Con la sucesión, se restauran la estructura y las funciones del bosque favoreciendo la recolonización de las especies de hormigas. Finalmente, estos himenópteros son un grupo clave en los programas de monitoreo para la conservación/restauración de los bosques ribereños locales.

The increasing anthropogenic pressure on Eastern Amazon makes imperative the diagnosis of forest degradation, particularly the effect on key communities within the riparian ecosystems, one of the last remaining Amazonian forests in Maranhão State. The ant family Formicidae is an abundant group in these types of forests plays a fundamental role on the soil and also reflects the land use changes. Therefore, this study aimed to determine the impact of riparian forest successional stages on the Formicidae richness, frequency, and composition. Sampling was performed during both dry and wet seasons using the TSBF method. Collected organisms were identified as morphospecies. Also, species-accumulation curves were created. Linear mixed models were used to evaluate the effects of seasonal, local, and successional stage on ant richness and frequency. Polynomial regression models were applied to investigate the relationship between ant richness and frequency with canopy cover and vegetation height. Lastly, the species composition was represented by the Jaccard similarity index. In total, we observed 1 940 individuals grouped into 86 morphospecies. We obtained more than 80 % of the probable species richness. Ant frequency and richness increased significantly, following the successional stage, with low values in the open areas, especially during the dry season. Canopy cover and vegetation height seemed to affect partially both Formicidae richness and frequency during the dry season. Intermediate and advanced successional areas presented similar composition (50) shared species, followed by the areas of early succession (43) and anthropic use (34). We concluded that the elimination of riparian forests produces a considerable effect on the richness and frequency of the Formicidae family, minimally affecting them in open areas during the dry season, but resulting in losses of 41 % in richness and 56 % in frequency in forest areas when they are transformed into agricultural systems. Nevertheless, succession restores forest structure and functions, thus favoring re-colonization of ant species. Formicidae reflects forest degradation and is a key group in monitoring programs for the conservation/restoration of local riparian forests.