Trinexapac-ethyl application time in the crop corn agronomic performance grown under different plant arrangements

Reduced row spacing promotes more uniform spatial distribution of plants in the field. However, the adoption of reduced row spacing only is possible with smaller plants, which may be obtained with the use of plant growth regulator. This study aimed to evaluate the agronomic performance of the first corn crop with Trinexapac-ethyl applied at the different plant development stages and grown under different row spacing, with the same plant population. The experiments were arranged in a split-plot randomized block design with four replications, with row spacing for the plots (0.45 and 0.90 m) and Trinexapac-ethyl (TE) application time to subplots (control without application, at the V3, V6, V9 and V12 phenological stages). The Trinexapacethyl application time interacted with row spacings changing the growth and yield performance of the corn crop. For 0.45 m spacing Trinexapac-ethyl application at V12 and for 0.90 m spacing application at V9 and V12 reduced plant height and ear height. Trinexapac-ethyl application at V9 for both row spacings changed the plant architecture without changing the ear length and grain yield.

USO DE COBERTURA MORTA E ÁGUA SALINA NA PRODUTIVIDADE DA CULTURA DO MILHO

USO DE COBERTURA MORTA E ÁGUA SALINA NA PRODUTIVIDADE DA CULTURA DO MILHO GEOVANA FERREIRA GOES1, GEOCLEBER GOMES DE SOUSA2, CARLA INGRYD NOJOSA LESSA3, FRED DENILSON BARBOSA DA SILVA2, CLAUDIVAN FEITOSA DE LACERDA4, RAFAELLA DA SILVA NOGUEIRA2 1Graduanda no curso de Agronomia da Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da Abolição, 3, centro, 62.790-000, Redenção/Ce, Brasil). E-mail: [email protected] 2Professores Doutores, Instituto de Desenvolvimento Rural, Agronomia da Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da Abolição, 3, centro, 62.790-000, Redenção/Ce, Brasil). E-mail: [email protected]; [email protected]; [email protected] 3Mestranda pelo Programa de Pós-graduação em Engenharia Agrícola da Universidade Federal do Ceará, Campus do Pici (Avenida Mister Hull,2977, Pici, 60.021-970, Fortaleza/Ce, Brasil) Email: [email protected] 4Professor Doutor, DENA/Programa de Pós-graduação em Engenharia Agrícola da Universidade Federal do Ceará, Campus do Pici (Avenida Mister Hull,2977, Pici, 60.021-970, Fortaleza/Ce, Brasil) Email: [email protected] 1 RESUMO O objetivo do trabalho foi avaliar a produtividade da cultura do milho irrigado com água de maior e menor salinidade em solo com e sem cobertura morta vegetal. A pesquisa foi realizada em campo, na Fazenda experimental da UNILAB, Redenção-CE. O delineamento experimental foi em bloco casualizado, em esquema fatorial 6 × 2, referente a seis estratégias de uso de cobertura morta vegetal: EC1= sem cobertura morta durante todo o ciclo - testemunha; EC2= com cobertura morta durante todo o ciclo; EC3= com cobertura morta até 45 dias após a semeadura (DAS) e sem cobertura morta até o final do ciclo; EC4= sem cobertura morta até aos 45 DAS e com cobertura morta até o final do ciclo; EC5= com cobertura morta até 60 DAS e sem cobertura morta até o final do ciclo e EC6= sem cobertura morta até 60 e com cobertura morta até o final do ciclo e duas condutividade elétrica da água de irrigação (A1=0,8 dS m-1 e A2=3,0 dS m-1), em cinco repetições. Foram analisadas as seguintes variáveis: massa de espiga com e sem palha, de 1000 grãos e a produtividade. O uso da estratégia EC3 possibilitou aumento para massa da espiga com e sem palha e 1000 grãos. A salinidade da água de irrigação foi atenuada pela estratégia EC3 para massa da espiga com e sem palha. As estratégias EC3 e EC5 apresentaram maior produtividade com água de baixa salinidade e com água de maior salinidade quando utilizou-se a estratégia EC3. Palavras-chave: salinidade, proteção do solo, Zea mays L. GOES, G. F.; SOUSA, G. G.; LESSA, C. I. N; SILVA, F. D. B; LACERDA, C. F.; NOGUEIRA, R. S. USE OF DEAD COVERAGE AND SALINE WATER IN THE PRODUCTIVITY OF CORN CROP 2 ABSTRACT This work aimed to evaluate the productivity of the corn crop irrigated with water of greater and lesser salinity in soils with and without mulch. The research was carried out in the field, at the experimental farm at UNILAB, Redenção-CE. The experimental design was a randomized block, in a 6 × 2 factorial scheme, referring to six strategies for using vegetable mulch: EC1= no mulch throughout the cycle - control; EC2= with mulch throughout the cycle; EC3= with mulch up to 45 days after sowing (DAS) and without mulch until the end of the cycle; EC4= no mulch up to 45 DAS and with mulch until the end of the cycle; EC5= with mulch up to 60 DAS and without mulch until the end of the cycle and EC6= without mulch up to 60 and with mulch until the end of the cycle and two electrical conductivity of the irrigation water (A1=0.8 dS m-1 and A2=3.0 dS m-1) in five repetitions. The following variables were analyzed: ear mass with and without straw, 1000 grains and yield. The use of the EC3 strategy allowed an increase in ear mass with and without straw and 1000 grains. The salinity of the irrigation water was attenuated by the EC3 strategy for ear mass with and without straw. Strategies EC3 and EC5 showed higher yields with low salinity water and high salinity water when the EC3 strategy was used. Keywords: salinity, soil protection, Zea mays L.

A climatological study of soil moisture under corn crop at Campina Grande (NE Brazil)

ABSTRACT. Results of a climatological study of soil moisture under corn crop at Campina Grande (NE Brazil) are presented in this paper. Daily values of available moisture content during the crop growing period are evaluated for a period of 25 years. A six zone versatile soil moisture budget model is used for this purpose and approximately 5. 7.5, 12.5, 25, 25 and 25% of the available water capacity (AWC) are attributed to zones one to six respectively. Different root activity coefficients are assumed for the six zones in different growth stages and the dependence of these coefficients on moisture content is taken into consideration. The same moisture releasing characteristics are assumed for all soil zones. On rainy days moisture loss due to evapotranspiration is assumed to take place before precipitation. Four AWC values and three corn growing periods between March and September are considered in this study. A first order Markov chain model is applied to the daily soil moisture data. Soil moisture averages and probabilities are used to identify the optimum growing period for corn at this station. The irrigation requirements of the crop are briefly discussed.

Energy balance and efficiency in crop rotation systems

The production system model that has been adopted in most Brazilian regions, the soybean/second corn crop succession, has led to problems in water and soil conservation and favorable conditions for diseases, pests, and weeds in the agricultural system and, consequently, increasing its energy use. Crop rotation is an alternative to this production model, directly interfering with the problematic aspects of the crop succession system and, consequently, its energy balance. Therefore, this study aimed to identify the crop rotation system with the best energy balance and efficiency. The data on the quantity of inputs (seeds, fertilizers, pesticides, and fuel), labor, and grain yield used in the study were collected from a crop rotation experiment conducted at the experimental station of the Rural Development Institute of Paraná - IAPAR-EMATER, Londrina, PR, Brazil, from 2014 to 2020. The experimental design consisted of randomized blocks, with six treatments and four replications. The treatments consisted of T1 (second corn crop/soybean), T2 (white oat/soybean, triticale/corn, and wheat/soybean), T3 (rye + black oat/soybean, black oat + fodder radish/corn, and congo grass/soybean), T4 (canola/corn, crambe/corn; canola/soybean); T5 (buckwheat-fodder radish/corn, bean/soybean, and buckwheat-white oat/ soybean), and T6 (wheat/corn, canola/corn + congo grass, and bean/soybean). The different crop rotations and the traditional second corn crop/soybean system provided positive energy balance and efficiency, that is, they produced more energy than they consumed. The canola/corn, crambe/corn, and canola/soybean rotation systems had the highest energy balance and efficiency, with values of 866,442.27 MJ ha−1 and 10.27, respectively, mainly due to corn cultivation in the summer, which resulted in a higher energy return than the other grain-producing crops.

Weed discrimination based on the spectral response of the corn crop, Manabí, Ecuador

Precision agriculture allows to gain efficiency, sustainability and profitability, since it provides great benefits in reducing the environmental impact of agriculture, economic risks and at the same time contributes to controlling the vigor of crops and improving the quality of their yield. The objective of this research is to discriminate weeds within the corn crop, based on their spectral response. For this, the advanced EBEE SQ agricultural drone was used, with which multispectral images were captured through its Parrot Sequoia camera. The images were processed with software in Geographic Information Systems (GIS). With the multispectral bands, different vegetation indices were calculated such as NDVI, NDVIAS, NGRDI, NDRE, GNDVI, using map algebra tools in specialized programs. A supervised classification was applied to the different indices to discriminate the different land covers, which obtained a precision of 93% and a Kappa index of 0.93. The results allowed to clearly differentiate the coverage of crops, weeds and bare soil. The data showed that both early-growing and developed weeds occupy 38% of the crop area. With this information, it is possible to improve the planning of agronomic practices, adding the herbicide at the specific site of the weeds.

The Importance of Nitrogen in Corn Culture

Corn is one of the most cultivated cereals in the world and is used for various purposes and its production is linked to its economic importance, requiring the use of means and methods that enable the increase of its production, and one of them is fertilization with nitrogen. The objective of this work is to carry out a brief literature review on the importance of nitrogen for the corn crop, highlighting the benefits of its use and the need for its use in the crop. Plants need many nutrients for their development, and nitrogen is one of the main nutrients, being important for many chemical and physical functions in the plant. In addition, nitrogen is necessary in the corn crop, as it is a nutrient that is required in large amounts and has a great impact on crop production. Nitrogen has many benefits in the corn crop, as it is essential to the plant and to many crops, providing benefits throughout the plant, ensuring an increase in production components. However, the importance of nitrogen in the crop, refers to the plant, its use in the corn crop and the benefits provided, which generate positive results for its use, increasing various components of crop production, demonstrating that it is important for the crop, in its development and in the increase of maize productivity. Thus, it is noted that nitrogen is very important for the development of corn, composes several chemical and physical functions of the plant, it is necessary in the corn crop due to its requirement, provides many benefits to the crop, increasing production components and has many good results with its use in corn.

Application Technology in the use of Correctives in Corn Culture

Corn is one of the most cultivated cereals in the world and is used for various purposes and its production is linked to its economic importance, requiring the use of means and methods that enable the increase of its production and one of them is the correction of the ground. The objective of this work is to carry out a brief literature review on the application technology in the use of correctives in the corn crop, highlighting the benefits of its use and the need for its use in the crop. The present study was developed based on a literature review and relevant research on the technology of application of correctives in corn crop, highlighting the benefits of its use and the need for its use in corn crop. Agriculture went through a long development, improving its production system and application technology came with one of the alternatives helping to maintain and improve soil quality, enabling the application of correctives in the soil with greater efficiency. The need for soil correction has to do with the relationship between the plant and the soil, highlighting the acidity, which in many cases is a problem for the cultivation of crops. The use of correctives to correct soil acidity brings many benefits to the physical and chemical characteristics of the soil, reduces fertilizer losses caused by leaching, provides calcium and magnesium to the soil adjusting the soil profile so that plants can benefit from available nutrients. Thus, application technology is essential for the corn crop and for the entire production system, even more in the application of correctives, as acidity is one of the causes of yield limitations. Thus, application technology favors soil correction, ensuring the benefits provided by proper application, becoming a means of increasing crop productivity and corn as well, due to the various productive aspects provided by the correct application in the soil.

Influence of Dosages of Biofertilizers Composed of Mycorrhizae and Diazotrophs on the Corn Productivity

Corn (Zea mays L.) is a crop of world importance, however, one of the problems present during its development is the lack of nutrients or the presence of these in a form not available to the plant. Because of this, the objective of this review article is to gather information on the influence of different dosages of mycorrhiza and diazotroph biofertilizers on the corn crop. A meticulous bibliographic research was carried out, detailing the methods used by various authors; Among the most repetitive and significant factors are the use of mycorrhizae and nitrogen-fixing bacteria plus fertilization with P, the following treatment stands out: 200 gr ha−1 (using mycorrhizae and nitrogen-fixing bacteria); the common response variable of the authors mentioned in methodology was grain yield. The results obtained by the majority of authors show that grain yield improves significantly in the interaction of mycorrhizae and diazotrophs plus chemical fertilization; As a result of the aforementioned treatment, the yield of corn kg ha−1 was increased by 37%, by virtue of these results it is concluded that the most appropriate thing would be to take it into account to apply it on the corn crop. Keywords: Inoculants, Nitrogen Fixing Bacteria, Symbiotic Fungi. Resumen El maíz (Zea mays L.) es un cultivo de importancia mundial, sin embargo, uno de los problemas presentes durante su desarrollo, es la falta de nutrientes o la presencia de estos en forma no disponible para la planta. Debido a esto, el objetivo de este artículo de revisión es recopilar información sobre la influencia de las diferentes dosificaciones de biofertilizantes a base de micorriza y diazótrofos sobre el cultivo de maíz. Se realizó una minuciosa investigación bibliográfica, detallando métodos utilizados por varios autores; entre los factores más reiterativos y significativos están el empleo de micorrizas y bacterias fijadoras de nitrógeno más la fertilización con P, sobresaliendo el siguiente tratamiento: 200 gr ha−1 (usando micorrizas y bacterias fijadoras de nitrógeno); la variable respuesta en común de los autores mencionados en metodología fue el rendimiento del grano. Los resultados obtenidos por la mayoría de autores muestran que el rendimiento del grano mejora significativamente en la interacción de micorrizas y diazótrofos más la fertilización química; producto del tratamiento mencionado anteriormente, se aumentó un 37% el rendimiento del maíz kg ha−1, en virtud a estos resultados se concluye que lo más adecuado sería tomar en cuenta para aplicarla sobre el cultivo de maíz. Palabras Clave: Inoculantes, bacterias fijadoras de nitrógeno, hongos simbiontes.