Report on the construction of portable NIRS equation to estimate forage quality in Brachiaria decumbens-ruzisiensis-brizantha species complex

The nutritive value of Brachiaria Hybrids is one of the most important parameters in the forages breeding program at the International Center for Tropical Agriculture (CIAT). It supports the selection and identification of promising genotypes. Using Near infrared reflectance spectroscopy (NIRS) we have been able to estimate protein contents (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) with satisfactory results in the benchtop NIRS of the sample dried and ground. During 2021, the portable NIRS has been explored for the prediction of nutritional quality parameters without the destructive preprocessing of plants. This allows a rapid assessment of nutritive values. The objectives of this study were to evaluate the potential use of portable NIRS technology into the breeding program to predict the nutritional quality of interspecific Brachiaria Hybrids and extend the data set of calibration for building models for measure dry matter (DM), NDF, ADF and CP. The methodology applied used wavelengths of full range (350-2500nm) and NIR (1000-2500nm). Prediction accuracy of the obtained equations were in general better than previous models, but unfortunately still not robust enough to be applied. Further enrichment of the calibration set is required

Effect of genotype interaction by environment on quality traits in Brachiaria hybrids population Br12

We aim to understand the magnitude of the interaction genotype by environment over several important traits, including those associated with nutritional quality, in a population of 100 hybrids of interspecific Brachiaria. In cooperation with Colombian National Agriculture Research Center (AGROSAVIA), four field trials have been stablished and another one will be stablished in 2020, for a total of 5 locations. The trials follow alpha lattice designs in each location, with two replicates. Each trial is evaluated at least four times, trying to cover two rainy and two dry seasons. For each evaluation measurements of visual and drone biomass and quality, parameters with NIRS are taken. Currently, data capture has been completed in 3 locations. One is at 50% and another is still pending of establishment. The present report shows partial results for some of the data that has been collected

Preliminary report on calibration of chemometric equations of portable NIRS, suitable for screening of nutritional quality traits in Brachiaria brizantha-ruzisiensis-decumbens genetic pool

Near infrared reflectance spectroscopy, (NIRS) technology has been used as a rapid and low-cost method for analysis of quality nutritional parameters. However, this requires a preprocessing of plants that involve cutting, drying and milling of sample. This preliminary study was undertaken to explore the potential of field spectral measurements for a nondestructive prediction of crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Canopy reflectance data were acquired before harvest using a ASD LabSpec 4 Standard-Res (Analytical Spectral Devices, Inc., Boulder, CO) spectrometer over the 350 to 2500 nm wavelength range (1 nm spectral resolution). The population study correspond to 110 genotypes of Brachiaria Hybrids established in two locations from Colombia with an experimental design Alpha lattice ( 10X 11) in plots measuring 1 X 1 m, and two repetitions. The field experiment was conducted during the years 2019 and 2020 on research stations of Agrosavia (Nataima, Tolima, Colombia) and CIAT (Palmira, Valle del Cauca, Colombia). The spectral data was collected directly in plants before harvest. For the process of development preliminary equations, sixty-five samples of hybrids harvested were selected and used to measure in laboratory parameters contents PC, ADF and NDF. Additionally, this number of samples were used to reinforce the existing equations for stationary NIRS in the case of Brachiaria Hybrids in Quality nutricional laboratory at CIAT. The preliminary equations designed for fresh samples and direct measurements in leave tissue of the plants before harvest and without any preprocessing (drying, milling) are still not showing satisfactory results. In contrast, the equations with dry samples presented better statistical parameters and allowed predictions to all BR interspecific population of the breeding program during 2020. In recommendation, for next studies with portable NIRS is necessary to add more samples in the process of calibration for obtain good results and equations

Report on quality estimation for selection purposes in 300 apomictic interspecific hybrids of the population Br19

The aim of this work was to estimate the nutritional value of 300 hybrids from Urochloa interspecific breeding program. Plant biomass was harvested and subjected to a bromatological analysis to evaluate crude protein, neutral and acid detergent fiber, and in vitro digestibility using standardized methods. A large proportion of the hybrids showed better nutritional values than the genotypes used as controls. We expect to build a selection index with nutritional quality values and other previously evaluated traits to identify the best hybrids for selection

Report on the identification of nutritional quality in the population of promising apomictic hybrids

A group of 131 selected hybrids were evaluated for nutritional quality traits during 2020. Acid detergent fiber ranged from 27.8 to 37.0% with an average of 32.9%; Digestibility ranged from 41.5 to 55.4% with an average of 47.7%; Dry mater values ranged from 21.8 to 35.1% with an average of 28%; Neutral detergent fiber ranged from 62.4 to 73.9% with an average of 68.2%; and Crude protein ranged from 4.6 to 11.3% with an average of 7.5%. For all the evaluated traits, some hybrids performed better than the commercial benchmark

Report on the field performance and identification of nutritional quality in the population of promising apomictic hybrids Pm16 (20 hybrids)

Megathyrsus maximus plays an important role in livestock production systems in developing countries. M. maximus breeding program at CIAT started in 2016. The best apomictic hybrids were selected and planted in the field in order to compare their agronomic traits with five cultivars. The experiment was conducted in Alpha lattice design. Genotypes were evaluated for five morphological traits during 2020 (plant biomass, plant height, growth habit, number of inflorescences, and leaf to stem ratio. Statistical analysis was carried out in META-R and R software. ANOVA revealed significant differences (P 0.8) in all evaluation dates except for plant height in evaluation no. 4 when it was moderate (0.69). Flowering dynamics showed that more than 50% of the genotypes showed the highest flowering index at 31 days of regrowth

Models for estimating nutrition quality of Urochloa humidicola using near infrared reflectance spectroscopy

Breeding forage crops requires a genetic evolution to optimize the agronomic and compositional characteristics of the new hybrids. As a dynamic process, it is necessary to evaluate with precision and speed the parameters that determine the nutritional quality, in particular the contents of digestibility and fibers. Near infrared reflectance spectroscopy (NIRS) offers a low cost-effective alternative to measure these parameters

Report on a population of Urochloa hybrids (Bh16) and their associated information, released to private sector for multienvironment testing and dissemination

The aim of this report is to summarize the information concerning to different evaluations performed on the hybrid population Bh16 conformed by 27 genotypes, which were qualified as superior and selected from an initial cohort of 3050 hybrids. We present the results obtained from evaluations of i) resistance to biotic stress imposes by the spittlebug A. varia (Hemiptera: Cercopidae); ii) progeny test to corroborate previous results with molecular markers; and iii) an agronomic comparison against two commercial cultivars (cv Llanero and cv Tully). We discuss the results obtained in each evaluation and the proposal of the following stages to continue in the selection process of the best 10 Bh16 hybrids

Determinación de la eficiencia en el uso del nitrógeno (UEN) por principales pasturas forrajeras de trópico bajo en respuesta a diferentes fertilizantes nitrogenados

El tratamiento pasto Estrella-Nitromag fue el que generó más emisiones de N2O, seguido de Cayman-Nitromag, y por último Mombasa-Urea 2. En los tratamientos Estrella-Nitromag y Cayman-Nitromag las emisiones de N2O incrementaron proporcionalmente con la dosis de N aplicado por fertilización, mientras que Mombasa-Urea no presentó diferencias en las emisiones por dosis 3. Las menores emisiones en el tratamiento Mombasa-Urea podrían explicarse por la fuente de N empleada, la cual provee menos sutrato (respecto a Nitromag: nitrato de amonio calcáreo) para procesos de nitrificación/desnitrificación o por mayor consumo de agua por parte de la planta, lo cual reduce la actividad microbiana de nitrificantes y desnitrificantes del suelo. Una tercera hipótesis es la Actividad de inhibición biológica de la nitrificación. 4. Los tratamientos fertilizados que presentaron menor intensidad de emisiones fueron 1. Cayman-Nitromag 20 kg N ha-1 2. Estrella-Nitromag 20 kg N ha-1 3. Mombasa-Urea 30 kg N ha-