Origin and characteristics

The variety of oats Ágata is of habit of spring, intermediate cycle (108 days to physiological maturity on average), medium height (97 cm on average), is tolerant to lodging, resistant to moderately resistant to stem rust and rust of the crown (Puccinia coronata f. sp. avenae), tolerant to foliar disease complex and responds favorably in any type of production environment under temporary. This variety was generated in the Oats Genetic Improvement Program of the National Institute of Forestry, Agriculture and Livestock Research (INIFAP) based in the Valley of Mexico Experimental Field (CEVAMEX), through a process that included genetic recombination, selection and evaluation. The variety was obtained through a simple cross identified with the number I-4 533 and the application of the combination of mass or population selection methods and that of derived families. The mass was used under the principles of the gravimetric method for the selection of grain with greater weight. Next, the obtaining process is described.

The crossing was carried out in Spring-Summer (SS) 1999, the F₁ was evaluated in Autumn-Winter (AW) 1999-2000 and its cross was identified with the number 4 533, the F₂ was planted in SS-2000 and it was applied selection under the gravimetric method, in F₃ the plant number 12 was selected, in F₄ the family number 185 was harvested massively, in F₅ the family number 96 was massively harvested, in F₆ the plant number 3 was harvested individually and in F₇ it was harvested massively the uniform line (Table 1), which was identified with the following genealogy and pedigree:

Genealogy: KAR/GAL//ZAF/KAR/3/BLEN/KAR

Pedigree: I-4533-0C-12C-0R-0C-3C-0R

As of the summer of 2005, the experimental line was evaluated in the different tests. It was initially tested in the preliminary performance test (PPR) in localities of the State of Mexico, Puebla, Hidalgo and Tlaxcala. Subsequently, from 2006 to 2010, it was included in the respective oat selection nurseries (VISAVENA) and from 2011 to 2015 it was evaluated in the eleventh to fifteenth national uniform test of oats (11^th EUAVENA to the 15^th EUAVENA), respectively, in up to 81 localities located in 11 states of the Mexican Republic that included Aguascalientes, Chihuahua, Durango, State of Mexico, Guanajuato, Hidalgo, Jalisco, Oaxaca, Puebla, Tlaxcala and Zacatecas.

Reaction to rusts and foliar diseases

Ágata is resistant to moderately susceptible to stem rust (Puccinia graminis f. sp. avenae), is resistant to moderately resistant to crown or leaf rust (P. coronata) and is tolerant to the foliar disease complex caused by Helminthosporium avenae (leaf spot), Septoria avenae f. sp. avenae (leaf spot) and Colletotrichum graminicola (anthracnose).

Table 2 shows the reaction to diseases of Ágata and control varieties after 81 evaluations under temporary. Stem rust recorded readings from 0 to 30MR, a type of reaction less than Turquesa that in some places reached readings of up to 60S; likewise, it also presented lower readings than the other control varieties that already present a susceptibility reaction with percentages from 50% to 100% of infection. In crown or leaf rust Ágata was the genotype with the greatest resistance, since it presented incidences of TR at 20MS, lower than Turquesa, as well as the rest of the witnesses that had incidences of 50% up to 100% susceptibility reaction to said disease, with the exception of Diamond R31, which continues to show good tolerance.

In areas with higher altitude and higher incidence of rainfall, foliar diseases occur more aggressively because these sites have humidity and temperature conditions conducive to their development (^{Prescott et al., 1986}). The Ágata variety equated tolerance to these diseases with most of the control varieties, showing greater tolerance than the susceptible varieties Papigochi and Menonita; due to its tolerance to these pathogens, Ágata is a good option to be recommended in this type of environment (Table 2).

Grain yield potential

In the Table 3 shows the comparison of the yield of Ágata grain and the control varieties in 81 evaluations carried out in 11 states of the country that were located from Oaxaca to Chihuahua. In general, Ágata exceeded the grain yield of all varieties from 14% (Turquesa) to 56% (Ópalo), observing that as the variety was more susceptible to stem rust, Agatha was better.

Favorable environments (Fav.) (23 environments with a yield greater than 3 000 kg ha^-1): Calera, Zac. 2012; Chapingo, Mex. 2011, 2014, 1F 2015, 2F 2013, 2F 2015; Coatepec, Mex. 2011, 2012, 2F 2013; Huamantla, Tlax. 2012; Jilotepec, Mex. 2011; Juchitepec, Mex. 2011, 2014, Mixteca, Oax. 2014; Nanacamilpa, Tlax. 2011, 2012, 2014, 2015; Roque, Gto.; Sta. Lucia, Mex. 1F 2011, 2012; Yanhuitlan, Oax. 2012, 2014.

Intermediate environments (Inter.) (29 environments with performance between 1 500 to 3 000 kg ha^-1): Chapingo, Mex. 2012, 1F 2013; Chimalpa, Hgo. 2012; Coatepec, Mex. 1F 2013, 2014, 2015; Cusihuiriachi, Chih. 2011; Fco. I.Madero, Tlax. 2015; Jesus Maria, Jal. 2012; The Concepcion, Pue. 1F and 2F 2013; Roque Gto. 2011; San Pedro Xula, Oax. 2012; Sta. Lucia, Mex. 2014, 1F 2013, 2F 2011; Sinaxtla, Oax. 2012; Soltepec, Tlax. 2011, 2014; Teacalco, Tlax. 2012; Tepatitlan, Jal. 2011, 2012; Terrenate, Tlax. 2F 2013; Tlalmanalco, Mex. 2014, 2015; V. of Guadiana, Dgo. 2014; Velasco, Tlax. 2012, 2014; Yanhuitlan, Oax. 2011.

Critical environments (29 environments with performance lower than 1 500 kg ha^-1): Atlangatepec, Tlax. 2011; Axapusco, Mex. 2014; Carbajal, Oax. 2012; Chalco, Mex. 2012; Cuyoaco, Pue. 2011; Fco. I. Madero, Dgo. 2012, 2014; The Calaveras, Mex. 2012, Nanacamipa, Tlax. 2013; Pabellon, Ags. 2011, 2012, 2014; Paramo, Chih. 2012; Roque, Gto. 2014; Sandovales, Ags. 2012, 2014; Sta. Lucia, Mex. 2015; Sinaxtla, Oax. 2011; Soltepec, Tlax. 2015; Terrenate, Tlax. 2011, 2012, 2014, 2015; V. of Guadiana, Dgo. 2011, 2012; Velasco, Tlax. 2013, 2015; Veloz, Tlax. 2013.

The greatest advantage of Ágata over the control varieties was in intermediate production environments, where there were generally severe incidences of stem rust, as the production condition was improved so that greater grain yield was expressed, the advantage of Ágata was reduced on the control varieties, among other causes, because in favorable environments there is usually a lower incidence of stem rust. In environments of low productivity, where drought conditions generally occurred, Ágata surpassed all varieties, but its advantage was lower, especially on Turquesa, which has been characterized by its good response under water conditions (^{Villaseñor et al., 2009}).

Conclusions

Ágata is a new variety of oats with a high grain yield potential that is recommended for sowing in critical, intermediate and favorable production environments in the seasonal areas where oats are produced during the Summer in the states of Oaxaca, Puebla, Tlaxcala, Hidalgo, State of Mexico, Queretaro, Michoacan, Jalisco, Aguascalientes, Zacatecas, Durango and Chihuahua. It is suitable for use from early plantings to late dates, as for example in the High Valleys of Mexico, from the beginning of June to the end of July, in the first case for the production of grain and in the second for the production of groomed forage.