Origin

The Barley National Program of INIFAP generates varieties through artificial crosses and selections by the pedigree method. Maravilla variety is the result of the selection of segregating barley lines originated from a multiple crossing, which was carried out in Experimental Field Valley of Mexico during the spring-summer 1998 cycle. The F1 generation was planted in the Experimental Field Bajío during the autumn-winter cycle of 1998-1999 and the segregating generations were sown alternately in both experimental fields. Mass harvesting was performed in the F6 generation when uniformity of agronomic characteristics was observed. Its genealogy is CV98-352-6C-1R-1C-1R-0C and was released in 2016 for commercial cultivation under the name of Maravilla. This variety was described following the parameters of the International Union for the Protection of New Varieties of Plants (UPOV) and registered with Servicio Nacional de Inspección y Certificación de Semillas (SNICS-SAGARPA). Its registration is CEB-014-170316.

Characteristics

Maravilla is a barley variety with a spring growth habit. It has early vegetative cycle, flowering ranges from 45 to 57 days and physiological maturity occurs from 94 to 115 days; intermediate size ranging from 0.70 to 0.90 m. Its behavior depends on environmental conditions, planting date and agronomic management. Regarding other barleys planted in the target region, Maravilla has an earlier cultivation cycle than the Esmeralda malt barley variety, for example.

Maravilla shows tolerance to infections of yellow linear rust (Puccinia striiformis f. sp. hordei West) and leaf rust (Puccinia hordei Otth), in addition to moderate tolerance to reticular spot (Helminthosporium teres Sacc) and leaf scald (Rhynchosporium secalis (Oud) J. J. Davis). Good plant health has been observed through several evaluation cycles in High Valleys, these characteristics allow to omit the application of fungicides, which helps to reduce the production costs of the crop.

Maravilla was evaluated in more than 30 experimental sites in different environments of the barley growing regions of High Valleys during the 2012 to 2015 period. The observed grain yield was 2.1-5.2 t ha^-1; which was similar and sometimes 5% superior to that of the Esmeralda malt barley variety. The differential behavior of Maravilla through the evaluation sites is a response to the different contrasting environments evaluated in High Valleys.

Adaptation areas

Maravilla is a variety adapted to different barley growing regions of High Valleys with yields varying depending on the production environment and crop management. Regarding the production environment, Maravilla yields are delimited by the edaphoclimatic features present in each zone. Due to the wide variability of environments in High Valleys, these have been classified into zones of: 1) good yield, with rainfall greater than 500 mm and soils with good moisture retention;2) medium yield, with precipitation of 450 to 500 mm, soils with regular moisture retention and early frosts; and 3) low yield, with precipitation lower than 450 mm, thin soils with low moisture retention and early frosts (^{Zamora et al., 2014}).

Agronomic management

Planting depends mainly on the establishment of rains; however, considering the rain period of each production area, it is recommended to plant: between May 1st and June 15th in environments with godd yield; and from June 10th to 30th in medium yield environments; and between June 10th and 30th in low productivity environments (^{Zamora et al., 2014}). Seed density may vary from 80 to 100 kg ha^-1. The recommended fertilization dose in good and medium yield environments is 46-46-30 (N-P-K), and in low-yield environments, fertilization is not recommended unless there is good soil moisture.

In order to improve grain quality and yield, it is recommended to supplement soil mineral fertilization with foliar fertilization at the peaking stage. The recommendation is to sprinkle 4 kg ha^-1 of urea in the foliage diluted in 200 liters of water adding 400 ml of an adherent (^{Rojas and Gómez, 1997}). This is supported by the fact that the application of nitrogen fertilizers during the peaking stage increases the protein concentration in the barley grain (^{Bulman and Smith, 1993}; ^{Thomason et al., 2012}).

Maravilla does not present problems of varietal susceptibility by herbicides applications recommended in barley. In general, pests are not considered a problem of economic importance; however, the lack or excess of water can induce the attack of aphids with considerable damages, so they must be controlled when ten or more aphids are observed per leaf, stem or spike.

Grain quality

One of the reasons for the high proportion of barley used in livestock diets is its nutritional suitability for a wide range of animals, an aspect related to the supply of amino acids, minerals, energy content and digestibility (^{Blake et al., 2011}). In terms of metabolic energy and proteins digestibility, lipids and carbohydrates, barley grain has a behavior comparable to that of other cereals such as maize, oats and wheat (^{Foster and Prentice, 1987}).

From the proximal analysis in the grain it can be corroborated that Maravilla has a higher protein content than the malt barley varieties, which is a great advantage in the design of feed rations for cattle fattening.

The chemical composition of the Maravilla grain is as follows: the crude protein varies from 10 to 14.5%, the starch concentration ranges from 61 to 66%, the average mineral content is 3.5%, the average crude fiber is 3.5%, the average ethereal extract is 1.8%, the nitrogen free extract average 74%, and the average dry matter digestibility 95%. The chemical composition of the Maravilla grain varies according to the environmental conditions and the agronomic management of the crop. ^{Foster and Prentice (1987)} mention that the percentage of suitable protein in the barley grain for an adequate nutrition of the cattle is in the range of 14 to 15.5%, reason why a proper agronomic management of Maravilla allows to obtain a protein concentration within that range, placing it as a source of food suitable for livestock purposes.

On the other hand, silage barley has shown satisfactory results in the feeding of cows, calves and sheep. It is recommended to harvest between milky and soft-dough stages, because those show the highest nutritional value and have an optimal preservation (^{Foster and Prentice, 1987}; ^{Kabal et al., 2013}).