Maize is one of the most important species in the world, both for animal feed and for its use in human food, is high in energy and can be used in large quantities in diets of dairy cows (^{Nuñez et al., 2006}). Hybrids with high digestibility, high energy content and low fiber content favor higher milk production per ton of dry matter (^{Peña et al., 2006a}). Regarding human consumption, maize has a wide range of uses, both in the industrial sector and direct consumption in various presentations.

In Mexico the demand for maize grain for human consumption and livestock is around 38 million tons (^{Panorama agroalimentario Maiz, 2016}), in 2016 there were 28.25 million (^{SIAP, 2016}), the rest was imported mainly from the United States America. The average grain yield in the irrigated areas of North Central Mexico is 7.95 t ha^-1 and the silage green forage of 47.6 t ha^-1, compared to the potential of more than 14 t ha^-1 grain and 70 t ha^-1 of forage obtained experimentally (^{Peña et al., 2004}; ^{Gonzalez et al., 2005}; ^{Nuñez et al., 2005}).

Similarly, in good weather regions of western Mexico and The Bajío, where more than half a million hectares are planted, an average yield of 6.47 t ha^-1 of grain (^{SIAP, 2016}) is obtained, compared to experimental yields higher than 10 t ha^-1 that have been obtained in the central part of Jalisco. The above, it is indicative that there is a potential that has not been reached due to poor management of the crop or a poor choice of the hybrid for planting. In the seed market, there are hybrids with high grain and forage production that can be used to improve maize production in the region, but it is also necessary to expand the supply of public seeds so that producers have greater options for using high quality materials.

Due to the above, a genetic improvement program was conducted in the Experimental Pavilion (CEPAB) of INIFAP between 2000 and 2008, aimed at obtaining hybrids of high yield of grain with the objective of contributing to the improvement of production of maize in irrigated areas of the North Central region of Mexico and The Bajio, as well as in good weather areas of the West of Mexico. Derived from this breeding process, the single-cross hybrid H-383 of white grain formed by the combination of the progenitor lines PAB7 and PAB8 was obtained.

The PAB7 line is the female of the H-383 which was derived from a late-stage white subtropical PGB population using the pedigree method (^{Fehr, 1987}), which was selected for high yield, plant and ear health and tolerance to lodging for seven generations, his pedigree is PGB-2-1-3-1-1-N1-3-b-b-b. The PAB8 line is the male of the hybrid, corresponding to CIMMYT’s subtropical public line CML312, to which CEPAB performed three more generations of inbreeding, in which it was selected for greater ear health. In 2006, the best lines of the PGB population were crossed with the PAB8 line to evaluate their combinatorial ability.

The most outstanding crosses for yield of grain and forage, production stability and health of plant and cob, was the combination of the lines PAB7 x PAB8 that corresponds with the hybrid H-383.

The phenotypic description of the H-383 hybrid was carried out in the CEPAB in the spring-summer (SS) cycle of the years 2010 and 2011, according to the maize technical guide (^{UPOV, 2009}). The hybrid has a plant height of 2.8 to 3.2 m, curved leaves of dark green color, open spike with 12 to 14 primary branches and stigmas of light wine color. The cob is cylindrical from 20 to 25 cm in length, from 5.1 to 6 cm in diameter, with 16 rows on average, from 41 to 50 grains per row and white grains of semidentated texture (Figure 1). Male flowering occurs between 84 and 87 days and physiological maturity between 150 and 160 days after sowing.

Figure 1 Type of plant and ear of the maize hybrid H-383. 

The PAB7 line has a plant height ranging from 1.9 to 2.2 m, the cob is cylindrical from 15 to 20 cm in length and 4 to 5 cm in diameter, has 12 to 14 rows and 31 to 40 grains per row, is white and toothed texture (Figure 2). The spike is open, 31 to 35 cm in length, with 7 to 9 slightly curved lateral branches, has anthocyanin intensity intermediate in glumes and tenuous in the anthers, the stigmas are green to light yellow and green leaves lemon slightly curved. Male and female blooms occur between 85 and 90 days and 86 and 91 days, respectively.

Figure 2 Type of plant and ear of the parent PAB7. 

The progenitor PAB8 has a plant height of 1.6 to 1.9 m, male flowering occurs between 86 and 91 days and female between 90 and 94 days, has dark green curved leaves, semi-open spike between 41 and 60 degrees, with 10 to 12 primary branches and stigmas of cherry color. The cob is cylindrical, 15 to 20 cm long, with 12 to 14 rows and 21 to 30 grains per row, is of white grain with a semicrystalline texture (Figure 3). According to the description of ^{CIMMYT (1999)}, this line has a rating of 2, 1.9 and 3 for P. Sorghi, E. turcicum and cob rot, respectively.

Figure 3 Type of plant and ear of the parent PAB8. 

The H-383 hybrid adapts to transitional regions and areas with subtropical climate. In spring-summer, it can be planted in the irrigated areas of the North Central Plateau of Mexico and the Bajio in the states of Durango, Zacatecas, Aguascalientes, Guanajuato, San Luis Potosi and Queretaro; as well as in areas of good weather in the West of Mexico. In 25 localities of evaluation carried out from 2006 in different states of the country, an average yield of 10.6 t ha^-1, was obtained, equal to the one of the best commercial witness with which it was evaluated.

Potential grain yield under irrigation conditions was higher than 16 t ha^-1, with a population density of 80 000 ha^-1 plants and a fertilization rate of 240-100-00 + 20 kg of smaller elements. Under good weather conditions in western Mexico, experimental yields of up to 14 t ha^-1 were obtained. It has not been evaluated in the autumn-winter cycle (A-W), but it is expected to present a good response also in the Pacific coast of Mexico such as Sinaloa, Nayarit, Jalisco and Colima.

In irrigation validation plots with producers in the Aguascalientes Valley, commercial grain yields of 13.7 t ha^-1 and forage for silo of 98.3 t ha^-1 have been obtained and in a locality of San Pedro de Mojarras in Santa Maria del Oro, Nayarit, of 8.4 t ha^-1 of grain. In the evaluations carried out, it has not presented problems of economically important diseases such Fusarium verticillioides, Helmintosporium turcicum, charcoal (Sphacelotheca reiliana) or Ustilago maydis. Occasionally he has submitted rootmail.

In three years of evaluation for production and forage quality, the H-383 hybrid produced between 24.7 and 26 t ha^-1 of dry matter, with values between 71 and 74% in dry matter digestibility and between 40 and 48% in digestibility of the fiber. These yields are higher than those reported by ^{Peña et al. (2006b}; ^2006c; ²⁰¹⁰) with other hybrids, and similar to the controls with which it was compared. The results show that the H-383 is competitive with the best commercial hybrids and may be an option for national companies lacking research programs and for agricultural producers who depend on hybrids from transnational companies offering their seeds at high prices, which sometimes represents more than 15% of the total cost of the crop.

The hybrid H-383 was registered in 2012 before the National Seed Inspection and Certification Service (SNICS) with the key: MAZ-1352-190712 and in December 2013, obtained the title of breeder number: 1109 for its exploitation and exclusive exploitation of INIFAP. The registered seed of both parents for the commercial reproduction of the H-383 hybrid is available in the INIFAP Pavilion Experimental Field.