Agronomic behavior of populations of maize Jala race in Nayarit and State of Mexico

Abstract

The Jala race of maize ( Zea mays L.) is one of the most important in Mexico and has been cultivated for centuries in the Jala Valley, Nayarit, on an area currently no more than 30 ha, and its ear is recognized worldwide as the largest one (up to 60 cm in length), being an ecotype; however, due to severe “genetic erosion” a dramatic reduction in its cob and grain length has been observed. In order to contribute to its conservation and genetic improvement, we studied the productive potential and agronomic attributes, especially the cob length (LM) of Jala maize. We evaluated 14 populations: five collections of producers in the Jala region, seven semi-improved Jala populations, and two varietal hybrids with 50% of Jala germplasm as performance controls. The experiment was carried out under dry conditions in five localities: San José of Mojarras, Ixtlan del Río, Jala and Xalisco, in Nayarit, and Postgraduates College in the State of Mexico, in a randomized complete block experimental design with three repetitions. There was significance among populations and between localities for all variables; the interaction between localities and populations was significant for nine variables. Between localities the LMZ varied from 17.7 to 20.7 cm, and between populations of 17.1 to 20.8 cm. The highest grain yield was obtained by the P5 population and the A4 environment 18.6 t ha^-1 and 10.9 t ha^-1 , respectively. The P5 population had the highest LMZ, but none of the populations had the LMZ characteristic of the Jala race, so it is proposed to increase this by the recurrent selection of long ears. In contrast, populations and environments with high grain yield capacity were identified.