Varietal improvement and agronomic studies of maize (Zea mays L.) in the dry zone [Sri Lanka]

agricultural chemicals agronomic characters asia asie breeding cereales cereals clima climat climate climatic zones composition condiciones ambientales condition de milieu contenido proteico crops cultivation cultivo cultivos cultivos de grano economic plants engrais environment environmental conditions environnement espacement espaciamiento feed crops feed grasses fertilizers glumiflorae grain crops gramineae gramineas graminee grasses industrial crops irrigation medio ambiente methode methods monocotyledons oil crops plantas plantas azucareras plantas feculentas plantas forrajeras plantas industriales plantas oleaginosas plante plante de culture plante industrielle plants pratique culturale productividad productivity produit agrochimique profitability protein content rendement rendimiento rentabilidad riego site factors spacing sri lanka starch crops sugar crops yields zea mays zone climatique zone semi-aride