Seed production of onion in plastic houses with different ventilations

agronomic characters alliaceae allium allium cepa biometria biometrie biometry bulbous vegetables chemicophysical properties control ambiental crops cultivation cultivo cultivo protegido cultivos culture sous abri developmental stages dimension dimensions economic plants economic sectors engineering environmental control etapas de desarrollo etapas de desarrollo de la planta germinability germination hortalizas (plantas) hortalizas de bulbo industria industria de semillas industrie industrie des semences industry liliiflorae measurement mesure methode methods monocotyledons peso plant developmental stages plantas plante plante de culture plants poder germinativo poids pratique culturale production de semences productividad productivity profitability propagation materials protected cultivation protection rendement rendimiento rentabilidad secondary sector secteur secondaire sector secundario seed seed industry seed production semence semillas vegetable crops ventilation weather control weight yields