Desuniformidad espacial y temporal de plantas en el cultivo de maíz: influencia de la densidad y de la distancia entre surcos.

GIULIANO, D.; CIRILO, A.G.; OTEGUI, M.E.

Rosario, Santa Fe, Argentina

Congreso; VIII Congreso Nacional de Maíz.; 2005

A.I.A.N.B.A.

Plants in maize (Zea mays L.) crops are usually nonuniform. Deficiencies in planter machines, sowing operation, soil conditions or seed quality result in uneven crops. Plant spacing and emergence variability may affect plant growth and grain yield. These effects can be expected to vary from different crop densities and row spacing. The objective of this work was to analyze the effect of plant density and row spacing on growth and grain yield of plants growing in even or uneven stands, and the resulting crop yield. A field experiment was sown at Pergamino (Argentina) during 2004-2005 with the hybrid NK900 TD MAX (Syngenta Agro S.A.) under no water or nutrients limitations. The factors under study were: plant density (6.5 and 8.7 pl m-2), row spacing (50 y 70 cm), plant spatial variability (even and uneven distance between plants in the row), and plant temporal variability (even and uneven emergence between plants). Late emergence significantly affected plant growth and grain yield. At the high density, these plants became barren plants. Plants were less responsive to plant spacing variability than plant emergence variability. Plants inside a gap increased their growth only when emerged early but they did not yield more than plants grown in an even stand. Variations in plant emergence always reduced crop yield (from 19 to 33%). Crop yield increased with uniform plant spacing only when plants emerged contemporarily, revealing significant interaction between both plant variabilities. Narrow rows also yielded more only with uniform plant emergence, but did not improve crop yield when there was within-row plant spacing variability.