NITROGEN FERTILIZATION SAVINGS WITH NEW COTTON CULTIVARS: YIELD, YIELD COMPONENTS AND FIBER QUALITY

Abstract

The nitrogen rate now recommended in the Comarca Lagunera for cotton (Gossypium hirsutum L.) was obtained from cultivars with a longer cycle and higher foliar biomass than the new ones, so the latter could require a lower N rate to show their yield potential. The objective of this research was to evaluate the response of four new cotton cultivars: CIAN 95 and CIAN Precoz (early maturity), Laguna 89 (medium cycle) and Deltapine 80 (long cycle) to six nitrogen fertilization rates: 0, 40, 80, 120, 160 and 200 kg N/ha, during two years. They were planted at high density (90 000 plants/ha) with three postplanting irrigations. The cotton lint yield was affected by the year (Y), the cultivar (C), the N rate, the Y x C and the Y x N interactions. The best nitrogen fertilization response was obtained with 80 kg of N/ha and the best yield with Laguna 89. The boll weight, seed index, and number of bolls per plant rose as the N rate was increased, while the lint percentage fell. Fiber quality was higher than the minimum requirements of the textile industry