ABSTRACT

A row spacing of 30 inches may increase yield and/or increase the efficiency of multiple crop farm enterprises, compared with a row spacing of 40 inches. This study was initiated in 1992 to compare the yield and growth of eight cultivars in 30- and 40-inch row spacings grown on Commerce silt loam and Sharkey clay with and without Pix. The cultivars were Deltapine 20, 4 1, and 5415; Stoneville 453 and LA887; Hyperformer HS46; Gumbo 500 and Tamcot HQ95. Cotton in 30-inch rows yielded 130 pounds of seed cotton per acre higher than cotton in 40-inch rows in the experiment on Sharkey clay. The row spacing by cultivar interaction was not significant. In the silt loam experiment, the row spacing by cultivar interaction for yield was significant. Only Deltapine 41 and Tamcot HQ95 yield higher in 30- vs. 40-inch rows. Deltapine 20, however, yielded higher in 40- vs. 30-inch rows. Pix had no effect on yield on either soil type. Canopy size was not affected by row spacing, but was reduced 20% in each row spacing by application of Pix. The effects of row spacing and Pix on earliness was inconsistent. All cultivars at each row spacing had a higher harvest index with Pix compared with the no Pix treatment. These data show that cotton in 30-inch rows produced similar or higher yield, and the same quantity and distribution of vegetative biomass as cotton grown in 40-inch rows.