Effect of Skip-Row Planting Pattern on Yield, Yield Components, Lint Quality and Diseases Infection in Two Cotton (Gossypium hirsutum L.) Genotypes

To evaluate the impacts of different skip-row planting patterns on yield, yield components, lint quality and infection to Verticillium wilt, Boll rot and Alternaria leaf spot diseases in non-irrigated cotton (Gossypium hirsutum L.) a field experiment was conducted in Karkandeh Experimental Field Station, Gorgan, Iran, in 2007 growing season. The experiment was carried out in split-plot arrangements using randomized complete block design with three replications. Two cotton genotypes; Tabladila and N200 were assigned to main plots and 80-cm row spacing in solid (80-cm conventional rows), 1×1 skip-row planted and one left unplanted) and 2×1 skip-row (two rows planted and one left unplanted with 16 cm skip) pattern were randomized in sub-plots. Results showed that the two genotypes with different growth habit differed in their response to planting row patterns. The lint quality and infection severity of some diseases were not affected by skip-row pattern. The lint yield (3027-3070 kg/ha) and earliness (78.0-81.7%) were higher in skip-row pattern as compared with solid pattern. Fiber length 2.5% and micronair of lint were in the range of 29.5-30.5 and 3.3-3.9 in skip-row, respectively. The genotype × skip-row interaction indicated that N200 × (2 × 1 skip-row), and 80-cm solid rows had more Verticillium wilt disease index, however, Alternaria infection was lower in Tabladia × (2 × 1 skip-row). Skip-row planting pattern reduced boll rot disease infection as compered to solid planting pattern as boll rot (%) was lower (1.3%) in (2 × 1 skip-row) × Tabladila. These results showed that planting row pattern could reduce boll rot and increased quantity and quality of yield and earliness in cotton.