Alley effect on several cotton cultivars in small plot research

Small plot research often necessitates the use of alleys or fallow areas al ong plot ends. To determine if there is an interaction between cotton (Goss ypium hirsutum L.) cultivars of differing maturity group and the alley effe ct on plant yield, field studies were conducted in 1997 and 1998 in northea st Louisiana and south central Georgia. A randomized complete block arrange ment of treatments was used with the cotton cultivars "Stoneville LA887" (S TV LA887), "Delta Pine 5690" (DPL 5690), and "Paymaster 1215RR" (PM 1215RR) . Plots were approximately 15 m long with 3 m alleys and were hand harveste d in 0.3 m increments. Overall plot yield increased 12-15% by inclusion of lint from plants bordering the alleys. Lint yields were increased for the f irst 0.6 m from the alley. There was no interaction between cultivar and di stance from the alley for yield although the change in boil number and boil size from the alley was not the same among cultivars. Plant height and num ber of main stem nodes was negatively correlated with distance from the all ey across cultivars. Micronaire and fiber length were affected by cultivar, distance from the alley and their interaction. These results suggest that end trimming is not necessary for studies investigating cotton cultivars if lint yield is the only factor of interest. However, if fiber quality or yi eld components are of interest, plants within 0.6 m of the alley should be removed or not included for measurement.