By Bill Robertson, Cotton Agronomist
Recommendation: A minimum stand of 1.5 plants per row foot (38” rows) is recommended. On irrigated fields, it may be possible to accept a uniform stand of 1 plant per foot of row, but some yield loss may occur. Yield loss from delayed plantings often exceeds the yield loss experienced with thinner stands. Generally, if the decision to replant is not clear, keep it.
Cotton – Replanting Guidelines
The decision to replant can be very difficult. The concern of a later crop and the consideration that the success of a second planting is not certain must weigh heavily on the decision. The cost of seed, labor, machinery, pesticides, and time may be greater than the loss from keeping a less than satisfactory stand. Once a stand is established, even though we may consider it inadequate, many factors should be considered before replanting. However, an old rule of thumb that still has merit states that up to a two percent loss of yield potential may be experienced for every day planting occurs after May 20.
A minimum stand of 1.5 plants per row foot (38” rows) is recommended. On irrigated fields, it may be possible to accept a uniform stand of 1 plant per foot of row, but some yield loss may occur. Skips greater than 3 feet are a concern as yield loses are often assumed to be 50% for the skip. However, plants in neighboring rows will compensate if skips are not adjacent to one another and the existing plants are in good shape. Weed pressure, seedling vigor, thrips injury, herbicide injury, seedling disease and other problems should also be evaluated. The frequent occurrence of skips greater than 3 feet in length with 3 foot or greater skips in stand immediately adjacent in the next row signal the need to replant. Generally, if the decision to replant is not clear, keep it.
Cotton seeding rates should be increased 10 percent on average when planting late. Higher seeding rates are necessary to ensure an even stand and to maintain earliness. Higher plant populations will result in fewer 2nd and 3rd position fruit. The ideal live plant population for later planted cotton is 2.5 to 2.75 live plants per foot of row (38”), or approximately 34,000 to 38,000 plants per acre.