Carolina Cotton Notes - NC State University Cotton Team

Planting Decisions

Keith L. Edmisten, Cotton Extension Specialist
Joel Faircloth, Graduate Assistant

North Carolina State University
(CCN - 01 - 4a  April 2001)


With April approaching, NC cotton growers will soon be deciding when to plant their cotton. This decision is usually a combination of two factors: 1) when a grower thinks timing is optimal for planting and 2) when it is feasible to plant cotton based on time constraints of their overall farm management program. Knowledge of research results from past NC planting date studies can aid growers in making sound planting decisions. While April and May are usually very hectic months for most growers, it is imperative that they are informed of the risks of yield losses if planting is not executed in a timely manner.

Cotton Information reports that yields drop off when cotton is planted after May 1 by 12 lbs a day. As pointed out in an earlier cotton note (CCN 97 5-a), this rule of thumb was generated using linear regression. A combination of five years of planting date studies in Rocky Mount, NC shows that yields do not always drop off in a linear fashion (Figure 1). Instead, they often drop off gradually to a certain point and then drop off sharply. In addition, the point at which yields decline at a rapid rate varies annually (Figure 2). In 1998, the yields from 5-13 to 6-12 dropped gradually by 0.25 lb/day and from 6-12 to 6-25 they decreased rapidly at a rate of 40 lb/day. Although not shown in Figure 2, similar trends (yields dropped due to late planting in early June) were observed in both 1994 and 1999. In 2000, drastic yield reductions due to late planting were observed on earlier dates where yields dropped consistently from 5-17 to 6-26 at a rate of 19.8 lb/day. Planting date studies in 1992 resulted in similar relationships between planting dates and yields (drastic reductions in yields occurring in mid to late April).

In summary, our research demonstrates that as planting is delayed past mid-May, the probability of a grower experiencing significant yield losses increases. As previously stated, it is important for growers to realize this so they can weigh these risks in their overall farm management programs. While early planting may not always be feasible to a grower, there are many advantages. They often include but are not limited to 1) avoiding bollworm flights into cotton, 2) improving the earliness profile, 3) earlier harvests, and 4) improved yields. It is also noteworthy that planting prior to late April may increase the threat of losses due to poor seedling vigor, seedling disease, and thrips.


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Carolina Cotton Notes CCN-01-   April 12, 2001
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