Using Cultivar Mixtures to Improve Yield Stability of Cotton (Gossypium hirsutum L.) in Unpredictable Environments
NC Cooperative Extension
Cultivar selection is a critical decision growers make before the growing season begins. One of the best predictors for a cultivar’s performance is yield stability, or consistent performance across soil types, rainfall patterns, years, seeding rates, tillage practices, management practices, etc. However, there is not one cultivar that will outperform competitors in all environments. Blending cultivars that perform well in contrasting environments, or blending cultivars known to portray a high degree of yield stability across environments, may help spread the risk and improve yield stability in multiple environments when accounting for the uncertainty of growing conditions for any given year.
Five cultivars were chosen for this experiment based on prior performance in replicated trials that each have unique ideal environments and growing conditions. Some cultivars were chosen based on a high degree of yield stability across a broad range of environments in years with frequent rainfall and years with noticeable drought stress. Other cultivars were chosen based on consistent performance in either high-yield or low-yield environments. There were eight treatments which included each cultivar planted alone, all five mixed in equal proportions by seed count, and two binary cultivar treatments in a 50 percent mixture by seed count. Trials were conducted across 23 environments during 2017 and 2018. Stand counts were collected along with yield and fiber quality at harvest.
Statistically, mixtures did not produce a yield significantly different than an individual cultivar 61 percent of the time. A mixture was as likely, or more likely, to produce a lint yield lower than the highest yielding cultivar in a given year, as opposed to producing a lint yield higher than the lowest yielding cultivar. The data suggest that using a cultivar mixture will not help improve yield stability the majority of the time compared to the highest of the component cultivars.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
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Authors: Blake Szilvay
Szilvay, B. Extension Agent, North Carolina Cooperative Extension, North Carolina, 27203