By Bob Hutmacher
University of California
Despite the continuing impacts of a long-term drought in California, quite a few cotton growers in the San Joaquin Valley saw some good to excellent yields in 2016. The exceptions were certain locations where alternative water supplies were unavailable or decisions were made to redirect available water to other crops on the farm.
Unfortunately, once again, as we go into the winter months, the big question marks for most producers are the uncertain irrigation water supply situation, and the degree to which growers may have to rely on groundwater pumping to augment or replace surface water supplies.
Although some rain and snowfall in November boosted hopes a bit, weather forecasts as of mid-December suggest average to below-average precipitation. Now we will just have to see what materializes.
Decisions are right around the corner and include the type of cotton to grow (Pima versus Upland), variety choice, and soil fertility and amendments to built or at least maintain adequate soil structure and fertility. In recent years, seed supplies of the most popular Pima varieties are spoken for pretty early, so choices need some thought and action fairly soon, in my opinion.
While difficulties with the 2016 production season are still on your mind, it is useful to think about which fields had the most severe growth and yield problems. This information can help you decide where alternative varieties with better vigor or conversely, more manageable vegetative growth, would best fit your operations. Basic seed-cotton yield results from the University of California trials will be available by late December. To obtain this information, contact your UC Farm advisor or visit the UC cotton web site: http://cottoninfo.ucdavis.edu. As ginning and high volume instrument (HVI) quality analyses are completed (probably later in January), that information also will be available on the website.
With a smaller number of locations in UC variety trial programs, producers should consider looking at information from both University of California tests and from seed company trials. Considering the results of both sources represents a range of conditions and gives a better idea of what to expect in your area or soil type with Pima, Acala and Non-Acala California Upland plantings.
Data from several university trial locations and field calls last year, including some drip irrigated cotton with very high yields, indicated there were a number of fields that could benefit from increased efforts with fertility management decisions.
There may be a tendency for producers to cut back on soil fertility evaluations and phosphorous (P) and potassium (K) fertilizer applications due to cost constraints.
However, periodic assessments in university trials have pointed out some K deficiencies (and even some P deficiencies) with the potential to be yield limiting in high fruit load situations with both Pima and Acala cotton varieties.
Lastly, if you have fields either confirmed with or suspected of having significant Fusarium race 4 inoculum issues, it is recommended that you pay particular attention to the relative Fusarium race 4 susceptibility ratings of varieties, which are also available on the UC cotton website mentioned above.
Contact Bob Hutmacher at 559-884-2411 or firstname.lastname@example.org.