30 January, 2018
After spotting my first open boll this morning, it feels as though we are now on the home stretch towards the end of the season. So where are we currently sitting and what can we expect should we remain on this trajectory?
In the central valleys, irrigated crops are currently set up to achieve some high yields – in fact, some very high yields could be possible when looking at current boll numbers. From the CSD Ambassador Network, the target at cut out is to have a least 160 bolls per metre for a 12 bale/ha yield. With most crops now heading towards or just reaching cut out, boll numbers are largely around 150 to 180 bolls/m, with some exceeding this and hovering around the 200 bolls/m mark.
Boll factors are always a hot topic post cut out, but they can also be notoriously misleading. The CSD variety trials provide us with lint weights per boll each year, which are used to calculate boll factors. Generally, weights were down last year, and thus the boll factors will be affected. With three years of Bollgard 3 variety trial data now available, the boll factors across the industry average out to the following:
Sicot 746B3F – 13.17
Sicot 748B3F – 12.29
Sicot 714B3F – 13.96
Sicot 754B3F – 12.79
So, a boll count of 180 bolls/m in Sicot 746B3F at this stage could predict a yield of 13.7 bales per hectare. Keep an eye on your Facts on Friday for more information on boll counts soon, including their accuracy and what to watch out for when predicting yields.
To look at the irrigated cotton plant now, we’re seeing some textbook architecture across much of the industry. Most crops, at least in the central valleys, have their first fruiting branch at the fifth or sixth node. Second and third, even fourth positions are filling, and first position retentions remain high in the vicinity of 80 to 90%. It’s been a great season for plant mapping!
So whilst we’re not through the “yield months” yet, we are in a very good position for achieving high yields. Forecasts are looking milder and this will be a huge relief on some very tight water budgets at the back end of the season.
By Alice Devlin, Extension & Development Agronomist – Gwydir Valley
General guide only, not comprehensive or specific technical advice. Circumstances may vary from farm to farm. To the fullest extent permitted by law, CSD expressly disclaims all liability for any loss or damage arising from reliance upon any information, statement or opinion in this document or from any errors or omissions in this document.