November 17, 2016

Is lack of Zinc limiting early growth in your cotton?

By: David McRae

Better than average rainfall for winter and spring has been a pleasant change from the last few years but it has also brought some challenges as well. Moderate day time temperatures have been accompanied by cold night time temperatures, causing stress and cold shock in cotton and summer crops and reducing Day Degree accumulation (see table below).  Table: Day Degree Details for Wee Waa Ag. Res. Stn. Date 2016 2015 2014 2013 Hi 2015 Low 1964 Average Hot Days 1 0 9 3 0 0 1.6 Cold Shock 26 3 13 16 3 30 15.6 13-Nov 355.5 511.8 496.8 468.3 511.8 283.8 400.9 Day Degree Accumulations for the period 1 October to 13 November in the years 1957 to 2016. Stress and cold shocks reduce not only above ground growth, but root growth as well. When root growth is compromised it reduces the plants ability to find immobile nutrients such as zinc and phosphorus. Root exploration through growth is critical for finding these immobile nutrients as illustrated below.

Foliar application of zinc and phosphorus provides readily available source of nutrients that supplies plant’s requirements for growth. Zinc and phosphorus absorbed by leaves is utilised rapidly, boosting  shoot and root growth and supporting important biochemical pathways in the plant such as carbohydrate metabolism and auxin production.

The type of field activity and it’s timing creates opportunities for applying zinc and phosphorus foliars.  Listed below are 3 Yara foliar fertilisers which can either be applied broad-acre or in banded applications.

·       YaraVita GLYTREL ZnP contains complexed zinc and phosphorus and can be applied with Glyphosate to Roundup Ready cotton with no reduction in weed control. Yara Vita GLYTREL ZnP is easy to handle, safe on the crop and is a fully formulated product containing wetters and stickers to enhance leaf uptake of zinc. 

·       YaraVita ZINTRAC is a highly loaded, fully formulated suspension concentrate, which allows low application rates, reduces handling and is designed for safe foliar applications. It contains it’s own wetters and stickers to ensure optimum zinc uptake through the leaf. 

·       Yara Liquids P-FOL Zinc is a zinc phosphate fertiliser that can be applied as a band or broadcast to correct zinc and or phosphorus deficiency. 

For further information on the importance of zinc in cotton production and Yara options for adequately supplying crop demands, click on “Zinc Solutions for Cotton”.