The importance of establishment for the success of summer crop

By: David McRae

Adequate phosphorus and zinc nutrition is very important for quick establishment of cotton & sorghum seedlings. Applying these nutrients with the germinating seedling reduces the negative effects of early season stresses, allowing plant’s potential to develop.
 
Rapid plant establishment has always been important for cotton and sorghum. With the shift to new small seeded varieties of cotton and the unreliability of follow up rainfall after planting, optimising plant establishment conditions is more necessary than ever.

The importance of establishment for the success of summer crop
Adequate early season phosphorus (P) and zinc (Zn) nutrition is vital for good plant establishment as P & Zn deficiencies will reduce seedling vigour, reduce root development and decrease plant establishment. Affected plants appear ill thrifty and stunted, with a red/purplish colour and less able to tolerate negative stresses such as insects, disease and adverse weather conditions.
 
Delays in early season development will delay flowering/fruiting and crop maturity. Delaying flowering in sorghum crops generally causes issues with sorghum midge and as cotton moves into cooler areas, delayed crop may negatively impact cotton harvest.
 
Cotton plants need to develop an extensive root systems before flowering commences to supply the required maximum nutrient uptake rates per day to allow potential yields to develop. Restricting early season root development will reduce the cotton plant’s ability to access required nutrients from flowering onwards, when a large proportion of nutrient uptake occurs (Table 1).
 
Supplying a readily plant available source of P & Zn with the seed at planting as Yara Liquids Flowphos will promote early growth. Flowphos can be mixed with insecticides or fungicides to protect young seedlings. Products tested with Yara Liquids FlowPhos 15 and 13Z in good quality water are;
• Rhizolex  (Sumitomo Chemical)
• Bifenthrin
• Chlorpyrifos

Hard water, containing high levels of calcium, magnesium and/or carbonates, or high in EC may causes compatibility issues.  For more information regarding rates and compatibility, please contact your local Yara Sales agronomist.

Table 1

Table 1

Source: Australian Cotton Production Manual 2017