“A job worth doing, is worth doing well.”
Our 5 Tips for Better Summer Spraying.
2018 has been a good reminder of the importance of retaining subsoil moisture with a good summer spraying program. The severe lack of rainfall and continual battering of frosts meant that crops were forced to finish on stored moisture within the soil. The very dry season also meant that the majority of soil moisture was actually from the previous year’s rainfall. However, this was only available if last year’s summer spraying was efficiently actioned. The stored summer moisture was not only noticeable in Spring, but also during March-June where it made a large difference in germination and crop establishment during the horrendously dry conditions.
It should be a priority in the minds of growers to get summer spraying right.
· Summer spraying is not a luxury item. It should be considered an essential expense.
· The financial rewards of timely summer weed control far outweigh the costs.
· Expenditure on summer weed control can be minimised if weeds are sprayed early.
· Control can be maximised by spraying in the right conditions, where droplet survival and penetration of the target are ensured.
Given that one application of herbicide over summer can be an outlay of $10-$25/ha, it pays to ensure maximum return on every dollar spent.
So, here are our 5 Tips for better summer spraying results:
1. Select the right product, the right rate and the right time.
Product selection will be influenced by weed spectrum, weed size and the degree of stress that the plants are under. Make sure what you’re using is designed for the weeds you are targeting. Timing: Spraying within 2 to 4 weeks after germination is the key to achieving good results. The benefits of spraying on time and early include minimising soil moisture loss and nutrient loss. Spraying early also seems to result in less wheel tracking problems. Also, late spraying onto more established weeds will require higher rates of herbicide. This increases the cost of the operation, plus results are often variable. Not to mention the damage has already been done in terms of seed set, and soil water and nitrogen loss.
2. Keep the rates up.
Keeping glyphosate rates robust will help counteract less than ideal conditions. Skimping on rates in summer weed spraying can be counter productive. You may end up having to apply a second spray. Do it once, do it properly.
3. Keep the water rates up.
Keep your water rates up, 80 to 100 litres is what we recommend. Higher water rates result in better efficacy by ensuring better coverage, particulary when using coarser nozzles (as required when now using 2,4-D products).
4. Include SOA and LI700.
Always add ammonium sulphate (SOA) and a penetrant regardless of water quality. Research has found 0.25% LI700 to be equally effective as 1% Hasten on heliotrope. Oil-based adjuvants may be required to maintain droplet size and on particularly woody weeds.
5. Be vigilant when using 2,4-D.
Always take care when using volatile 2,4D products (Ester 680/ Amicide). Our top 5 requirements for spraying 2,4-D products include:
– Don’t spray during conditions where there will be an inversion layer
– Spray only during wind speeds between 3-15km/h
– Boom height must be at a maximum height of 50cm above the crop canopy
– Spray nozzles have to be a minimum of Very Coarse droplet size and no smaller. But in summer spraying the APVMA advise to use Extremely Coarse to Ultra Coarse nozzles. We recommend just going straight to Ultra Coarse and using these as your summer spraying nozzles, but ensure correct water rates are used to ensure efficacy.
– Keep spray records of everything. Make sure you got yourself covered.
Contact our agronomists if you have any questions.