RESEARCH & EVENTS
A number of growers attended the field days and received knowledge on dealing with wet conditions , disease management and much more .
On February 1 , Griffith growers gathered at Garry Carlon ’ s orchard to look at the recovery of a seven-yearold block of trees that were flooded for three days in late October , but were bouncing through thanks to a variety of strategies . The following day , Hillston growers visited the Select Harvests side of Mooral to discuss managing almonds in heavy clay soils in a season of regular rain . Everyone had plenty of experience to share of managing excess water in their orchards , either rain or flood water , so I will summarise them here . During a wet spring and periods of short-term flooding , a quick response is crucial . Getting the water off the top of the mounds as soon as possible and letting oxygen back into the root zone is paramount . Weather also plays a significant role ; if the temperature is cool then some blocks recovered from up to 10 days of flooding . In fact , almonds can tolerate water lying in the rows for months in cool weather . However , if flooding occurs in summer temperatures then tree health is significantly compromised within days . Tree health prior to the event was also crucial ; healthier and younger trees started to reshoot much earlier than older trees or those with a history of stress ( e . g . salt , poor drainage , diseased ). If the trees were able to recover quickly then they also held onto their crop and
carried it through to harvest despite losing a significant amount of leaf .
Once the floodwaters subsided , a variety of tools were deployed : q Careful irrigation to flush salts brought up with the high-water table , but without flooding the root zone . q No fertiliser applications , particularly nitrogen , until the trees started to show signs of recovery . Pushing growth after a stress event , particularly when the root system has been significantly impacted , could cause the tree to collapse . q An application of Phosphorous Acid to manage infections of Phytophthora , once the roots had begun to recover . q Quality biostimulants to assist the tree in coping with the stress . Timing is crucial for efficacy though . q If the tree reshoots , then supporting the new growth with sprays of fungicide , and trace elements such as zinc and iron to help improve leaf colour .
Orchards around Hillston didn ’ t have flash flooding events from heavy rainfall like those further south , but still required a mix of the above strategies to maintain canopy health and manage the shallow root system that developed with the regular rain . Now that the season is wrapping up , the trees are establishing their potential crop for next season . Therefore , the objective over the post-harvest period is to prepare for next season by building reserves with a healthy canopy and a healthy root system ready for the draw down at flowering .
Aspects to consider include : q Leaf and soil sampling to design a strategic fertiliser and foliar plan . q Careful irrigation management by strategically stressing the tree for harvest but still promoting recovery . q Fungicides after harvest to reduce disease carryover into next season . q Applications of phosphorous acid if required to manage phytophthora . q Foliar nutrition , building up the buds and managing any reshooting that could occur . q Quality biostimulants to assist in taking the stress off the tree and / or promote root health , and ; q Soil amelioration programs , such as gypsum , to manage soil structure and salts that have entered the root zone during the season . While the rain may have stopped and the potholes are ( mostly ) fixed , we will continue still seeing the effects of spring into next season . Diseases are slowing with the hot dry weather but are ready to explode at the next shower of rain , and insects numbers are high . Using some of the strategies discussed will help the trees recover by laying down good foundations for next season ; root health , building carbohydrate reserves , and minimising disease carryover .
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