The 2015 almond season is in full swing. Many orchards have went through their drop, fertilizer applications and irrigation have began, and pest management concerns are beginning to form. Below are some thoughts and considerations from recent field visits.
1. Crop development is ahead of schedule – by as much as a month. Kernel fill is beginning in many ‘Nonpareil’ orchards, meaning that ‘Butte’/’Padre’ orchards won’t be far behind. This timing is important as about 80% of the season’s nitrogen budget should be applied prior to kernel fill – which may occur as early as early May! Secondly, it indicates that at this point – “What you see is what you’ll maximally get” in regards to kernel size, and farming practices – more particularly irrigation practices – can only reduce crop size.
2. Peach Twig Borer’s (PTB) “May Spray” timing looks to be an April timing. In the Merced area, our traps picked up a biofix around March 15th, which means we will be approaching 300 DD in about 7-10 days. Keep in mind that the spring spray timing for PTB is 300-400 degree days after the biofix. It may also be possible for the May Spray to have some effect on NOW. Frank Zalom (UC Davis Entomologist) has found through research trials that timing the spray to 100 DD post NOW biofix (egg traps) and around 400 DD post PTB biofix can provide good control of NOW and PTB at harvest.
3. Rain is predicted for Tuesday (the 7th). Hopefully some rain will fall in the valley to help with the multitude of water issues. This rain may also bring some potential for fungal disease – especially rust and scab. Consider an application if there has been a history of disease. This application can be made 1-2 days after the rain event and still provide the wanted protection. If more storms begin to line up in the following weeks, it may be important to spray prior to those rain events if this application is not made. A fungicide application that has several hours to dry will provide about 2 weeks of protection while an application prior to the rainstorm may only last 7-10 days.
4. With the anticipated early harvest, it may also be important to apply ant baits earlier than normal. Scouting should occur now to determine the need for treatment. If warranted, baits need to be applied 4-6 weeks prior to harvest. More information can be found at the UC IPM webpage on ants.
5. We have been observing weird symptoms of growth in ‘Nonpareil’ (as well as poor set) and other varieties (see picture above). This bud-failure-like symptom is unique in which only a few buds on last year’s growth will push, giving a “poodle tail” look to the branch. We are unsure of what may be causing the problem, but believe that high heat experienced in the late fall might have something to do with it.