Freezing cold weather is set to wash over the state of Florida tonight into tomorrow night, so please be prepared!
A few comments about freeze protection in orchards:
Be sure that your orchard is well-watered – we will be getting sun each day, and wet soil has a greater capacity to absorb heat, and also release it during the night, offering a few degrees of protection.
Watch the weather – and keep your coffee pot going. For those in Central Florida and to the south, it looks like the temperature will drop to a critical period around 2 a.m. on Friday morning. However, if the wind is too high, you may induce evaporative cooling rather than protect the fruit, which can do more severe damage.
Know what your irrigation system capabilities are to be able to meet the appropriate water output.
See: http://edis.ifas.ufl.edu/ch182 – this is for citrus, but the principles that they go over, like reading a sling psychrometer are useful to understand.
Hold off on any orchard related activities, like thinning fruit – the cold weather may do a good job of that for you!
Weather Related Resources:
The National Weather Service – http://www.noaa.gov/ – just put in your city or zip. I find that the best resource is a graph like this which gives you the temperature and wind speed which is important:
I hope that everyone had a FANTASTIC Christmas vacation (ala Clark Kent style) and is having a great start to their new year. As we start off this new year, cold weather comes knocking on our door in north central Florida, a normal occurrence.
Freeze warnings/wind chill advisories (1/7/15)
There maybe some of you in north central Florida that are closely watching the weather tonight. For the following counties, there is a hard freeze warning:
The good news is that hopefully, the peach trees are still resting are not in full bloom. For a guide to bud stages and their tolerance to cold temperatures – click here.
For counties to the south and east, it’s a freeze warning:
Again – I don’t think it’s anything to be concerned about unless the wind speed drops down. However, NOAA is forecasting a blustery night with wind speeds sustained at over 15 mph. In most cases, frost protection would not be turned on with these advective conditions. Most all others in the peach growing region of Central Florida will have mid to upper 30s so stay warm!
Well, here we go with the rollercoaster of temperatures in central and south central Florida. So what is going on with the peach trees right now?
Don’t worry! The peach trees are headed into dormancy, and although the buds have the possibility of suffering a minor amount of damage (<10%), we don’t anticipate any major issues with flower bud damage. There is NO need to turn on irrigation for frost protection tonight and it is expected to warm slightly tomorrow night, so no frost protection for the next night as well.
The UF Stone Fruit Research/Extension team has a new project in cooperation with Georgia (UGA) for both blueberries and peaches and we will be tracking bud damage as a result of the expected freeze event tonight at our research plots in Citra, FL. We be looking at flower buds in TropicBeauty peach and Emerald and Jewel blueberry varieties. When we have the information, we will be posting it here on the blog, as well as on our website, http://hos.ufl.edu/extension/stonefruit.
As we head into full bloom and early fruit set for the growers down south, please don’t forget about application of your fungicide sprays to combat peach scab. This, along with peach leaf rust, are our major diseases here in Florida.
Please check the latest version of the Southeastern Peach, Nectarine, and Plum spray guide for options. Please also pay attention to the suggested spray material choices, such as Captan and sulfur. Sulfur is a good choice for this time of year, because it is relatively inexpensive and does a great job to cover the young fruit and protect it. The downside is that it has a shorter efficacy length, meaning that you will have to spray more often than if you used a synthetic chemical like Captan. Additionally, as we head into the bloom period and leaves begin to push open on the tree, be sure to begin your fertilization and irrigation regimes. We still can get some rain during this time of year, so take that into consideration when you set up or run your irrigation programs. For help on irrigation requirements, you can check the FAWN site for information on the evapotranspiration (ET) for the day or week. Although we do not have an irrigation scheduler for peaches at this point, there is a citrus irrigation scheduler that may be helpful. However, some growers are cutting the recommended amount for irrigation to peaches by various percentages according to their soil type and tree response.
A group at UF have a project in conjunction with the SWFWMD to investigate peach irrigation and reduction of water applications after harvest. We are working with growers to establish best management practices for irrigation management, knowing that the afternoon thunderstorms often rolling through in June, July, and August can stymy our plans.
As always, be sure to let your county extension agent or myself know of any questions you have! We are here to help. Good luck and enjoy the beautiful blossoms!
In January and early February, we all deal with the waves of cold fronts that dip down from the Canadian Arctic. However, as many growers are in full swing with bloom or have just started, these cold waves keep us all up at night.
At Citra in one of our plots that has some bloom occurring, we have turned on the water on the following dates:
Tuesday, January 7th
Friday, January 17th
Saturday, January 18th
Sunday, January 19th
Wednesday, January 22nd
We will continue to monitor tonight (Friday, January 24th) for cold weather, since it looks like the wind will be dying down. The graph below details the actual temperatures for the Gainesville Regional Airport (KGNV) which is a few degrees colder than what we observe in our research plots at Citra.
What are some tools that you can use to help decide when to turn the water on? One thing I can offer – the wind will almost always kick the temperature up a degree, so be on the lookout and carry a good thermometer with you as you are driving around the orchard. Your car thermometer may not be the most accurate, so don’t count on that.
Recently, there were two new apps released that will be helpful to Florida growers of both fruit and vegetables. Growers can get real-time local weather data from the “My Florida Farm Weather” Program. The website address is: http://fawn.ifas.ufl.edu/mffw/ – and there is an app for the Android platform at this point, with an iPhone app coming soon (the release of iOS 7 most likely delayed its release).
Key information on rainfall, temperature, humidity, dew point, wind speed and wind direction can be found from both FAWN and grower sites. Historical data will be added to the site – which will be a useful tool for site selection and variety selection.
Web Soil Survey 3.0
The California Soil Resource Lab has released an iPhone and Android app to navigate the USDA-NRCS web soil survey maps. This is a handy tool for those evaluating sites and determining irrigation systems and rates for a new planting. There are also links on the website for linking to Google Earth images and Google Maps images showing soil information. A neat tool for on-the-go soil information!