Hurricane Sandy Aftermath

Hurricane Sandy southeast of Cape Hatteras, NC, October, 27, 2012. Source: http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2279

As Hurricane Sandy starts to slip northward, there are some things that caneberry growers in NC and adjacent states should think about. First if you are in eastern NC, you may have wet soils. If your soils tend to stay wet, caneberry plants do not like wet feet. I asked Dr. Phil Brannen Plant Pathologist, from UGA, and here are his thoughts on diseases:

"Assuming that drainage is good, long-term saturated soils could still result in root rot from Phytophthora, but I have rarely seen this in well-drained soils.  Assuming that there is a risk, Ridomil Gold SL can be applied through drip tape; phosphonates could be applied foliarly, assuming that leaves are still active.  There would be no harm in either of these actions, and application of a fungicide could provide some breathing room till the soils dry out.  The plantings may be too wet for a tractor and sprayer to enter for some time, so all applications may be delayed (unless drip-tape Ridomil is the preferred route)."

He also mentioned pruning and leaf spots:  "Any open, fresh wounds would be susceptible to cane blight, but there is really limited value in spraying a fungicide days after pruning -- especially if it has been wet for days already (infections would likely have already occurred).  Not sure therefore of the value of spraying for cane blight at this point, but some systemic fungicides may provided limited kickback if applied within a couple of days.  

Relative leaf spots, I suspect we are far enough along towards leaf fall that we would not currently worry about these."

If you are in western NC, and you are growing fall fruiting red raspberries, your season like ours came to an end abruptly today with the snowfall in the mountains. (We pulled the plastic off late last week in anticipation of this storm). We had a nice crop of berries under high tunnels still producing fruit. Most of our early and mid season primocane fruiting cultivars were done, however, Nantahala had a week or so left and Nova had a couple of weeks left. Our harvest crew was not too upset.

The winds have been strong and may blow some of the leaves off your plants. This is a bit early, but in general the plants have finished the majority of their root building for the season and the lost leaves will not impact your plants too much. Winds can also do damage to your trellises and plants may be laying on the ground. Get the plants up and off the ground as soon as possible and as Phil mentioned, hold off on pruning, until you can get a fungicide on.

Those are my thoughts for now. Let me know if you have any particular questions or concerns: Gina_Fernandez@ncsu.edu

Hot days ahead

Temperatures are predicted to soar into the 100's in NC in the next few days. Raspberries and even their more heat tolerant cousins blackberries will be stressed.  The most important thing you can do at this time is to make sure your plants are well watered. This will help reduce the stress to the plant and enable your berries to continue to ripen and get plump.

Raspberry roots are usually in the top 10" of soil, while blackberries roots can be much deeper. However, the majority of the water is taken up by the roots in the top 6" of soil. Water stress before or during harvest can seriously reduce productivity. Water is the most critical factor for optimal fruit growth and primocane development, a berry is afterall more than 90% water! A shortage of water will limit fruit size and also the number and diameter of primocanes for next years crop.

Flooded berry fields

This article is provided courtesy of Cornell University. Although it was written for flooding situations in the northeast, some information may be useful for parts of NC as well.


DEALING WITH FLOODED BERRY FIELDS

Steve Reiners and Marvin Pritts

Dept. of Horticulture

Cornell University

Record-breaking rains in the East have left many berry growers with unmarketable crops.  What had been shaping up to be a decent season for fall raspberries and dayneutral strawberries has quickly turned into a bad situation. 

FLOODS AND FOOD SAFETY

There are two types of flooding.  The first is more typical and occurs after a heavy downpour when fields become saturated and water pools on the soil surface.  This type of flooding can reduce yields and even kill plants but usually will not result in contamination of produce with human pathogens.  The second type of flooding is more severe and unfortunately occurred with the recent storm. This occurs due to runoff from stream/river overflows will more likely be contaminated with human pathogens, as well as chemicals. Unless you are absolutely sure that flooding is not from streams and surface water, do not use berries that were covered with flood water.

PLANT SURVIVAL UNDER WATER

How long a crop can live once it is flooded and what may be the effect on yield? Berry crops can tolerate a great deal of flooding when they are dormant, but when actively growing in summer, flooding for any length of time can be detrimental. This time of year is particularly bad because plants are preparing to make flower buds for next year, and stress can compromise this process. If plant roots were under water for more than 48 hours, expect next year’s crop to be compromised as well.

Plants previously flooded may develop an off-green or yellowish color.  These plants are suffering from a complex of nutrient deficiencies, nitrogen, phosphorus, potassium and perhaps others, even though the soil contains adequate amounts. But the main deficient element is oxygen. Plant roots need oxygen to take up nutrients and water to utilize the photosynthate from the tops and to grow. With the heavy rains we have had, soils are saturated; that is, nearly all of the pore space is filled with water, leaving little room for air. Ideally, for good root growth 50 percent of the pore space should be filled with air. As soils drain, air is drawn into the soil, but when it rains, the water forces the air out of the pores. As is obvious to all, what is needed now is several rain-free days so the soils can drain and draw in air to stimulate root growth and help disperse toxic compounds that accumulate when plants lack oxygen.  Once the plant roots get adequate oxygen they will begin to grow and take up the nutrients present in the soil. Anything that can be done to remove surface water will be helpful.

Many plant diseases will be much worse following flooding rains (e.g. Phytophthora and Botrytis), so closely monitor crops and manage these diseases. Phytophthora spores are spread under flooded conditions, so chemical treatment may be warranted in susceptible crops (e.g. red raspberries and strawberries).

(Thanks to Steve Rieners and Marvin Pritts at Cornell University for sharing this with us.)