Blossom End Rot, Cat Facing, & Blossom Drop! OH MY!

Oh, my precious tomato plants are having their fits-and-starts growing pains right now!

It's been unseasonably hot and uncommonly windy for this windy state! It's been damp with loads of rain, too, demonstrating that with climate change, Oklahoma is the new Louisiana (would that we had the same lovely cuisine!). Last night it rained about 2 ½” and since March 1, it’s rained 24 inches - TWO FLIPPIN' FEET!!! Outside it’s green and humid and smells like growing things. And it’s been raining since midnight last night which means over twelve hours!

It also means trouble for my tomatoes…I’ve found blossom end rot on a couple of Green Zebra tomatoes and the Opalkas are having trouble with blossom drop. Several of the Paul Robesons are showing cat-facing. The first two problems have to do with weather. The second is likely caused by some jack-ass spraying herbicide. Did you know that herbicide can drift up to 5 blocks (did I mention it’s been windy?)??? It’s probably damage from 2-4 D. Now my tomatoes are paying the price for some yay-hoo who wanted to get rid of weeds or grass in the cracks of his driveway. Thank you for your consideration, yay-hoo! Next time, bend down and pull them out yourself. It’ll help with the beer gut. (Rant ends here.)

Meow!

(Picture from Purdue Plant & Pest Diagnostic Library)

This post is more about the other two problems, though. I found out quite a bit about blossom end rot. I knew it was caused by calcium imbalances and that it could be triggered by fluctuations in soil moisture (this was the extent of the info offered in my old stand-by edition of Rodale’s. I was kinda disappointed!). Beyond that brief bit of trivia, I was a babe in the woods.

To start off, blossom end rot is a physiological problem rather than a disorder. It can be caused by a number of different factors and can be made extra-nasty by a combination of these factors. These include: low calcium in soil (uncommon), too much nitrogen spurring excessive early growth (common), soil temps too low when tomatoes are set out, repeated soil drying, sudden interruption of moisture, or way too much moisture (as in our case currently, in OK). A sudden lack of water is the usual suspect but too much water early on can effectively drown the plant, smothering the root hairs and leading to BER during sudden hot weather. One source mentioned that it might be more serious on the windward side (it’s drier) than on the leeward side of your plants. That’s exactly where it hit mine – on the poor fellah who’s acting as a windbreak!

Sciency stuff: Normal cell development requires fairly large concentrations of calcium. Soluble calcium moves through the vascular system from the roots to the leaves. With moisture distress it moves quickly to the leaves where it is transpired (sweated) out into the air. Tomatoes (and peppers and eggplants and melons) don’t transpire as much as the leaves do – their cellular structure is different. When a tomato lacks access to calcium, the tissue breaks down, leaving the ugly patch at the blossom end (opposite the stem end, where you can sometimes find the little dried bits of the original flower).

(Picture from: The Ohio State University Extension Office)

So in effect, calcium can be present in the soil and present in the plant, but might not be making it down to the precious blossoms/nascent fruit. One site called this a localized calcium deficiency. Even a brief amount of water stress can cause it since the fruit are last on the receiving end of the calcium train.

Interesting tidbit: “Ninety percent of the calcium that the mature fruit will contain is in the fruit by the time the waxy suberin layer (the waxy layer on the final skin of the fruit) has formed, when the fruit is about thumbnail size. When this calcium deficiency occurs in the end of the fruit, an area of rapid growth, it causes cells to collapse producing the sunken lesion symptom of blossom-end rot.”

It was mentioned in several places that blossom end rot usually hits your first tomatoes (the ones you lust after) and then clears up. A logical fallacy made by many, as pointed out by Dr. Carolyn J. Male, is that adding eggshells or using a calcium spray after the first sign of blossom end rot takes care of it. Rather, she says that adding calcium doesn’t work and that plants largely take care of it themselves. (And we thought we were so crafty and had such green thumbs!) From this perspective, BER is caused by rapid plant growth coupled with water stress and inadequate root development to support the plant and take up the necessary calcium. When the roots develop adequately, they’ll take care of the job, thereby clearing up the BER. It’s not the eggshells! (They are good soil conditioners, though, and may help deter slimy bugs.)

It was also noted that infected tomatoes should be pulled off. They won’t be any good and the nasty patch can play host to other infections and fungi that can seriously foul up your plant. So pluck them off, say adieu, and wait for the next crop, which should be okay (longer growing time, better root system!).

I particularly liked this excerpt, again from Dr. Male:

“Many books and magazine articles tell you that by adding Ca++ in the form of lime or eggshells, for instance, that you can prevent BER. That does NOT appear to be true. University field trial experiments have so far failed to show that BER can be prevented by addition of Ca++…Some data strongly suggests that foliar spraying with Ca++ is of no use because not enough gets to the fruits to do any good. And it's known that the sprays for fruits that are sold are useless. No molecules can get across the fruit epidermis…So, BER is a physiological condition, cannot be cured, and current literature data suggests it cannot be prevented. It occurs on some, but not all varieties of tomatoes, is usually seen early in the season and then stops, for most folks. It would be nice to say that you could even out your watering, prevent droughts and heavy rainfalls, ensure even and not rapid growth of plants and not disturb the roots by shallow cultivating. But on a practical basis, I think we all know that's almost impossible. So, BER has never bothered me, I just ignore it, and it goes away with time.”

Now that’s a sensible woman!

Here is a catch-all of the recommendations I found to address BER:

· Don’t force you tomatoes to grow up to soon! Let them have a nice, easy-breezy childhood. Too much nitrogen can stimulate too much early growth and cause BER.

· Don’t be too hardcore with your hardening off when you move your transplants outside. Be gentle.

· Hot, drying winds can contribute – try to plant in protected areas or provide a windbreak.

· Definitely use mulch! For multiple reasons, but in this case, to even out water moisture and prevent BER. Avoid plastic sheeting in hot, wet environments.

· Don’t plant too early when the soil is still cold.

· Remove affected tomatoes to prevent secondary pathogens.

· Select cultivars that are appropriate for your region or be prepared for some headache.

· Prepare deep soil to aid with root development.

· Be careful when you’re cultivating or pulling weeds near the tomatoes. Watch the roots!

· Too much pruning can apparently lead to BER.

· Tomatoes need 1 to 1 ½” water per week. Aim for that!

· The addition of Epsom salts to acidic soil can aid in the uptake of calcium.

And now just for a short little bit on blossom drop…Helpfully, it can be caused by temperatures that are too low or too high, too little or too much nitrogen, too little or too much humidity, lack of water, lack of pollination, insect or disease stress, or too many tomatoes already set. Not much doesn’t contribute to blossom drop, it seems. I’m chalking mine up to the winds and the heat. Given that it’s just the Opalkas, they might have a sensitivity in this area (any other Okie gardeners have experience with Opalkas in the past?)

Specifically, blossom drop can be caused by high day temps (above 85ºF/29ºC), high night temps (below 70ºF/21ºC), or low night temps (below 55ºF/13ºC).

Some recommendations:

• Gently shake the plant to help with pollination (no need here, did I mention the wind??).
  
  
• Set out at the appropriate time – don’t try to rush it and don’t wait until it’s so late that it’s too hot for fruit to set.
  
  
• Watch the fertilizer (leads to leaf growth and not flowers).
  
  
• Hose the plants if humidity is low (but watch out for overhead watering during full sun which can cause sunburn…water droplets act like magnifying glasses). Probably don’t want to do this if there are a lot of diseases in your area which can be transferred through wet foliage.
  
  
• Plant varieties that like your weather.

Sources:

http://www.aces.edu/pubs/docs/A/ANR-1059/ANR-1059.pdf

http://plantclinic.cornell.edu/Factsheets/blossomrot/blossomrot.htm

http://www.ext.vt.edu/pubs/plantdiseasefs/450-703/450-703.html

http://ohioline.osu.edu/hyg-fact/3000/3117.html

http://extension.usu.edu/htm/faq/faq_q=427

http://www.victoryseeds.com/information/carolyn_ber.html

http://gardening.about.com/b/2006/06/13/tomato-blossom-drop.htm

http://www.kdcomm.net/~tomato/Tomato/blossom.htm