Fertility Advice From The Greenhouse Tomato Short Course

Joe Kemple

The 22nd annual Greenhouse Tomato Short Course has now come and gone. Participation was excellent this year, with growers from coast to coast in the U.S., as well as all the way from Brazil, the Bahamas, Trinidad,  Tobago, and Ghana!  

If you have never come to Mississippi for this national conference designed for greenhouse tomato growers, check the web site for information:
http://greenhousetomatosc.com.  

While there was too much presented during two days of seminars for an article like this, I’d like to focus on some nutrition and fertility information presented by Dr. Joe Kemble of Auburn University.

Mobile Elements

First of all, an understanding of how mobile elements are is important to trying to figure out which nutrient deficiencies your tomato plants may have.

Mobile elements — those that move easily within the plant from older growth to newer growth — include nitrogen, potassium, and magnesium.

Why is this important? If there is not enough of one of these elements in
the fertilizer solution, the older leaves will show deficiency symptoms first. Older leave are those at the bottoms of plants, as well as those half way or so up the plant.

On the other hand, iron is considered to be an immobile element. It will not move very much from older to newer leaves. Symptoms of not enough iron will show up first in the newer leaves, i.e. at the tops of the plants.

Calcium is the problem child. It is mobile — sort of. If the youngest parts of the root system are active and healthy, they will take up calcium and it will travel throughout the plant. If, however, there are any stressors on the plant that slow down these young roots from growth, calcium uptake is limited and deficiency symptoms will be evident. Calcium is taken in mostly through the very young roots and not much by older roots.
 
Look For Symptoms
With nitrogen, a general light green or greenish yellow coloration indicates deficiency. This will start with the older leaves, but can progress upward to include the whole plant if it continues unchecked. Deficiency also produces “leggy” plants, with thinner stems and longer internodes, and some purpling may show up on the undersides of leaves.

Low potassium will show up as necrotic (dead, brown) spots on the older leaves. The spots are interveinal — between the veins; veins remain green.

These will progress inward toward the main stem, and also upward toward new growth. Potassium symptoms may also show up as yellowing margins (edges) of the leaves. Fruit symptoms include whitish, unripe areas inside the fruit, and softening of fruit tissue.

With lack of magnesium, a pronounced interveinal chlorosis (yellowing) of older leaves is very evident. While veins remain green, the yellowed tissue between veins becomes very prominent. Sometimes the margins remain green. Often, this occurs about half way up the plant shortly after the fourth cluster has set fruit. This is probably the most common deficiency
in tomatoes grown in the greenhouse.

Since iron is immobile, a limitation will cause it to remain in the old growth and cause symptoms at the tops of plants. This occurs as interveinal chlorosis in the young leaves. Unique with iron is that the yellowing starts at the bottom of leaflets, and then progresses upward until the whole leaflets will be yellow or even whitish in severe cases. Veins normally remain green.

This occurs when iron in the fertilizer is too low, but can also happen if the growing medium is kept too wet or even waterlogged.

Prevention, Diagnosing Problems

A tissue analysis is probably the best single thing a grower can do to detect nutritional problems even before there are symptoms, or to diagnose a problem after it occurs. While there is a fee for testing, a biweekly schedule is advisable and not too expensive to keep plants healthy. Either a testing lab at your state university or a commercial analytical lab can be used. Test results will help growers decide how to make changes in the fertilizer program. 

Leave a Reply

Featured Stories
Biocontrols 2015 Conference
CitrusGrowers Go In-Depth At Biocontrols 2015 Conference & Tradeshow
March 9, 2015
The first-of-its-kind event brought growers, researchers, regulators, and suppliers together for a two-day discussion on the latest biocontrols tools and technologies. Read More
Crop ProtectionAt Paramount Farming, Mating Disruption Pays Off
February 10, 2015
To say Brad Higbee is an expert in mating disruption, the use of pheromones to confuse target pests and reduce Read More
Crop ProtectionGrower Experienced In Biocontrols Says: Be Patient
February 4, 2015
The use of biocontrols in all aspects of agriculture is becoming more widespread. But incorporating biocontrols in a vegetable farming Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Nitrogen To Double Output
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
Apples & PearsHow Will We Sell All These Apples? [Opinion]
March 30, 2015
Apple production is reaching heights that would have been unthinkable two or three decades ago. That's great news for growers — if we can sell them all profitably, Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollinator In Almonds
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
Richard Jones
Farm ManagementDon’t Burn Out This Spring
March 30, 2015
Finding ways to limit stress will benefit both you and your business. Read More
Apples & PearsSounding Off On GMOs: The Arctic Apple Decision
March 27, 2015
Industry leaders share their feelings on the recently approved genetically modified apples. Read More
BerriesBuilding A Better Black Raspberry
March 27, 2015
Studies focusing on consumer preference, aphid resistance, heat tolerance, and genetics aim to capitalize on an expanding market. Read More
CitrusMore California Citrus Placed Under Psyllid Quarantine
March 27, 2015
Asian citrus psyllid is found in Madera County – the heart of the San Joaquin Valley. Read More
FruitsIncrease Your Knowledge By Using Tree Fruit Resources
March 27, 2015
Get educated with great resources in the tree fruit industry available at your fingertips. Read More
Apples & PearsMeet USApple’s Class of 2015 Young Apple Leaders
March 27, 2015
Young decision-makers see trip as an opportunity make sure the voice of the apple industry is heard by representatives. Read More
GrapesGlassy-Winged Sharpshooter Found In Marin County
March 26, 2015
This pest, known to spread Pierce’s Disease, could devastate California winegrapes. Read More
The Latest
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Ni…
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
Apples & PearsHow Will We Sell All These Apples? [Opinion]
March 30, 2015
Apple production is reaching heights that would have been unthinkable two or three decades ago. That's great news for growers — if we can sell them all profitably, Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollin…
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
Richard Jones
Farm ManagementDon’t Burn Out This Spring
March 30, 2015
Finding ways to limit stress will benefit both you and your business. Read More
Apples & PearsSounding Off On GMOs: The Arctic Apple Decision
March 27, 2015
Industry leaders share their feelings on the recently approved genetically modified apples. Read More
BerriesBuilding A Better Black Raspberry
March 27, 2015
Studies focusing on consumer preference, aphid resistance, heat tolerance, and genetics aim to capitalize on an expanding market. Read More
CitrusMore California Citrus Placed Under Psyllid Quarantine
March 27, 2015
Asian citrus psyllid is found in Madera County – the heart of the San Joaquin Valley. Read More
FruitsIncrease Your Knowledge By Using Tree Fruit Resources
March 27, 2015
Get educated with great resources in the tree fruit industry available at your fingertips. Read More
Apples & PearsMeet USApple’s Class of 2015 Young Apple Leaders
March 27, 2015
Young decision-makers see trip as an opportunity make sure the voice of the apple industry is heard by representatives. Read More
GrapesGlassy-Winged Sharpshooter Found In Marin County
March 26, 2015
This pest, known to spread Pierce’s Disease, could devastate California winegrapes. Read More
GrapesFirst Raisin Grape That Dries Naturally On Vine Develop…
March 26, 2015
The new Sunpreme variety eliminates the need for growers to cut into woody canes before harvest. Read More
Fresh From Florida Strawberry Parfait recipe
BerriesNew Partnership Sends Florida Strawberries To Puerto Ri…
March 26, 2015
Latest addition extends Sunshine State’s agricultural export reach in the Caribbean. Read More
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
NutsWhy You Should Use Low-Rate Applications Of Potassium
March 26, 2015
These rates provide growers a low-cost method comparable to conventional applications. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research …
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-F…
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
Pennsylvania hard cider guild logo
Apples & PearsPennsylvania Hard Cider Producers Founded Independent T…
March 25, 2015
The Pennsylvania Cider Guild is designed to help promote and educate members and consumers. Read More
FruitsHow To Get Started With Partnerships And Sponsorships
March 25, 2015
Mark Saunders of Saunders Farm says your business is never too small or too big to get more value for what you do on your farm. Read More