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
Alan Jones takes a ride around Jones Potato Farm
Citrus
August 21, 2017
Take Alternative Routes to Find Conventional Farming Solutions [Opinion]
In order to grow, things have to change. Are you ready? Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for Dormant Apple Cuttings
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
young Florida citrus grove
Varieties & Rootstocks
August 19, 2017
Pressure Is on to Pick and Plant Citrus Winners
With even more variety selections available, information and communication are keys to success. Read More
honeybees
Citrus
August 19, 2017
More Forage Grants Distributed in Honor of National Honeybee Day
National forage program is scattering seeds from New York to California to celebrate pollinators. Read More
Citrus
August 18, 2017
Bayer Aims Research Prowess at Defeating Citrus Greening
Company enters collaboration with Citrus Research and Development Foundation to uncover antibacterial and plant defense tools against the disease. Read More
fine-tuning an orange
Citrus
August 18, 2017
How Florida Growers are Fine-Tuning Citrus Fertility
Some are tweaking nutrition programs to focus on root health along with foliar applications. Read More
Citrus
August 17, 2017
How Wicked Will Winter 2018 Be in the U.S.?
The 200th edition of the Farmers’ Almanac reveals wide-ranging weather patterns and events that would require everything from shovels to shorts. Read More
GenNext Growers
August 17, 2017
Young Growers See Evolving Orchard Production on Cornell Tour
A group of 30 got a chance to see operations boasting vertical integration and higher production per acre up close in the Champlain region of New York State and Vermont. Read More
More Vegetables
August 16, 2017
Variety Specs | Production Tips: Broccoli ‘Eastern Crown’ from Sakata
'Eastern Crown' is an outstanding variety for the East Coast and warm regions throughout the U.S. Read More
Fruits
August 15, 2017
California Nurseryman Settles With Feds Over Plowing Dispute
John Duarte admits no liability but will pony up more than $1 million in civil penalties and environmental mitigation fees. Read More
Apples & Pears
August 15, 2017
Wet Weather Breeds Phytophthora in Young Apple Plantings
Crown rot, root rot flourishing in very wet growing season. Read More
Agritainment
Citrus
August 15, 2017
New Conference to Shine Spotlight on Central Florida Agritourism
Education and interaction part of UF/IFAS-led agenda. Read More
Biocontrols Conference
August 14, 2017
Biocontrols: The South African Fruit Growers’ Perspective
While insect and disease pressure differs from U.S., South African fruit growers say education and slow transitions make for successful integration of biological products. Read More
Fruits
August 14, 2017
Spotted Lanternfly Quarantine Expands Again
Pennsylvania receives $3 million from USDA for outreach efforts, control measures for this invasive pest. Read More
Crop Protection
August 11, 2017
Do Fungicide- and Insecticide-Treated Seeds Boost Weeds?
The University of New Hampshire has received half a million dollars to investigate if seed treatments inadvertently protect weed seeds from its usual predators. Read More
The Latest
Citrus
August 21, 2017
Take Alternative Routes to Find Conventi…
In order to grow, things have to change. Are you ready? Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for…
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
Varieties & Rootstocks
August 19, 2017
Pressure Is on to Pick and Plant Citrus …
With even more variety selections available, information and communication are keys to success. Read More
Citrus
August 19, 2017
More Forage Grants Distributed in Honor …
National forage program is scattering seeds from New York to California to celebrate pollinators. Read More
Citrus
August 18, 2017
Bayer Aims Research Prowess at Defeating…
Company enters collaboration with Citrus Research and Development Foundation to uncover antibacterial and plant defense tools against the disease. Read More
Citrus
August 18, 2017
How Florida Growers are Fine-Tuning Citr…
Some are tweaking nutrition programs to focus on root health along with foliar applications. Read More
Citrus
August 17, 2017
How Wicked Will Winter 2018 Be in the U.…
The 200th edition of the Farmers’ Almanac reveals wide-ranging weather patterns and events that would require everything from shovels to shorts. Read More
GenNext Growers
August 17, 2017
Young Growers See Evolving Orchard Produ…
A group of 30 got a chance to see operations boasting vertical integration and higher production per acre up close in the Champlain region of New York State and Vermont. Read More
More Vegetables
August 16, 2017
Variety Specs | Production Tips: Broccol…
'Eastern Crown' is an outstanding variety for the East Coast and warm regions throughout the U.S. Read More
Fruits
August 15, 2017
California Nurseryman Settles With Feds …
John Duarte admits no liability but will pony up more than $1 million in civil penalties and environmental mitigation fees. Read More
Apples & Pears
August 15, 2017
Wet Weather Breeds Phytophthora in Young…
Crown rot, root rot flourishing in very wet growing season. Read More
Citrus
August 15, 2017
New Conference to Shine Spotlight on Cen…
Education and interaction part of UF/IFAS-led agenda. Read More
Biocontrols Conference
August 14, 2017
Biocontrols: The South African Fruit Gro…
While insect and disease pressure differs from U.S., South African fruit growers say education and slow transitions make for successful integration of biological products. Read More
Fruits
August 14, 2017
Spotted Lanternfly Quarantine Expands Ag…
Pennsylvania receives $3 million from USDA for outreach efforts, control measures for this invasive pest. Read More
Crop Protection
August 11, 2017
Do Fungicide- and Insecticide-Treated Se…
The University of New Hampshire has received half a million dollars to investigate if seed treatments inadvertently protect weed seeds from its usual predators. Read More
Citrus
August 11, 2017
Field Scouting Guide: Common Lambsquarte…
Take a look at these tips for identifying and treating this pervasive weed. Read More
Farm Management
August 11, 2017
Vegetable Growers’ Food Safety Vigilance…
When you hear about recalls, the horror stories come to mind first. That’s understandable, considering the human cost involved with Read More
Tomatoes
August 10, 2017
Getting to the Bottom of Better-Tasting …
Examining the essence of the problem, University of Florida scientists are seeking to squeeze more flavor into popular beverage. Read More