Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Illiana Vegetable Growers SymposiumJanuary 6, 2015

Liz MaynardDept. of Horticulture and Landscape Architecture

Managing Tomato Fruit Problems

Blossom End Rot

Yellow Shoulder Disorder

Catfacing

Zipper

Cracking

Rain Check

Physiological Disorders• Genetics• Environment

– Mineral nutrient supply– Temperature– Light– Relative humidity– Rain– Soil moisture– and more

Problem May Begin Before Fruit Appears

0 20 40 60 80 100

Visible buds

AnthesisRipe Fruit

Days after Seeding (approximate)

Flower Development Begins

Qui

. 200

6;57

:138

1-13

90ne

t M e

t al.

J. E

xp. B

ot

Catfacing

Catfacing• Misshaped fruit• Scars at blossom end• Holes at blossom end

Catfacing – USDA Grade Standards

NOT No. 1 if:• Area greater than a circle 1/2 inch diameter

even if catface is fairly smooth• Rough scar• Deep scar• Deep or wide channels• Channels extend into a locule(for a tomato 2.5 inches in diameter)

Catfacing – Cause• Abnormal development of flower• Cool temperatures 4 to 5 wk before anthesis• Strong genetic component• Exposure to growth regulator herbicides can

cause similar injury

Herbicide Injury

Catfacing – Management• Variety choice

– Large-fruited varieties more prone to catfacing– Very common in some ‘heirloom’ varieties

• Temperature management (protected environments)

Zipper

Zipper• Linear scar, usually from stem end down side

of fruit• Hole into fruit lined with scar tissue

Zipper – USDA Grade StandardsOK on No. 1 if:• Smooth • No depth • Do not aggregate more than a circle 3/8

inch diameter (for a tomato 2.5 inches in diameter)

Imag

e so

urce

: USD

A AM

S

Zipper – Cause• Flower parts stick to young fruit• Cool temperatures at fruit set

Zipper – Management• Temperature management (protected

environments)• Variety choice

Blossom End Rot

Blossom End Rot• Brown or black at blossom end• Becomes sunken and leathery• Secondary mold• Occasionally occurs internally with no

external symptoms

BER – USDA Grade StandardsNo specific standards for BER but standards for scars and decay apply.• No decayScar OK on No. 1 if:• Smooth • No depth • Do not aggregate more than a circle 3/8

inch diameter (for a tomato 2.5 inches in diameter)

Blossom End Rot – Cause• Localized calcium deficiency in young tomato• Lack of water• Excess N, Potassium (K), or Magnesium (Mg)• Inadequate root system• Low soil calcium• Genetic component

BER – Management• Adequate water• Balanced nutrients

– Avoid excess nitrogen (N)– Avoid excess potassium (K) or magnesium (Mg)

• Healthy root system• Adequate calcium in soil• Variety choice

– Roma types often more susceptible

• Reduce relative humidity (protected culture)

Yellow Shoulder Disorder

Yellow Shoulder Disorder• Yellow hard areas near stem end don’t ripen• Internal white tissue

Yellow Shoulder Disorder – USDA Standards

• Abnormal color is a defect• May not “materially detract from the

appearance or edible or marketing quality”• Visual aids show ‘sunburn’ as an example

Imag

e so

urce

: USD

A AM

S

YSD – Cause• Multiple factors• Genetics: ‘green shoulders’ more likely to

show disorder• High Temperatures/Sun• Inadequate potassium (K)• Low soil phosphorus (P)

YSD – Management• Adequate potassium (K)• Variety choice

– Uniform green, not green shoulders– http://cuke.hort.ncsu.edu/cucurbit/wehner/vegcu

lt/vgclintro.html

• Reduce fruit exposure to sun

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Making Use of a Soil Test

desiredP 45 – 90 ppm

desiredK 90 – 140 ppm

YSD – Management• ‘Hartz’ Ratio useful in processing tomatoes

K+ / square root (Mg++)

units = meq/100 ghttp://www.oardc.ohio-state.edu/tomato/HartzRatioCalculator.htm

YSD – Management

YSD – Management

http://www.oardc.ohio-state.edu/tomato/HartzRatioCalculator.htm

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Big Beef

Weave String

Cracking

Cracking• Linear breaks in the skin• Radial cracks start at stem scar and go out

like spokes on a wheel• Concentric cracks occur in arcs around the

stem scar• Fungus or bacteria may colonize crack

Cracking – USDA Grade StandardsOK on No. 1 if:• Well-healed• If tomatoes are at least turning,

need not be well-healed but may not be leaking

• Less than 1/8 in. deep• Individual radial cracks

less than 1/ 2 inch• All radial cracks more than 1 inch

(from edge of stem scar)(for a tomato 2.5 inches in diameter)

Image source: USDA AMS

Cracking – Cause• Rapid fruit growth, skin can’t expand fast

enough• Rain or irrigation after dry period• Genetics influences likelihood and pattern of

cracking• Tomatoes exposed to hot sun tend to crack

more

Cracking – Management• Variety choice• Even water supply• Healthy foliage to shade fruit• Don’t overprune• Harvest before completely ripe

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Effect of Support Method on Cull Number, 2013

Mountain Fresh had more early mkt. with string, prune

Rain Check

Rain Check• Many tiny (<1/8 or 1/16 inch), shallow

breaks in the skin of the fruit• Usually on shoulders• Appear, feel rough• May become discolored• “Shoulder Check”, “Micro-cracks”

Rain Checks – USDA Grade Standards

• May not “materially detract from the appearance or edible or marketing quality”

Image source: USDA AMS

Rain Checks – Cause• Rapid fruit growth, skin can’t expand fast

enough• Rain after dry period, high humidity • Fruit without foliage cover tends to have

more• Green and partially ripe fruit more

susceptible

Rain Check – Management• Healthy foliage • Don’t overprune• Variety choice• Protected culture

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

Thank Youand

Good Growing!

Liz Maynardemaynard@purdue.edu219-531-4200600 Vale Park Rd.Valparaiso, IN 46383

Blotchy Ripening