TOMATOES: WHAT’S NEWS AND MAKING THE END OF THE SEASON WITH GREAT TOMATOES

Steve Bogash

Horticulture Educator / Researcher

Laying out a plan for the entire season• What was in the field / tunnel last season?

• Preplant soil testing

• What varieties have and have not worked for you?

• Applying nutrients:

– Regular granular

– Slow release

• Staying ahead of consumption curves.

Tomato Nutrition Problems

Plus, yields less than #20 of marketable fruit per plant

Defining Terms• Soil pH

– pH = potential of hydrogen

– Greatly affects the availability of nutrients

– Relative acidity / alkalinity

– pH of 7 is considered neutral

– Tomatoes grow best at 6.2-6.5

– Logarithmic scale

– Test both soil and irrigation water• We often add acid(s) to irrigation water

Additional important terms• Sufficiency: Moving target that varies from

carrying a crop to carrying a profitable crop. Usually expressed as a percentage.

• Deficiency: Not enough nutrient present to satisfy even the most minimal plant needs.

• Toxicity: Overabundance to the point of damaging a plant or causing other nutrients to be out of balance.

Putting together a fertility plan• Know your soil or potting media

– Regular testing by a laboratory is the only accurate tool.

– Test the soil before planting

– Test the soil again at the onset of flowering

– How have the key nutrients changed (N, P, K, Ca and Mg) as the plants use these nutrients?

– Plow down 30-50% of overall needs at bed workup.

• Organic growers will want to plow down 60-80% why?

Know your water• Test water 1st use for:

– pH*

– Alkalinity*

– N, P & K

– Clogging particulates

– Fe

• Regularly test for pH and Alkalinity

• Well vs. Spring vs. Stream vs. Pond

Stages of a tomatoes life

• Planting - Rapid increase in vegetative mass

• 1st flowering– Flower bud initiation begin heavy K drop

• This is prior to you seeing the first buds

• Development of fruit– P drops rapidly as fruit begin to size

• Ripening of fruit

• Continued development of flowers and fruit (indeterminate plants only***)

• Determinate types 2nd fruiting potential

Seedling fertility program• No fertilizer at seeding

• First true leaves: 75-100 ppm N balanced

• 4-6 weeks: 100-150 ppm N

• 6-8 weeks: 150 ppm N

• 8 weeks: transplant and test

Early (vegetative) Growth• 20-20-20 or 20-10-20 up until initiation of flowers.

• 3-4-3 fish-based fertilizer is the same

• Plant tissue analysis at first flower.

• Tissue analysis:

– 10-15 whole leaves

– Collect from average plants

– Collect 4-5th leaf from top

• Most recent mature leaf

– Paper bags only!

– Overnight or pickup

– Take leaf below top flower cluster on determinate types.

Nutrition at flowering (two weeks prior)• Plant tissue analysis

• Adjust fertility program to 3-4K+ / 1N

• Bring Ca to 100% sufficiency

• Adjust Mg to Ca by using a ratio of 2-4 Ca to 1 Mg.

• K+ needs to be above 3% by dry matter

Plant maintenance• Monitor N, K+, P, Ca & Mg levels

• Monitor irrigation water pH weekly– With hydroponic systems, monitor daily or

constantly

• Weather considerations– Day length

– Relative sun / cloud cover

– Day / night temperature variations

• Creating high quality fruit requires careful irrigating.

Most growers primary packout challenge:

How much fertilizer?• Apply #.5 (minimum) actual N / acre / day to

1.5 acre tomatoes. We’re using 20-20-20. Applied every other day.

• .5 x 1.5 = .75 (fertilizer for the area / day)

• .75 x 2 = 1.5 (N needed over 2 days)

• 1.5 / .2 = #7.5 (amount of 20-20-20) every 2 days

• This could have been solved in almost any order and still gotten to #7.5.

More fertilizer math• Let’s work with 9-15-30

– Still use #.5 / acre actual N and same size field (1.5A)

– #.5 x 1.5 = .75 (Actual N for field per day)

– .75 x 2 = 1.5 (N needed over 2 days)

– 1.5 / .09 = #16.7 of 9-15-30 every 2 days

– If N is still high (above 4%) at next tissue test, one option is to change to 8-16-42 (KSC-Timac).

My tunnel standards• BrandyBoy

• Scarlet Red

• Primo Red

• Red Bounty

• Red Deuce

• Red Mountain

Primo Red

Nutrition at flowering• Plant tissue analysis• Adjust fertility program to 3-4K / 1N• Bring Ca to 100% sufficiency• Adjust Mg to Ca by using a ratio of 2-4 Ca to

1 Mg.• K+ needs to be above 3% by dry matter

– I refer to this as chasing potassium

• Nutrients: 9-15-30 (Miller Nutrichem)or 8-16-42 (Timac) plus Nutri K (Potassium Carbonate) or 4-10-40 foliarly– We increased drip irrigated nutrients weekly

based on tissue tests and often still fall behind.

What are we doing to keep up?• Plow down of aragonite (approximately 38% Ca) at soil prep

– Good source of slow Ca release

• Plow down of green potash (15% K) at soil prep

– This may be the trick to keeping K levels up

– This practice worked well in 2012, 2013 & 2014

• Foliar applications of Ca, Mg and K as needed

– Synergism between foliar K and soil K

• Ca is non mobile in plant

– What does this mean for nutrient application?

• Mg must be there with Ca– Epsom salts at soil prep at #30-100 / acre

More on Ca• Since it is non-mobile:

– Must always be in solution

– Tissue analysis is Monday AM refereeing for Ca

– Constant application necessary or

• Aragonite

– Since Ca is actually Ca++, you must use chelated forms foliarly.

• Formulation matters in getting nutrients past the cuticle or through the stomata

More on Mg• Must be in solution in a 3/1 ratio with Ca.

• Mg SO4 (epsom salts) are great for soil preparation, but lousy for in-season immediate fixes.

• Look for MagSi, MgO, Mg Citrate, or Magical

Getting your Potash numbers up• Along with applying enough

– Your soil solution pH must be between 6.2 and 6.5

– Potash availability drops quickly outside of this range

– Start early and stay with an aggressive program.

• Getting it there:

– Inject sulfuric acid whenever irrigating or fertigating

– Organic alternative: Citric acid

– You must work with a calibrated pH meter

Some notes of phosphorus consumption

• Through tissue testing we’ve noted a precipitous drop in P levels immediately after the first fruit set.

– Combining 12-48-8 with 9-15-30 for 2-3 weeks has brought our tissue tests back into the sufficiency zone.

– Not sure what specific effect these low P levels have on plant yield, but overall vigor is immediately evident in bringing levels up.

Where does soil biology fit into this discussion?

• Higher levels of active fungi make a huge difference in nutrient uptake by plant roots.

– Bacteria too, but to a lessor extent than fungi.

– Specific type of fungi makes a huge difference

• Most commonly mycorrhizal types.

• Trichoderma spp. have similar effects to mycorrhizae

• All organic matter is not created equally

– Carbon / Nitrogen (C/N) ratio matters

• Very high C / N ratio will use much of the N to degrade the carbon.

Disease management in a tomato tunnel

• Challenges:

– Septoria leaf spot

– Late Blight

– Bacterial Canker

– Leaf Mold

– Powdery Mildew (late season)

My nimble management program:• Mancozeb or Regalia-based until first harvest

is in sight.

• Then Regalia-based due to mancozeb 5 day PHI

• Basic program:

– Day 1: Regalia

– Day 5: Actinovate AG

– Day 10: Stimplex or other biostimulant

– Day 15: start over

Upping the ante’• Regalia + copper, then Actinovate AG +

Stimplex on 7 day schedule.

• Add in B.subtillus product for enhanced PM and LM control.

• Regalia + Ranman, Curzate, Tanos, or P. Flex for enhanced LB management.

• Inject Regalia + GreenStim + Actigard foliarlyfor enhanced bacteria mgt.

Our goal

THANK YOUYOUR QUESTIONS PLEASE!

Steve Bogash

Horticulture Educator

smb13@psu.edu

717-240-6500 ext 6507