ISSUES AND OPTIONS

Seed germination can be affected by extreme temperatures. For example, desert production areas, late spring and summer production, black “heat-absorbing” organic soils, and early spring and late fall conditions.

Why It’s Important

Uniform emergence of germinating seedlings and resulting stand establishment can be negatively affected by temperature extremes hot and cold; high heat conditions during germination can significantly increase the potential for heat induced seed dormancy

Options

Priming is a tool that can increase seedling vigor in cold weather germination conditions and reduce the potential for heat induced seed dormancy in sensitive crop varieties. Products include Prep-Coat®, Pre-Prep®, Prep-Coat® AirMaxx, PULSE® Prep-Coat®, or PULSE® Pre-Prep®.

Thermodormancy is caused by high temperatures during germination, and is common in lettuce seeds. For example, desert production areas, late spring and summer production, and black “heat-absorbing” organic soils.

Why It’s Important

Lettuce is commonly sensitive to thermodormancy.

Options

Priming can raise the upper germination limits enabling more uniform stands, increase germination success in high temperatures. Products include Prep-Coat®, Pre-Prep®, Prep-Coat® AirMaxx, PULSE® Prep-Coat®, or PULSE® Pre-Prep®.

Seeds don’t germinate at the same time. For example, seedlings are different sizes upon emergence, emerging cotyledons are different sizes, and there are larger and smaller emerging plants in the same planting.

Why It’s Important

Uniform emergence can increase yield and increase first pick harvest yield potential.

Options

Pelleting seeds results in more uniform spacing, plus consistent and accurate seed depth at planting time. Priming can increase seedling emergence uniformity. Seed treatments and seed-applied plant protectants can increase uniformity. Products include Gro-Coat®, Prep-Coat®, Pre-Prep®, Air-Maxx, and/or FarMore® Plant Protectants.

Planter Notes and Tips

Planting problems are most often caused by a disconnect between planter setup and use of the appropriate seed technology product. Inevitably the problem will be blamed on the seed pellet or coating.

There are many variables to consider when adjusting and tuning precision planters. They include soil type and condition, equipment type and condition, crop species, seed and seed condition.

The following planter recommendations are intended as suggestions only and apply to SDI products and vegetable seed. There is no substitute for planter user awareness and familiarity of use.

Pneumatic Planters, Vacuum Planters, and Air Planters

(does not apply to sheltered culture)

Seed Plate Hole Size Range Recommendations in General

• .08mm through 1.2mm seed plate hole sizes AirMaxx 65,000 seeds per Lb. and smaller (>65,000).
• 1.2mm through 1.4mm seed plate hole sizes AirMaxx 35,000-65,000 range, seeds per Lb.
• 2.1mm through 2.4mm seed plate hole size when using Gro-Coat and Prep-Coat 13.0 and 13.5 pellets.

Multiples

If multiple seeds of Prep-Coat, Gro-Coat or AirMaxx treated seeds are being held to a single vacuum plate hole, it can be for one or a combination of the following reasons;

1- Vacuum hole size is to large; reduce seed plate hole size.

2- Vacuum hole size and vacuum pressure set to high; reduce vacuum pressure, lower vacuum pressure can improve singulation by virtue of weakening the vacuum pressure enough to drop off multiples while maintaining vacuum pressure enough to hold a single seed.

3- Irregularly shaped and or small seed; reduce seed plate hole size and reduce vacuum pressure. If issue persists very careful adjustment of seed singulator* can improve singulation.

Skips or Blanks

If coated seed is not adhering to the vacuum plate holes it can be for one or a combination of the following reasons;

1- Vacuum pressure is set to low; increase vacuum pressure.

2- Seed plate hole is to small; use seed plates with larger holes; increase vacuum pressure.

3- Planter speed to fast; reduce planter speed/rpms.

4- Seed bridging or packing; reduce volume of seed in seed chamber/hopper; engage agitator**.

Singulators*

Seed singulators should only be considered for use if remedy for multiples using appropriate vacuum plate hole size and vacuum pressure adjustments have been attempted and failed.

In those rare incidences when seed singulators are deemed necessary, great care should be used when adjusting them. Improper adjustment of seed singulators on pneumatic planters planting pelleted or encrusted seed can damage and crack the material coating the seeds resulting in unsatisfactory planter performance and seed placement.

Agitators**

Generally speaking; when planting SDI seed enhancement products Prep-Coat, Gro-Coat and AirMaxx in vacuum planters, all seed singulators and seed agitators should be removed or adjusted out of play.In most instances seed agitators (fixed or adjustable) are not necessary when using Gro-Coat, Prep-Coat or AirMaxx. For most applications we recommend agitators not be used. Using agitators can chip and crack seed coatings. In the rare instance coated seed is bridging or packing in the seed hopper causing skips, reduction of seed quantity in the seed hopper should be tried before considering use of seed agitators.

Seed Containers

Materials used to coat, pellet and encrust seed attract and hold onto water; they are hydrophilic. Exposure to humidity can soften seed coatings reducing plantability and reducing shelf life of the seed. All effort should be made to effectively reseal any opened container of processed seed.

Why It’s Important

Seed placement: correct placement of seeds maximizes harvest opportunity; Accurate seed depth and spacing is the primary goal. Seed row skips and doubles will reduce yield, waste valuable seed and increase thinning costs.

Options

Pelleting, or encrusting can improve planter performance. See Gro-Coat®, Prep-Coat®, Gro-Coat® Air-Maxx, Prep-Coat® Air Maxx, PULSE® Gro-Coat®, and PULSE® Prep-Coat®.

Disease pathogens can destroy seed, seedlings and mature plants. For example, Xanthomonas campestris p.v. campestris (Xcc brassica black rot), Xanthomoas campestris p.v. zinniae, Pythium, Fusarium, Rhizoctonia, Helminthosporium, Fusarium, Aspergillus, and Penicillium.

Why It’s Important

Disease can have severe financial implications for growers.

Options

Seed treatments, seed-applied plant protectants, use of pathogen free seed, post emergence applications of appropriate chemical control. Products include FarMore® Plant Protectants, Pre-Prep® Brassica, or Pre-Prep® Zinnia.

Seed and seedling damage from insects. Such as aphid, flea beetle, whitefly, leafminer, cucumber beetle, wireworms, or seedcorn maggot.

Why It’s Important

Vector plant diseases, infects plants with diseases, damages or destroys seeds and seedlings, lower plant population, lower yield, and lower profit.

Options

Seed-applied plant protectants, seed treatments, pre-emergence field applied chemical control and post-emergence field applied chemical control. Use organic seed-applied protectants, or conventional seed-applied protectants.