Orchard Floor Management

B. A. Majek

Rutgers A. R. & E. C.

Bridgeton, NJ

Why Control Weeds in Orchards?

Weeds compete with the crop:

water

nutrients

sunlight

space

Alternate host for insect and disease pests.

Provide cover for rodents.

Interfere with pollination.

Reduce harvest efficiency.

Do NOT apply when bloom is present in the orchard!

Consider

Soil

Weeds

Insect Pests & Beneficials

Diseases

Rodents

Operations

Frost Risk

Tree Performance

Cultivation

Short TermEliminates Weeds

Increases Water Penetration

Prunes roots

Raises Oxygen Level

oxidizes organic matter

releases adsorbed nutrients

CultivationLong Term

Exposes Soil to Wind and Water EROSION

Increases Root Vulnerability to disease

Decreases Organic Matter & Destroys Soil

Structure

Reduces Water Penetration

Decreases Nutrient and Water Holding

Capacity of the Soil

Increases soil compaction

Soil

50% mineral and organic solids

25% micropores (holds water despite gravity)

25% macropores (water flows out due to gravity)

Sod Row Middles

&

Tree Row (weed free)

Desirable Orchard Floor Vegetation

Minimally competitive with the trees.

Good traction for equipment in all conditions.

Roots should be shallow, fine and fibrous.

NOT an alternate host for insect & disease pests.

Inexpensive to maintain.

Easily controlled.

Encourage beneficial organisms.

Sod Groundcover Establishment

site preparation

sod species

grass groundcover seeding

sod care for the first 22 months

Site Preparation

correct pH

adjust fertility

control established perennial weeds

improve drainage – ridging, field tiling or leveling

prepare seedbed

Sod Species

Kentucky bluegrass

perennial ryegrass

tall fescue

„Kentucky 31‟

turf type varieties

hard fescue

Sod Groundcover Seeding

(sod middles)

Timing

north Jersey – 8/15 to 9/1 (9/15 deadline)

south Jersey – 9/1 to 9/15 (9/30 deadline)

north & west – 8/1 to 8/30 (?)

Blend

100% tall fescue

95% hard fescue + 5% perennial ryegrass

Rate – 25 to 50 pounds of seed per acre

Equipment – drop seeder with rollers

Sod Groundcover Seeding

(tree row)

Timing

north Jersey – 8/15 to 9/1 (9/15 deadline)

south Jersey – 9/1 to 9/15 (9/30 deadline)

north & west – 8/1 to 8/30 (?)

Blend

100% perennial ryegrass – kill with Roundup or OLF at least 1 week before planting trees

Rate – 25 to 50 pounds of seed per acre

Equipment – drop seeder with rollers

Sod Care (first 22 months)

Fertility – 40 to 80 lb of N per acre

at seeding

early spring – March/April after seeding

early spring – 1.5 years after seeding

Mowing – never remove more than 1/3 the height

of the grass

Sod Care (first 22 months)

Weed Control

Fall

2,4-D – 0.5 pints per acre in late fall, at least

10 weeks after seeding

Spring

Prowl – 1.5 quarts per acre

+

2,4-D – 1 pint per acre in early spring

(before planting trees)

Sod Row Middles

&

Tree Row (weed free)

Split Herbicide Application Program

Fall & Spring

good labor dist. 2 app. trips

w. annual control hunting season

low light

act. rainfall

lower herb. rates

soluble herbicides work

perennial weed seedling control

----------THE NEXT STEP----------

What is the Potential of Mulches

in Peach Orchards?

• Which works better Organic or Fabric

mulch?

• Will reduced herbicide programs be

possible with mulch?

• How do mulches affect weed control,

tree growth and yield?

• Will mulch “create” new problems?

Split Plot Design

Main Plots

untreated

residual & postemergence herbicide applications

Prowl 3.3 lb ai/A

Gallery 1.0 lb ai/A

Grramoxone + NIS 0.6 lb ai + 0.25%/A

Split Plot Design

Main Plots

untreated

residual & postemergence herbicide applications

Sub Plots

tilled monthly

no-till

yard waste (leaf) mulch

landscape fabric

Untreated

Num. Dry Wt (g) Trunk Dia. Yld (lb/tree)

Tilled 0 0 1.6 1

No-Till 87 363 1.4 2

Yd Waste 3 141 16.4 7

L. Fabric 1 4 23.2 30

Res. Herb.

Tilled 6 21 14.1 15

No-Till 15 271 10.3 20

Yd Waste 0 0 19.3 27

L. Fabric 1 0 26.0 46

Summer Annual Weeds/Yd2 Impact on Tree Growth

Mulches – Concerns and Questions

Rodent Damage – may be more severe under mulch!

Leaf Mulch & Landscape Fabric suppressed or controlled weeds.

Increased tree growth and early yield with leaf mulch and landscape fabric could not be explained by improved weed control.

Questions concerning mulches that need answers:

fertility

root zone (soil) temperatures

moisture

Should we be growing our own mulch between the rows?

Questions?