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What Is the Best Rootstock for Citrus Production? A Practical Guide for Commercial Growers

Whether you’re starting fresh with a brand new commercial citrus tree operation or you’re an old hand at citrus tree cultivation, rootstocks can make or break the fruiting process. But which variety is designed for your needs? How do you know which will be best suited for your soil conditions and known diseases and pests in your local area? Who can you turn to with your questions and trust that you’ll get the right answers?

TreeSource is here to give you a breakdown on all things rootstocks. After reading this guide, you’ll have a much better idea of what to ask your nursery and what information to provide them when selecting the rootstock seedlings you need to start your new tree block.

Keep reading to learn why commercial citrus operations and greenhouse growers need rootstocks to be successful, six factors to consider when choosing one, five reasons why choosing the right one matters, and a handy checklist of things to know before calling your nursery.

Table of Contents

Which Rootstock Is Used in Citrus?

Most rootstocks can be categorized into two types:

Trifoliate and Trifoliate Hybrids (i.e., citranges, citrumelos, citrandarins)

  • Better cold-tolerance
  • More resistant to diseases
  • Predictable size controlling
  • Used in high-density planting

Non-Trifoliate (i.e., Rough Lemon, Volkameriana, Macrophylla, Sour Orange)

  • Heat and drought-resistant
  • Susceptible to diseases
  • Better for tough soils
  • More vigorous

New hybrid varieties are being developed daily to counteract pressures that could have wiped out an entire commercial operation only a few years ago.

What Is the “Best Rootstock” for Citrus? 6 Main Factors To Consider

There’s no such thing as a universal “best rootstock.” What is considered best for one orchard will not be best for all others. It depends entirely on your specific production goals.

Rootstock choice affects an orchard’s ROI through:

  • Survivability
  • Yield stability
  • Replant costs
  • And more

Management efficiency also comes into play because your orchard will need to handle:

  • Pruning
  • Harvest
  • Spray coverage
  • Equipment access

Here are six things growers should consider when deciding on rootstock selection.

#1: Scion Goals

Depending on whether your production is designed to produce early returns, long-term productivity, or market type, it should determine the best rootstocks to use for your orchard. Different scions perform better with different rootstocks because of their traits.

Common production goals and what they usually require:

  • Early yields for faster ROI: Precocious rootstocks like Volkameriana or some hybrids
  • Fresh fruit appearance and quality: Rootstocks with good root control and  soluble solids
  • Juice production with volume: Vigorous rootstocks with large canopies and high yields
  • Mandarins and smaller canopies: Size-controlling or compatible trifoliate hybrids
  • Long orchard life: Balanced vigor, disease-tolerant rootstocks with good compatibility

#2: Soil Profile

Your orchard’s soil is the one factor you can’t change, so choosing the right rootstock that will flourish in yours is essential. Citrus root systems are sensitive to their soil environment. If a rootstock and soil are not compatible, it will cause underproduction, stunting, and tree loss.

You must match your rootstock to your site’s limitations. The soil characteristics that can affect rootstock performance the most include:

  • Drainage: Poorly or heavily drained soil prevents oxygen from reaching the roots; bad for trifoliate types.
  • Salinity: Saline soils need salt-tolerant rootstocks like Cleopatra mandarin, some hybrids.
  • pH: Some rootstocks don’t perform well in Alkaline  soils > 7.5 pH.
  • Texture/Compaction: Sandy soils don’t retain moisture well; clay-heavy soils prevent roots from growing.

#3: Pest and Disease History

A main factor in root selection should be managing the risk associated with local pests and diseases that have already shown up in your block or region. You should take your orchard’s health history into account when choosing rootstocks, as many were developed with specific disease and pest-resistant properties.

Common pest and disease pressures that influence rootstock choice:

  • Phytophthora root rot
  • Nematodes
  • Tristeza virus (CTV)
  • HLB (Huanglongbing/Greening)
  • Exocortis or other viroid issues

#4: Planting Density and Canopy Plan

Your rootstock selection should also be determined by how closely you want your trees spaced together and the size of the canopy that your operation can handle without constant corrective pruning. Density and canopy size should be determined together, not as separate issues. You’ll need to consider both to choose the best rootstock that your grove can accommodate correctly.

If you’re planning on high-density groves, your rootstock needs to support:

  • Small to moderate canopy size
  • Efficient fruiting on a compact tree structure
  • Minimal corrective pruning

However, there are things to consider when planning a high-density planting area. If planted in an exposed area, size-controlling rootstocks may be more susceptible to wind and toppling risk, and too-tight spacing can limit long-term access for sprays and harvesting equipment, making both much more difficult and affecting their return on investment.

#5: Nursery Production Availability

Availability is a real-world issue you may run into when searching for the best rootstocks for your commercial operation. Despite putting the research work in to find your “perfect” rootstock, you may not be able to get it in the quantity and timeline you need.

Keep open communication with your nursery, and give them your acreage, scion type, and production timeline early. TreeSource is ready to make sure your timelines stay on track by helping align available rootstocks.

#6: Scion Compatibility

Scion compatibility is a simple pass or fail test. No other factors are important if the pairing doesn’t work. Even if the rootstock has perfect uniform growth, graft union health, and long-term stability, it doesn’t mean a thing if it isn’t compatible with the chosen scion.

This is a long-game decision, as some trees don’t prove incompatible until several years after planting, when the tree is underproducing, or is lost entirely.

To make sure rootstocks are compatible:

  • Use established nursery pairings
  • Consult reputable trials
  • Avoid experimental pairings

Compatibility is about how long the tree will last in commercial production, not just if it will graft. Commercially viable citrus trees need to last generations, not just a handful of harvest seasons.

5 Reasons Why Choosing the Best Rootstocks for Your Citrus Matters

Think of rootstocks as the foundation of the orchard. It determines everything from how well the tree will react to the site to how it will handle local stressors to what the return of the tree will be. Rootstocks can’t fix a scion’s poor genetics or mishandled management, but they can get the best production possible out of your scion.

Let’s break down five important ways that rootstock choice affects commercial citrus production.

#1: Canopy Size

Rootstocks play a vital role in determining the growth speed and size of the canopy over time, directly affecting:

  • Pruning needs
  • Spray penetration
  • Harvest efficiency
  • How fast trees fill their allotted space

Canopy size isn’t just about “big vs small”, it‘s also about “manageable vs expensive to manage.” But if a canopy develops too slowly, then it delays ROI and takes longer than desired to fill its space.

Operational impacts of canopy size include:

  • Amount and frequency of pruning required
  • Spray efficacy and penetration
  • Ease of harvest
  • Equipment access to rows
  • Time for canopy closure and production

#2: Precocity

Precocity simply means the amount of time it takes for a citrus tree to begin producing commercially viable fruit yields since the time of planting. Many operations favor quick yielding because it means a faster return on investment, especially if creating or replanting a new block.

Different rootstocks vary in how quickly they push the early production of their scions. It’s a true balancing act. Too much vigor early can cause an overgrowth of leaf foliage and delay fruiting; however, overly size-controlling rootstocks can delay canopy development, particularly in marginal soil.

The scion and rootstock combination is key to early yield with sustainable tree structure.

#3: Yield Efficiency

Yield efficiency is how much fruit a tree produces per harvest relative to its canopy size; basically, it’s productivity per unit of growth.

Commercial citrus is all about fruit yield, which depends on the size of the tree’s canopy. The right rootstock on a well-balanced tree can produce more fruit with less foliage, meaning less pruning and tree management is needed, and with better returns per acre.

Efficient citrus trees typically respond better to water and fertilizer, too, which supports sustainability and cost reduction. When used efficiently, less of both is needed, which means less money is spent on buying the products.

#4: Fruit Quality Tendencies

Rootstocks play an important role in fruit quality (sometimes subtly, sometimes significantly) by influencing traits like:

  • Soluble solids
  • Fruit size distribution
  • Juice content
  • Peel thickness and texture
  • Maturity timing

However, other factors play a role as well, such as:

  • Scion type
  • Site environment
  • Orchard management

#5: Tolerance to Stress

One of the most strategic reasons to put thought into rootstock selection is its stress tolerance. Two types of stress in orchard sites are biotic stress, caused by diseases and pests, and abiotic stress caused by water, soil, and weather conditions. Specific rootstocks perform better under certain stressors.

It’s important to talk to your nursery about the types of pressures your orchard experiences. Nurseries like TreeSource have the knowledge needed to help growers choose the rootstocks that will work best for different sites.

Buyer’s Checklist: What To Have Ready Before You Call a Nursery

It’s crucial to have a checklist of information before ordering from wholesale nurseries. Having this information ready and at hand will make the selection process easier for both you and the nursery employees. When you prepare ahead of time, it takes less time ordering and asking questions over the phone, and more time tending to your orchards. Make sure to have a list like this ready:

  • Scion/cultivar
  • Acreage
  • Space plan
  • Soil notes
  • Water quality
  • Known disease or pest pressures
  • Desired delivery window
  • Quantity needed

Commercial Citrus Rootstocks: How TreeSource Supports Informed Selection

TreeSource is a USDA/CFDA-certified full-service citrus tree nursery in California. We’re a trusted authority on citrus tree innovation and development. If you’re involved in the commercial citrus tree industry or are greenhouse growers, we are here to help answer your questions about rootstock selection, as well as provide your operation with top-quality rootstock seedlings perfect for your specific operational goals, soil conditions, and climate variables. Contact us today to get started or continue on your rootstock selection.