Tag: WatermelonProduction

Part II: A Deeper Look into Grafted Watermelon Production and Management

Posted on | by Josh Mays
Harvested Watermelons

In our last blog post we took a deeper look into grafted watermelon production and management by reviewing a 2020 watermelon trial in central North Carolina. In this post we want take you through year 2 results and our findings. The key focus points of the trial were increasing yields and maturity window of grafted plants using chloropicrin.

Trial details for background

  • The trial was on watermelons grown on plasticulture using TIF film since we found the best results the year prior with using that.
  • We made shank applied fumigant application using a Reddick Equipment Company RMC plastic layer 25 days prior to planting.
  • The grower had watermelons on this particular piece of land on a 3 year rotation with sweet corn, small grain, and tomatoes.
  • The land had heavy root knot nematode pressure and low fusarium wilt pressure so the Carolina Strong Back rootstock was used for the grafted watermelon plants.
  • The trial was planted on 8’ row centers x 3’ standard plant spacing (1,815 plants/acre) and 8’ row centers x 4’ grafted plant spacing (1,316 plants/acre).
  • We used 25% pollinators in-row between every 3rd and 4th seedless plant.

Harvest Events

  • The trial fields allowed for 3 harvest events.
    • June 30 (74 DAP)
    • July 12 (88 DAP)
    • July 26 (102 DAP)
  • The Joyride melon used is an 86 day melon.
  • The grafted maturity is the same as the standard Joyride plant maturity, but heavier yields were shifted 5-7 days.
  • We saw a strong yield response to the fumigant applications and vine health remained great all the way through final harvest on July 26th.
74 DAP
86 DAP
100 DAP
Click to see large chart image.

In summary, we saw results similar to our findings in 2020.

  • Chloropicrin is increasing yields in both non-grafted and grafted plant production systems
  • Fertility changes and addition of chloropicrin are speeding up grafted plant maturity
  • First harvest of grafted is approximately half of non-grafted, but the second harvest of grafted is much heavier
  • Longer harvest windows are possible with grafted plants, due to increased plant growth and durability to harvests
  • No significant differences were seen in size profiles or sugar content/brix between treatments

We saw comparable results in 4 different trials of similar design across North Carolina, Georgia and Florida in 2022. Some key findings:

Standard plant yields are increasing use of chloropicrin

  • North Carolina – 34% increase
    • Florida – 16% and 15% increase
    • Georgia – 20% increase

Grafted plant yields are increasing with the use of chloropicrin and specific fertility protocols

  • North Carolina – 22% increase
    • Florida – 12% and 23% increase
    • Georgia – 14% increase

Combining grafted plants and fumigation with chloropicrin is providing dramatic yield increases over grower standard practice yields in all trial areas

  • North Carolina – 70% increase
    • Florida – 28% and 44% increase
    • Georgia – 28% increase

To learn more please contact our very knowledgeable team at TriEst and be sure to sign up for the next installation of the TriEst Ag News series.

A Deeper Look into Grafted Watermelon Production and Management

Posted on | by Josh Mays

In our last blog we went over the obstacles that growers face in watermelon production and their potential solutions. In this blog and video presentation we will take a deeper dive into why we recommend grafted plants and fumigation as potential solutions to obstacles in watermelon production.

Before we get into the first broad study trial we conducted, I would like to focus on grafted plants as a tool and potential solution to grower obstacles.

Some advantages in grafted plants and differences over standard are:

  • Improved root system, increased vigor, better plant and vine health.
  • Disease resistance. (Fusarium, all races)
  • Nematode resistance. (Rootstock dependent)
  • Reduced crop rotation due to better disease resistance.
  • Prolonged harvest potential and higher yield potential.

A common question about grafted plants is about which rootstock is best for a farm. Rootstocks that Tri-Hishtil offers are the Interspecific Hybrid Squash and the Carolina Strongback. The Interspecific Hybrid Squash is susceptible to Root Knot Nematode while the Carolina Strongback offers resistance.

In a trial we conducted in Central North Carolina we looked at solving some of the problems that growers faced by focusing on grafted plants versus standard, fumigated versus non-fumigated, and standard fertility versus reduced fertility.

At the end of this first trial, we learned that grafted plants with the Carolina Strong Back rootstock had significant yield responses over the standard plants, while also performing better than the squash-based rootstock. We also saw increased yields from fumigation regardless of plant type (grafted or standard) and regardless of plant spacing. Lastly, we discovered that reduced plant populations within 20-30% did not result in yield loss when using grafted plants.

Chart description of end field performance results of non-grafted, squash-root grafted, and Carolina Strong Back on different row spacing.

Lastly, we learned from this trial that early fertility reduction would control vine density and promote earlier flowering in grafted plants; however, fertility decreases after fruit set resulted in yield loss. This information has led to specific fertility programs for grafted plants that increase yields, decrease costs and result in earlier harvests.

The 4 beds marked R have Reduced Fertilizer. The 4 beds marked F have typical fertilizer program.

To learn more please contact our very knowledgeable team at TriEst and be sure to sign up for the next installation of this blog. We’ll be going over more trial data and results from the field!

Overcoming Obstacles in Watermelon Production

Posted on | by Josh Mays

Sustainable crop production is a complex issue that every farmer faces each season. All crops present their own challenges and specific needs for maximizing yields and profitability. Let’s focus on discussing a few key impacts for watermelon production in the Southeastern US. The production issues for watermelon are not limited to those listed here by any means, but the following are the focal points of ongoing research that will be discussed over several blog installments in the coming months.

  • Soil borne pests – fusarium wilt, which can be devastating as crop rotations become limited and “new ground” isn’t an option
  • Nematodes – root knot nematode, a widespread issue across the Southeast US
  • Viruses – significant impacts on certain markets and very difficult to control
  • Crop rotation – ability to produce and market crops that aren’t a disease host for watermelon
  • Land availability – decreasing availability in almost all major melon production areas
  • Cultural production system – plasticulture vs bareground under many different styles of irrigation methods (drip, overhead, seep, flood etc)
  • Plant type and variety selection – Use of grafted plants for fusarium wilt control and/or use of tolerant varieties
  • Harvest windows – Watermelon markets are hyper sensitive to timely harvest events by geography. It is critical to understand how production system practices can impact these windows
Fumigated grafted plants (center) and grower standard plants (either side)
20 days after planting – fumigated melons on the left and non-fumigated on the right.

The task for every farmer is to find the balance between these challenges and potential control measures for each, while staying profitable. Solving this problem has to be taken one step at a time and our first step was to identify the products we had available to bring the farming community solutions to these problems. TriEst Ag Group and its affiliates are dedicated to providing soil solutions for the agricultural industry, so let’s take a look at the tools we’ve used to solve this puzzle in watermelon production.

  • Soil fumigation – TriEst has a variety of fumigants and product combinations that can be used for managing a wide range of soil borne pests and nematodes. In addition to managing pests, we have results to indicate that at low rates certain fumigates can be used to improve soil health and increase crop vigor in watermelon crop production. The right product is dependent on the specific pest and disease pressures of an individual farm. In our research we have used multiple products and we will discuss the pros and cons of each in this series.
  • Grafted plants – Like fumigants, there are several options for rootstocks available for grafted plants. Choosing a rootstock is also specific to the issues faced on an individual farm. The primary focus for grafted plants is fusarium wilt control and increased yields.
  • Cultural practices – There are many different cultural practices that are used in watermelon production. Each different scenario can impact the efficacy of fumigation, grafted plant performance, water availability and fertility. We focus on multiple cultural practices in our research, trying to find the best system possible and understanding how each changes the other products involved.
  • Fertility – Soil fertility and fertilizer use has a major influence on crop production. When looking at an overall system for control, fertility has to be considered. Fertility programs should change when they’re used with fumigation and grafted plants. The cultural system being used impacts timing and rates. Details on this will be outlined as we move forward in the series.

Over the past two years, with crops located all across the Southeast, we have worked to develop effective production systems using these tools. We will bring these results and concepts forward in this watermelon crop series, month to month. Next blog, we will take a deep dive into grafted plant production and the impact of fumigation in that system. Stay tuned!