1. 2012: Weed Management and Crop Injury when Intercropping Melons and Cotton
Traditionally, spring planted melon crops in southern Georgia are harvested by July allowing that land to be planted to sorghum. Returns on sorghum following cantaloupe are often marginal, prompting growers to seek other potential crops and strategies that may generate greater revenue; one such strategy is a melon-cotton intercropping system.
Peter Eure*, Stanley Culpepper, Brian Tankersley, and Rand Merchant
The University of Georgia
Tifton, Ga

2. Introduction Cantaloupe or watermelon intercropped with cotton
Increase resource efficiency
Improve grower profit
Stability in production
Land preparation, fertilizer, and irrigation are in place for the melons; therefore, intercropping cotton could potentially increase resource efficiency and improve grower profit.

3. Cantaloupe and Cotton Intercropped (Tift County, GA)
In 2010 Tift county, Ga had roughly 40 acres of cantaloupe and cotton intercropped together…. In 2011, there were nearly a 10x increases in the acreage of cantaloupe intercropped. The acrage intercropped in 2011 constitutes ~20% of the cantaloupe acres in tift county.
Weed management in this intercropping system can be problematic for grower, and growers may rely on hand weeding therefore…..

4. Objectives
Identify herbicide systems to manage troublesome weeds in melon-cotton intercropping production
Determine the profitability of melon-cotton intercropping versus a monoculture of melon or cotton

5. Hypothesis
Herbicide options exist to adequately control weeds in melon-cotton intercropping systems
Crop value per acre will be greater when melon and cotton are intercropped versus a monoculture of melon or cotton

6. Materials and Methods
Two separate field studies conducted at Ty Ty, Georgia on a Tifton loamy sand during 2011
Cantaloupe
Watermelon
Each study consisted of:
Two planting dates of melon-cotton intercrops, three herbicide systems and a non-treated control
Melon and cotton alone were planted for each planting date to serve as comparisons
We conducted two separate field studies….
Growers often spread out their melon planting, therefore each study consisted of two planting dates of melon-cotton intercrops and for each planting date, 3 herbicide systems were evaluated.
Our goal in the monoculture systems was to adequately manage weeds to an extent that would eliminate weed crop competition.
Melons grown in monoculture received ethalfluralin (0.75 lbs ai/A) + fomesafen (0.25 lbs ai/A) preplant. Herbicide systems for monoculture cotton included sequential applications of glufosinate + S-metolachlor or glyphosate + acetochlor at recommended rates when sensitive weeds were less than three inches tall.
A layby application of glufosinate + diuron was made just prior to cotton canopy closure.

7. Materials and Methods
Melons were transplanted into a 0.8 mil plastic mulch having an 18” wide bed top
Cotton plantings for each planting date were made when the initial melon vine reached the mulch edge
PHY 499 WRF was planted on 36 inch row spacing, using a 2-row planter centered over the plastic mulch

8. Intercropping systems were managed for melon production until harvest
Cotton
Managed for melons
Harvested melons
Desiccated melon vines around July 1 and begin management for melon production
Intercropping systems were managed for melon production until harvest

9. Material and Methods Data recorded throughout the season:
Visual estimates of Palmer amaranth control
Melon and cotton injury
Melon vine length
Cotton height
Melon and cotton yield
Melon harvested by hand
Cotton harvested using a spindle picker designed for small plot research
Total crop value/A = value of total products generated - cost to produce each crop

10. Material and Methods
Total crop value per acre of intercropping systems and monoculture systems were calculated
Total crop value/A=value of total products generated-cost to produce crop
Data subjected to ANOVA and means separated using Fisher’s Protected LSD (p≤0.05) when appropriate
Total crop value/A = value of total products generated - cost to produce each crop

11. Cantaloupe-cotton intercropping
“Athena” cantaloupe transplanted:
Transplant date 1: April 5, 2011
Transplant date 2: April 20, 2011
Herbicide treatments in intercropping systems:
Ethalfluralin (0.75 lbs ai/A) preplant
Ethalfluralin + Fomesafen (0.25 lb ai/A) preplant
Ethalfluralin + Fomesafen preplant fb Halosulfuron (0.032 lb ai/A) + NIS (0.25% v/v) 10 days after transplant
Non-treated control
Herbicide treatments in monoculture systems:
Melon: Ethalfluralin + Fomesafen preplant
Cotton: Sequential applications of Glufosinate + S-metolachlor or Glyphosate + Acetochlor when sensitive weeds were less than three inches tall
Our preplant treatments were broadcast 2-3 day prior to melon transplanting. Resulting in herbicide residue on our plastic mulch.

12. Therefore, herbicide residue was washed from the plastic mulch using overhead irrigation. This also activated our preplant herbicides.

13. Palmer amaranth control prior to cantaloupe harvest
Immediately prior to cantaloupe harvest and combined over planting dates, Palmer control with ethalfluralin alone as 55%. Fomesafen systems controlled Palmer amaranth greater than 95%.
Ethalfluralin
Ethalfluralin Fomesafen
Ethalfluralin +
Fomesafen fb
Halosulfuron
LSD(P≤0.05)=2

14. Non-treated control Ethalfluralin + Fomesafen fb Halosulfuron
*Average of 57 Palmer amaranth in NTC
**Picture taken 8 weeks after transplant

15. Ethalfluralin + Fomesafen
Cantaloupe Yield
NTC
Ethalfluralin
Ethalfluralin +
Fomesafen
Ethalfluralin +
Fomesafen fb
Halosulfuron
Ethalfluralin + Fomesafen
(Cantaloupe Only)
LSD(P≤0.05)=558
*Data pooled over planting and harvest dates

16. Palmer amaranth control prior to cotton harvest
Immediately prior to cantaloupe harvest and combined over planting dates, Palmer control with ethalfluralin alone as 55%. Fomesafen systems controlled Palmer amaranth greater than 95%.
LSD(P≤0.05)=5
*Data pooled over planting dates

17. Lint Cotton Yield LSD(P≤0.05)=119 NTC Ethalfluralin Ethalfluralin +
Fomesafen
Ethalfluralin +
Fomesafen fb
Halosulfuron
Cotton Only
LSD(P≤0.05)=119

18. Cantaloupe-cotton intercropping vs. monoculture
When calculating value of the products generated from each crop minus the cost to produce each crop, intercropping cantaloupe and cotton increased total value/acre 11-14% when compared to cantaloupe grown in monoculture and % when compared to cotton grown in monoculture.
What is really interesting is that an acre of intercropping genereated about the same crop value/A as ONE acre cantaloupe and cotton combined.
*Data pooled over planting dates
**Calculated using $530 and $2,450 as the cost to produce and harvest cotton and cantaloupe, respectively. Cotton value set at $0.92/lb. and cantaloupe value set at $1.00/fruit.

19. Watermelon-cotton intercropping
“Melody” (seedless) watermelon transplanted:
For pollination, “Sangria” transplanted every fourth plant
Transplant date 1: March 23, 2011
Transplant date 2: April 7, 2011
Herbicide treatments in intercropping systems
Ethalfluralin (0.75 lbs ai/A) preplant
Ethalfluralin + Fomesafen (0.25 lb ai/A) preplant
Ethalfluralin + Fomesafen + Terbacil (0.2 lb ai/A) preplant
Non-treated control
Herbicide treatments in monoculture systems:
Melon: Ethalfluralin + Fomesafen preplant
Cotton: Sequential applications of Glufosinate + S-metolachlor or Glyphosate + Acetochlor when sensitive weeds were less than three inches tall

20. Palmer amaranth control prior to watermelon harvest
Ethalfluralin
Ethalfluralin +
Fomesafen
Ethalfluralin +
Fomesafen +
Terbacil

21. Non-treated control Ethalfluralin + Fomesafen
160 Palmer in NTC
NEED A BETTER PICTURE
Non-treated control
Ethalfluralin +
Fomesafen
*Average of 160 Palmer amaranth in NTC
**Picture taken 8 weeks after transplant

22. treatments that included terbacil resulted in undesirable cotton injury (96%) while no other herbicide system injured cotton.
Terbacil Injury

23. Ethalfluralin + Fomesafen
Watermelon Yield
NTC
Ethalfluralin
Ethalfluralin +
Fomesafen
Ethalfluralin +
Fomesafen +
Terbacil
Ethalfluralin + Fomesafen
(Watermelon Only)
LSD(P≤0.05)= 6696
*Data pooled over planting and harvest dates

24. Palmer amaranth control prior to cotton harvest
LSD(P≤0.05)= 7
*Data pooled over planting dates

25. Ethalfluralin + Fomesafen
Lint Cotton Yield
Cotton yield from intercropped systems were 14-24% less than monoculture cotton yield.
NTC
Ethalfluralin
Ethalfluralin Fomesafen
Ethalfluralin +
Fomesafen +
Terbacil
Cotton Only
LSD(P≤0.05)= 41

26. Watermelon-cotton intercropping vs. monoculture
When calculating value of the products generated from each crop minus the cost to produce each crop, Intercropping watermelon and cotton increased total value/acre 24% when compared to watermelon grown in monoculture and 384% when compared to cotton grown in monoculture.
*Data pooled over planting dates
**Calculated using $530 and $2900 as the cost to produce and harvest cotton and watermelon, respectively. Cotton value set at $0.92/lb. and watermelon value set at $0.15/lb.

27. Conclusions
Melon-cotton intercropping improved total crop value per acre as compared to a monoculture of melons or cotton
Herbicide options exist for adequate control of troublesome weeds in melon-cotton intercropping systems
Fomesafen is not registered for use in watermelon or cantaloupe
Halosulfuron and ethalfluralin are not registered for use in cotton

28. Future Research
Registration of fomesafen for use in watermelon and cantaloupe
Registration of preplant applications of halosulfuron and ethalfluralin for cotton
Complete a comprehensive economic budget comparison of these systems
Fomesafen: The way the label reads, 18 months before you can transplant melons. Important to understand that fomesafen is currently label in dry beans and snap beans. Both edible from the field.
Halosulfuron: 4 month rotation interval for cotton.

29. Questions or Comments?

30. Introduction Background on spring melon production
Transplant late March to late April
Harvest mid to late June
Melons followed by plant grain sorghum
Now typically, growers plant around April 15 and harvest sometime in mid-late June. Once they are done harvesting, they may plant sorghum. Returns on sorghum are marginal, so growers sought out other potential crops. Which leads us to the grower idea
Smith and Smith, 2011