Plant Growth Regulators in Other Grass Seed Crops

Roger Burak, Dip AgMFSA Research Manager

Plant growth regulators (PGR) have been researched in other grass seed crops for a number of years in both Canada and the United States. The Manitoba Forage Seed Association (MFSA) together with Saskatchewan and Alberta have been gathering data to help attain registration of plant growth regulators on a variety of grass species such as annual ryegrass, fescues and bromegrass . It is also the focus of MFSA to investigate a number of plant growth regulators and their effects on grass species. It was from this investigation process that we decided to continue our work with Parlay (trinexapc-ethyl) and to include Manipulator (chloromequat chloride) in this year's investigation.

The trials are set out as field scale screening strips in a producer's field. It should be noted that these were not replicated. This procedure allows us to investigate the interaction of the PGR on the crop in a not replicated. This procedure allows us to investigate the interaction of the PGR on the crop in a field setting without affecting a large area of a producer's production. The data gathered from this screening process can then be taken to a replicated setting and scientifically studied. In 2018 we were able to investigate annual ryegrass at Riverton MB, tall fescue and hybrid bromegrass at Minnedosa MB.

The treatments consisted of:

1. Parlay @ .7L/ac2. M anipulator @ .7L/ac3. Mix Parlay @ .35L/ac with Manipulator @.35L/ac4. untreated check

All treatments were made at the 2nd node stage, with producer-supplied field sprayers. This allowed for a single 100 – 120 ft strip to be made within the field. All other field operations and applications were made equally during the year with no other variables applied to the treatment areas other than the plant growth regulators.

The annual ryegrass was sprayed with a reduced rate of plant growth regulator, as the dry conditions had stressed the crop and it was agreed that the full application may produce crop injury. Therefore a half rate for each treatment was applied to the annual ryegrass trial only.

Height ratings were taken from each treatment every seven days, from the same marked plants to ensure constancy in the ratings. At harvest the producers agreed to swath and harvest two swaths from the center of each treatment and have the production weighed in a weigh wagon. Subsamples were taken from each harvested plot area for analysis. The subsamples were cleaned to derive an approximate dockage percentage and also for moisture content, which

Plant Growth Regulators in Other Grass Seed Crops

Roger Burak, Dip AgMFSA Research Manager

Plant growth regulators (PGR) have been researched in other grass seed crops for a number of years in both Canada and the United States. The Manitoba Forage Seed Association (MFSA) together with Saskatchewan and Alberta have been gathering data to help attain registration of plant growth regulators on a variety of grass species such as annual ryegrass, fescues and bromegrass . It is also the focus of MFSA to investigate a number of plant growth regulators and their effects on grass species. It was from this investigation process that we decided to continue our work with Parlay (trinexapc-ethyl) and to include Manipulator (chloromequat chloride) in this year's investigation.

The trials are set out as field scale screening strips in a producer's field. It should be noted that these were not replicated. This procedure allows us to investigate the interaction of the PGR on the crop in a not replicated. This procedure allows us to investigate the interaction of the PGR on the crop in a field setting without affecting a large area of a producer's production. The data gathered from this screening process can then be taken to a replicated setting and scientifically studied. In 2018 we were able to investigate annual ryegrass at Riverton MB, tall fescue and hybrid bromegrass at Minnedosa MB.

The treatments consisted of:

1. Parlay @ .7L/ac2. M anipulator @ .7L/ac3. Mix Parlay @ .35L/ac with Manipulator @.35L/ac4. untreated check

All treatments were made at the 2nd node stage, with producer-supplied field sprayers. This allowed for a single 100 – 120 ft strip to be made within the field. All other field operations and applications were made equally during the year with no other variables applied to the treatment areas other than the plant growth regulators.

The annual ryegrass was sprayed with a reduced rate of plant growth regulator, as the dry conditions had stressed the crop and it was agreed that the full application may produce crop injury. Therefore a half rate for each treatment was applied to the annual ryegrass trial only.

Height ratings were taken from each treatment every seven days, from the same marked plants to ensure constancy in the ratings. At harvest the producers agreed to swath and harvest two swaths from the center of each treatment and have the production weighed in a weigh wagon. Subsamples were taken from each harvested plot area for analysis. The subsamples were cleaned to derive an approximate dockage percentage and also for moisture content, which

Spray Application

Harvest Data Collection

Parlay

Check

Tank Mix

Manipulator

Initial height

45

45

45

45

08-Jun

47.5

51

47

47

12-Jul

83

76.5

77.25

80.25

03-Jul

74.25

75

69

75.75

19-Jul

89

92

90.5

95

Heights cm

Table 1: Annual Ryegrass

Hybrid Brome – Minedossa

Untreated check

Parlay

Manipulator

Parlay and Manipulator

132cm

115cm

103cm

96cm

Table 2: Brome heights

Tall Fescue – Minnedossa

Untreated check

Parlay

Manipulator

Parlay and Manipulator

126cm

108cm

123cm

103cm

Table 3: Tall Fescue heights

would be deducted from the harvested weight to arrive at an approximate clean seed basis.

The annual ryegrass showed no significant height differences with the reduced rates of plant growth regulators, however there was a 12-17% yield advantage with the Parlay treatment and the mix treatment of parlay and manipulator. The Manipulator treatment had no significant yield difference over the untreated check.

With regards to the tall fescue and hybrid brome, we also noticed a significant difference in the mixed treatment on the plant heights over the untreated check. The hybrid brome showed a 27% height reduction at the end of the year, as well as the tall fescue producing an 18% reduction in heights. The yields taken did not show any significant difference. MFSA hopes to take this trial into a small plot replicated setting in the upcoming years.

It should be noted that the results gathered here are only a single strip trial within a production field. It must be noted that this research is not scientifically proven and will need to be substantiated before any official recommendations can be made. It should also be noted that the products used are not currently registered for these crops, and with the aid of the data from these screening trials we can apply for registration in the future.

Kg per Ha

2000.0

1500.0

1000.0

500.0

0.0

Parlay, 1888.0

Parlay

Check, 1575.0

Check

Tank Mix, 1780.0

Tank Mix

Manipulator, 1557.0

Manipulator