Vol. 15—1961 - NorthEastern Weed Science Society

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Table 1.. 1960, Rainfall
University
and Temperature
Park, Pa.
1ieek Inches Temperature Week Inches Temperature
Ending Rainfall Max. Min. Ending Rainfall Max. Min.
May 9 1.96 "7"fr~ August ! 0.i3 SO.';f"
16 1.40 74 36 8 0.96 86 56
23 2.42 82 48 15 0.01 ·83 55
30 0.83 77 U4 22 0.07 83 So
June 6 0.79 88 52 Sept. 5 0.96 89 49
13 0.45 83 44 12 3.01 86 54
20 1.17 87 55 19. 0.82 76 44
27 0.15 83 54 26 0.38 75 46
July 4 1.26 85 56 Oct. 3 0.27 74 38
11 0.30 85 49 10 0.35 68 36
18 1.58 85 46
25 0.29 85 54
Results and Discussion
Turf Tolerance. Discoloration and/'Or injury data on' areas 1, 2 and.3 (red fes­
CUe';Merion bluegrass and colonial bent, respectively) are shown in Tables 2,
.3 and 4, respectively. No data are shown for area' 4, commonKentucky' bluegrass,
due to ab~ence.of any visible injury from the treatments applied.
Granular chlordane and the commercial Halts formulations showed no
detrimental effects, however, the Ortho emulsion resulted in instant discoloration.
The effects of the 120 rate persisted for 12 'WE?ekson the Merion
and bent, and for five months on the fescue •. A slight thinning and chlorosis
was noted on the fescue.
All Dacthal forniulations were severe in both discoloration and injury
on the fescue, and bent, but showed no toxicity on Merion bluegrass. Initial
di so 010rs'ti on' showed. approximately 17 days following applications. The plots
received 0.3 inches of rain three days folloWirig application, and 7.17 inches
in 17 of the 23 remaining clays in May.' The Granular form was more toxic than
the w-50 or Rid in both discoloration and turf reduction. Greater turf reduction
occurred on the fescue, but this was believed due to its slower recovery
growth during the fall months compared to the bent.
Granular Zytron, M-1662, was similar to the Dacthal formulations in its
effects on the various turf species. It was nontoxic to Merion and showed the
sane injury pattern on fescue and bent , The emulsion, M-1329, discolored
fescue, Merion and bent immediately following application. The Merion remainod
discolored for approximately 10 weeks and showed no permanent injury. Fescue
and bent remainded discolored by the M-1329 all season and were moderately
thinned. As for the M-1662 and Dacthal formulations the fescue showed more