Crab grass

Jackson, Kenneth T. (1985). Crab grass frontier The suburbanization cf the United States. New York Oxford University Press. 

Digitaria sanguinalis summer grass large crab grass... 

DSMA is an organic arsenical having contact, postemergence activity. It was first utilized for crab-grass control in turf. It is an effective herbicide in cotton and in citrus trees, but must be used as a directed spray to avoid contact with the crop foliage. 

Increased stands of wild carrots show up, for example, after Propazine treatment, of birdsfoot trefoil after Simazine treatment and of green foxtail and crab grass after Atrazine treatment. Are these biological particularities not amazing in view of the very small structural differences ... 

Terbutol is mainly a soil herbicide, but it is also effective postemergence for the control of grass weeds. It has a selective action in cotton, maize, tomato and soybean, and is recommended for the control of crab grass in established turf. It is particularly effective for the control of Digitaria spp. 

DMPA is a preemergence soil herbicide which has been used in turf for the control of crab grass Digitaria spp.), and in soybeans, peas, beans and onions against grass weeds (Roberts et ai, 1966), but it has been superseded today. 

Another area related to fluazolate (17) and pyraflufen-ethyl (18) chemistry is a series of 2,4,5,6-tetrasubstituted-phenyl pyrazoles 89 (Fig. 3.23) from Ishihara Sangyo Kaisha [96]. These compounds differ from previous phenyl pyrazoles in that they have substituents at the 6 position of the phenyl ring. Pre-emergence application of 89 provided 100% control at 63 g-a.i. ha of barnyardgrass, crab-grass, green foxtail, redroot pigweed, prickly sida, and velvetleaf Soybean was reported to have 20% injury for compound 89 at this rate of application. 

Table III shows the effect of alkyl groups bond to nitrogen of an aminocarbonyl substituent at the 3-position. Although all of the analogs showed high safety on com, no compound was found to be superior to 81 950 with respect to herbicidal activity against crab grass.

Table IV shows the influence of a methyl group introduced as a second substituent on the pyridine ring, holding the N,N-dimethylaminocarbonyl group at the 3-position. It is seen that, judging from both activity against crab grass and safety for com, SL-950 is far superior to the methylated compounds, except for the one substituted at position 6, which is almost as good as 81 950, both for activity against weeds and safety on com.

It is apparent from the data discussed above that 81 950 not only has high activity against crab grass, but also is extremely safe on com. 

Position Substituent. Herbicidal activity decreased in the fo1 lowing order (dosage in g a.i./ha required for 95% damage to crab grass given in parentheses) ... 

It was found that most alkylphosphinates IIIC showed higher inhibition activity against monocot species such as crab grass and barnyard grass than their corresponding alkylphosphonates IC, IE, or IF. Several alkylphosphinates however exhibited a higher selectivity between wheat and weeds than their corresponding... 

Bra rape Amr common amaranth Med clovta- Eeh barnyard grass Dig crab grass... 

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