Search

Festuca filiformis is a common perennial grass in lowbush blueberry fields, but little is known about the general biology, seedbank characteristics, seedling recruitment or susceptibility of seedlings to currently registered herbicides. The objectives of this research were to determine (i) the presence of F. filiformis seedbanks in lowbush blueberry fields, (ii) whether F. filiformis seedbanks accumulate near the soil surface in lowbush blueberry fields, (iii) the dormancy status of fresh F. filiformis seeds, (iv) the temporal patterns of seedling recruitment in established F. filiformis populations, (v) whether F. filiformis has a vernalisation requirement for flowering in lowbush blueberry and (vi) susceptibility of F. filiformis seedlings to various herbicides currently registered in lowbush blueberry. Festuca filiformis formed a seedbank in lowbush blueberry fields, with an average of 1660 ± 272- 5680 ±1409 seedlings m m-2 emerging from soil cores collected from two infested fields. Most seeds were located at the soil surface, providing opportunities for seedbank management through predation or burning. Fresh seeds lacked dormancy and readily germinated, although germination was reduced by dark conditions. New seedlings emerged in spring and autumn and required vernalisation to flower. Seedlings were susceptible to several currently registered herbicides in lowbush blueberry, although mortality rates were highest in plants treated with glufosinate, flumioxazin, glufosinate + flumioxazin and terbacil. Growers should avoid movement of seeds on machinery, and additional research should be conducted to determine the effects of registered herbicides on F. filiformis seedling recruitment under field conditions in lowbush blueberry. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Preemergent and postemergent herbicides were evaluated in the Mediterranean climate of the southern San Joaquin Valley and the desert climate of the Imperial Valley from 1998 through 2000. Sixteen herbicide treatments were applied both as preemergence (PRE) and postemergence (POST) applications to carrot (Daucus carota L.). Carrot was generally more tolerant to PRE herbicide applications than to POST applications. Carrot was tolerant to PRE and POST imazamox and triflusulfuron at both locations. Carrot root losses due to herbicide were consistent with visual ratings. Treatments that injured carrot tops early in the growing season did not always reduce yield at the end of the season. PRE applications of imazamox and triflusulfuron did not affect carrot tops or the number or weight of marketable carrots. Carrots grown in the Imperial Valley and in the San Joaquin Valley were tolerant to PRE applications of carfentrazone, sulfentrazone, and imazamox. Results were similar for POST applications, although carfentrazone slightly injured carrot roots. PRE application of herbicides increased forked roots more than POST. Chemical names used: α, 2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl5-oxo-1H-1, 2,4-triazol-1-yl] -fluorobenzenepropanoic acid (carfentrazone); N-[2,4-dichioro-5-[4-(difluoromethyl) -4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide (sulfentrazone); N-(2 carbomethoxy-6- chlorophenyl)-5-ethoxy-7-fluoro (1,2,4) triazolo-[1, 5-c] pyrimidine-2-sulfonamide (cloransulam-methyl); 2-chloro- N-[(1methyl-2-methoxy)ethyl]-N-(2,4-dimethyl-thein-3-yl)-acetamide (dimethenamid); (2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5- (methoxymethyl)-3-pyridinecarboxylic acid) (imazamox); 3-chloro-5-[[[[(4,6-dimethoxy-2-pyrimidinyl) amino] carbonyl] amino] sulfonyl].l-methyl-1H-pyrazole-4-carboxylic acid (halosulfuron); N[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(ethylsulfonyl)-2-... [ABSTRACT FROM AUTHOR]