摘要:

Summary.The effect of sub‐lethal doses of MCPA‐sodium on the growth, yield and marketability of summer cabbage lettuce was studied in seventeen replicated field experiments.Initial epinasty was produced by doses as low as 0.002 lb/ac a.e., and formative effects of the leaves developed at doses below 0.01 lb/ac. In plants treated at early or intermediate growth stages, two distinct types of formative effects occurred, With doses in the range 0.0025‐0.03 lb/ac, a zone of characteristic abnormal leaves developed. This reduced the marketability of the crop and the maturity was delayed, but the weight per plant at harvest was not affected. At higher doses these a abnormal leaves were not evident but the whole plant became distorted, growth was suppressed and few marketable plants were produced. In plants treated at the hearting stage, plant weight and maturity were not affected, but the marketability was reduced at doses of 0.01 lb/ac and above. The effects produced by MCPA in cos and curly crisp lettuce were compared with those produced in cabbage le

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00207.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.Granulated compound fertilizers were tested as solid carriers for a variety of herbicides known to be active when applied as liquids.Pasture and cereal experiments with 2,4‐D and MCPA as fertilizer additives indicated considerable loss of herbicidal activity in comparison with spray formulations.Residual herbicides such as TCA, propham and diuron retained their activity when added to fertilizer for application to root crops. The most effective of the herbicides used as fertilizer additives were TCA and propham, both of which gave good control ofAvena fatuain sugar beet, and a mixture of chlorpropham and diuron gave promising results as a general weed control treatment in carrots.It is concluded that the addition of these or similar herbicides to fertilizer granules may have advantages over conventional spray formulations for those crops which require broadcast pre‐sowing applications of herbicides and fertilizer. For such crops the use of a granular fertilizer as the carrier instead of inert material could also have advantages over conventional granular herbicides, particularly by reducing transport and application co

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00208.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.14CO2together with autoradiographic techniques was used to stuy the movement of labelled carbon within wheat plants at different stages in their development. Movement of14C about the plain was found to be extensive in the early stages, gradually bccoming more localized until at a stage after ear emergence there was little transference of labelled carbon between tillers within a 24‐hour period.In the early stages of development14C from leaves on the main shoot was transported throughout the plant but accumulated in greatest amounts in the meristematic regions. Assimilates produced by the leaves of newly formed tillers were distributed mainly to the meristematic regions of those tillers although labelled carbon was moved in into the rest of the plant. In the later stages of development of each tiller the labelled assimilate was restricted to the tiller itself and to any very young tillers associated with it. After car emergence the pattern of distribution of the labelled carbon from the youngest and second youngest leaves was found to differ. Movement was predominantly towards the ear from the flag leaf and towards the root system from the leaf below the flag.It was noticed that mature leaves accumulated some labelled material and the possibility that this occurred via the transpiration stream following migration from phloem to xylem, as is the case with some of the case with some of the translocated herbicides, was investigated, but no indication of xylem transference was obtained.The possible application of these studies to investigations into the relationship between the movement natural assimilates and of translocated herbicides is discusse

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00209.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.The results of a pot experiment on the mutual interference between kale and three weed species are reported. The puts were sunk in soil and surrounded by kale plants so as to provide illumination conditions similar to those likely to be found in a field crop of kale. Of the three weed species,Polygonum lapathifoliumappeared to be the most, andP. avicularethe least, competitive towards kale.P. persicariawas slightly less competitive thanP. lapathifolium. The two latter species were much higher in dry‐matter production thanP. aviculareand showed greater responses to changes in the number of kale or weed plants per po

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00210.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.The effect of herbicides on coltsfoot (Tussilago farfara L.) varies according to the plant's constitution resulting from different environments. 4‐CPA‐ester had the best effect of all the auxin‐type herbicides. The application of 4‐CPA in cereals is not possible because of its phytotoxicity, but this chemical could be promising for the control of coltsfoot in grassland. Fenoprop (2,4,5‐TP) is somewhat less effective but cereals, especially wheat (Triticum setivum L.) and oats (Avena sativa L.), are more tolerant. All the other auxin‐type herbicides, including mecoprop (CMPP) and 2,4,5‐T were unsatisfactory. Control of coltsfoot after harvesting the cereals was most satisfactory with amitrole (7.5‐10 kg/ha in one application or two applications of 4 and 6 kg within 3‐4 days). Shallow ploughing 4‐6 weeks after spraying increased the effect as did the addition of Nad (10‐20 kg/ha) to the spray‐fluid. Good results with amitrole can be obtained only when the plants are growing vigorously and have a sufficient amount of large and healthy leaves at che time of application, not damaged at harvest and without fungus infection. There should be dry weather 2‐3 days prior to the application. The regrowth in the following spring is usually so weak that it cannot compete with the crop plants. The soil should be cultivated immediately after harvest, so that the still living remains of coltsfoot plants can also be killed and re‐establishment prevented. It is advisable to plant root crops after the chemical control of coltsfoot, so that the weak regrowth can be killed by the normal cultivation practices of these crops. The residual effect of amitrole in the soil can vary widely. Under conditions in the Rhine Valley the residues are partially broken down biologically, partially leached during autumn (and winter), so that the following summer cro

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00211.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00212.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00213.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY