2 - ethyl - 1 , 3 - hexanediol is a liquid of low toxicity and volatility and can be stored indefinitely without physical , chemical or biological degradation . concentrates of the diol can be readily prepared , up to the limit of its solubility , in water or in a suitable organic diluent such as a lower alkanol , ethanol being especially preferred . it is , of course , within the scope of this invention to dissolve the diol in an aqueous solution of organic solvent , again , ethanol being preferred . it is understood that mixtures in all proportions of 2 - ethyl - 1 , 3 - hexanediol in appropriate diluent media are contemplated , and certain of such mixtures may be preferred for selected applications . commonly , a solution or emulsion of concentrated agent is prepared for dilution with water in a spray device for such purpose . where surfactant is employed as desired , the spray can actually form a foam of benefit in localizing the agent . it is , of course , possible to admix 2 - ethyl - 1 , 3 - hexanediol with other agents for sucker control or regulation of meristematic tissue , such as the tertiary or secondary fatty amine , fatty acid ester or fatty alcohol contact agents ; or the systemic agents such as maleic hydrazide . somewhat less conveniently for mass application , the agent can also be provided as a paste or grease as by compounding with soaps or other thickening agents such as silicas , modified clays , etc . although the growth control agent of this invention is commonly applied to tobacco after topping , it is also possible to effect simultaneous topping and agent application as by utilizing the clip - oil device described in information series bulletin # 3 , october 1950 , dept . eng ., n . c . agri . exp . station . the agent can be applied , however , within 1 - 3 days and can be reapplied 10 - 21 days later as needed . more commonly , the initial chemical pinching is followed within 7 - 14 days with an application of maleic hydrazide . the rate of mass application is usually 20 to 100 lbs . per acre of cultivar as an aqueous spray of 5 % to 50 % growth control agent , or 1 . 35 to 13 . 5 ml . per plant . somewhat greater amounts * up to 2x ) are of course involved with foliar application . 2 - ethyl - 1 , 3 - hexanediol can be diluted with any essentially inert liquid , and some advantage may be seen in admixtures with the alcohol corresponding to the diol . where desired , any wetting agent , emulsifier or surfactant may be used . suitable surfactants may be selected from the anionic , cationic and nonionic types including primary , secondary and tertiary alkyl amines , ethoxylated alcohol sulfates , alkyl sulfates , water soluble salts of a sulfonated alkyl , alkylbenzene , or alkyl glycerol ether , quaternary ammonium salts , quaternary imidazolinium salts , alkyl pyridinium salts , dialkyl morpholinium salts , ethoxylated fatty acids and / or sorbitol esters etc . preferred are the sorbitan fatty acid esters and the ethoxylated derivatives , ethers of polyoxyethylene glycol , and fatty acid esters of polyethylene glycol . the amount of surfactant can range from the ordinary low level of 0 . 1 to 2 . 0 % up to that commonly used with sucker control agents , i . e ., 15 to 50 % by weight of the active agent . it is of course also possible to combine the application of sucker control agent with other plant agents including fertilizers , herbicides , fungicides , insecticides , rodenticides , miticides , sterilants , minerals , hormones , pheromones , and like materials commonly used in agriculture for the maintenance of nurture of plant life , or the control of eradication of pests or disease therein , or the presence of undesired species thereabout . in fact , the alkane diol aqueous solution or emulsion may serve as a vehicle for such additives . in the experimental data which follows , reference is made to contact application , by which is meant the direct contact of the active composition with the tissue for frowth suppression or necrosis as by hand applying to suckers , or dripping agent down the stem . foliar application refers to a general aerial spray to which the entire surface area of the plant is exposed . reference to meristematic tissue is inclusive of terminal and axillary buds . it is understood that the invention has applicability to all tobacco types , including nicotiana glutinosa , nicotiana tabacum and nicotiana rustica as well as the treatment of other ornamental and agricultural species including herbaceous plants such as ageratum , coleus , cotton , marigold , peanut , snapbean , snapdragon , soybean and tomato ; semi - woody plants such as carnation , crysanthemum , forsythia , geranium , hydrangea and poinsetta ; and woody plants such as apple , azalea , chamaecyparis , elm , euonymus , juniper , kolkwitzia , ligustrum , lonicera , maple , paper birch , pyracantha , taxus , weigela and pear . for the preferred tobacco species , it has been observed that the tobacco plant , and particularly the leaves for harvest , are unimpaired in quality , exhibit a high retained filling value , and can be converted to products of excellent aesthetic properties . further , since the alkane diols are presently in use as humectants on tobacco , no new ingredient is introduced to the smoke chemistry . a 75 % concentrate of 2 - ethyl - 1 , 3 - hexanediol was diluted with water to weight concentrations of 3 . 0 , 4 . 0 and 5 . 0 % of active ingredient . suckers on sets of field tobacco plants grown in different counties of north carolina , topped in the button stage immediately prior to treatment , were subjected to a contact spray from a hand held atomizer dribbled down the length of the stem with approximately equal amounts of concentrate being delivered to each plant . the results were compared with a commercial systemic control agent , off - shoot t - 85 , with and without treatment by another commercial systemic control agent , maleic hydrazide . the results are set forth in table i as follows : table i__________________________________________________________________________results of flue - cured tobaccosucker control number suckers */ plant percent control ** caswell johnson caswell johnsonno . treatment county , n . c . county , n . c . county , n . c . county n . c . __________________________________________________________________________1 . 2 - ethyl - 1 , 3 - hexanediol 3 % 3 . 2 6 . 0 44 212 . 2 - ethyl - 1 , 3 - hexanediol 4 % 2 . 0 4 . 6 67 453 . 2 - ethyl - 1 , 3 - hexanediol 5 % 1 . 4 2 . 9 79 534 . control - topped , not suckered 3 . 4 6 . 6 0 05 . off - shoot - t85 4 % ( 2gpa ) 1 . 0 4 . 1 88 426 . off - shoot - t85 4 % + royal mh - 30 ( 1 . 5 gpa ) 3 . 0 . 6 98 957 . no . 1 + royal mh - 30 ( 1 . 5 gpa ) . 1 . 3 100 958 . no . 2 + royal mh - 30 ( 1 . 5 gpa ) 0 . 6 100 949 . no . 3 + royal mh - 30 ( 1 . 5 gpa ) 0 . 3 100 9710 . royal mh - 30 ( 1 . 5 gpa ) . 2 1 . 8 99 88__________________________________________________________________________ * sucker numbers and percent control are averages of two replications . the data was based on five plants per plot in caswell county and ** percent sucker control was determined by dividing the weight of suckers from the control into the difference in weight of suckers from the treatment and control . variations are evident in the data summarized in table i , as a result of the different conditions under which to tobacco plants were grown . however , in all cases 2 - ethyl - 1 , 3 - hexanediol provided effective suckering control , without significant phytotoxicity especially when combined with treatment by maleic hydrazide . these results were surprising , in that greenhouse testing had shown unacceptable levels of phytotoxicity with useful sucker control . comparison was made between 2 - ethyl - 1 , 3 - hexanediol and the commercial agent , off - shoot t - 85 , applied to 15 field tobacco plants ( variety , speight g - 28 ) in the early button stage growing in gainesville florida . approximately 30 ml . of concentrate per plant were applied with a three - nozzle boom . observations were made on the twenty - fifth day following application of the concentrates . the results are set forth in table ii as follows : table ii______________________________________treatment suckers concen - per sucker weight % suckeractive agent tration * plant per plant , lbs . control______________________________________topped , notsuckered -- 8 1 . 87 -- 2 - ethyl - 1 , 3 - hexanediol 1 . 5 17 1 . 39 262 - ethyl - 1 , 3 - hexanediol 2 . 2 8 1 . 09 422 - ethyl - 1 , 3 - hexanediol 3 . 0 11 1 . 43 242 - ethyl - 1 , 3 - hexanediol 3 . 8 8 1 . 11 41off - shoot t - 85 1 . 7 9 0 . 93 50off - shoot t - 85 2 . 6 9 1 . 02 45off - shoot t - 85 3 . 4 6 0 . 98 48off - shoot t - 85 4 . 2 ** 4 0 . 57 70______________________________________ * concentrations are based on active ingredient . 2ethyl - 1 , 3 - hexanediol was formulated as 75 . 0 % active ingredient and offshoot t85 as 85 % active ingredient . concentrations of the formulated product were 2 , 3 , 4 and 5 % respectively . ** slight degree of leaf burn was noted with the highest concentration of these active agents . this data demonstrated 2 - ethyl - 1 , 3 - hexanediol to be an effective antisuckering agent , at times approaching the effectiveness of the antisuckering preparation in current use . another comparison field test was carried out comparing 2 - ethyl - 1 , 3 - hexanediol and off - shoot t - 85 applied to burley tobacco plants growing in waynesville , north carolina approximately 20 mls . of diluted solution were applied to each plant employing a hydra - gun . two replications of twenty plants each were used while the plants were for the most part in early flower , although some of the plants were in full flower . the results are set forth in table iii as follows : table iii__________________________________________________________________________ rate sucker suckers / pl . weight / leafcompd . ml / l control , % no . wt ., g sucker , g . injury drop__________________________________________________________________________topped , notsuckered -- 00 . 0 5 . 80 258 . 0 44 . 5 none noneoff - shoot t - 85 46 . 0 92 . 6 0 . 75 19 . 1 24 . 5 none none2 - ethyl - 1 , 3 - hexanediol 39 . 9 67 . 3 4 . 50 84 . 3 18 . 7 none none2 - ethyl - 1 , 3 - hexanediol 53 . 3 84 . 6 3 . 25 39 . 7 12 . 2 none none2 - ethyl - 1 , 3 - hexanediol 66 . 6 87 . 9 2 . 10 31 . 2 14 . 9 none none__________________________________________________________________________ again , the active antisuckering agent of this invention , 2 - ethyl - 1 , 3 - hexanediol demonstrated its effectiveness to control suckering in tobacco plants . no injury to the leaf was exhibited by the application of 2 - ethyl - 1 , 3 - hexanediol a required characteristic of any commercially useful antisuckering agent . in a further example , 2 - ethyl - 1 , 3 - hexanediol was effective in providing sucker control in flue - cured field tobacco grown in beltsville , maryland , where 20 ml of spray solution was applied per plant ( ten plants per replicate ). at 2 weight percent active ingredient , no control was evidenced , but most suckers were killed with 58 % overall control ( average of two replicates ). increased levels of additive , while showing control up to 95 %, tended to evidence increasing axil necrosis . other exemplary aspects of the invention involve particularly treatment of crysanthemum , soybean and cotton plants in the same manner . constructive compositions comprising combinations of , e . g ., higher fatty alcohols and esters thereof and 2 - ethyl - 1 , 3 - hexanediol in all proportions , are contemplated in aqueous or water - lower alkanol solutions or emulsions . in view of the generally low phytotoxicity of 2 - ethyl - 1 , 3 - hexanediol in field tests it is expected that effective sucker control agents can be advantageously extended to these materials and at low expense .
a chemical pruning , and contact composition for the selective inhibition of suckering in plant species subject thereto , particularly tobacco , said composition comprising as an active species 2 - ethyl - 1 , 3 - hexanediol .