الفهرس | Only 14 pages are availabe for public view |
Abstract In potted pure sand culture, two varieties (Giza 69, as resistont one and Giza 7~as sucep~ tible to the FupariHm disease) of Egyptian cotton p~ants we~e grown in two successive season (1979 and 1980) in the gre~n house. ~oth seeds and sands ~ere infested by t~e spores of the EHePr~~f~”S (ji\s¥.im o.X:VSROmra r, spvp.s,;fJ1£eC,typ) before sowing . . . ... - -” . and the resulting se.d~s W(;)~e treated ’by v~rious l~ve+s qf each. of th(i) q1:f’:fer~nt nutrient elementQ in addition to the OODlplete n~t:ri@t aoLutd.cnas. acont,ro; • .411 these treatment;3 were compar-ed with in!ested’;’;;freeoontrol recieying the some oomplete .:nutrient sol~tion. All criteria of germination, pos~amergenoe da.p1ng-oft~ survival s~edlings, disease index, growth (hieghta and dry weights of both root and tops) and the foliar ohemical contents {~ugars. total amino ooids, phenolic compounds , pigments (ch+oropnylls Qndcurote~oids) ~d t40 n~t~1ant el~menta concentration $.n the leaves were 011 detem.1ned.and tabulnted. -lIBThe average results of the two aeasons we+-e ~~ied oo~idernb~y according to the type ’Ot tren~ 1;mlmt~~ 1) ~e~to~1PYII’t ~b~ted germination pa~t1culn:rlyof the su.<goept.ib~evar!aty ~ PQst-emerge:p.o~damping~off WP.S also genera~ly inpr~nsed.whileseedling ~~v1Val$ dearensed.· I)1~e~seindex inorefJ.El(ilo. while g1”Owt4generally decre-n’sed ;.n susc~ptib~e one as w~11 ps the tQtQl, amino acids, in n4dition it 1npreU$ed phenol~(1n G~za 14)’. The decrease in thep:l.gment~ in ~he susc~ptibl~ Qne (Giza 74) was more than in the ~~sist~n~ one (C~iza 69)” It seems thnt infestation inhibited tne upta~e of f anQ JC more in Cjiza 74 than :Ln’Giza 69 vnriettea. ,!rlle decr eaae in foJ.in;’cqntent at Zn and cu nn qiza 74 v~1ety was 0159 noti.ced. 2- Nitrogen (N): It inoreased germination, post-emergence damping-off but decreased survivals all at the medium or high concentration of this element in the nutrient solution while the deOllease in these criteria lovere noticed at the marlmumconcentration of nitrogen used. It increased disease index in both varieties and decreased total sugars especially in the susceptible variety (Giza 74). Total aJD,ino acids decreaseJ. as the nitrogen in the nutj~ent solution increased up to the medium level in the aus()eptibk one and phenol oompounds were also decreased. Total pigments were increased as nitroeen increased in -the solution ot both varieties. The absorption of Zn, Mn and Ou bY’ the auacep t ible var:Lety generally increased bY’ increasing N in the nutrient so l’L1tion • 3- Phosphorus (P):- Application of low or high P-inc:ceaaed ge:cllin.:ltion in ’both varieties but increased post-emergence damping-off’ in the resistant variety and increased stn.1 vivaJ.s in general. Disease index was suppressed by low or high concentration of this element in the nutrient solution in the susceptible one.Dry weigh t was increased in both varieties in both season$b1 P application in high levels. Total. sug~s were also inoreased with the ioo rease o:f phosphorus in the nutrie nt ao Lut10n in both varieties. There ?rere no effect either 1n total amino acids or phenolic -Gompounds while totaJ. chlorophylls and carotenoids were flactuated in plants wl.tb. P concentration in tba solution especially in the susceptible variety. Phosphorus uptake was increased by increasing its conoentration in the nutrient solution. 4- PotassiUJl1 (K): High K decreased germination in t~ resistant while in,oreased it and survivals in. the susceptibl-e variety. It inoreased dry weight in both varieties. No recular ef’f’ects either in phenols, sugars or amino acids in the resistant variety (Giza 69) were founa. while inoreasing potassium in the nutrient solution seeMd to inorease phenols in the susceptible var!et:y_ High Ie enhanced the pigment concentration il’1 leaves of suscep’~ible variety. Increasing K decreased phosphorus and Oa in both varieties and de~reased Fe and Cu content in susceptible variety • However, this decrease was very small to affect general plant growth. 5- Calcium (Ca): Germination was enhanced by application of this element at the moderate level in the resistant variety. owor hiGh Cs decreased the germination and survivals in the susceptible variety. It decreased the disease index of the resistant one while it increased it in the susceptible one. CalciUUl had its fa~,~on:’.’,,;.’t.10effect on growth of plants especially in the susceptible one ’;thenused at the medium level. It increased total sugars, phenols and total. arrLino acids especially in Giza 69 variety and phenols in Gizn 74 variety by its application at hieh laveln • Calcium at low levelS iuoreased tile piguam:s of Giza 69 Va1’iet,. mile it increased them in the suscept ible Va1’iet,.wIJJa.ll its levels particularly’ the h:!gh one. H:Igh Ca increased P abSorption in both varieties while nitrogen oontent wa.s decreased only in the gusceptible one. Calciumat low level increased Fe and Zn in the resistant variety while it deoreased them in the susceptible variet,.. The reverse was true in ~ln ,.”d Cu in the susceptib 1e one. 6- Zino (Zn): It improved ger~ination anu survivals when used in at low concentration ’liza 69 and suppressed them in x Giza 74- At low ievels, it decreased the disease index espec;aJ.l,. with the susceptible va1’iet,. as well as increasing the dry weight particularly in the suscept ible one. J.>urthermore. Zn st:iJnUatedth~ fo”””ti on or auga1’S, phenols, total- ..,.ino acids .,n both varieties particularly’ in the resistant one. ..ore over, it iI1Ore•••e•d the total cnlorophylls in both varieties especiall” tbe resistant Olll’ at all its levels in the DLltrient solution. Carotenoids were increased in the resistant one at low or hi;eh Zn a?pl:tc~tir):’~. ’.:1~ilethe reverse was true in the susceptible variety. Zn at low level had improving effect on both P and Oa absorpti on by resist ant one anll the opposite on the susceptible om. High Zn decreased Fe absorption in the resistent one but low or high Zn increased it in the suscept ible one. Increasing Zn in the nutrient solution increased its uptake by the susceptible variety. 7- Boron (B) 1- It had its improving inf’luence on gemination and survivals in both varieties. Furthermore, it decreased the di sea.se ind.ex and increased the dry weight more in the resistant one than the susceptible one on the condition that its concentration in the nutrient S 01- ution will be at the mediumlevel. Boron decreased the foliar content s of sugars, phenols, totaJ. amino acids and the pie;o.ents particularly’ in the res1stant one while increased chlorphylls 6Dd carotea~ds in the susceptiDle one. Boron had its eDbslc1.ng influence 0 n the It}’)t n.ke of 11,P and K while decreased the abso:rptior. of Os in the %”9sist:arrt: variety. -124- 8- gopper (Cu): It inoreased germination, survivals in both varieties espeoially the resistant one. It decreased the diseasE! index in the susceptible one but it seemed to IncreaEle the dry weight in both varieties. It increased the total amino acids while did not ~ffect the phenols or sugars in the resistant av·and deoreasred phenols and sugars in the susaepti ble cv , ’I’he chlorophylls were increased in both varieties by Cu applioation. C!Uat the medium.level.” had its influence in the nutr1e.n,t concentration in the leaves as it increased P, Oa and K 1n both varieties especially in the first season • .A~so, 1t increased Zn but decreased Fe in the susceptible one. 9- !Mgaaese (JIn):- It increased germination particularJ.y in the resistant variety. It increased the post-emergenoe damping-off wbenused at the highest concentration in boUl varieties while the lower concentration inoreased the survivals in both varieties • • ]lIn improving effect on growth (dry weight) was fairly :L11 resistant but considerably in the susceptible vSl”iety. At fairly high levels, Mnincreased the tota,i. sugars and amino acids in ”t!18 resistant while decreased them in the susceptibl,} CJV •• Furthermore I Mnincreased carotenl)ids in the resistant ·,f~iety ,mile increased chlorophylls in the susceF~ible va.riety. Mn. increased the absorption of P ,mile it decre aaed Ca in the resistant one and aid not a.ffect K, P or Os. in the suscept ible one. :Mnat medium levels in the nutrient solution encouraged its absorption by both varieties of cotton plant sunder investige.t ion. from all results and discussion previously presented the following recoIlllISndations C an be easily deduced: 1- The use ot potassium in cotton nutrition oi6ht be advisable to induce the Growthand suppre ss the disease. 2- Phosphorus application to these plants is also recommended especially whenit is we-II krI.0..n that the Egyptian soil is svverely contaminated with this fungus. -126- 3- Ni1irogen at excessive use might render plants more BUnoeptible to infection with this :fungus. 4- Zino as indu c1ve of ohlaro phylls. growth, sugars. phE!nols and total amino acids and inhibitive of diElease, its applioation at moderate levels is rec:ommendedfor the plant s under investigation. 5- Caloium as induoing P absorption, grOW’th and chemical contents ~ the suscept ible cotton plant s could be~plied at moderate levels tor the nutrition of cotton 6rowing in infested soils. 6- It :aUghtbe adventageoUs to use Mnat its regular concentration in th.e nutrition of cotton varlet ies for improving its growth and P absorption. |