Efecto de la fertilización con potasio y de la aplicación foliar de zinc y fósforo en el rendimiento de aceite y proteína y en las propiedades del aceite de algodón. Para maximizar la cantidad y calidad del valor nutricional de una semilla en términos de ácidos grasos y proteínas es necesario identificar los factores que los afectan y proponer métodos que favorezcan los resultados deseados a través de cambios o mejoras en las prácticas utilizadas. Los experimentos se llevaron a cabo en dos campañas sucesivas en el Agricultural Research Center, Giza, Egipto, en el cultivo "Giza 86" (Gossypium barbadense L.) para estudiar los efectos de la fertilización con potasio (a 0.0 y 47.7 kg por ha) y las aplicaciones foliares de zinc (a 0.0 y 57.6 g por ha, dos veces, 70 y 85 días después de la plantación) y fósforo (a 0.0, 576, 1152, y 1728 g por ha, dos veces, 80 y 95 días después de la plantación). La aplicación del potasio junto con la pulverización de las plantas con zinc y fósforo causó un incremento en el rendimiento del algodón, el índice de semilla, el contenido graso, los rendimientos de aceite y proteína, el contenido de materia insaponificable en el aceite y el contenido total de ácidos grasos insaturados (oleico y linoleico). Por el contrario estos tratamientos disminuyeron el índice de acidez, el índice de saponificación y el contenido de ácidos grasos saturados. La mayor concentración de fósforo produjo los mejores rendimientos de algodón, de índice de semilla, de los rendimientos de aceite y proteína, y de materia insaponificable en el aceite.

Field experiments were conducted during two successive seasons in the Agricultural Research Center, Giza, Egypt (a clay loam soil), to study the effects of phosphorus fertilization (addition at rates of 44 and 74 kg of P # O & \ha) and foliar application of zinc (at 0n0 and 40 ppm of Zn applied twice, 75 and 90 days after planting) and calcium (at 0n0, 20, 40, and 60 ppm of Ca applied twice, 80 and 95 days after planting) on seed, protein and oil yields and oil properties of the Egyptian cotton cultivar Giza 75. Application of P at the high rate and spraying plants with zinc and calcium at any concentration increased cottonseed yield\ha, seed index, seed oil content, oil and protein yields\ha, seed oil unsaponifiable matter, and total unsaturated fatty acids (oleic and linoleic). Conversely, decreases in oil acid value, saponification value and total saturated fatty acids occurred. The seed protein and oil refractive index tended to increase when the high P rate and Zn were applied. Seed protein content tended to decrease slightly with Ca application. Regardless of the slight decrease in protein content as a result of Ca application, the yield of protein increased, due to the fact that there was an obvious increase in seed yield which counterbalanced the negative effect of the decrease in protein content. The highest Ca concentration (60 ppm) gave the highest values of cottonseed yield\ha, seed index, seed oil and protein yields\ha and oil unsaponifiable matter, followed by the concentration of 40 ppm. The concentration of 40 ppm gave the lowest total saturated fatty acids. The effect of Ca concentrations on oil refractive index was very limited.

RESUMENEfecto del nitrógeno, potasio y retardantes del crecimiento de plantas sobre el contenido en aceite y sobre la calidad de la semilla de algodón El objetivo de los experimentos de campo fue investigar el efecto del nitrogeno, potasio y retardantes del crecimiento de plantas sobre el contenido en proteínas y aceite de una semilla de algodón cultivada en Egipto (Gossypium barbadense Giza 86). Los tratamientos consistieron en la aplicación en suelo de N (95 and 143 kg N ha Ϫ1 en forma de nitrato amónico), aplicación foliar de K (0, 319, 638 or 957 g K ha Ϫ1 como sulfato potásico) y aplicación foliar de cloruro de m mepiquat (MC) (0 and 48 + 24 g de ingrediente activo ha Ϫ1) sobre un cultivar de algodón «Giza 86» (Gossypium barbadense). La aplicación de la cantidad más elevada de N, unida a la aplicación de potasio y del retardador MC, aumentó significativamente el rendimiento en semilla, así como el contenido en proteinas y en aceite. Respecto al aceite, aumentó el índice de refracción, la fracción insaponificable y el contenido total en ácidos insaturados (oleico y linoleico). Por el contrario, la acidez del aceite y su índice de saponificación disminuyó con la aplicación foliar de K y MC. El contenido en aceite de la semilla disminuyó cuando sólo se aplicó N. PALABRAS-CLAVE: Aceite de semilla -Ácidos grasosAlgodón -Cloruro de mepiquat -Nitrógeno -Potasio -Proteina. SUMMARYNitrogen, potassium and plant growth retardant effects on oil content and quality of cotton seedThe aim of this field experiment was to investigate the effect of nitrogen, potassium and a plant growth retardant (PGR) on seed yield and protein and oil content of an Egyptian cotton cultivar (Gossypium barbadense Giza 86). Treatments consisted of: soil application of N (95 and 143 kg N ha Ϫ1 in the form ammonium nitrate), foliar application of potassium (0, 319, 638 or 957 g K ha Ϫ1 as potassium sulfate) and foliar application of mepiquat chloride (MC) (0 and 48 + 24 g active ingredient ha Ϫ1) on seed, protein and oil yields and oil properties of Egyptian cotton cultivar "Giza 86" (Gossypium barbadense). After applying the higher N-rate, foliar application of potassium and plant growth retardant MC significantly increased seed yield and the content of seed protein and oil, seed oil refractive index, unsaponifiable matter and total unsaturated fatty acids (oleic and linoleic). In contrast, oil acid and saponification value as well as total saturated fatty acids were Nitrogen, potassium and plant growth retardant effects on oil content and quality of cotton seed decreased by foliar application of potassium and MC. The seed oil content was decreased with soil application of N.

The increase in the population in Egypt makes it imperative to explore promising approaches to increase food supply, including protein and oil, to meet the needs of the Egyptian people. Cotton is the principal crop of Egyptian agriculture. It is grown mainly for its fiber, but cottonseed products are also of economic importance. Cottonseed is presently the main source of edible oil and meal for livestock in Egypt. Field experiments were conducted in two successive seasons at the Agricultural Research Center (Giza, Egypt) on cotton (Gossypium barbadense L. cv. Giza 75) to determine the effect of nitrogen (N) fertilizer rate (107 and 161 kg of N/ha applied as ammonium nitrate containing 33.5% N in two equal doses at 6 and 8 wk after sowing), together with foliar applications of plant growth retardants (mepiquat chloride "Pix," chloromequat chloride "Cycocel," and daminozide "Alar," each applied once at 288 g active ingredient/ha, after 75 d from sowing) and zinc (Zn) (applied in chelated form after 80 and 95 d from sowing at 48 g of Zn/ha) on seed, protein and oil yields and oil properties of cotton. The higher N-rate, as well as the application of all growth retardants and Zn, resulted in an increase in cottonseed yield, seed protein content, oil and protein yields/ha, seed oil refractive index, unsaponifiable matter, and total unsaturated fatty acids (oleic and linoleic). These treatments tended to decrease oil acid value, saponification value, and total saturated fatty acids. The seed oil content tended to decrease as N-rate increased and increased with the application of all growth retardants and Zn. There were some differences between Pix, Cycocel, and Alar regarding their effects on the studied characters. The highest increase in seed, oil, and protein yields/ha was found with Pix, followed by Cycocel. The Cycocel treatment gave the lowest total saturated fatty acids oil content, followed by Alar.

die dem Gleichgewicht entsprechende Konzentration, was sich p i t der vorgiingig ausgefiihrten Desorptionshemmung der Olsaure interpretieren 1 a t .Die Selektivitat und das Ausmal3 der geometrischen Isomerisierung kann, wenn auch nur in begrenztem Umfang, durch die Reaktionsbedingungen beeintluBt werden. Dabei steht der Wasserstoffdruck im Vordergrund. Durch Druckreduktion kann die Linolselektivitat noch etwas gesteigert werden. Durch einen niedrigen Wasserstoffdruck wird him gegen die Isomerenverteilung zugunsten der trans-isomeren Elaidinsaure beeintluBt, w h e n d unter hohem Wasserstoffdruck mehr Olsaure als Zwischenprodukt entsteht. Die phanomenologische Beschreibung der Fetthydrierung ist mit erweiterten Langmuir-Hinshehd-Ansatzen moglich. Unter der Annahme nicht eingestellter Adsorptions-/Desorptionsgleichgewichte an der Katalysatoroberflache lassen sich die gemessenen Konzentrationsverlaufe in Abhhgigkeit der Temperatur und des Wasserstoffdrucks simulieren. Das Isomerisierungsverhalten der 01-und Elaidinsaure kann mit unterschiedlichem Sorptionsverhalten plausibel erkl&t werden, da die Weiterreaktion zur Stearinsaure unabhhgig von der geometrischen Konfguration der Monoene gleich s h e l l ablauft. L i t e r a t u r WZchau, Fette . Seifen . Anstrichmittel 81,303 [ 19791. M. Mtiwing, Dissertation ETH Nr. 8066,1986. A. S e h , H. Pardun u. M . A r m , Fette ' Seifen . Anstrichmittel 80, 58 [ 19781. Landolt-Bomstein, 6. Auflage, II. Band, 4. Teil, Tabelle 241122/1, Springer-Verlag, 1961. G. Gut, Swiss Chem. 4/3a, 17 [ 19821. L. F Albnght, J. h e r . Oil Chemists' SOC. 40,16 [ 19631. G. Gut, J. Kosinka, A . Babuki u. A. Schuerch, Chem. Eng. Sci. 34, 1051 [ 19791.N o m e n k l a t u r Symbol Bedeutung Einheit C C H JZ k k* Ki L Ln mK P r S Q S I SU SI t T T @H Konzentration mol/L OIsaure (cis) Henrykonstante L bar/mol Jodzahl(= Anzahl GrammJod, die mit 100 g 0 1 unter Addition an Doppelbindungen reagieren) Reaktionsgeschwindigkeitskonstante mol/(L min %Kat) druckabhhgige Reaktionsgeschwindigkeitskonstante (= k e H ) mol/(L min %Kat) Sorptionsgleichgewichtskonstante Wmol Linolsaure Linolensaure Katalysatormenge Druck Sorptionsquotienten Reaktionsgeschwindigkeit Stearinsaure Linolenselektivitat holselektivitat Trien -kl-> Dien -k2-> Monoen -B-> gesiittigt Isomerisiemngsindex (= A%trans/AJZ) Reaktionszeit min Elaidinsaure (trans) Redeckungsgrad der Katalysatoroberflache mit Wasserstoff (= rL4-X") = [CL~CLnI max) (= rc+&(-d = [(CC+CT/CLlrnax) Temperatur OC GewO/n bar moV(L min) Eingegangen a m 14. Juli 1986.The seed chemical composition and oil physical and chemical constants of two imported rapeseed German varieties and one locally produced in Egypt were studied. Rapeseeds are chamcterized by high lipid and protein contents. The fatty acid analysis indicated that palmitic and oleic acids were the most prevalent saturated and unsaturated acids, respectively. Also, the rapeseed oils under study were free from long-chain fatty acids (>C,,). The unsaponifiables were fractionated by GLC into 36 different compounds of ...

In field trials at Giza in 1986-1987, cotton cv. Giza 75 was sown at 166,000, 222,000 and 333,000 plants/ha and given foliar applications of 0, 250, 500 and 750 ppm Cycocel {chlormequat) or Alar (daminozide}. As plant density increased, there was a decrease in cottonseed yield]ha, seed index, seed protein content, oil and protein yields/ha, oil refractive index, iodine value, unsaponifiable matter and unsaturated fatty acids {myristoleic, oleic and linoleic). In contrast, as plant density increased, there was an increase in oil acid value, saponification value and saturated fatty acids (caprylic, capric, lauric, tridecylic, myristic, palmitic and stearic). Application of Cycocel or Alar increased cottonseed yield/ha, seed index, seed protein content and oil and protein yield/ha, oil refractive index, iodine value, unsaponifiable matter and unsaturated fatty acids. However, there was a decrease in oil acid value and saponification value. There were no differences among application rates of either chemical on cottonseed yield/ha. The highest oil and protein yield/ha was observed with Cycocel applied at 750 ppm, followed by Aiar at 250 ppm. Applying Cycocel at 250 ppm gave the highest oil refractive index and unsaponifiable matter, and the lowest acid value. Application of Aiar at 250 ppm gave the highest oil iodine value and the lowest saponification value, and also at 250 or 500 ppm gave the highest oil unsaturated fatty acid composition. Interaction was positive between plant density, Cycocel and Aiar and affected cottonseed yield/ha. The 166,000 plants/ha and application of Cycocel at 750 and Aiar at 250 ppm are recommended for the improvement of cottonseed yield and quality.KEY WORDS: Cottonseed yield, growth retardants, oil fatty add composition, plant density, seed index, seed oil content, seed oil prope~ ties, seed protein content.

Field experiments were conducted in two successive seasons at the Agricultural Research Centre, Giza, Egypt (on a clay loam soil), to determine the eects of N fertilization (added at rates of 107 and 161 kg N ha ±1 ) and foliar application of plant growth retardants (Pix, Cycocel and Alar; each applied once at 300 p.p.m., 75 days after planting) and zinc (applied at 0.0 and 50 p.p.m., two times, 80 and 95 days after planting) on cottonseed, protein and oil yields and oil properties of the Egyptian cotton cultivar Giza 75. The higher N rate, as well as the application of all growth retardants and zinc, resulted in an increase in cottonseed yield ha ±1 , seed index, seed protein content, oil and protein yields ha ±1 , seed oil refractive index, unsaponi®able matter and total unsaturated fatty acid content (oleic and linoleic). However, those treatments decreased the oil acid value, saponi®cation value, and total saturated fatty acid content. The seed oil content tended to decrease when the high N rate was applied, but tended to increase with the application of all growth retardants and zinc. There were some dierences between Pix, Cycocel and Alar regarding their eects on the studied characters. The highest increase in seed yield ha ±1 , seed index, and oil and protein yields ha ±1 was found with Pix, followed by Cycocel. The Cycocel treatment gave the lowest total saturated fatty acid oil content, followed by Alar.

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