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Phosphorus, Potassium and Phytohormones Promote Chlorophyll Production Differently in Two Cotton (Gossypium hirsutum) Varieties Grown in Hydroponic Nutrient Solution  [cached]
Adebusoye Olulayo Onanuga,Ping-an Jiang,Sina M. Adl
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n2p157
Abstract: The effectiveness of phosphorus (P), potassium (K), indole-3-acetic acid (IAA), gibberellic acid (GA3), zeatin (Z) and their combinations on chlorophyll a, b and total chlorophyll production was investigated in the hydroponic nutrient solution. The cotton plants were cropped without hormones application in different levels of P and K in the first cropping and with hormones application in the second cropping in high level of PK. In the first cropping, low K and high PK significantly influenced formation of chlorophyll a, b and ab from 83 to 91 days after planting (DAT) while the application of GA3, IAA, Z and IAA x GA3 x 2Z treatments significantly increased chlorophyll a, b and ab only at 80 DAT. However, two cotton varieties planted in two cropping seasons expressed different abilities in time to promote chlorophyll formation.
Determination of Endogenous Hormones Content in Cotton Varieties (Gossypiumhirsutum) as Influenced by Phosphorus and Potassium Nutrition  [cached]
Adebusoye O. Onanuga,Ping-an Jiang,Sina Adl
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n7p76
Abstract: Two experiments were conducted to evaluate the endogenous hormones content of cotton plants grown hydroponically, and supplied with varying levels of phosphorus (P) and potassium (K) mineral nutrients in the first cropping. In the second cropping, varying levels of exogenous indole-3-acetic acid (IAA), gibberellic acid (GA3) and zeatin (Z) and their combinations were applied to high level of PK in the hydroponic. In the first experiment, low K and low P treated plants had higher content of gibberellic acid (GA3) in the leaves than high PK treated plants, and low K treated plants also produced more Zeatin (Z) in the leaves than either low P or high PK treated plants. Furthermore, low K treated plants had higher Zeatin (Z) content in the root than either low P or high PK treated plants. However, the two cotton varieties expressed different hormones content in the leaves, stem and root. In the second experiment, GA3 concentration was highest in the cotton stem treated to IAA x GA3 x Z. Moreover, Zeatin content in the leaves, stem and root was highest in the cotton treated to IAA x GA3 x Z and 2IAA x 2GA3 x 2Z for leaves, IAA x GA3 x Z for stem and Z, IAA x 2GA3 x Z for root. Nevertheless, two cotton varieties possessed different hormones content in the leaves, stem and root. In general, there was no relationship between the first cropping and second cropping. The results demonstrated influence of exogenous hormones application in altering the endogenous hormones content of cotton plants.
Effect of Phytohormones, Phosphorus and Potassium on Cotton Varieties (Gossypium hirsutum) Root Growth and Root Activity Grown in Hydroponic Nutrient Solution  [cached]
Adebusoye Olulayo Onanuga,Ping-an Jiang,Sina Adl
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n3p93
Abstract: Modern agriculture using hydroponics allows in-depth study of root morphology and physiology. Two experiments were conducted to evaluate effectiveness of mineral nutrients, phosphorus (P) and potassium (K) and phytohormones, indole-3-acetic acid (IAA), gibberellic acid, (GA3 ) and zeatin ( Z) on cotton plant varieties root area, root volume and root activity. During the first cropping, Low P, low K and high PK treated plants significantly influenced total root absorption area, active absorption area, percentage active absorption area ratio, specific surface area and root volume. Furthermore, treatments applied did not favour root activity at the early growth stage but effects were known as from 104 to 148 days after transplanting. During the second experiment, however, cotton plants treated with hormones significantly affected active absorption area, percentage active absorption area ratio, root volume, specific surface area and root activity at 80 and 90 days after transplanting. In general, there was no relationship between the first cropping without hormones application and second cropping with hormones application except percentage active absorption area ratio (-0.999*) which was negatively correlated. This report shows effect of mineral nutrients and stimulatory tendency of hormones in root growth regardless of different cropping time between first and second cropping.
Impact of Nitrogen Fertilizer on Newly Developed Cotton Varieties under Sakrand Conditions  [PDF]
Abdul Aziz Memon,Abdul Wahid Soomro,Ghulam Hyder Kalwar,Mohammad Hussain Arain
Journal of Biological Sciences , 2001,
Abstract: A field experiment was conducted during the cotton season 1998 to study the optimum nitrogen requirements of three new cotton varieties developed by Central Cotton Research Institute, Sakrand viz., CRIS-18, CRIS-21 and CRIS- 9. The studies concluded that 100 kg N/ha is the optimum requirement of nitrogen fertilizer for these three cotton varieties under Sakrand conditions. More over, the cotton crop did not respond to higher dose of 150 kg N/ha.
Intra-Specific Variations of Phosphorus Utilization Efficiency
Zaheer Ahmad,Muhammad Aslam,Maqsood Ahmad Gill,Muhammad Yaseen
Pakistan Journal of Biological Sciences , 2000,
Abstract: Soils of Pakistan are frequently characterized as deficient in plant-available phosphorus (P). The option of fertilizer applications to cope the situation has proved cost-intensive for resource-poor farmers of the country. Under the circumstances, exploitation of genetic variations in crops for P-use efficiency and identification of P-efficient crop cultivars hold great promise. Experiments conducted at the University of Agriculture, Faisalabad indicated significant growth differences among varieties of wheat, rice, chickpea and cotton when grown under P-deficient as well as P-adequate conditions. Differences in relative adaptability of varieties to P-deficiency stress were also considerable. In this paper, work done in Pakistan and elsewhere on genotypic variations of P-nutrition of crops is briefly reviewed. Various physiological mechanisms responsible for such variations are also discussed.
Effect of Potash on N, P and K Content of Young Mature Leaves and Nitrogen Utilization Efficiency in Selected Cotton Varieties  [PDF]
Aneela Sardar,Muhammad Ashraf,Muhammad Ehsan Akhtar
Pakistan Journal of Biological Sciences , 2003,
Abstract: A pot experiment was conducted in a glasshouse at National Agricultural Research Center (NARC), Islamabad to study the effect of potash levels viz. 100 and 200 K 2 O ha 1 on Nitrogen, phosphorus, Potassium, chlorophyll and protein content of young mature leaves at flower initiation stage (50 days after seeding) in three resistant cotton varieties namely CIM443, CIM109, CIM446 during the year 1999. Potassium content was significantly increased with increasing K2O levels and it was maximum at 200 kg K2O ha-1 in all the varieties. Nitrogen content of young mature leaves decreased significantly with increasing K2O levels while protein content of young mature leaves increased significantly with increasing K2O levels and overall maximum increase of 37.5% was observed at 200 kg K2O ha-1. Phosphorus content of young mature leaves increased significantly with potash application and it was maximum at 100 kg K2O ha-1. In conclusion, application of potash did not affect the leaf chlorophyll content but significant differences in leaf chlorophyll content of different varieties were observed. However, an increase of 15.63% in leaf chlorophyll content was found with addition of 200 kg K2O ha-1.
Phosphorus requirements by maize varieties in different soil types of Western Kenya
CJ Wasonga, DO Sigunga, AO Musandu
African Crop Science Journal , 2008,
Abstract: Phosphorus and nitrogen deficiencies limit production of maize (Zea mays L.) in many soils of western Kenya. Considerable amount of work has been done on N nutrition of maize in the region. There is, however, paucity of information on which to base fertiliser P recommendations for increased maize production considering potential differences in responses due to varieties, soil type, and climate. External and internal P requirements, and P utilisation efficiencies of two open pollinated varieties (Ababari and Oking’) and one hybrid (H513) were examined at four P-deficient on-farm sites (2 Ferric Alisol, 1 Haplic Ferralsol, and 1Ferric Acrisol) in western Kenya. The varieties were grown under P fertilisation rates of 13, 26, 39, 52 kg P ha-1 and a check (no P application). Maize performance varied with site, rate of P application, and variety. The highest grain yields (15% moisture content) at the sites varied from 2,732 to 6,479 kg ha-1 for Ababari, 2,350 to 5,835 kg ha-1 for H513, and 2,299 to 4,459 kg ha-1 for Oking’. Internal P requirements ranged from 7 to 24 kg P ha-1 for Ababari, 4 to 18 kg P ha-1 for Oking’, and 5 to 18 kg P ha-1 for H513. Internal P requirements depended on both variety and environment, but more on environment than on variety. Phosphorus physiological efficiency (kg grain kg-1 P) ranged from 111 to 314 for Ababari, 145 to 277 for Oking’, and 127 to 390 for H513. Ababari performed as well as did H513, and the two were better than Oking’. Ababari is, therefore, recommended for the region since it is open pollinated and, hence, the peasant farmers do not have to buy the seeds every season. Row application of P is inappropriate in case determination of crop external P requirement is required.
Influence of phosphorus on the performance of cowpea (Vigna unguiculata (L) Walp.) varieties in the Sudan savanna of Nigeria  [PDF]
A. Singh, A. L. Baoule, H. G Ahmed, A. U. Dikko, U. Aliyu, M. B. Sokoto, J. Alhassan, M. Musa, B. Haliru
Agricultural Sciences (AS) , 2011, DOI: 10.4236/as.2011.23042
Abstract: Savanna regions of Nigeria are deficient in nitrogen and phosphorus, which retard the growth and yield of crops. Therefore, a study was conducted in the wet season of 2006 at the Dry Land Teaching and Research Farm of Usmanu Danfodiyo University, Sokoto to evaluate the effect of phosphorus on the growth and yield of two cowpea varieties sourced from Republic of Niger. Treatment consisted of four (4) rates of phosphorus (0, 20, 40, 60 kg.ha–1) factorialy combined with (2) varieties of cowpea (kvx303096G and TN5-78) and laid out in a randomized complete block design (RCBD) replicated three (3) times. Results showed significant response to applied P on pods per plant, grain and stover yield and 100-seed weight with highest response to the application of 60 kg.P.ha–1. From this study it can be concluded that KVX303096G and TN5-78 could both be sown under Sokoto condition to obtain reasonable yield of about 1 t.ha–1 of grain and 1.6 t.ha–1 of stover. Irrespective of the varieties, application of 60 kg P2O5 ha–1 could be recommended for higher yield of cowpea (1.4 t.ha–1) relative to 0 kg.P.ha–1 that yielded 1.0 t.ha–1.
Residual Level of Phosphorus and Potassium Nutrients in Hydroponically Grown Cotton (Gossypium hirsutum)  [cached]
Adebusoye Olulayo Onanuga,Ping-an Jiang,Sina Adl
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n5p149
Abstract: Sustainable agriculture requires economical and judicious use of mineral fertilizers and other farm inputs such as synthetic plant hormones so as to benefit crop growth, development and yield. The present study investigated residual levels of phosphorus (P), potassium (K) nutrients and nutrient solution level in the hydroponics by application of low P, low K and high PK nutrients to hydroponics pots in the first experiment, and by spraying cotton plants with indole -3- acetic acid (IAA), gibberellic acid (GA3), zeatin (Z) and their combinations at high level of PK nutrient in the second experiment. In the first experiment, nutrient solution level in the hydroponics irrespective of varieties of cotton planted in them and those with specific cotton varieties were significantly affected by the treatments. However, low P, low K and high PK treatments irrespective of the two cotton varieties planted in the hydroponics pots significantly influenced residual level of P and K nutrients. During the second experiment, the exogenous hormones applied irrespective of two cotton varieties planted in the hydroponics pots did not affect nutrient solution level in the hydroponics except at 43 and 80 days after transplanting (DAT). Nevertheless, taken the two cotton varieties into consideration, Zhong cotton variety had higher nutrients solution level than Xin cotton variety. In general, hormones applied did not affect residual P and K in the nutrients solution after every nutrients change except at 43 DAT. However, varietal differences were observed for high residual P and K nutrients at 80 and 90 DAT for P and 74 and 90 DAT for K in the nutrient solution grown with Xin cotton variety. It is clear from these results that wise usage of mineral fertilizers and synthetic plant hormones should be taken into consideration in order to avoid wastage.
Effect of potassium on micromorphological and chemical composition of three cotton (Gossypium hirsutum L.) genotypes
M.E Akhtar, M.Z Khan, S Ahmad, M Ashraf, A Sardar
African Journal of Biotechnology , 2009,
Abstract: An experiment was conducted at National Agricultural Research Centre (NARC), Islamabad, Pakistan to study the effect of potassium on yield and internal leaf tissues composition of cotton varieties, CIM-443, CIM-109 and CIM-446. Nitrogen (N) and phosphorus (P) were applied at 150 mg N/kg soil and 75 mg P 2O5/kg soil to all the pots, while potassium (K) was applied at three levels; control (no K), 100 and 200 mg K2O/kg soil. It was observed that epidermal and mesophyl cells were more turgid, uniform, flaccid, symmetrical and structurally improved with potassium application. Larger number of starch grains was observed in plant leaves grown without potassium application while in leaves supplied with K their number decreased. Thickness of the epidermal region (cuticle plus epidermis) increased significantly with potassium application and same was true for leaf thickness in all the varieties. Application of K decreased N content of leaves significantly while protein content increased. Protein contents were maximum (65 μg/g) at 200 mg K2O/kg soil over that of control treatment. Phosphorus concentration also affected positively with potash application and it was maximum at 100 mg K2O/kg soil. An increase of 15.63% in leaf chlorophyll content was recorded with K at 200 mg K2O/kg soil. Seed cotton yield of all the varieties increased significantly with K application, maximum in case of CIM-446 followed by CIM- 109 and CIM-443 variety. A strong positive correlation was observed among applied K, leaf thickness, epidermis layer, chlorophyll contents, protein and seed cotton yield.
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