Foliar NPKS application to cotton from full flowering to boll filling

Two field experiments were carried out at different locations to test the effect of NPKS sprays on cotton in addition to soil applied fertilizers. The differences in lint yield and average boll weight between treatments were not significant. Four foliar application (10 kg N, 1 kg P, 3 kg K and 0.5 kg S/ha/application) tended to increase the lint yield and the average boll weight in the location with the lower fertility. It seems that utilization of foliar nutrient application is dependent upon the availability of these nutrients in the soil. N was added mainly as urea, P and K as potassium polyphosphate and S as potassium or ammonium sulphate.Contribution from the Dept. of Soil Chemistry and Plant Nutrition, Agricultural Research Organization. The Volcani Center. Bet Dagan, Israel No 2167-E 1987 series.     

Nutrient uptake and export from an Australian cotton field

Soil fertility may decline as a result of nutrient export from high-yielding cotton crops and this may limit the productivity of future crops unless these nutrients are replaced. Uptake of nutrients by cotton (Gossypium hirsutum L.) and nutrient export from the field in seed were measured within two cropping systems experiments from 1999 to 2005 in a flood-irrigated cotton field. Lint yields of the seven crops assessed ranged from 975 to 2725 kg lint/ha. Nutrient uptake was measured at mid to late boll-fill and nutrient removal determined from analysis of delinted seed. Cotton crops accumulated an average of 180 kg N/ha (range 67–403), 27 kg P/ha (range 18–43), 167 kg K/ha (range 88–264), 41 kg S/ha, 160 kg Ca/ha, 36 kg Mg/ha, 7 kg Na/ha, 890 gm Fe/ha, 370 gm Mn/ha, 340 gm B/ha, 130 gm Zn/ha and 51 gm Cu/ha. On average, the seed within harvested seed cotton removed 93 kg N/ha (range 38–189), 18 kg P/ha (range 8–34), 29 kg K/ha (range 13–51), 8 kg S/ha, 4 kg Ca/ha, 12 kg Mg/ha, 0.2 kg Na/ha, 136 g Fe/ha, 12 g Mn/ha, 41 g B/ha, 96 g Zn/ha and 20 g Cu/ha. Nutrients contained in the lint and trash were not included. For crops yielding about 1800 kg/ha, 70% of the Zn and P taken up was removed in the seed, also 52% of N, 38% of Cu, 34% of Mg, 21% of S, 17% of K and Fe, 12% of B and only 3% of Ca, Mn and Na. Predictive equations were developed to allow growers to estimate the removal of nutrients given the lint yield measured from their cotton crops.     

1.8%复硝酚钠水剂对棉花生长的调节作用

通过田间小区试验,筛选了1.8%复硝酚钠水剂对棉花生长的调节作用,结果表明:药后10d和20d时,1.8%复硝酚钠水剂均能增加棉花的株高,枝条数和棉铃数。随着药量的增加,1.8%复硝酚钠水剂对棉花株高、枝条数、棉铃数促进作用增加。棉花品质和测产结果表明:1.8%复硝酚钠水剂各处理剂量对棉花的品质没有明显的影响作用,但对棉花的铃重和小区籽棉产量都有所提高。     

Aflatoxin in Arizona cottonseed: Field inoculation of bolls byAspergillus flavus spores in wind-driven soil

Conditions typical of an Arizona monsoon were mimicked in the field to inoculate cotton plants withAspergillus flavus. Spores, mixed with autoclaved local soil, were blown onto cotton plants having bolls at all stages of maturity, using a modified commercial leaf blower. Half the plants were sprayed with water following inoculation. After one month, plants were pulled and the position of bolls mapped. All bolls were examined for bright-green-yellow fluorescence (BGYF) of lint, and ginned seeds from each boll were assayed for aflatoxin. Control non-wetted, non-inoculated bolls had no BGYF lint and no aflatoxin-containing seed. In contrast, 15% of the bolls from wetted, inoculated plants exhibited BGYF; 18% of these BGYF bolls had toxin. Only 3% of the non-wetted bolls had BGYF lint and none contained toxin. Lower bolls (fully fluffed at inoculation) were not infected, nor were upper bolls (flower stage at inoculation). Infection occurred only in bolls that had opened during the 30 days following inoculation. While the position of BGYF bolls on naturally contaminated plants was the same as for the inoculated, the ratio of toxic bolls to BGYF bolls was different. All BGYF bolls from plants naturally contaminated withA. flavus contained aflatoxin.     

Relationship of BGYF spots detected on the sides of trailers and modules of seed cotton to aflatoxins in ginned seed

Sides of 146 trailers and 60 modules packed with freshly harvested seed cotton from commercial fields were examined at night using a long-wave ultraviolet lamp for bright-green-yellow fluorescent (BGYF) spots caused by contamination of cotton lint withAspergillus flavus. During ginning, a 22.7 kg (50 lb sack) of seed was removed from each trailer or module for determination of aflatoxin content. For both carriers, as the number of BGYF spots increased, the level of toxin in ginned seed increased. Assays of seed from 90% of the trailers and 64% of the modules with 0–1 BGYF spots were below 20 μg/kg.     

Yield and chemical composition of sesame,Sesamum indicum L., as affected by variety and location grown

Summary Observation nurseries including 24 varieties of sesame were grown at 23 locations in 16 states. Data for yield, oil and protein content of the seed, and for iodine value of the oil were obtained from certain locations. Sesame seems reasonably well adapted on the better soils of most of the southern one-half of the United States. Average seed yield for varieties at 14 locations was 506 pounds per acre. Average yield of seed, oil, and protein per acre for seven varieties grown at eight locations was 662, 344, and 163 pounds per acre, respectively. The chemical composition of the seed was found to be well within the acceptable range but was markedly influenced both by the varieties and by the locations where they were grown. The average oil and protein contents on a moisture-free basis were 53.53% and 26.25%, respectively. The average iodine value of the oil was 110.0. Average protein content on the moisture- and oil-free basis was 57.28%. The genetic and environmental influences that affect protein content of the seed also inversely affected the oil content. It was suggested that in sesame protein synthesis is favored over oil synthesis as the nitrogen supply to the seed increases. Contribution of the Division of Tobacco, Medicinal, and Special Crops, Bureau of Plant Industry, Soils, and Agricultural Engineering, and the Southern Regional Research Laboratory, Bureau of Agricultural and Industrial Chemistry, U. S. Department of Agriculture. Agronomist, Division of Tobacco, Medicinal, and Special Crops in cooperation with the Department of Agronomy, Texas Agricultural Experiment Station; and chemist, Southern Regional Research Laboratory, New Orleans, La., respectively. The authors wish to acknowledge the assistance of workers in the various state agricultural experiment stations and government agencies who grew the tests and made data and seed samples available.     

Aflatoxin in Arizona cottonseed: Lack of toxin formation following aspergillus flavus inoculation at sutures

Aflatoxin assays were conducted on seeds from cotton bolls inoculated withAspergillus flavus in commercial fields in Arizona. Inoculations were at sutures at the initiation of boll opening either in the morning or evening in August over a three-year period. One morning inoculation was followed by a water treatment that simulated rain. Fully fluffed bolls were harvested after two or four weeks, and lint and seed linters were examined for bright-green-yellow-fluorescence (BGYF). Ginned seed were assayed for aflatoxin. While BGYF of lint was detected, no seed linters exhibited BGYF and no seeds from the 140 bolls examined contained aflatoxin. Results imply that boll infection byA. flavus occurs before the initiation of boll opening, an observation that is in agreement with recent reports ofA. flavus infection but contrary to conclusions made in earlier reports.     

Effect of nitrogen and zinc fertilization and plant growth retardants on cottonseed, protein, oil yields, and oil properties

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.     

Effect of modular storage of arizona seed cotton on levels of aflatoxins in seed

Samples were drawn from 40 free-standing modules of commercially grown Arizona seed cotton and analyzed for aflatoxin at the time of moduling and after 27 days of field storage. Thirty modules derived from spindle harvested cotton showed no significant increase in aflatoxins following modular storage, while all 10 modules packed with seed cotton derived from ground harvesters yielded significantly higher levels after storage than were detected at the time of moduling. Increases in toxin levels ranged from 12–232% with an average value of 67%. Even under ideal module making conditions significant increases in aflatoxins can be expected in ground-gleaned seed cotton harvested in areas where chronic aflatoxin contamination exists.     

Tocopherol oil concentration in field-grown sunflower is accounted for by oil weight per seed

Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil⁻¹) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed⁻¹. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil⁻¹) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.     

Relationship of seed boron concentration to germination and growth of soybean (t Glycine max)

Soybean seeds with B concentrations ≤ 10 mg B kg-¹ have been reported to have deformed cotyledons. This paper examines the relationship of seed B concentration to seed germination, seedling normality, and plant growth of soybean (Glycine max) cv. NW1 sown in soil with a range of B levels. Seed with 7 mg B kg-¹ performed poorly, with 80% failing to germinate. Moreover, 70% of the seedlings which emerged were abnormal when sown on a low B soil. Increasing soil B had no effect on germination but decreased the percentage of abnormal seedlings by one third. Seed with 10 mg B kg-¹ germinated as well as seed with 14 or 20 mg B kg-¹, but when sown on a low B soil, 80% of the seedlings were abnormal compared with 50 and 20%, respectively. Increasing soil B almost eliminated the incidence of seedling abnormality when seed contained 10 – 20 mg B kg-¹. When grown to maturity on the lowest soil B, plants from seed with 10 mg B kg-¹ produced less than half the seed yield of plants from seed with 14 or 20 mg B kg-¹. They had fewer pods per plant and fewer seeds per pod. They responded strongly to increasing soil B, so that in soil with higher B levels, plants from seed with 10, 14 or 20 mg B kg-¹ gave the same yield. The results suggested that soybean seed with a low concentration of B have permanently damaged seed embryos, preventing their germination or producing defective seedlings. At slightly higher concentrations, embryos are not permanently damaged, but require a higher level of external B for their normal development than do those with higher concentrations of seed B. In the present experiments, the critical concentration of B in soybean seed for permanent damage was between 7 and 10 mg B kg-¹, and for normal seedling development in low B soils was between 14 and 20. This revised version was published online in August 2006 with corrections to the Cover Date.     

我国棉花病害发生情况及防治进展

棉花是我国最重要的经济作物。棉花病害遍布我国广大棉区，每年因病害损失皮棉约３６万吨，价７０亿元。苗病在南方棉区重于北方棉区，成株期主要是枯萎病和黄萎病，分布全国，年损失皮棉１０万吨以上；在多雨年份有些棉区铃病严重，病、烂铃率在５０％以上。近年推广种衣剂和苗病净等农药，提高了苗病防治效果，用抗病品种防治棉枯、黄萎病是重要措施。铃病防治则仍依赖农业技术措施。棉花病害综合治理（ＩＰＭ）把经济、生态、社会效益统一起来，提高了棉病防治层次，已在推行。但棉花抗黄萎病育种滞后；安全，高效、低毒农药开发尚待加强；植物生理保护体系的研究刚刚起步。所有这些都需大力加强。     

Properties and structure of never-dried cotton fibers. III. Cotton fibers from bolls in early stages of growth

Like other kinds of cotton fibers already studied, American cotton fibers taken from cotton bolls immediately before and after opening show high angles of torsional rotation during ambient humidity changes. Cotton fibers taken from cotton bolls at 19 and 24 days postanthesis show remarkably higher angles of rotation and much lower dry and wet tensile strengths than the fibers taken from cotton bolls immediately before and after opening. The wet tensile strength of cotton fibers at 24 days postanthesis is higher than the dry strength like the fibers taken from bolls immediately before and after opening, but fibers at 19 days postanthesis show almost the same tensile strength in the never-dried, dried, and rewetted states. CP/MAS ¹³C NMR spectroscopy reveals that the never-dried cotton fibers at 19 days or longer postanthesis have high crystallinities. It seems that the degree of crystallinity is somewhat decreased in the dry state and restored by rewetting. The crystallinity increases with the age of growth.     

Yield and leaf composition of sunflower in relation to N,P, K,and lime treatments

Sunflower (Helianthus annus L), a drought resistant crop, is cultivated widely throughout the world. Still, few studies on the fertility requirements of the crop have been published, particularly in relation to cultivation on highly weathered soils and in terms of using foliar analysis as a tool in diagnosing nutritional needs.Two 3⁴ (N, P, K, lime) factorial experiments (high and low fertility levels) with trace elements as split plots were conducted on Farningham clay loam, a Typic Haplorthox. No significant yield response to added N or micronutrients was found on either experiment. Liming and P fertilization increased seed yields in the low fertility experiment. Increased K application gave significant yield increases in both experiments.Preliminary foliar diagnostic norms were developed using the Diagnosis and Reccommendation Integrated System (DRIS). The prognostic value of these norms was tested using the low fertility experiment. In 32 of the 37 cases where the DRIS analysis could be checked against actual experimental yield results, application of the nutrient diagnosed as the most yield limiting resulted in a positive yield response. These data suggest that sunflowers can be a successful crop on Oxisols provided fertility is adequate.     

Evaluation of soil extractants for Mn availability and response of wheat to applied Mn in soils of semi-arid zone of Punjab, India

Seven chemical extractants were tested for their relative performance to predict the response of wheat to Mn application in coarse textured alkaline soils of semi-arid region. Five out of the seven extractants were found to be promising for the estimation of critical level of available Mn in these soils, as the amount of Mn extracted by these extractants was positively and significantly correlated with relative grain yield as well as Mn uptake. The critical deficiency level of soil available Mn with 0.005 M DTPA, 0.02% hydroquinone, 0.02 N sodium pyrophosphate, 0.1N H3PO4 and 0.05N HCl+0.025N H2SO4 was 3.1, 13.8, 23.5, 5.3 and 17.8 mg kg-1 soil, respectively. The 1N ammonium acetate and 0.01M CaCl2 were found to be unsuitable extractants for these soils. Further field trials at eight locations with varying levels of Mn deficiency showed successive increase in the grain yield of wheat with foliar Mn application, emphasizing the need for Mn fertilization when wheat is grown on Mn deficient soils.     

Soil and crop management technologies for enhancing rice production under micronutrient constraints

Micronutrient deficiency is considered as one of the major causes of the declining productivity trends observed in ricegrowing countries. The submergence created for rice cultivation influences electrochemical and biochemical reactions, and alters pH, pCO2 and the concentration of certain ions. This environment increases the availability of Fe and Mn with concomitant decrease in Zn and Cu. It is well known that Zn deficiency is predominant in lowland ecosystems. Sodic and upland soils and calcareous coarse-textured soils with low organic matter content suffer from Fe deficiency, besides Zn and Cu deficiencies. Rice cultivars do not experience deficiency of B and Mo. The acid soils and the lowlying, poorly drained alluvial and colluvial soils are prone to Fe toxicity. Experiments in different agroecological zones all over India showed that Zn doses to correct Zn deficiency varied from 2.5 to 22 kg ha-1; 5.3 kg Zn ha-1 proved optimum and economical, with a maximum rice yield increase of 4.8 t ha-1. In the lowland ecosystem, amending the soil with the required amount of Zn before transplanting was effective and easy to adopt, compared with repeated foliar sprays of 0.5% ZnSO4 or use of Zn-enriched seedlings through seed soaking in 2–4% ZnSO4 solution, fertilizing the nursery with Zn, or seedling root dipping in 2% ZnO slurry. Hepta as well as monohydrated ZnSO4 were better than other sources of Zn (ZnO, ZnCl2 and Zn frits). The Zn-blended diammonium phosphate (Zn-DAP), superphosphate, and nitrophosphates also proved effective. The Zn-enriched organic manures (farmyard manure, green leaf manure, and coir pith compost) were found advantageous for the direct and residual crops. Zinc fertilization with an optimal dose of 25 kg ZnSO4 ha-1 once a year yielded high economic return. A differential response of rice up to a maximum increase in yield of 4.8 t ha-1 was observed with the foliar spray (1–2% FeSO4 solution) or soil incorporation of Fe (50 kg FeSO4 ha-1) with bulky organic manure (12.5 t ha-1). The application of 12.5 kg CuSO4 ha-1 ameliorated Cu deficiency and significantly enhanced rice production. Management strategies such as liming and additional multinutrient supply (P. K, Mg, Zn, Cu, and B), besides improving drainage, enhanced the rice productivity of soils prone to Fe toxicity by correcting the multinutrient deficiency syndrome.     

Effect of plant population densities and application of growth retardants on cottonseed yield and quality

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 Alar at 250 ppm. Applying Cycocel at 250 ppm gave the highest oil refractive index and unsaponifiable matter, and the lowest acid value. Application of Alar 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 Alar and affected cottonseed yield/ha. The 166,000 plants/ha and application of Cycocel at 750 and Alar at 250 ppm are recommended for the improvement of cottonseed yield and quality.     

Assessing internal crop nitrogen use efficiency in high-yielding irrigated cotton

Improving the efficiency of nitrogen (N) fertiliser use is one means of reducing greenhouse gas emissions, particularly in irrigated crops such as cotton (Gossypium hirsutum L.). Internal crop N use efficiency (iNUE) was measured within two N fertiliser rate experiments that covered a wide range of N fertility over six cropping seasons. Crop iNUE was determined by dividing lint yield by crop N uptake. No nutrients other than N limited cotton growth or yield and the crops were irrigated to avoid drought stress. The optimal N fertiliser rates were determined from fitted quadratic functions that related lint yields with N fertiliser rates for each cropping system in each year. When the optimal N fertiliser rate was applied, crop iNUE averaged 12.5 ± 0.2 kg lint/kg crop N uptake. The crop iNUE was then used to determine the degree to which N fertiliser was under or over-applied, with respect to the economic optimum N fertiliser rate. Low iNUE values were associated with excessive N fertiliser application. Crop iNUE was determined in 82 commercial cotton crops in six valleys over the final 4 years of this study. The crop iNUE value was high in 8 fields (10%), optimal in 9 fields (11%) and low in 65 fields (79%). Crop N uptake averaged 247 kg N/ha, yield 2,273 kg lint/ha and crop iNUE 10.1 kg lint/kg crop N uptake for these sites. Averaged over all sites and years, about 49 kg N/ha too much N fertiliser was applied. Apparent N fertiliser recovery by cotton in the N rate experiments ranged from <20% in N-fertile treatments where legume crops had been grown, to more than 60% following winter cereal crops. Information on crop iNUE will enable cotton producers to assess their N fertiliser management and adjust N fertiliser rates for future crops. This study has demonstrated that there is scope to substantially reduce N fertiliser inputs to Australian cotton fields without reducing yields.     

Growth response,yield and yield components of upland cotton (Gossypium hirsutum L) as affected by rates and time of nitrogen application in the Nigerian savannah

Effects of rate and time of nitrogen fertilization on growth, yield and yield components of upland cotton (Gossypium hirsutum L) were studied in two years (1975–76). Four rates of nitrogen application (0, 26, 52 and 78 kg ha^–1) timed at 3 or 8 weeks after sowing were compared. Seed cotton yield components increased significantly with increased N application at least up to 52 kg N ha^–1, with yield increases between 49% and 73%. Seed cotton yield was influenced by treatments mainly through boll number. Both crop growth rate and fruiting were enhanced by nitrogen fertilization. Applying N at 8 weeks (flowering) favoured yield only slightly over that at 3 weeks (thinning), but improved crop growth and fruiting by about 64% and 24%, respectively. There were significant N rate × time interactions in favour of fertilization at flowering. Applying 52 kg N ha^–1 at 8 weeks seems best for cotton in the Nigerian savannah.     

增产胺的合成与应用

在相转移催化条件下，３，４－二氯苯酚和二乙氨基乙基溴合成增产胺，产率达９４％。田间实验表明，增产胺促进棉花早发，增花增蕾，提高成铃率，从而使皮棉亩产增加了３３．５６％。