GROWTH AND IRON-MANGANESE RELATIONSHIPS IN DRY BEAN AS AFFECTED BY FOLIAR AND SOIL APPLICATIONS OF IRON AND MANGANESE IN A CALCAREOUS SOIL

Manganese (Mn) deficiency may be induced by adding large quantities of iron (Fe), provided that soil manganese is marginally deficient. Results of a greenhouse study showed that iron soil application did not influence shoot dry matter yield of dry bean due to the fact that the iron:manganese ratio in aerial parts of dry bean was higher than 0.4. A foliar spray of 2% iron sulfate significantly reduced it probably due to the high level of shoot iron and iron:manganese ratio greater than 4. Iron application decreased concentration/uptake of shoot manganese due to the iron-manganese antagonistic relationships. Mangenese soil application is not an effective method in correction of manganese deficiency induced by iron fertilizers. Iron did not affect root manganese uptake, indicating that manganese absorption was not affected by iron application. Both manganese/iron soil tests are recommended in calcareous soils with manganese soil test in marginal range.     

POTATO TUBER YIELD AND QUALITY AS AFFECTED BY RATES AND SOURCES OF POTASSIUM FERTILIZER

Among the major nutrients, potassium (K) not only improves yields but also improves quality parameters. Field experiments were conducted to assess the comparative effect of sources and rates of K fertilizer on potato yield and quality on a sandy loam soil. Graded doses of potassium, i.e., 0, 150 and 225 kg ha^?1 K₂O from sulfate and muriate of potash were applied in triplicate. Recommended dose of nitrogen (N) and phosphorus (P) applied uniformly. Significant increase in tuber yield was observed with 150 kg ha^?1 K₂O from both the sources over control. Increase in tuber yield with 225 kg ha^?1 K₂O was statistically non significant compared to 150 kg ha^?1. The dry matter and specific gravity were more affected with sulfate of potash (SOP) than muriate of potash (MOP). The quality parameters like dry matter, specific gravity, starch contents, vitamin C, chips color and taste were improved with K application.     

ADDITION OF PULP MILL ASH RAISES PH,MODIFIES PHYSICAL PROPERTIES,AND ALTERS YOUNG TOMATO PLANT GROWTH AND MINERAL NUTRITION IN A PEAT-BASED SUBSTRATE

Pulp and paper mills often burn wood waste to fuel their boilers. The ash from a Mississippi pulp mill boiler was evaluated for potential use as an amendment to peat moss-based greenhouse substrates for production of young tomato plants. Between 0 and 50% ash was added to a custom-blended peat moss-based substrate, and these were compared to a commercially available substrate without ash. Addition of ash increased substrate pH, conductivity (EC), bulk density and water holding capacity, while reducing airspace and average particle size. In general, tomato plants grown in 0–40% ash had similar growth indexes as plants grown in commercial substrate. Increasing amounts of ash decreased tomato shoot nitrogen (N), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentration, and increased concentrations of phosphorus (P), calcium (Ca), sulfur (S), and boron (B). These results indicate that pulp mill ash has the potential to be used as a substrate component for greenhouse container production of tomato.     

EFFECTIVENESS,AMMONIUM IMPACT AND POTASSIUM ADEQUACY OF SOYBEAN-BASE LIQUID FERTILIZER ON BEDDING PLANTS

A greenhouse study was conducted to compare the effectiveness of a soybean-base liquid fertilizer [Daniels Plant Food; 10 nitrogen (N):1.8 phosphorus (P): 2.5 potassium (K)] to two inorganic, greenhouse-type formulations containing 25 and 75% of nitrogen in the ammoniacal form on four bedding plant species (pansy, petunia, salvia, and vinca). Flowering was unaffected, foliage was deeper green, and substrate electrical conductivity was lower when fertilized with the soybean-base fertilizer. Plants were desirably more compact (lighter with less leaf area) when fertilized with the soybean-base and 75% ammoniacal fertilizer. While ammonium toxicity did not develop in any treatments at the standard lime rate, it occurred at low lime in all species with 75% ammoniacal and only lightly in pansy with soybean-base fertilizer, in spite of its 81% reduced nitrogen. Soybean fertilizer caused less acidification than 75% ammoniacal fertilizer. The potassium content of the soybean-base fertilizer was adequate to meet the requirements of the four species tested.     

正常和高铵条件下氯化钠对万寿菊生长、开花和代谢的影响

在温室中以养分平衡的肥料组合和含250mg/L NH_4~+的组合栽培万寿菊(Tagetes patula L.)。每种组合中以一半植株每天每盆加250 mL 27.5 mmol/L NaCl溶液,进行盐胁迫处理。盐处理结果,使每株鲜重、株高和开花数都减少。盐处理2周后,根、叶细胞膜相对透性显著增加,叶子热处理渗出物中游离NH_4~+、根渗出物中Na~+。以及叶子中的过氧化物酶、Mg~(2+)-ATP酶和Ca~(2+)-ATP酶活性都明显提高,而根、叶渗出液的pH和蛋白质含量显著降低。根渗出物中游离NH_4~+、K~+和Ca~(2+)含量,叶子中叶绿素、可溶性蛋白质、无机磷和多酚氧化酶活性也下降,但未发现叶子渗出物中Na~+有所增加。在正常营养条件下,盐胁迫对叶子中的类胡萝卜素和花青素影响较小,但高NH_4~+处理使这些色素含量显著降低。高NH_4~+一般使NaCl的效应加剧。     

EFFECT OF ZINC NUTRITION ON GROWTH,YIELD, AND QUALITY OF FORAGE SORGHUM IN RESPECT WITH INCREASING POTASSIUM APPLICATION RATES

A two-year field study was conducted to determine the effect of two zinc (Zn) levels [0 and 10 kg zinc sulfate (ZnSO₄) ha^?1] in respect with four potassium (K) levels (0, 20, 40 and 60 kg K₂O ha^?1) on growth, yield and quality of forage sorghum. The soil of the experimental field was loamy sand (Inceptisol), carrying 70, 08, 77, and 0.51 mg nitrogen (N), phosphorus (P), K, and Zn kg^?1 soil, respectively. Increasing K levels significantly improved most of the growth, yield, and quality attributes gradually irrespective of the Zn levels. Zinc applied at 10 kg ZnSO₄ ha^?1 proved significantly better than no zinc application at various K application rates. The benefit of zinc application increased progressively with increasing K rates for most of the parameters studied, indicating significant response of the crop to positive K × Zn interaction in plants in respect with K and Zn application to the soil. Accordingly, 60 kg K₂O ha^?1 applied with10 kg ZnSO₄ ha^?1 boosted most of the attributes maximally. It resulted in about 20–40% increase in growth attributes, 25% increase in fresh matter yield, 36–38% increase in dry matter yield, and 38% increase in protein yield compared to the comparable K level applied without zinc. It also enhanced N uptake by 38%, P uptake by 5–19%, K uptake by 40–42%, and Zn uptake by 114–144%. Across the K rates, application of 10 kg ZnSO₄ surpassed no zinc application by 30–35% in N uptake, by 8–15% in P uptake, by 33–36% in K uptake, by 120–140% in Zn uptake, by 19–21% in fresh matter yield, by 29–31% in dry matter yield, and by 30–34% in protein yield.     

EFFECTS OF DIFFERENT NITROGEN,PHOSPHORUS, POTASSIUM RATES ON THE QUALITY AND QUANTITY OF CITRUS PLANTS,VARIETY THOMSON NOVEL UNDER RAINFED AND IRRIGATED CONDITIONS

Plants require nutrients including nitrogen (N), phosphorus (P), and potassium (K) for their growth and production. Although there have been previously extensive research work regarding the effects of NPK on plant growth, data related to the effects of long term application of NPK on the quality and quantity of citrus under rainfed and irrigated conditions are little. Accordingly, such effects were evaluated in this research work using different chemical fertilization factorially combined and on the basis of a completely randomized block design. Using ammonium sulfate (100, 150 and 200 g tree ^{? 1}), triple super phosphate (0, 25, 50, and 75 g tree^?1) and potassium sulfate (0, 50, 100, 150 g tree ^{? 1}) the quantity and quality of citrus fruit, variety Thomson were determined in a 10-year experiment in two different research stations in Ramsar, Iran. NPK fertilization significantly affected the quality and quantity of citrus fruits, indicating the significance of NPK fertilization for citrus production.     

水生植物对水体中氮、磷的吸收与抑藻效应的研究

研究了不同水生植物对富营养化水体氮、磷的净化效果及其抑藻效应。结果表明:金鱼藻(Ceratophyllum demersum)、苦草(Vallisneria spiralis)、空心菜(Ipomoea aquatica)、浮萍(Lemna minor)和菹草(Potamogetom crispusLinn)对富营养化水体中总氮、总磷、硝态氮、氨氮都有较好的去除作用,其中以空心菜和金鱼藻效果最好。培养21d后的空心菜对总氮和硝态氮的吸收率分别为76.93%和71.9%;培养21d后的金鱼藻对总磷和氨氮的吸收率分别达到了93.15%和91.2%。水葫芦(Eichhornia crassipes)、金鱼藻、浮萍都具有较好的抑制藻类生长的作用,培养过以上3种水生植物的水体也表现出抑藻效应。