Effect Of Potassium Application Research Articles

Effect of potassium application on maize to sandy soil under deficit irrigation conditions

Maize is widely growth in arid and semi-arid region where, drought is common and a limiting factor for crop production. Potassium plays a key role in enhancing plant growth under drought condition. The objective of this study is to determine the effect of K fertilization with and without NP on maize growth grown in sandy loam soil under adequate and deficit irrigation conditions. The following treatments were investigated in pot experiment: (1) control with no fertilizer application (C); (2) 128 kg N + 328 kg P2O5 ha-1 (NPK0); (3) 128 kg N + 328 kg P2O5 ha-1 + 152.5 kg K2O ha1 (NPK1); (4) 128 kg N + 328 kg P2O5 ha-1 + 305 kg K2O ha-1 (NPK2); and 128 kg N + 328 kg P2O5 ha-1 + 457.5 kg K2O ha-1 (NPK3). Treatments were investigated under adequate and deficit soil moisture content. Each pot filled with 3.5 kg air-dry soil and seeded with maize and pots were watered according to the treatments. The results indicated that plant growth and nutrient uptake were significantly reduced under water stress condition. The application of NP increased plant growth and nutrient uptake and further were increased with K application. K application also enhanced plant tolerance to deficit soil moisture condition. In addition, K enhanced nutrient uptake and leaf chlorophyll content. Based on the results, it can be concluded that application of NP for maize was not adequate to achieve the highest plant growth, unless it is combined with K application. In addition, K application enhances plant tolerance to water stress.

Effects of potassium application on growth, yield, and quality of dryland cotton

AbstractPotassium (K) deficiency reduces cotton (Gossypium hirsutum L.) growth, development, lint yield, and fiber quality. The study's objective was to compare the effects of K fertilizer rate on cotton plant height (CPH), yield, and fiber quality in three cotton cultivars. Three cotton cultivars studied were NG 5711 B3XF (C1), PHY 480 W3FE (C2), and FM 1953GLTP (C3). Granular K fertilizer was surface broadcast and incorporated 1 week before planting at 34, 50, and 67 kg ha−1. The CPH and canopy width were measured from 30 to 105 days after planting. The cotton CPH increased by 13%, 17%, and 12% in 2020 and by 6%, 4%, and 8% in 2021 with 34, 50, and 67 kg ha−1 K fertilizer rates compared to control. The K application increased cotton canopy width by 39% in 2021 compared to 2020. The K application at 50 kg ha−1 yielded significantly more cotton yield than the control in 2020. The cotton lint yield increased by 25%, 34%, and 9% in 2020 and by 4%, 17%, and 11% in 2021 with 34, 50, and 67 kg ha−1 K fertilizer application rates than control. The cotton fiber staple length and color grade increased significantly with the 50 kg ha−1 K application rate than the control in 2020. Cultivars significantly impacted Col‐Rd and Col‐b in 2020 and 2021. This study shows that fertilizer‐K application improves not only yield, but also staple length and color grade in rainfed cotton crops.

Effects of Potassium Application on Yield, Protein and Oil Content of Selected Soybean Varieties in Trans Nzoia County, Kenya

There is low soybean production due to poor agronomic techniques, such as sub-optimal application of fertilizer among other factors. There are limited studies on the effects of potassium fertilizer application which is crucial in productivity, quality, and drought resistance. A study was conducted at the Kenya Agricultural Livestock and Research Organization, Kitale demonstration farm to determine the effects of potassium fertilizer application on the yield and quality of soybean varieties. A 3 x 4 factorial experiment was laid down in Randomised Complete Block Design and replicated three times. The study had two factors, that is three soybean varieties (DPSB19, Gazelle and SB24) and four levels of potassium (0 [control], 22.5, 45, and 67.5 kg K2O ha-1) applied as sulphate of potash fertilizer (50% K2O) at planting, making a total of 12 treatments. Data collected included number of pods per plant, number of seeds per plant, weight of seed per plant and 1000-seed weight, grain yield, protein and oil content. Data collected was subjected to analysis of variance using Statistical Analysis System version 9.3 and significantly different means separated using Least Significance Difference at α = 0.05. Application of potassium at the rate of 67.5 kg K2O ha-1 resulted to higher number of pods per plant and number of seeds per plant at 78.97 and 243.40, and 44.47 and 141.20 in the varieties DPSB19 and Gazelle, while in SB24 higher recording of 51.23 and 162.40 was observed with 22.5 kg K2­O ha-1. The higher 1000-seed weight was recorded in 22.5 kg K2O ha-1 in DPSB19 and Gazelle varieties, while for SB24 it was recorded in 67.5 kg K2O ha-1. The highest grain yield recorded was 9156.45 kg per ha, in DPSB19 in 22.5 kg K2O ha-1, 4517. 67.5 kg per ha in Gazelle variety in 67.5 kg K2O ha-1 and 6432.78 kg per ha in SB24 variety in 22.5 kg K2O ha-1. The higher percentage oil content was observed in 45 K2O kg ha-1 in DPSB19 (28.48%) and SB24 (23.38%) varieties, and in 22.5 kg K2O ha-1 in Gazelle (19.38%) variety and the higher percentage protein content was recorded in 45 K2O kg ha-1 in DPSB19 (42.99%) and Gazelle (40.56%), and in 45 K2O kg ha-1 in SB24 (48.87%). These findings show that soybean farmers should apply potassium fertilizer for appropriate growth, increased yield, protein and oil content in different soybean varieties. It is recommended that application of potassium at 67.5 kg K2O ha-1 be done for better soybean growth, yield and protein content and application of potassium at 45 kg K2O ha-1 is done for high oil content.

Comprehensive evaluation of the optimal rates of irrigation and potassium application for strawberry

Accurate and effective management of irrigation and fertilization is essential for efficient greenhouse strawberry production. Here, the effects of the combined application of water and potassium on strawberry growth were evaluated by experimenting with 12 treatments, including four transpiration (ETC)-based irrigation levels (W1: 100% ETC, W2: 85% ETC, W3: 70% ETC, and W4: 55% ETC) and three potassium levels according to the target yield (K1: 369.5 kg/hm2, K2: 307.9 kg/hm2, and K3: 246.3 kg/hm2). Various indexes of strawberry yield, fruit quality, water and fertilizer utilization efficiency, and soil nutrient residues were measured. Irrigation and potassium application had significant effects on strawberry production. Higher irrigation levels increased yield (Y), and moderate water and potassium application increased single fruit weight (SFW), water utilization efficiency (WUE), total soluble sugar (TSSC), and the sugar-acid ratio (SAR). While low-application of potassium increased the soluble protein content (SP), partial factor productivity of potassium (PFPK), and reduce nutrient residues in soil effectively. A comprehensive system for evaluating strawberry growth and its benefits to the soil environment was developed. The FAHP and CRITIC methods were used to calculate the subjective weight and objective weight of each index, respectively. The largest subjective weight was observed for Y (0.200), and the largest objective weight was observed for soil-available potassium (0.101). The final weight was determined using Game theory; Y had the highest weight (0.185), and free amino acids (FAA) had the lowest weight (0.047). Grey relational analysis (GRA) was used to evaluate the optimal irrigation and potassium scheme for accomplishing multiple objectives. The response of the comprehensive score of strawberries to irrigation and potassium exhibited a negative parabolic relationship, and the effect of irrigation was greater than the effect of potassium application. There was a significant interaction between irrigation and potassium application, and an irrigation amount of 2053-2525 m3/hm2 with a potassium application rate of 288.1-334.2 kg/hm2 was optimal for promoting strawberry yield, fruit quality, and efficiency and reducing soil nutrient residues. The results of this study provide new insights that could aid the development of sustainable approaches for enhancing agricultural production. Keywords: strawberry, irrigation, potassium, FAHP, CRITIC, nutrient residues DOI: 10.25165/j.ijabe.20231602.7591 Citation: Yang X Q, Du R C, Zhang M C, Feng H W, Wang Z Q, Zhang Z. Comprehensive evaluation of the optimal rates of irrigation and potassium application for strawberry. Int J Agric & Biol Eng, 2023; 16(2): 65-72.

Effect of potassium application on yield and quality of green gram (<em>Vigna radiata L</em>.) on coarse textured soils of southern Haryana

Crops need large quantity of potassium for enhancing their yield as well as quality. Pulses are important crops grown in India but their productivity is low. Among production inputs, recommendations for N and P fertilizers are made in most states with no K application resulting in imbalanced nutrient supply and lower crop yields.To quantify optimum dose for green gram ( Vigna radiata L.), a series of field experiments were conducted at Regional Research Station, CCS HAU, Bawal, Haryana, to assess the response of green gram to fertilizer potassium on coarse textured (Typic Haplustepts) soils of southern Haryana. After completion of research trials, crop was tested on farmer’s field through demonstrations and on farm trials (OFTs) to evaluate the response and adoptability of green gram as per the fertilizer potassium doses concluded in research experiment. Five levels of fertilizer potassium (0, 10, 20, 30 and 40 kg K2O ha-1) were evaluated for the response of green gram in randomized block design replicated thrice. The results of research trials revealed that the yield, protein content and growth parameters of green gram increased significantly with the application of fertilizer potassium @20 kg K2O ha-1. Significantly higher yield of green gram was recorded (5.87, 16.29, 19.23 and 22.36 %) due to application of 10, 20, 30 and 40 kg K2O ha-1, respectively over control. The total K uptake by green gram increased significantly with the incremental doses of potassium application which helped to prevent the depletion of available soil K and build-up its content in the soil. The mean K use efficiency varied from 38.30 to 54.15 and maximum (54.15 %) was recorded with the application of 20 kg K2O ha-1. The benefit cost ratio was also increased with the application of potassium and reflected in terms of additional returns per rupee (Rs. 10.94, 15.63, 12.17 and 10.72) invested on application of K @ 10, 20, 30 and 40 kg K2O ha-1, respectively. The farmer’s field trial results with 0 and 20 kg K2O ha-1 revealed that application of 20 kg K2O ha-1 increased the yield of green gram by 10.87% over control.

Effect of potassium application and follar spraying of boron at different stages on faba bean production

A field experiment was conducted at the Experimental Farm, Department of Field Crops, College of Agriculture, University of Baghdad/Abu-Ghraib during winter season of 2013-2014. The main objective was to find out the effect of potassium levels (0, 41.5 and 83) kg K.ha-1 and foliar application of boron (100 mg.L-1) at different flowering stages (flower buds emergence, 25%, 50% and 75% flowering) in addition to control treatment (water spray only) on faba bean Spanish cultiver. Luz de Otono on setting and pod yield, layout of the experiment was a factorial experiment in randomized complete block design with four replications.Results showed that there was significant effect of potassium levels and the application of potassium at 83 kg K.ha-1 was superior in No. of racemes.plant-1 (124.7), No. of flowers.plant-1 (357.4), fertility percentage (6.6%), No. of pods per plant (24.3 pod. Plant-1), and green pods yield of plant (117.5 gm.plant-1).Foliar application of boron at flower buds emergence, flowering 25%, 50% and 75% of plants was superior in in giving least days to 100% flowering (102 day), and highest means for No. of racemes per plant (126.8), No. of flowers per plant (357.5), fertility percentage (6.3%), No. of pods per plant (23.2 pod.plant-1) and green pods yield of plant (118.4 gm. plant-1)Key words: faba bean , potassium, boron.

Potassium Application Enhanced Plant Growth, Mineral Composition, Proximate and Phytochemical Content in Trachyandra divaricata Kunth (Sandkool).

Wild leafy vegetables are commonly included in the diet of people in rural homesteads. Among various wild edible vegetables in South Africa, Trachyandra divaricata (Sandkool) is one of the most abundant but underutilized due to the dearth of literature on its cultivation and nutritional value. In the present study, the effect of potassium application and pruning on growth dynamics, mineral composition, and proximate and phytochemical content in T. divaricata were evaluated. Treatments consisted of three potassium concentrations (0.0072, 0.0144, and 0.0216 M) supplemented in the form of potassium sulphate (K2SO4) with four pruning levels (unpruned, 5, 10, and 15 cm) applied in each treatment. The potassium doses were added to the nutrient solution, while the control treatment was sustained and irrigated with nutrient solution only. The results revealed a significant increase in flower bud yield, height, total dry and wet weight of shoots and roots, as well as ash and neutral detergent fibre in plants irrigated with 0.0072 M of K2SO4 without pruning. Conversely, chlorophyll content and Ca were comparable among treatments, while the highest yield of Na, P, N, and Zn was recorded in treatment 100 mL of K2SO4 with 10 cm pruning. Likewise, the highest antioxidant value (Polyphenols, Flavonol and DPPH) was obtained from plants irrigated with 0.0072 M of K2SO4 with 10 cm pruning. Based on these findings, T. divaricata is a promising leafy vegetable as a minimum dose (0.0072 M) of K with moderate pruning optimised its productivity in terms of growth, biomass parameters, nutritional content, and antioxidant potential. Due to its rich nutritional value, the plant should be domesticated and studied further for its potential nutraceutical benefits.

Effect of potassium application on crop productivity in Boro rice production

Effect of potassium application on crop productivity in Boro rice production

Effects of potassium application on vegetative growth, fruiting, and nutrient status of Kinnow mandarin under Indian sub-tropical conditions

Kinnow mandarin is the predominant citrus crop of Punjab state. The area and production of Kinnow are increasing in the southern–western districts of the state because of its high adaptability, yield potential, and better fruit quality, which ensure higher economic returns to the growers. However, soils of sub-mountain and in some areas of central zones of Punjab are deficient in potassium which hinders the quality and production of Kinnow in these regions. Considering these facts, the present study was undertaken during 2009–2020 to find out the optimum level of potassium fertilization in addition to recommended doses of nitrogen and phosphorous required under sub-mountain and central zones of Punjab. The results showed that soil application of potassium significantly increased the plant height, spread, and canopy volume. Fruit weight, fruit number, yield, TSS, and TSS/acid ratio were also markedly improved with soil application of potassium. Leaf analysis revealed that nutrient uptake like N, K, Mg, Fe, and Cu increased with increased soil K application. However, P, S, Mn, and B did not show any linear trend with an increase in the K application. The results indicated that all rates of K application improved fruit quality and yield in Kinnow. So, it is recommended that soil application of K100 and other recommended doses of nitrogen (N100) and phosphorous (P50) should be made to enhance fruit yield and quality in Kinnow mandarin under sub-mountain and central zones of Punjab state.

Effects of straw incorporation and potassium fertilizer on crop yields, soil organic carbon, and active carbon in the rice–wheat system

Active soil organic carbon (SOC) fractions play a key role in agricultural soil fertility. However, the effects of potassium application and straw incorporation on SOC and active SOC fractions as well as the relationships among these factors in a rice–wheat system are less well-studied. Hence, the objective of this study was to analyse the effects of potassium fertilization and straw incorporation on SOC sequestration, active carbon fractions, and crop yields in a long-term (6 years) field experiment. Four treatments were examined: no addition of potassium fertilizer and straw (CK), straw incorporation only (SI), potassium-fertilizer application only (K), and straw incorporation plus a recommended amount of potassium fertilizer (SI + K). SOC, dissolved organic carbon (DOC), light fraction organic carbon (LFOC), microbial biomass carbon (MBC), easily oxidizable carbon (EOC), crop yields, and the carbon pool management index (CMI) were determined. After 6 years, SOC content and labile C fractions in the SI treatment increased significantly, by 7.95–25.0 % and 23.6–185 %, respectively, compared to the CK treatment. Significant and positive correlations were observed between SOC, DOC, LFOC, MBC, EOC, and the CMI (r = 0.449–0.899, P < 0.01). Among the five C fractions, LFOC, DOC, and EOC were the most sensitive indicators of changes in SOC induced by incorporating straw with or without potassium fertilizer. The highest SOC contents and labile C fractions were observed in the SI + K treatment. Rice yields increased from 8.55 and 7.59 t ha−1 in the CK plots to 9.56 and 8.54 t ha−1 with SI + K at Guangde (GD) and Jiangyan (JY) sites, respectively. Wheat yields increased from 0.53 and 5.33 t ha−1 in the CK plots to 5.86 and 6.43 t ha−1 with SI + K at GD and JY sites, respectively. Overall, based on crop yields and C storage, straw incorporation in combination with a moderate amount of potassium fertilizer appears to be the best practice for improving soil fertility and productivity in the rice-wheat cropping system.

Effects of Potassium Application and Straw Returning on Potassium Management and Benefit of Banana

HighlightsThe effects of potash fertilizer and straw returning on a banana orchard were studied by field experiment.Fertilizer with straw was more conductive to potassium nutrient balance and improved banana yield and quality.The economic benefits of straw replacing different amounts of potassium fertilizer were compared.Abstract. To explore the effects of potash fertilizer and straw returning in banana production, a field experiment was carried out, and four treatments were set up: NP fertilizer (NP), NP fertilizer and banana straw (NP+St), NPK fertilizer (NPK), and NPK fertilizer and banana straw (NPK+St). Through the soil potassium balance, the effects of potash fertilizer and straw returning on the yield, quality, and economic benefits of bananas were studied. The results showed that the application of potash fertilizer and straw could improve banana yields. Compared with the NP treatment, the banana yields of the NP+St, NPK, and NPK+St treatments increased by 17.5%, 50.5%, and 71.6%, respectively. The order of banana yield, potassium balance coefficient, and nutrient accumulation was NPK+St &amp;gt; NP+St &amp;gt; NPK &amp;gt; NP. The NPK+St treatment also improved the recovery rate and agronomic utilization rate of potash fertilizer, which were higher than that of potassium application without straw (NPK) and straw application without potassium (NP+St). Potassium application with straw improved the banana yield, increased the total accumulation of nitrogen, phosphorus, and potassium, and improved the efficiency of potash fertilizer uptake by the crop. Therefore, this study demonstrates the importance of straw for maintaining the soil potassium balance in banana production. The input cost of potassium fertilizer was reduced, and the resource utilization of banana straw was realized by straw returning, which can be promoted in local agricultural production. Keywords: Banana, Potassium application, Potassium balance, Straw returning, Yield.

Effect of potassium application on Deglet Noor date production and quality

ISHS XXX International Horticultural Congress IHC2018: VII International Symposium on Tropical and Subtropical Fruits, Avocado, II International Symposium on Jackfruit and Other Moraceae and II International Symposium on Date Palm Effect of potassium application on Deglet Noor date production and quality

Effects of potassium application on soil ecological resistance to Verticillium wilt of cotton (Gossypium hirsutum L.)

ABSTRACT Verticillium wilt (V-wilt) causes huge and irreparable losses to cotton worldwide every year. Potassium (K) is considered to be a critical nutrient for resistance to biotic and abiotic stresses. To verify the effect of K application on the establishment of an ecological-friendly soil microenvironment resistant to V-wilt, a two-year field experiment was conducted. Two cotton varieties (ND-601, resistive and JM-11, sensitive) with different resistance to V-wilt were used in this study, and five different K rates (0, 75, 150, 225, and 300 kg ha−1 K2O) were set for each variety in the field inoculated with Verticillium dahliae (V. dahliae). The results showed that different levels of K application had significant effect on the reduction of cotton V-wilt. K application increased the content of K and total phenolics in rhizosphere soil, but decreased the content of soluble sugar and alanine. Moreover, K application reduced the number of bacteria, fungi, and total microorganisms in rhizosphere soil, especially the number of V. dahliae. In conclusion, K application can create a good micro-ecological environment for the root system by changing the K status, root exudates, and microorganisms in rhizosphere soil, which are beneficial to reduce the symptoms of cotton V-wilt.

Enhancement of frost tolerance of almond flowers using potassium

Using mineral nutrients is recommended as a plan to alleviate or avoid spring frost damage to blossoms. The purpose of this study was to investigate the effects of potassium application on reducing or preventing spring frost damage of almond (Prunus dulcis Mill.) flowers. Treatments were four levels of K2SO4 (0, 1, 2, and 4%). The nutrition solutions were sprayed on trees in two times (bud swell stage and green tip stage) in 2018–2019. The spurs containing flower buds were collected during the full blooming phase. The spurs segments were exposed to three different freeze test temperatures (0, −2, and −4 °C), and some relevant physiochemical changes were evaluated. The application of K2SO4, especially 4% K2SO4, decreased freezing injury, electrolyte leakage percentage, hydrogen peroxide (H2O2), and malondialdehyde (MDA) concentrations of flowers after freezing tests compared with control. The nutrient treatments, especially 4% K2SO4, increased significantly the contents of soluble proteins, soluble carbohydrates, total phenolic compounds, and proline of flowers. The results of the present study could have implications for the use of potassium in freezing tolerance improvement of other temperate fruit trees grown in low temperatures regions.

The Effects of Potassium Applications on Drought Stress in Sugar Beet

Drought is a major environmental stress affecting agricultural productivity around the world. Application of potassium to plants can increase the ability of plants to tolerate drought stress while maintaining turgor pressure at low leaf water potentials. In this research, the effect of potassium applications under drought stress on some physiological parameters of sugar beet, which is a strategic plant, was investigated. In the experiment, irrigation levels were kept at 33%, 66% and 100% of field capacity. Different doses (10–20–40–80 mg kg−1) of potassium were applied to the plants. The plants were grown with Hoagland nutrient solution in the growth chamber. Relative water content increased at the 33% irrigation level with potassium applications to 67.39, 68.93, 68.20 and 74.41%, respectively, while membrane damage and MDA content decreased (70.66, 71.10, 65.91, 68.43% and 35.94, 25.38, 21.74, 18.84 nmol g−1). In addition, vitamin C and SH compounds decreased at the 33% irrigation level with potassium applications to 252.15, 198.40, 125.06, 134.25 µg g−1 and 69.16, 66.94, 55.89, 54.59 µg g−1, respectively. According to the results obtained from the experiment, the potassium applied to the plants under drought stress led to an increase in the relative water content and the reduction of membrane damage, and especially to the reduction of non-enzymatic antioxidants produced for defence purposes when faced with plant stress. Therefore, it can be said that potassium may play a critical role in reducing the negative effect of drought stress in sugar beet.

Response of Lentil (Lens culinaris Medik.) to Potassium Application under Deficient Soils

The field experiments were conducted at the Punjab Agricultural University Regional Research Station, Gurdaspur, Punjab during the year 2016-17, 2017-18 and 2018-19 to evaluate the effect of Potassium application on the yield, yield attributes, nutrient uptake and agronomic efficiency under potassium deficient soils. The results revealed that the application potassium significantly increased the branches per plant, pods per plant, grain yield, biomass yield, 1000 seed weight (g), grain K content and grain K uptake. The data on the correlation analysis indicated that the K uptake was more where grain yield and biomass yield were higher. The data on partial factor productivity revealed the application of 30 kg K2O ha-1 as the best treatment to achieve highest productivity. However, data on Agronomic Efficiency indicated that the application of 30 kg K2O ha-1 may be recommended to achieve highest lentil grain yield.

Effects of potassium application on yield attributes, yield and grain quality of lentil in terrace soil of Joydebpur

An experiment was conducted in the research field of Pulses Research Sub-Station, BARI, Gazipur during two consecutive years of 2015-16 and 2016-17 to determine the suitable dose of potassium for achieving higher yield attributes, nodulation, nutrient concentration and yield maximization of lentil. There were 5 treatments viz. T1 = Control, T2 = 30 kg K ha-1, T3= 40 kg K ha-1, T4= 50 kg K ha-1 and T5= 60 kg K ha-1 along with the blanket dose of fertilizers of N, P, S, Zn and B @ 15, 20, 10, 2 and 1.5 kg ha-1, respectively for all treatments. The experiment was laid out in randomized complete block design (RCBD) with three replications. Results revealed that the highest seed yield (1092 kg ha-1) of lentil (mean of two years) was found in T4 followed by T5 treatment and the lowest (736 kg ha-1) was noted in K control (T1) treatment. The highest % yield increase over control (48.3%) was recorded from T4 treatment. The maximum nodulation was found in T5 followed by T4 treatment. The highest protein (26.9%), N, P, K, S, Zn and B concentrations of lentil seed were recorded in T4 treatment. Therefore, the results suggest that the appliction of 50 kg K ha-1 along with N15P20S10Zn2B1.5 kg ha-1 are optimum for achieving higher yield potential of lentil in terrace soils of Bangladesh.&#x0D; Bangladesh J. Agril. Res. 44(4): 599-607, December 2019

Effect of potassium sulfate on the physiological characteristics of canola cultivars in late season drought stress conditions

In order to reduce the damage caused by the late-season drought stress of canola, a factorial split-plot experiment was performed based on the randomized complete blocks design with three replications in Karaj, Iran. The treatments were Potassium sulfate in two levels, including application and non-application of potassium sulfate, irrigation at three levels including normal irrigation (control), restricted irrigation from the flowering and pod formation stage, as factorial were in main plots and winter canola cultivars including Opera, L72, KR1, GKH3705, GKH0224 were in subplots. The simple effect of irrigation and potassium sulfate on all of the studied traits and the simple effect of cultivar on all traits except chlorophyll b were significant. The interaction effect of irrigation × cultivar on soluble carbohydrate, stomatal resistance, proline content, chlorophyll a and total chlorophyll content was significant. The interaction effect of irrigation × potassium sulfate on the amount of soluble carbohydrates, stomatal resistance and proline content of leaves was significant. In irrigation interruption from the pod formation stage, the promising line of L72, and in irrigation interruption from the flowering stage, the Neptune cultivar exhibited the most positive effect of potassium application on the studied traits. As a result, the application of potassium sulfate in addition to the L72 and Neptune cultivars is recommended in areas similar to the tested area encountering the late-season drought stress.

Documenting production process and the ranking factors causing yield gap in rice fields in Sari, Iran

The documentation process is very important for identifying yield constraint factors and yield gap. For this purpose, all managing practices were recorded by monitoring of paddy rice fields in Sari region, Iran from 2015 to 2016. Field identifications were undertaken in such a way that they included all the main production procedures with variations in management viewpoints. The results revealed that seed consumption varied from 40 to 95 kg ha-1 and the range of seedling age varied from 20 to 50 days. Planting density was 10 to 66 plants per m2. Nitrogen application by 30% of the farmers ranged from 46 to 83 kg ha-1, and 40% of the farmers applied 83 to 138 kg of nitrogen per hectare. In 73% of the fields, nitrogen was not used after flowering stage. The range of yield varied from 3100 to 5430 kg ha-1, and in 60% of the studied fields, the paddy yield varied from 4205 to 5200 kg ha-1. In the comparative performance analysis (CPA) model, the actual yield and the yield potential were estimated to be 4495 and 6337 kg ha-1, respectively, and the yield gap was 1841 kg ha-1. Among the five variables entered in the model, the effects of potassium application and biological fight were remarkable, which the paddy yield increase by these variables was 709 and 806 kg ha-1, respectively, and equal to 39% and 44% of the total yield variation. Therefore, since the calculated potential yield was achieved through actual data in each paddy field, it seems this yield potential is attainable.

Effects of Potassium Applications on Changes of Chlorophyl, Ion and Enzyme Activity in Heat Sensitive Bean Genotypes

Serada yetiştiriciliğindeki en önemli problemlerin başında yüksek sıcaklığın olumsuz etkisi gelmektedir. Sera fasulye yetiştiriciliğinde yüksek sıcaklık verimi ve kaliteyi olumsuz etkileyen stres faktörlerinin başında gelmektedir. Bu çalışmada üretim dönemindeki yüksek sıcaklık nedeniyle fasulyede oluşacak verim ve kalite kayıplarını azaltmak amaçlanmıştır. Potasyum uygulamalarının etkinliğinin araştırıldığı çalışmada yüksek sıcaklık stresine hassas olan Zulbiye çeşidi ile önceki çalışmalarda yüksek sıcaklığa hassas olduğu belirlenen V71 genotipi kullanılmıştır. Fasulye tohumları 2:1 oranında torf perlit karışımı içeren 2 litrelik saksılara ekilmiştir. Potasyum (K) dozları: 0 (kontrol) ppm, 500 ppm, 1000 ppm ve 2000 ppm şeklinde yer almış olup, çalışma dört tekrarlı ve her tekrarda 4 saksı ve her saksıda iki bitki olacak şekilde tesadüf parselleri faktöriyel deneme desenine göre dizayn edilmiştir. Tohumlar ekilip deneme sonlandırılıncaya kadar Hoagland besin çözeltisiyle sulanmıştır. Tohum ekiminden itibaren 24. güne geldiğinde kontrol bitkilerinin sıcaklığı serada 20 - 25 0C arasında değişirken, yüksek sıcaklık uygulanan bitkiler ise sera içinde ek bir tünele alınmıştır. Stres uygulanan 24 günlük fasulye bitkilerinde stres etkisinin değerlendirlmesi için katalaz (CAT), süperoksitdismutaz (SOD), askorbatperoksidaz (APX), malondialdehit (MDA), Klorofil-a, Klorofil-b, toplam klorofil, K, Ca ve Mg içerikleri incelenmiştir. Sonuç olarak, özellikle 1000 ppm K dozunun yüksek sıcaklığın olumsuz etkilerini azaltmada kullanılabilir olduğu belirlenmiştir.