Dose Of Potassium Fertilizer Research Articles

Improvement in the physical quality of genotype G1 arabica coffee beans as a result of applying rice husk ash and KCl fertilizer

Abstract Arabica Gayo coffee has earned global acclaim for its exceptional flavor profile. Its exports primarily consist of green coffee beans, making the physical quality a crucial criterion. Several factors are considered in assessing the physical quality of coffee beans, including shape (normal, single, and damaged) beans as well as size. Therefore, this study aimed to find out the improvement in the genotype G1 arabica coffee beans physical quality through the potassium from rice husk ash and KCI fertilizer. A total of 132 genotype G1 arabica coffee were selected randomly with specific criteria including eight years of age, a 2.5 m x 2.5 m planting distance, well-pruned, grown under shade from lamtoro trees with slightly dense density, and adequately maintained. Moreover, a non-factorial randomized block design was used. The treatments comprised a control, and the potassium application at doses of 29, 58, 87, 116, and 145 kg K2O ha−1 from KCl fertilizer (containing 58% K2O) and rice husk ash (containing 2% K2O), totaling 11 treatment units. Each unit was replicated four times and consisted of three coffee trees, resulting in a total of 132. The research results showed that the potassium fertilizer application from both KCl and rice husk ash increased the 100 beans weight (water content 14-18%), the normal beans percentage, single beans, small and medium beans size, but can reduce the damaged beans percentage and large beans size. The application of 250 kg ha−1 KCl, equivalent to 156.25 g of KCl per coffee trees was found to be the best potassium fertilizer dose for improving all the quality variables of genotype G1 Arabica coffee beans.

Response of growth, yield, and seeds quality of G0 potato on different potassium fertilizer doses and retardant concentrations in Jatinangor medium land

This study aims to determine the best interaction of potassium (K) fertilizer dose and retardant concentration on the growth, yield, and seed quality of G0 potato grown in the medium land of Jantinangor. The experiment was conducted at Screen House Station Ciparanje, Jatinangor, Faculty of Agriculture Universitas Padjadjaran from November 2022 until January 2023 at an elevation of ± 685 meters above sea level. The experimental design used was the Factorial Randomized Block Design (RBD). The first factor was the K fertilizer dose including 50%, 100%, and 150%. The second was the retardant concentration including without retardant, 100 ppm paclobutrazol, 100 ppm prohexadione-Ca, and 150 ppm prohexadione-Ca. The experimental results showed that there was an interaction effect between the K dose and retardant concentration. The interaction effect of 150% K and 100 ppm prohexadione-Ca showed the highest percentage of L class seed tuber and the lowest tuber weight loss. Independently, 150% K improved growth rate, number of tubers (6.67 knol/plant), and weight of tubers (73.33 g/plant). Independently, 100 ppm paclobutrazol concentration increased the chlorophyll content index. 150 ppm prohexadione-Ca concentration suppressed leaf area and plant height but increased stomatal conductance, fast emergence shoot time, and shoot length. 100 ppm prohexadione-Ca concentration produced the highest number of tubers and the weight of tubers, i.e., 6.78 knol/plant and 74.33 g/plant, respectively.

Effect of potassium fertilizer dose and compost dose of empty palm oil bunches (EFB) on the growth of lemongrass (Cymbopogon nardus L.)

This study aims to determine the effect of potassium fertilizer and compost of Empty Palm Oil Bunches (EFB) on the growth of citronella (Cymbopogon nardus L.). The research was started in February-June 2022 at BPTP Banten, and the Laboratory of the Department of Agroecotechnology, Sultan Ageng Tirtayasa University. This study used a factorial Randomized Block Design (RBD) method which consisted of two factors. The first of potassium fertilizer dose has 4 levels, 0 kg/ha potassium (K0), 15 kg/ha (K1), 30 kg/ha (K2) and 45 kg/ha (K3). The second factor of EFB compost has 4 levels, 0 tons/ha (T0), 20 tons/ha (T1), 30 tons/ha (T2) and 40 tons/ha (T3). The results showed the dose of potassium fertilizer 30 kg/ha gave the best results on plant height parameters at the age of 3, 4, 5, 6 weeks after planting (WAP). Dosage of 40 tons/ha of EFB compost gave the best results on the number of leaves aged 5 and 6 WAP. There was no interaction between the dose of potassium fertilizer and the dose of EFB compost on all.

THE EFFECT OF DOSING POTASH FERTILIZER AND COMPOST DOSES OF EMPTY BUNCHES OF OIL PALM (TKKS) ON THE GROWTH OF CITRONELLA PLANTS (Cymbopogon nardus L.)

Citronella is a biopharmaceutical plant that has the main content of citronella and geraniol as raw materials in the manufacture of essential oils (citronella oil) which have high economic value. The production of citronella increases every year although the amount is still small when compared to the production of other biopharmaceutical plants. So it is necessary to increase the productivity of citronella plants with the use of the right dose of fertilizer. This study aims to determine the effect of potassium fertilizer dose and Compost Dose of Empty Palm Oil Bunches (EFB) on the growth of citronella (Cymbopogon nardus L.). The research was started in February-June 2022 at Balai Pengkajian Teknologi Pertanian (BPTP) Banten, Ciruas District, Serang Regency, Banten and the Laboratory of the Department of Agroecotechnology, Faculty of Agriculture, Sultan Ageng Tirtayasa University. This study used a Randomized Block Design (RBD) method which consisted of two factors, namely potassium fertilizer dose and Compost Dose of Empty Palm Oil Bunches (EFB). The first factor has 4 levels, 0 kg/ha potassium (K0), 15 kg/ha (K1), 30 kg/ha (K2) and 45 kg/ha (K3). The second factor has 4 levels, 0 tons/ha (T0), 20 tons/ha (T1), 30 tons/ha (T2) and 40 tons/ha (T3). There were 16 treatment combinations with 3 replications so 48 experimental units were obtained. Each experimental unit contained 2 polybags where each polybag contained 2 plants, so the total plants in the study were 192 plants. The results showed that the dose of potassium fertilizer 30 kg/ha gave the best results on plant height parameters at the age of 3, 4, 5, 6 WAP, the dose of potassium fertilizer 15 kg/ha gave the best results on the number of leaves aged 1 WAP. Dosage of 40 tons/ha of TKKS compost gave the best results on the number of leaves aged 5 and 6 WAP. There was no interaction between the dose of potassium fertilizer and the dose of TKKS compost on all parameters at the age of 1-12 WAP

Performance, Selection indices for six cotton genotypes to yield and some Components

According to the randomized complete block design, a field experiment was conducted at the Agricultural Research Station in the Daquq Research Station located 40 km south of Kirkuk at the longitude 28 - 44 ° east and latitude 8 - 35 ° north as a factorial experiment with three factors, six genotypes, three doses of potassium fertilizer, and two spacing between lines, the data were analyzed as a factorial experiment using the analysis of variance method, and the trait averages were compared using Duncan's multi-range test at a probability threshold of 5% for all of the traits evaluated. Montana genotype shows the superiority of No. of fruiting branches with an average of (8.15), Coker 310 genotypes No. of balls per plant with an average of (17.81), Montana genotype boll weight with an average of (4.85), and Coker 310 genotypes of Seed cotton yield per plant show an average of (87.26). While for fertilizer, it exceeded (200) Kg h-1, No. of fruiting branches with an average of (8.29), No. of balls per plant of (17.66), boll weight with an average reached (4.86), and Seed cotton yield per plant, with an average of (84.36). As for the distances between the lines, the distance exceeds 60 cm, in Seed cotton yield per plant with an average of 83.99. As for the best selection index, it was (the number of boll per plant and seed cotton yield per plant which amounted to (124.9922), and the expected genetic improvement was I1234, which included (number of fruiting branches, number of boll per plant, boll weight, and seed cotton yield per plant), which amounted to (8.7753), and the highest relative efficiency of the I2 index, which included (number of bolls per plant) as it reached 3109.95).

Fixation of Potassium and Magnesium by the Soil of Agrocenoses

It was found that the soil of the agrocenosis with a long-term deficit balance of potassium and magnesium recorded 60-70% of potassium introduced with fertilizer and 20-30% of magnesium. With a positive balance of these elements in the agrocenosis, the fixation of potassium by the soil decreased to 40, and magnesium - to 6-10%. The introduction of increasing doses of potassium fertilizer did not affect the soil level of the content of exchangeable magnesium, the use of magnesium fertilizers did not change the content of exchangeable potassium in the soil. The combined use of moderate doses of potassium and magnesium fertilizers contributed to a decrease in potassium fixation by 10-16% compared with its separate application, while the intensity of magnesium fixation did not change. With increased doses of potassium, its fixation by the soil did not depend on the additional addition of magnesium, and magnesium fixation significantly decreased.

Physical and chemical characterization of yacon (Smallanthus sonchifolius) roots cultivated with different doses of potassium fertilization

The already marked tendency for functional food consumption, low in calories, and with biologically active properties, has been increasing. In this scenario, yacon tuberous roots, with high levels of nutraceutical fructooligosaccharides, gain importance. However, these nutraceutical properties depend on fertilization management. Thus, our study aims to evaluate different doses of potassium fertilization on the physicochemical characteristics of yacon roots. The experimental design consisted of randomized blocks, with 4 replications and 5 treatments: four doses of potassium fertilization (50%; 100%; 150%; 200%) of the reference value, corresponding to 178.7 kg.ha-1; 357.4 kg.ha-1; 536.1 kg.ha-1; 714.8 kg.ha-1 of potassium chloride – (KCl), and a control (soil without fertilization). The chemical features evaluated were pH, total titratable acidity, soluble solids, conductivity, turbidity, moisture and ashes. The texture profile was analyzed through toughness, adhesiveness, cohesiveness, chewability index, elasticity, and gooeyness. Most of the variables were influenced by potassium soil fertilization. Only turbidity, conductivity and gumminess showed no response to the applied doses, not fitting the tested models. Potassium fertilization improved both chemical (higher levels of soluble solids and less acidity) and physical characteristics (less hardness, chewability, cohesiveness, and adhesion) of yacon tuberous roots, bringing greater quality to the final product. Highlights Yacon is considered a prebiotic food. Several immunostimulatory characteristics promote antimicrobial, anti-inflammatory, and antioxidant activity. Potassium is associated with root size, shape, texture, color, flavor, acidity, nutrient transport resistance, nutritional value, and even market value. Texture constitutes an important factor and quality criterion for the sensory acceptance of food. Thus, the results obtained show that potassium fertilization improves both physical and chemical characteristics of yacon roots. The best results were observed with the maximum dose of potassium fertilization (357.4 kg.ha-1 of KCl).

Effect of various varieties and dosage of potassium fertilizer on growth, yield, and quality of red chili (Capsicum annuum L.)

Abstract Red chili is one of the important commodities with increasing demand. However, the quality, continuity of supply, and quantity have not been realized to meet domestic market demand. Increasing growth, yield, and quality can be pursued through superior varieties, and the effort to increase crop productivity is the application of various doses of potassium fertilizer. Therefore, this study aimed to determine the effect of various varieties and doses of potassium fertilizer on the growth, yield, and quality of red chili. The split-plot experimental design consisting of two factors was also used. The first factor is the variety, as the main plot consisting of UNPAD CB2, Tanjung 2, and Lingga. The second factor was the dose of potassium fertilizer as sub-plots which consisted of four levels, namely 0, 100, 200, and 300 kg/ha KCl. The results showed an interaction between variety and dose of potassium fertilizer on plant height at 8 weeks after planting (WAP), stem diameter at 8 WAP, and leaf area index at 9 WAP. Meanwhile, UNPAD CB2 showed the best results for 6 WAP plant height, fruit weight per plant, number of fruits per plant, fruit length, dihydrocapsaicin, total capsaicinoid, and scoville heat unit. Potassium fertilizer doses of 200 and 300 kg/ha KCl showed high yields for stem diameters of 6 WAP.

Effects of K Fertilizer and Different Soil Content on Chickpea(Cicer Arietinum L.) Yield and Membrane Permeability under Dry Conditions

This study was conducted as a pot experiment potassium fertilizer different doses effects were investigated plant growth and membrane permeability on chickpea plants in dry conditions in Gaziantep province. The experiment was designed as a randomized block design with 3 replications. The 18 pots were composed of two different textures as 1:1 torf+soil and only soil in the experiment. Three different doses potassium fertilizer (Control: 0ppm K, 100ppm K, 200ppm K) were given with seed sowing. Chickpea plant was harvested at the end of 8 weeks and results were evaluated. Plant dry matter yield was found between 19.60g/pot and 52.25g/pot. As applied potassium fertilizer dose has decreased plant root and leaf dry matter yield has also decreased when potassium doses increased these values have increased. Torf+soil mixture texture has supported plant growth. The effect of potassium fertilizer on plant growth and membrane permeability was found statistically significant (p

Effects of types and doses of potassium fertilizers on growth and yield of Phan Rang garlic variety (Allium sativum L.)

The study was conducted at the Experimental Farm of the Faculty of Agronomy, Nong Lam University, Ho Chi Minh City. The objective of the study was to determine the effects of type and dose of potassium fertilizer on growth and yield of Phan Rang garlic variety. The two-factor experiment was arranged in a randomized complete block design with 8 treatments and 3 replicates. The factor A included 2 types of commercial potassium fertilizers (KCl, K2SO4) and the factor B was 4 different doses of potassium fertilizers (110 kg/ha, 140 kg/ha, 170 kg/ha, 200 kg/ha). The results showed that the application of 200 kg K2SO4/ha increased the plant height (51.8 cm). Bulb diameter (24.7 mm), number of cloves/bulb (12.3 cloves), bulb weight (4.83 g), percentage of dry matter (92%) and bulb yield (1.36 kg/100 pots) were highest in the garlic plants with potassium application at 200 kg/ha.

Effects of nitrogen and potassium levels on growth and quality of pot-planted vicks cultivars (Plectranthus hadiensis var. tomentosu (Benth. ex E. Mey.) Codd) in Ho Chi Minh City

The study was conducted to determine the suitable dosages of nitrogen and potassium fertilizer for growth, quality and economic efficiency of Plectranthus hadiensis pot–planted. The experiment was carried out from April to June 2021 in the experiment field of faculty of Agronomy, Nong Lam University, Ho Chi Minh City. A two-factorial experiment was carried out in a completely randomized design (CRD) in three replications. The treatments consisted of 3 doses of nitrogen fertilizer (0.50; 1.00 (control) and 2.00 g N/pot) and 4 doses of potassium fertilizer (0.25; 0.50; 1.00 (control) and 2.00 g K2O/pot) in combinations. The results indicated that plants supplied with 0.50 g N/pot and 1.00 g K2O/pot gave the best results in terms of plant height (16.70 cm), stem diameter (5.45 mm), number of primary branches (10.09 branches/ plant), canopy diameter (20.37 cm), number of leaves (201.04 leaves/plant), leaf length and width (35.06 and 24.13 mm), duration on vase life (40.00 days), commercial pot ratio (94.67%). The revenue was 29,933 thousand VND per 1000 pots with the highest profit margin of 1.33 times at 60 days after planting.

Thermal requirements and agrometeorological modeling of cotton growth under soil fertility levels

The objective was to quantify the thermal requirements and model the growth of cotton as a function of air temperature and degree-days, under levels of soil saturation and potassium fertilization, grown in a protected environment, in Bom Jesus, Piauí. The experimental design used was a completely randomized design (DIC) with a 3 X 3 + Witness factorial scheme, consisting of three levels of base saturation (V%) (50%, 60% and 70%) and three concentrations of potassium fertilization doses (50% below recommended; recommended, according to soil analysis; 50% above recommended) and Control, without K application, with four replications. Plant height, stem diameter, number of nodes, midrib length and leaf area were evaluated. The meteorological data were obtained in a portable meteorological station, installed inside the protected environment. Among the stages, the First Boll-Harvestpresented the highest thermal demand, with an average of 551.7 °gd and 34 days of duration, followed by the Emergence-First Floral Bud (435.6 °gd), First Floral Bud- First Flower (362.5 °gd) and First Flower-First Boll (300.3 °gd), the Sowing-Emergence phase obtained 51.4 °gd. Air temperature is the meteorological element with the greatest impact on cotton development.

Estimation of Potassium Nutrient Content in Tea Plants Using Sentinel-2 Satellite Imagery

Tea plant (Camellia sinensis) is a plantation crop commodity that has a significant role in Indonesian tea industry. Currently, the determination of a single dose of potassium fertilizer on a tea plant begins with soil and leaf laboratory analysis. The cost of laboratory analysis for testing nutritional content of potassium in a tea plant has always been a challenge for many farmers. the necessity of minimizing the estimate of nutritional content of potassium in tea plants affordably and accurately is the goal of this study. This study aims to estimate the nutrient content of potassium in tea plants using sentinel-2 satellite imagery. The study began by sampling tea leaves and taking satellite images. The data obtained were then correlated with multiple linear regression analysis to create a model. The model obtained is K%= 0.619 + 0.001876 b3 - 0.001264 b4 -0.000201 b8, using the grouped data for the maximum time distance of sampling with image acquisition for 5 days and processed using backward regression method. The coefficient of determination (R-sq) obtained is classified as moderate at 50.18%. the model was validated and well characterized in making estimates with a MAPE percentage of 15.18% and a correctness of 84.82%.

A study on wheat crop for estimation of potassium efficiency, effect on growth, potential yield under agricultural and botanical practices

Wheat (Triticum aestivum L.) is one of the important crops of human diet around the globe. Purify flour of wheat contains less vitamins and causes constipation and malnourishment. The experiment was designed to study on wheat crop, botanical and agricultural parameters and advances in plant sciences and accomplished in Randomized Complete Block Design. Sowing was done in field with plot size of 216 m2. LAI is very crucial growth index which directly controls the interception of solar radiation and consequently dry matter production and accumulation. The LAD exhibits the tenacity of leaves to remain photo synthetically active during the growth season of a crop. The NAR indicates the dry matter accumulation in plants per unit canopy area. Recorded data was subjected to analysis of variance by using Statistix 8.1 software. It presented mean values of all treatments for crop growth rate. Maximum results for CGR observed under T3 with 14.3 mean values. While minimum observations had been shown by T1 that is 13.4. It showed mean values for all applied treatments and wheat showed maximum value of leaf area index of (3.3367) under treatment (T4) and minimum value of leaf area index that is 3.0233 was shown by plants under treatment (T7). Maximum results for flag leaf area observed under T4 with 114.73 mean values. While minimum observations had been shown by T1 that is 88.03. It is recommended that the farmers should use split dose of potassium fertilizer for better growth and yield of wheat and it may also be helpful in future prospects.

GROWTH CHARACTERISTICS OF SHALLOT var. TINOMBO FOLLOWING APPLICATION OF POTASSIUM FERTILIZER AND MANURE

ABSTRACT The response of shallot plants to potassium differs substantially depending on the cultivar, organic matter, soil conditions, and weather in the cultivation area. This research aimed to determine some of the growth characteristics of a Tinombo variety of shallot following treatment with an organic fertilizer comprising manure and potassium in the area of Palu, Central Sulawesi. This research took the form of a greenhouse experiment with planting in pots arranged in a completely randomized factorial pattern. The first factor was the application of chicken manure at 0 and 10 tons.ha-1, while the second factor was the dose of KCl fertilizer: 0 kg.ha-1; 30 kg.ha-1; 60 kg.ha-1 and 90 kg K2O.ha-1. Each treatment was replicated three times. The application of potassium and manure significantly affected the accumulation of dry matter and the linear growth rate of shallot var. Tinombo. Manure applied at 10 tons.ha-1 increased the leaf area index when combined with 0 to 60 kg K2O.ha-1. However, the addition of manure increased the net assimilation rate at all doses of potassium fertilizer. The number of bulbs and harvest index were affected by the amount of manure and potassium fertilizer applied, but there was no significant interaction between these two factors. Applying manure and K2O fertilizer resulted in a significantly higher number of bulbs and a better harvest index than in those cases where the two types of fertilizer were not applied.

Pengaruh Dosis Pupuk Kalium dan Pupuk Organik Cair terhadap Persentase Serangan Penyakit Bulai dan Potensi Hasil Benih Jagung Manis (Zea mays saccarata L.) Hibrida

Downey Mildew is an important disease in corn plantation, the disease attacks the plantation in young phase until 100% and causes significant loss for farmers. the purpose of this study is to get a recommendation for an appropriate dose of potassium fertilizer and organic liquid fertilizer in suppressing the percentage of downey mildew attack and increase the production of hybrid sweet corn (Zea mays saccarata L.). This study used factorial randomized completely block design in order of potassium fertilizer (K) consist of 3 stages: K0 (0 gr/plant), K2 (3 gr/plant), K3 (6 gr/plant) and the second factor is in order of organic liquid fertilizer (P) consist of 3 stages: P0 (0 ml/liter), P1 (4ml/liter), P2 (8ml/liter) each treatment is replicated 3 times. The result was showed potassium treatment (K) gave significantly differen effects for the parameter of plant height k2 with an avarage of 179.0 cm, weight of cobs without husk per plantation K2 with an avarage 298.5 g, cob lenght K2 with an avarage21.3 cm, weight 1000 grains K2 with an avarage 157.6 gr, and potential harvest per hectare K2 with an avarage 15.3 ton. Gave significant effect for parameter leaf width K2 with an avarage 9.5 cm and harvest cobs K2 with an avarage 1.8. The treatment of liquid organic fertilizer (P) also gave significantly differen effects for parameter of harvest cobs P2 with an avarage 1.9. Gave significant effect for parameter weight of cobs without husk per plantation P2 with an avarage 293.4 gr, cob lenght P2 with an avarage 21.4 cm and potential harvest per hectare P2 with an avarage 15 ton. Together, the two treatments gave significantly differen effects for the parameter of number of seeds per cob K2P2 with an avarage 385.5 seed, and gave significant effect for parameter except the percentage of downy mildew attack K2P2 with an avarage 55.2%.

Adubação potássica e seu impacto na produção e composição mineral de pessegueiros

Abstract This study aimed at evaluating production parameters of peach trees subject to different doses of potassium fertilization and at establishing the critical level of this nutrient in the soil and in peach tree leaves. The experiment was conducted in the 2016, 2017 and 2018 seasons in a commercial orchard located in Morro Redondo, Rio Grande do Sul state, Brazil. Peach trees of the cultivar Sensação were fertilized at the following doses: 0, 40, 80, 120 and 160 kg ha-1 K2O as potassium chloride applied to the surface of the soil. In the 3-year study, production per plant, number of fruit, fruit mass and fruit diameter were evaluated while soil and leaf samples were collected to undergo chemical analyses. Potassium fertilization in peach orchards increases levels of this nutrient in the 0-20 cm soil layer. Potassium fertilization via soil increased potassium contents in peach tree leaves. Productivity of peach trees responds to superficial potassium application via soil but it does not affect mean fruit mass. The critical level between relative productivity and potassium content in the soil could not be established while the one between production and potassium content of leaves of peach trees was 2.84%.

The Growth and Production of Three Sweet Potato Varieties as Affected by Dosage of Potassium Fertlizer on the Ultisols of Bengkulu Province

This study aims to study the interaction between varieties and the correct dose of potassium fertilizer, determine the right dose of potassium fertilizer and the appropriate variety of sweet potato in Ultisol. In this study, the research design used was a completely randomized block design (RAKL) with two (2) factors with three replications. The first factor is three varieties of sweet potato, namely Cilembu, Atin 3, and Beta 1. The second factor is the dose of KCl fertilizer which consists of 4 levels of dosage, namely 0 kg ha-1, 150 kg ha-1, 300 kg ha-1, and 450 kg ha-1 KCl fertilizer. The results showed no significant interaction between the dose of KCl fertilizer and the three varieties of sweet potato. The Antin 3 variety produced the most extended tendril length compared to the other two varieties. The lowest number of branches was produced by Beta 1 variety. The Cilembu variety produced the most significant tuber weight per plot and estimated weight per plot. The Cilembu variety is proven to have the highest level of sweetness.

Influence of Rainfall and Water Deficit in the Efficiency of Potassium Fertilizer on the Productivity of Oil Palm (Elaeis Guineensis Jacq.), Grown in Southeastern Côte d’Ivoire

In Côte d’Ivoire, palm oil occupies a preponderant position in agricultural production, in the economy, as well as consumer fats. Yield remains low, even with improved plant material being popularized whose productivity is estimated at more than 25 tons/ha/year. Trials have been set up in La Mé and Ehania (South-east Côte d’Ivoire), to help improve oil palm productivity, through a comparative study of the efficiency of potassium fertilization applied according to the locality. The experiments were conducted in Fisher blocks, including 5 treatments and 4 repetitions. The treatments included 5 doses of potassium fertilizer (T1, T2, T3, T4, T5) corresponding, respectively, to 1; 1.5; 2; 2.5; 3 kg KCl/tree/year. The results showed that the rainfall recorded in the locality of Ehania was significantly higher than that of La Mé. The average annual rainfall was 2000 mm of water in Ehania against, approximately, 1700 mm of water in La Mé. The yield and its components (weight of the bunch and number of bunches) were gradually improved according to the locality of cultivation by the different doses of fertilizer applied. This improvement was significantly higher on the Ehania plantation compared to that of La Mé. This improvement was approximately 30% and 27% compared to the standard dose of 1 kg KCl/tree/year, respectively, in Ehania and La Mé. It appears that the locality intervenes in the efficiency of potassium fertilizers, in the improvement of yield and its components. Rainfall appears, as, a main factor of productivity observed on the plot of the oil palm. Strict compliance with the choices of suitable areas, combined with reasoned potassium fertilization, will allow a better expression of the production potential of new oil palm plant material, currently being popularized.

Enhancement of antioxidant activity of kencur rhizome in the shade by potassium fertilizer

s. Kencur has been traditionally used as a medical plant for a long time. The potential content of kencur rhizomes as a medical plant lead to the idea of conducting a study that aims to determine the yield and antioxidant content of rhizomes cultivated in the shade and the effect of potassium fertilizer application. The research was conducted in two stages. The first stage was kencur cultivation in the AgroTechno-Park UB in Jatikerto from November 2020 to June 2021 designed according to the Split-split plot design (3 factor treatments). The main factor was the shade, sub plots were accession of kencur, and t doses of potassium fertilizer. The second stage was conducted in the Plant Physiology Laboratory to analyze the antioxidant content after the field experiment. The results showed that there was increased antioxidant activity in kencur rhizomes due to the use of potassium fertilizer and shade. The 25% shade produced higher antioxidants than 50% shade in both Lumajang and Nganjuk’s accessions.