scholarly journals Yield Response of the Puerto Rico and Columnaris Coffee Cultivars in Two Latosols of Puerto Rico, as Affected by Different Levels of Nitrogen, Phosphorus, Potassium, and Lime

1969 ◽  
Vol 48 (3) ◽  
pp. 255-262
Author(s):  
Saulo J. Rodríguez ◽  
R. Bosque-Lugo ◽  
R. Pérez-Pérez ◽  
A. Rodríguez-Cabrera

A set of four experiments with increasing levels of the three main plant nutrients and liming were established in two lateritic soils at two locations in the coffee-growing area of Puerto Rico. Two coffee cultivars were used in the experiments. The results obtained can be summarized as follows: 1. Nitrogen levels significantly affected coffee yields of the Puerto Rico cultivar in a Catalina clay at Maricao grown under shade. 2. Phosphorus and potassium did not significantly affect the yields of these coffee cultivars at the two locations. 3. Liming did not significantly affect the yields.

2019 ◽  
Vol 11 (4) ◽  
pp. 311-316
Author(s):  
L. Nenova ◽  
M. Benkova ◽  
Ts. Simeonova ◽  
I. Atanassova

Abstract. The aim of the study was to assess the influence of different fertilizer doses on the content of macroelements (nitrogen, phosphorus and potassium) in dry biomass and grain of maize during the 2016 – 2018 period. A field experiment with fertilization of maize was carried out on Alluvial-meadow soil (Fluvisol) in the region of Tsalapitsa village, near Plovdiv. Three variants of mineral fertilization were studied V2 (N15P10K0), V3 (N20P15K0) and V4 (N25P20K0), and a control variant V1 (N0P0K0) – without fertilization. It was established that N% content in maize dry biomass was affected significantly by the variants of fertilization (18% of the variance). Significant differences (P≤0.05) between the control variant and all the variants of fertilization were established. Increasing the fertilizer dose, nitrogen content in dry biomass increased, too. The highest was the average content of nitrogen in maize leaves (0.94%), followed by the cobs (0.71%) and the lowest was the content in the stems (0.58%). Phosphorus and potassium content of dry biomass were affected significantly by the year of the study (10% and 9% of the variance, respectively). At the 7-8th leaf growth stage of maize, the highest nutrients content (N, P, K) in dry biomass were reported. With aging of plants the nutrient content in their biomass decreased. Nitrogen, phosphorus and potassium content in maize grain was significantly affected by the year of the experiment. Mineral fertilization had impact mostly on the nitrogen content of the grain, which was the highest in V3 variant, accepted as optimal – 0.66% on average.


2020 ◽  
Vol 31 (4) ◽  
pp. 01
Author(s):  
H. P. G. T. N. Kulasinghe ◽  
U. W. A. Vitharana ◽  
R. S. Dharmakeerthi ◽  
D. N. Sirisena ◽  
W. M. U. K. Rathnayake

Author(s):  
Isaac Tum ◽  
John Mutiso ◽  
Joseph Koske

The response surface methodology (RSM) is a collection of mathematical and statistical techniques useful for the modeling and analysis of problems in which a response of interest is influenced by several variables, and the objective is to optimize the response. The objective of the study was to model the rose coco beans (Phaseolus vulgaris) through an existing A-optimum and D-efficient second order rotatable design of twenty four points in three dimensions in a greenhouse setting using three inorganic fertilizers, namely, nitrogen, phosphorus and potassium. Thus, the objective of the study was accomplished using the calculus optimum value of the free/letter parameter f=1.1072569. This was done by estimating the parameters via least square's techniques, by making available for the yield response of rose coco beans at calculus optimum value design for the first time. The results showed that, the three factors: nitrogen, phosphorus, and potassium contributed significantly on the yield of rose coco beans (p<0.05). In GP3G, the second-order model was adequate for 1% level of significance with p value of 0.0034. The analysis of variance (ANOVA) of response surface for rose coco yield showed that this design was adequate due to satisfactory level of a coefficient of determination, R2, 0.8066 and coefficient variation, CV was 10.30. This study demonstrated the importance of statistical methods in the optimal and efficient production of rose coco beans. We do recommend a randomize screening of all the fertilizer components with which it has influence on rose coco beans be done to ascertain the right initial amount of each fertilizer that could achieve maximum yield than this study realized.


2002 ◽  
Vol 1 (5) ◽  
pp. 548-549 ◽  
Author(s):  
Razaullah Khan ◽  
Sher Ahmed . ◽  
Salimullah Khan . ◽  
Fayaz Ahmed . ◽  
Meer Zaman . ◽  
...  

1993 ◽  
Vol 23 (1) ◽  
pp. 1-6 ◽  
Author(s):  
John Dighton ◽  
Helen E. Jones ◽  
Jan M. Poskitt

The nutritional requirements of Eucalyptusgrandis Hill ex Maiden seedlings were studied in glasshouse pot experiments. Nitrogen (N), phosphorus (P), and potassium (K) demand was assessed by bioassays, in which the uptake of tracers (15N, 32P, or 86Rb) by roots excised from the seedlings grown at different levels of nutrient supply was measured. A pilot study showed that there was an inverse relationship between nutrient supply and influx. The measured influx was affected by the length of time that the roots were stored before the bioassay was applied. In a 33 N, P, and K factorial nutrient experiment, growth was primarily influenced by N. Maximum growth occurred at the highest level of supply of each of the three nutrients. N and K influx in the root bioassay was inversely related to foliar N and K concentration, but P uptake was not related to foliar P concentration. These results indicate that the root bioassays are more sensitive determinants of nutrient limitation than. foliar analysis. Interactions between N and P and between N and K alter the stem:leaf ratio, which may be of importance in optimizing wood production.


1970 ◽  
Vol 21 (2) ◽  
pp. 243 ◽  
Author(s):  
HW Tulloch ◽  
WB Harris

A long-term factorial trial with nitrogen, phosphorus, and potassium fertilizers was started at Nuriootpa Viticultural Station, South Australia on the grape cultivar Shiraz in 1944. Results show a significant yield response to superphosphate. Long-term applications of ammonium sulphate resulted in severe reduction of vine growth and yield, and a significant lowering of soil pH. No direct response to potassium sulphate was obtained except in one year, but a positive interaction between potassium and phosphorus occurred in some years. An analysis of the components of yield in 1964 showed that the increase in yield with superphosphate was due to an increase in the number of berries per bunch. The nitrogen, phosphorus, and potassium contents of petioles were determined and related to available reference standards.


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