Average Tuber Yield Research Articles

Influence of Nitrogen Application Rates on Yield and Yield Attributes of Long Duration Varieties of Cassava (Manihot esculenta Crantz)

A field experiment was carried out at ICAR- Central Tuber Crops Research Institute (CTCRI), Sreekariyam, Thiruvananthapuram, Kerala, India to investigate the effect of different nitrogen application rates on yield and yield attributes of two long-duration cassava varieties during March, 2021 to February, 2022. The experiment was set up in Factorial Randomized Block Design (FRBD) with three replications involving two factors- two cassava varieties (Sree Pavithra and Sree Reksha) and five different nitrogen application rates (0%, 25%, 50%, 100% and 125%) of recommended nitrogen dose of 100 kg ha-1. The study revealed that the application of super optimal dose of nitrogen (125%RD of nitrogen @ 125 kg ha-1) significantly increased the yield (52.61 t ha-1) and yield attributes namely number of tubers (3.55) plant-1, average lenth of tuber (25.48 cm), average diameter of the tuber (12 cm) and average tuber yield plant-1 (4.24 kg) in cassava. Also, super optimal dose of nitrogen positively influenced SPAD 502 chlorophyll meter reading (45.13), leaf chlorophyll a content (1.52, 1.72 mg g-1), chlorophyll b (0.64, 0.72 mg g-1) content and total chlorophyll content (2.20, 2.49 mg g-1), leaf carotene content (0.42, 0.48 mg g-1) in V1 (Sree Pavithra) V2 (Sree Reksha) respectively. Super optimal level of nitrogen positively influenced nitrogen content in leaf,stem and tuber along with phosphorous and potash content in both varieties of cassava.

Effects of Combination of Copper Fungicide and Plant Activator on Late Blight and Quality Criteria of Potato

Late blight caused by Phytophthora infestans is one of the most important fungal diseases that cause damage to both the green parts and tuber of the potato plant and limits potato cultivation. Systemic fungicides are mostly preferred by farmers in the control of potato late blight. The fact that systemic fungicides cause health problems in terms of human and environmental health has revealed the need for research on control methods that do not threaten environmental health. In recent years, successful results have been obtained in the control of many diseases with plant activators known as Induced Systemic Resistance (ISR) promoters. This study was carried out in the spring season of 2016-2017 to observe the effect of copper fungicide and plant activator (Lactobacillus acidophilus fermentation product) combination on the control of potato late blight disease and some quality criteria of potato tubers in the experimental plots of Ege University Ödemiş Vocational School in Ödemiş district of İzmir province. The experiment was planned as two separate experiments with Marabel and Melody potato cultivars. The experiment was established according to a split-plot experimental design with four replications. In this study, the effect of the treatments on potato quality and yield criteria such as tuber number, tuber width, tuber length, single tuber weight, yield per decare, and the effects of the pesticides on potato late blight disease and disease severity parameters were evaluated. When the data obtained as a result of the study were evaluated, it was determined that the combination application had a positive effect on the control of potato late blight disease in both potato cultivars compared to the control plots. When the quality criteria of potato tubers were evaluated, the highest number of tubers was obtained from the plots where copper fungicide and plant activator (Isr-2000) combination was applied. Significant increase was obtained in potato quality and yield criteria such as tuber width, tuber length, average tuber weight and yield per decare when the combination plots were compared with the control plots. In conclusion, the use of contact fungicides and plant activator combinations in the control of late blight in the spring period within the scope of sustainable agriculture is promising as an application alternative in the control of plant diseases in organic agriculture.

Quantifying source-sink relationships of drip-fertigated potato under various water and potassium supplies

Water and fertilizer supply can affect the processes of assimilate production (source) and assimilate accumulation (sink), thereby causing differences in potato yield. However, little is known about the coupling effects of irrigation amount and potassium rate on potato tuber yield and its potential source-sink relationships. The objective of this study was to quantify how water and potassium supplies affected the source-sink relationships of drip-fertigated potato after tuber emergence. A two-year field experiment was conducted during the potato growing seasons of 2019 and 2020, with three irrigation levels (W1: 60% ET c , W2: 80% ET c and W3: 100% ET c , where ET c is the crop water requirements) and four potassium rates (K0: 0 kg ha -1 , K1: 135 kg ha -1 , K2: 270 kg ha -1 and K3: 405 kg ha -1 ). The results showed that compared with K0, the treatments viz ., K1, K2 and K3 increased average tuber yield by 1.3%, 17.3% and 15.5% in 2019 and 10.7%, 24.0% and 19.3% in 2020, respectively. However, compared with W3, the treatments viz ., W1 and W2 reduced the average tuber yield by 8.0% and 12.9% in 2019 and 8.9% and 14.7% in 2020, respectively. The beta sigmoid growth function well fitted the relationship of source capacity and sink capacity. The source capacity and source activity increased with the increase of potassium rate under W2 and W3 in 2019 and under W3 in 2020, while the sink capacity and sink activity first increased and then declined with the increasing potassium rate. Increasing water and potassium supply generally increased the vegetative growth and tuber growth time. The tuber growth rate first increased and then decreased with the increase of potassium rate, while it increased with the increasing irrigation amount. The sink-source ratio decreased with the increase of potassium rate, but there was no significant difference between K1 and K2, and the sink-source ratio under K3 was significantly lower than that in the other potassium treatments. It was concluded that potato was in source-sink balance under K1 and K2, but not under K3. The quantitative approach produced parameters that characterized the differences of source and sink capacity in response to various water and potassium supplies. Sufficient irrigation (W3) with moderate potassium application (K2) increased potato yield mainly by maintaining its source-sink balance. • A model approach was proposed to quantify source-sink relationships of potato under various water and potassium supplies. • The mechanism analysis of yield difference from various water and potassium supplies was conducted by source-sink balance. • Source-sink capacity was affected by different water and potassium management practices. • The sink-source ratio was not significantly different between 135 and 270 kg ha -1 , indicating the source-sink balance. • Various water and potassium application amounts influenced plant potassium absorption and tuber yield.

Modeling Potential production and yield gap of potato using modelling and GIS approaches

Understanding yield potential (Yp) and yield gap (Yg) in current intensive potato (solanum tuberosum L.) production is essential to meet future food demand with the limited resources. Evaluating yield gap is a strong approach to estimate maximum production potential when all factors are in the best condition. A complete estimation of yield gap and potential yield across all major potato producing regions in Iran is lacking. The global yield gap atlas (GYGA) protocol was used to estimate potential yield of potato in Iran. This protocol is based on the climatic zones (CZs) and the reference weather stations (RWS) buffer zones, soil types in each buffer zone. Thirty-five RWS buffer zones in potato producing regions were selected, and total potato area in the RWS buffer zones covered 83% of the whole potato harvest area. According to the results, the average Yp was 67.3 t ha–1 and actual yield (Ya) was 30 t ha–1. Therefore, the average tuber yield gap was 37.3 t ha–1. These results indicate that the Potato producers achieved 45% of the potential yield in Iran. Iranian farmers produced 5 million tons of potato from about 164,000 ha. If they can obtain only 80% of Yp (53.8 t ha–1), amount of potato production will be 8.8 million tones. As result, they can produce 5.2 million tons tuber yield of potato in 97,000 ha cultivation area. Thus, with closing yield gap and increasing potato production, it is possible to decrease potato lands.

Effects of Liming and Nutrient Management on Yield and Other Parameters of Potato Productivity on Acid Soils in Montenegro

This study was conducted to evaluate the effect of liming (CaCO3 1000 kg ha−1) and application of organic fertilizers (rotted farmyard manure 40 t ha−1) and six different combination of mineral fertilizers: NPK 15:15:15 800 kg ha−1 + KAN (calcium ammonium nitrate) 240 kg ha−1; NPK 15:15:15 400 kg ha−1 + MCB (water-soluble mineral fertilizer NPK 13:11:20 + 2MgO + microelements + humic acid) 300 kg ha−1 + KAN 125 kg ha−1; MCB 400 kg ha−1; MCB 400 kg ha−1 + KMg (water-soluble mineral fertilizer Multi KMg 13:0:43 + 2MgO) 100 kg ha−1; MCB 600 kg ha−1 + KMg 100 kg ha−1 and MCB 800 kg ha−1 + KMg 100 kg ha−1 on yield and other productivity parameters of potato (Kennebec variety). The aim of the research was to optimize the system of potato plant nutrition for maximum profitability in the future potato production on acid soils of mountainous region of Montenegro. The experiments were carried out during 2015 and 2016, on Dystric Cambisols. The results obtained suggested that in both years, the highest values for all studied parameters were measured on plots with combined application of liming, organic and mineral fertilizers. In addition, a significant influence on the increase in the number of tubers per plant, the average tuber weight and the total yield was also demonstrated in all individual trials of potato nutrition, and the interaction of organic manure and mineral fertilizer. Fertilizing with rotted farmyard manure had significantly increased potato productivity, with the effect more pronounced in treatments with liming. The highest number of tubers (6.2 and 7.2), average tuber weight (93.5 g and 101.0 g) and yield (27.6 t ha−1 in 2015 and 34.8 t ha−1 in 2016, respectively) were obtained using combinations of MCB 800 kg ha−1 + KMg 100 kg ha−1 on variants fertilized with rotted farmyard manure and liming. This research is a valuable source of information for potato growers and scientists from this region as the results have shown how fertilization is raising productivity in this environment and its importance in the future potato growing on acid soils in mountainous regions of Montenegro and Western Balkans.

Yield and grading of potato tuber for processing purpose as affected by vermicompostand potassium sources

Gradding of potato tuber for different processing purposes may reduce the main constraints of establishing export industry in Bangladesh. From this perspective the experiment was conducted to assess the effect of potassium sources and vermicompost level on yield and grading of potato tuber. The potato tuber of variety BARI Alu-25 (Asterix) was used as the planting material for this experiment. The experiment consisted of two factors: Factor A: 3 sources of Potassium such as-K1: KCl, K2: KNO3, K3: K2SO4; Factor B: 4 levels of vermicompost such as-Vm0: 0 t ha-1 , Vm1: 4 t ha-1 , Vm2: 8 t ha-1 and Vm3: 12 t ha-1 . The two factor experiment was laid out in a split-plot design with three replications. The highest yield of potato tubers (27.86 t ha-1 ) was recorded from K2SO4, whereas, the lowest (26.02 t ha-1 ) was found from KNO3. The number of tubers hill-1 , average tuber weight, yield and different categories of potato tuber were increased with the increasing of vermicompost level. Among the 12 treatment combinations, the highest yield of potato tubers (31.17 t ha-1 ) were found from K3Vm3, whereas, the lowest (22.09 t ha-1 ) was recorded from K2Vm0. However, K1Vm2, K1Vm3, K3Vm2, K3Vm3 showed statistically similar results regarding yield and grading. So, K2SO4 or KCl as a source of potassium and 8 or 12 ton vermicompost ha-1 was found to be better in respect of yield and grading of potato tubers compared to the other treatments. Among potassium sources, KCl may be economic and will found available for producing good quality potato in Bangladesh.

Stability Analysis for Yield of Advanced Potato Genotypes for Commercial Cultivation in Bangladesh

Five advanced potato genotypes, along with three check varieties were evaluated at six locations in order to find out the stable varieties for commercial cultivation in Bangladesh. Combined analysis exhibited a highly significant variability among the genotypes, locations and GEI. The average tuber yield at 90 days after planting (DAP) of the genotypes ranged from 31.18 t ha-1 in the check BARI Alu-28 to 43.8 t ha-1 in the clone 9.35. The result of AMMI analysis of tuber yield at 90 DAP also showed that the first IPCA1 captured 55.30% of the interaction SS. IPCA2, IPCA3 and IPCA4 explained 29.01, 8.55 and 7.08% of GE interaction SS, respectively. In general, the AMMI2 model contained 99.94% of the treatment SS, while the residual contained 0.06%. In ASV method, the clone 9.125, followed by the check BARI Alu-28 and clone 9.91 were more stable than 9.35. Biplot of IPCA1 and IPCA2 covers 84.3% of GE interaction. Biplot analysis also showed that clone 9.44 and 9.35 and the environment of Gazipur and Jashore had a better result in the GE interaction. Clone 9.44 had specific adaptation with the environment of Gazipur and Jashore, while 9.35 had specific adaptation with Gazipur and Jamalpur. Clone 9.125, 9.91, BARI Alu-28, BARI Alu-8 and clone 9.112 were located toward the center of the biplot and can be considered as stable. Based on the GSI the most desirable genotype for both stability and high tuber yield is the clone 9.125 followed by clones 9.112, 9.91 and 9.35.
 SAARC J. Agri., 18(1): 73-86 (2020)

Effect of drought and waterlogging on hydrophilic antioxidants and their activity in potato tubers

Maintaining a strong antioxidant system is essential for preventing drought or waterlogging stresses damage in potato tubers. In the two-year pot experiment, the effect of long-term drought and waterlogging stresses on the content of phenolic acids, ascorbic acid, and antioxidant activity in potato tubers and relative water content of four cultivars was evaluated. Drought stress significantly (P < 0.05) decreased relative water content (RWC) in the leaves of all genotypes. The evaluation of the relationship between phenolic acid content and the level of plant stress expressed as RWC showed a negative correlation between RWC and most phenolic acids, but these correlations were not statistically significant, with the exception of l-tyrosine. A significant positive correlation was found between total and individual phenolic acid content and antioxidant activity (R = 0.657), confirming the main responsibility for the increase of antioxidant activity. The average tuber yield and weight as well as their average number correlated negatively with total phenolic acids. Drought stress decreased l-ascorbic acid content by reduction of biosynthesis, and its content was positively correlated with decreased RWC, tubers yield, weight, and number. The increase of phenolic antioxidants in potato under stress conditions can be a distinctive marker of cultivar resistance against abiotic stresses.

Performance of advanced potato genotypes in organic and conventional production systems

ABSTRACT Potato is responsive to intensive agricultural input use; however, it can be produced in less intensive production systems (such as the organic system) by using appropriate production techniques and genotypes adapted to this system. This study aimed to evaluate the performance of advanced potato genotypes for tuber yield under conventional and organic production systems, in order to select potential genotypes to become new cultivars adapted to these systems. Fifteen advanced potato clones and two controls were evaluated under organic and conventional production systems, in 2016 and 2017, in Brasília-DF, Brazil. The experimental design was randomized blocks with three replicates and plots composed of two rows with 10 plants each, spaced 0.35 m between plants and 0.80 m between rows. Total (mass) and marketable (mass and number of tubers) productivities were evaluated. Variance analysis showed significant differences among genotypes for all traits. Despite the lower average tuber yield in the organic system, selecting genotypes with high potential productivity was possible in this system, such as F158-08-01 and F158-08-02, showing high marketable tuber yield, with values equivalent to the conventional system. Clones F102-08-04, F13-09-07, F-18-09-03, F-183-08-01, F-21-09-07, F31-08-05, F63-10-07 and F97-07-03 also outperformed the control cultivars in organic system. For conventional system, F158-08-01, F158-08-02 and F183-08-01 were superior, and F18-09-03, F21-09-07, F63-10-07, F97-07-03, PCDINV10 and PCDSE090 showed performance similar or superior to the most productive control (cultivar Asterix). Genotypes F158-08-01 and F158-08-02 were superior in both conventional and organic systems, with potential to become new cultivars recommended for both production systems.

Effects of the frequency and amount of drip irrigation on yield, tuber quality and water use efficiency of potato in sandy soil of Yulin, northern Shaanxi, China

Reasonable irrigation is still lacking for potato production in the sandy areas of Yulin, northern Shaanxi Province. To solve this problem, field drip fertigation was conducted to examine the growth, yield and quality of potato during the whole growing season. We further analyzed the responses of these indices to different irrigation frequencies and amounts. There were three irrigation frequencies (d), i.e. 4 (D1), 8 (D2) and 10 (D3), and three irrigation amounts, i.e. 60%ETc (W1), 80%ETc(W2) and 100%ETc(W3), where ETc was the crop water requirement, resulting in a total of nine treatments. Under the same irrigation frequency, plant height, leaf area index, dry matter, tuber yield and economic benefits of W3 were higher than those of W1 and W2. W1 had the highest irrigation water use efficiency (IWUE), while water use efficiency was not significantly affected by irrigation amount. The average tuber yield of W3 was 43442 kg·hm-2, which was 23.3% and 11.6% higher than that of W1 and W2, respectively. The net income of W3 was 23492 yuan·hm-2, which was 40.4% and 18.7% higher than that of W1 and W2, respectively. Tubers from W3 had the highest starch and vitamin C contents but the lowest reducing sugar content, which were 14.4%, 18.54 mg·(100 g)-1 FW and 0.7%, respectively. At the same irrigation amount, tuber yield, IWUE, starch and vitamin C contents of D1 were the highest, but the reducing sugar content was the lowest at the low and medium irrigation amounts. At the high irrigation amount, D2 had the highest tuber yield, IWUE, net income, starch and vitamin C contents but the lowest reducing sugar content, which were 46572 kg·hm-2, 23.04 kg·m-3, 26,622 yuan·hm-2,14.6%, 19.53 mg·(100 g)-1 FW and 0.7%, respectively. Based on the interacting effects of drip irrigation frequency and amount, both yield and quality of D2W3 reached the maximum. Results from the principal component analysis showed that D2W3 had the highest score. D2W3(8 d, 100%ETc) had the greatest yield and quality and relatively higher water use efficiency, which was thus considered as the optimal combination of drip irrigation frequency and amount. The results could provide a scientific basis for the drip irrigation scheduling design for high-yield, high-efficiency and high-quality potato production in the sandy areas of Yulin, northern Shaanxi.

Growth and Productivity of Different Potato Cultivars

During the experimental years of 2017 and 2018 eight potato cultivars were evaluated for their growth traits and productivity in tuber yield. The potato cultivars used in these experimental seasons were; Bubu (as a standard check), Chiro, Gebisa, Belete, Gudene, Badasa Jarso and Dedafa. The first six consecutive potatoes are improved cultivars which were released by Ethiopian research institute and University while the last two potatoes were collected from farmers and cultivated as local (native) cultivars. The objective of this study was to compare the growth and productivity potato cultivars grown at eastern regions of Ethiopia. The results revealed that performance of improved potato cultivars were high in both evaluated yield related traits and average tuber yield. The performances of evaluated potatoes were not similar among cultivars and within cultivar throughout experimental seasons. The experimental design was a randomized block design in three replications. The field management; seed tuber selection, land preparation, planting, fertilizer application method and amount, ridging, weeding, cultivation, harvesting, data collection method and collected data analysis has been carried out for all potato cultivars in similar manner. Potato tubers from four middle rows were analyzed for parameters such as tuber yield, tuber number, marketable and total tuber yield. The highest tuber yield was revealed with cultivar Bubu (39.4 t ha-1) while the lowest with Jarso (20.89 t ha-1). The highest tuber number was showed with cultivar Badasa (12.73 plant-1) and the lowest with Belete (7 plant-1). Hence, there were no correlation between average tuber yield and number.

Soil salinity management for increasing potato yield in the coastal area of southern Bangladesh

The study was conducted at farmers’ field of Charfashion upazila in Bhola district under AEZ-18 during the Rabi season of 2015-2016 and 2016-2017 to find out suitable soil salinity management practice(s) for maximizing potato yield as well as farmers’ income. Two planting systems viz. raised bed and flat land, and four management systems with fertilizers and mulching were considered in a factorial experiment. The rate of increase in soil salinity in raised beds was significantly lower than that of flat land. On an average, raised bed planting produced 13.04% higher tuber yield than flat land planting. The combination of raised bed + recommended fertilizer (RF) with cowdung @ 5 t ha-1 as IPNS+ straw mulch (@ 3.5 t ha-1) produced the highest tuber yield in both the years (average 21.66 t ha-1) and it was 75.10% higher than flat planting system with no mulch. This treatment combination also provided the highest average gross margin (Tk. 115945 ha-1) and BCR (2.26). Besides, combination of raised bed + RF+25% K+ straw mulch provided average tuber yield (20.91 t ha-1), gross margin (Tk. 110969 ha-1) and BCR (2.25), which were very close to above treatment combination. The lowest average potato yield (12.51 t ha-1), gross margin (Tk. 39835 ha-1) and BCR (1.50) were obtained from combination of flat land planting + RF +no mulching. So, combination of raised bed + mulching+ RF along with IPNS basis cowdung @ 5 tha-1 or 25% extra K can help minimize soil salinity and produce significantly higher potato yield in the coastal areas.Bangladesh J. Agril. Res. 43(4): 655-668, December 2018

Irrigation method and application timing effect on potato nitrogen fertilizer uptake efficiency

Establishment of proper guidelines for irrigation and nitrogen (N) fertilizer management may lead to higher crop fertilizer N use efficiency (FNUE), increasing water conservation and reducing nutrient losses from agricultural systems. The objective of this study was to determine FNUE of potato for three application timings: at planting, emergence and tuber initiation cultivated under three irrigation methods: seepage, subirrigation and sprinkler. A total of 168 kg ha−1 of N was equally split into three applications of 56 kg ha−1 as ammonium nitrate (NH4NO3). FNUE from each application timing in all irrigation methods was evaluated substituting the conventional N fertilizer by an isotope labeled-ammonium nitrate (15NH 4 15 NO3) with 1.18% enrichment in excess. Irrigation method had no significant effects on tuber yield and FNUE. The average tuber yield was 32.1 Mg ha−1 and overall FNUE was 41%. Across the N application timing treatments, the lowest FNUE was measured for the at-planting application (18%), followed by the emergence N application (44%) and tuber initiation N application (62%). Unaccounted N fertilizer during the potato season amounted to 98 kg ha−1 from the total 168 kg ha−1 of N applied. N applied at emergence and tuber initiation were important to increase FNUE and tuber yield, however, some N was required at planting, even with the high potential of N losses for that application.

Comparative Study of Various Organic Fertilizers Effect on Growth and Yield of Two Economically Important Crops, Potato and Pea

In the present experiment, the effect of various house hold wastes i.e. T1 (egg shell powder), T2 (wood ash), T3 (banana peel), T4 (used tea waste), T5 (egg shell tea) and T6 (control) used as organic fertilizers on growth and yield of two important vegetables i.e. potato and pea was investigated. Among all the treatments, the minimum average number of days to germination was observed in T3 in both potato and pea. The overall growth and development of potato and pea plants increased and the average plant height after 30, 60 and 90 days was greater in plants of treatment T1 (egg shell powder). In case of potato, the highest mean plant height (14.75 cm) was observed in treatment T1, followed by T3 and T4 (10.62 cm and 9.87 cm) respectively after 90 days of the emergence. T1 treatment increases the no. of leaves, no. of nodes, no. of branches and leaf area. Regarding tuber yield, the tubers were classified as large (>30 grams), medium (15 - 30 grams) and small (0.4 - 15 grams). T1 treatment produced greater average number of large size tubers (2.25) per plant, followed by T3 (1.25); however, the medium and small tubers followed comparable trends with differences among treatments. The average tuber yield (per potato plant) in treatment T1 was higher (113.78 g). In case of pea, T4 treatment (used tea waste) showed the highest mean plant height (82.25 cm). The treatment T1 (eggshell powder), T3 (banana peel) and T4 (used tea waste) showed positive effect on average pod yield (64.82 g, 66.67 g and 114.35 g) respectively. Number of grains per pod and pod size has been found higher in case of treatment T4. It has been concluded that among the different organic treatments, eggshell powder, banana peel and used tea waste were found best as organic fertilizer source for the two vegetables i.e. potato and pea.

Reducing Severity of Late Blight (Phytophthora infestans) and Improving Potato (Solanum tuberosum L.) Tuber Yield with Pre-Harvest Application of Calcium Nutrients

The efficiency of pre-harvest application of calcium chloride alone, calcium nitrate alone, and combined application of calcium chloride and calcium nitrate (1:1) was evaluated in reducing the severity of P. infestans and improving potato tuber yield. Pot experiment was conducted in randomized complete block design with four replications. The treatments consisted of combination of two potato varieties (Shenkola and Gera) and three types of calcium nutrients (calcium chloride alone, calcium nitrate alone, and calcium chloride mixed with calcium nitrate), each at three levels (5, 10, and 15 g per liter per plant) and the control treatment (0 g of calcium nutrients). In comparison to the control treatment, the application of calcium nutrients significantly decreased the severity of late blight disease and improved potato tuber yield. The effect of calcium nutrients on the severity of late blight disease and potato tuber yield differed among the two potato varieties. The maximum severity reduction (60%) was noticed in the Gera potato variety with the application of calcium chloride mixed with calcium nitrate (1:1), supplied at 15 g per plant. However, the highest average tuber yield was obtained with the application of calcium nitrate at 15 g per plant, and average tuber yield was increased by 77% in both potato varieties. Hence, foliar application of either calcium nitrate alone or calcium nitrate mixed with calcium chloride was found to be more efficient than the application of calcium chloride alone. This result suggests that the nitrate ion present in the calcium nitrate may make a difference in terms of reducing the severity of late blight disease and improving potato tuber yield. The lowered severity of late blight disease and the increased tuber yield in potato plants sprayed with calcium nutrients may be because of the higher accumulation of calcium in the plant tissue.

Potassium impact on nitrogen use efficiency in potato - a case study from the Central-East Europe

Potato yield is affected by an interaction between nitrogen (N) and potassium (K) supply. This hypothesis was verified in a series of field experiments conducted during 2010–2013 in Albania (AL), Czech Republic (CZ) and Poland (PL). The two-factorial experiment was founded on relative scales of K (0, 50, 100, and 150%), and N application rates (75% and 100%) of the recommended doses, which were country-specific. The average tuber yield was doubled for AL, increased by 50% for PL, and by 15% for the CZ in response to K and N interaction. These differences are caused by an increase in the apparent nitrogen efficiency (ANE), which rose significantly by the progressive Krates. Maximum average ANE of 90 kg tubers/kg N was recorded in AL; it was 2-fold lower in CZ. Top average apparent potassium efficiency (AKE) of 65 kg tubers/kg K was recorded in PL; it was 4-times lower in CZ. The relationships between AKE and ANE clearly demonstrate the tight interaction between the N and K, and its effects on potato yield. However, a sound K application management should be adjusted to the local edaphic and climatic conditions.

Reserving winter snow for the relief of spring drought by film mulching in northeast China

Drought is a widespread problem in crop growing areas and a threat to food security worldwide. Mulching has become an important practice for maintaining soil moisture, reducing weed growth, mitigating soil erosion and improving soil temperatures in arid and semiarid areas. In northeast China, winter snow is heavy and spring drought frequently occurs, partially due to the loss of melted snow water by evaporation in spring. As such, this study assessed the use of plastic mulching in potato crops to minimize drought by accumulating and reserving water from winter snowfall. In field experiments conducted at two locations in the Heilongjiang Province, China (Keshan in 2011 and 2013, Heihe in 2011 and 2012), black and colorless transparent films were used as mulch during the thickest snow from late winter to early spring. The effects of plastic mulching on soil moisture content and temperature at various soil depths and its influence on potato growth and yield were evaluated. The results showed that film mulching increased the temperature and moisture content of the plow layer (0–10cm). Black film retained more solid snow than colorless film. The black and colorless films advanced potato emergence by 7 and 14days, respectively, compared with the control; higher temperatures under the colorless film resulted in earlier emergence than under the black film. The colorless and black film mulching increased soil water contents by 2.5 and 1.5 percentage points, respectively, compared with the control. Average tuber yield over the three-year study at both sites increased by 68.6% and 110.9% with black and colorless film, respectively, with yield increases more apparent in the year with spring drought. The effect of film mulching on yield mainly depended on differences in soil water content between mulching treatments and the control. Snow conserved by winter film mulching supplied water to the plow layer. Our results revealed that film mulching in winter significantly increases soil moisture content, ensures good stand establishment, and effectively solves a severe problem with spring drought in northeast China.

Farklı Organik Gübrelerin Tohumluk Patates (Solanum tuberosum L.) Çeşitlerinde Verim ve Kalite Üzerine Etkileri

This study was conducted to determine the effects of use organo-mineral fertilizers and poultry manure on yield and quality of seed tubers different potatoes varieties (Solanum tuberosum L.). The study was designed in three replicated completely randomized block factorial design with eight potato cultivars (Madaline, Provento, Marfona, Agata, Arizona, Mustang, Rumba and Saviola) and including three different fertilizer as Hexaferm organo-mineral (%20 organics, 8-21-0+Zn), compost (1 t da-1) and fermented poultry manure (1 t da-1). In order to determine the effect of fertilizer forms on the yield and quality characteristics of different varieties of potatoes were examined features like output time of the tuber, output rates, plant height, stem number per hill, tuber yield per hill, total tuber yield, cracks tuber yield, dry matter content, starch content and specific gravity. Used fertilizers have no significant effect on output time of the tuber, output rates, plant height, stem number per hill, total tuber yield, dry matter content, starch content and specific gravity of varieties. The difference observed in terms of output time of the tuber, output rates, plant height, stem number per hill between the varieties was insignificant. The difference between the average tuber yield per hill, total tuber yield, cracks tuber yield, dry matter content, starch content and specific gravity of varieties were significant. Similarly, the fertilizers had a significant effect on the average tuber yield per hill of varieties . The significant interactions were found on traits average tuber yield per hill and average specific gravity between Fertilizer x Varieties. As a result, considered economically the fermented and compost poultry manure can be used instead of organo-mineral fertilizers in the production of seed potatoes.

Patatesin Kısa Süreli Kuraklık Uygulamasına Fizyolojik Tepkileri

The study aimed to identify physiological response of potato to drought. For this aim, a drought experiment was carried out by using two different potato varieties, cv. Desiree and Russet Burbank, under environmentally controlled greenhouse conditions. Drought treatment was initiated at 45 days after emergence (early tuber bulking period) by withholding irrigation for 10 days. Physiological traits such as stomatal conductance, transpiration rate, photosynthetic rate, chlorophyll index, leaf temperature, proline content, malondialdehyde (MDA) accumulation and hydrogen peroxide (H2O2) accumulation, in addition, some yield components average tuber weight, number of tubers and plant tuber yield were evaluated in the study. While the first significant decline in stomatal conductance, transpiration rate, and photosynthetic rate of both varieties was occurred at the 5th day of withholding irrigation, the highest decline was observed at 9th and 10th days of withholding irrigation. Proline content in both varieties increased two times at 10th day of withholding irrigation, however, H2O2 accumulation was not changed significantly by drought treatment. Even though MDA accumulation was increased in both varieties under drought stress conditions, the increase was significant in Desiree whereas, it was not significant in Russet Burbank. In addition, while drought treatment did not change the plant tuber yield in both varieties, it caused to a significant decline in average tuber yield of Russet Burbank, being an important trait for marketable tuber yield.

Rate and timing of nitrogen fertilizer application on potato ‘FL1867’. Part I: Plant nitrogen uptake and soil nitrogen availability

Knowledge of seasonal nutrient demand is necessary to maximize potato (Solanum tuberosum) yield and profitability while also minimizing the risk of excess fertilizer leaching into waterways. The objective of this study was to determine the effect of the N fertilizer rate and timing of application on the N use efficiency (NUE) and yield of chipping potato ‘FL1867’. This study was conducted with grower collaboration on three commercial farms for two years (2011 and 2012) using subirrigation on course textured soils in Florida. All treatments received 56kgha−1 of N as ammonium nitrate applied as a band approximately 40 days before planting (Npre-pl). Liquid urea ammonium nitrate was then band applied at 0, 56, 112, or 168kgha−1 at plant emergence (Nemerg) followed by 56 or 112kgha−1 applied as a side-dress at tuber initiation stage (Ntuber init). The treatments were arranged in a factorial design with four replicates. The total amount of N fertilizer applied ranged from 112 to 336kgha−1. Maximum daily N uptake by the potato crop occurred between 55 and 65 days after planting, coinciding with the onset of the tuber bulking stage. Heavy rainfall prior to planting the 2011 crop reduced soil N availability from pre-plant applied N fertilizer indicating the high susceptibility of that application timing to leaching. Average tuber yield ranged from 25.6 to 47.2Mgha−1, with the lowest yields occurring when heavy rainfall close to harvest increased yield loss to decay. While higher Nemerg rates increased soil inorganic N, tuber yield was either not affected by N application or responded quadratically peaking at Nemerg levels between 95 and 125kgha−1. N application rates above this range decreased yield and NUE while increasing soil residual N at the end of the season. Plant N uptake and tuber yield did not increase with Ntuber init rate above 56kgha−1 and it was associated with lower NUE and also higher residual soil N.