Affect Potato Yield Research Articles

Targeting Cancers: Uncovering the Potential Roles of Potato Tissue Culture as Anti-Cancer Agents — A Secondary Publication

Plant tissue culture is a technique that enhances the quality and quantity of potatoes. Potatoes are a significant crop and are primarily used in the world. It is a staple food in many countries, where millions of tonnes are produced annually. It is an essential source of many nutrients, such as proteins, carbohydrates, vitamins, and beta-carotene. In addition, potatoes are being used as therapeutic agents against cancer and other human diseases as well. Potatoes are on the third list after wheat and rice. To overcome food shortages and malnutrition, there are two methods used for producing potatoes: the first is sexual, which is seed propagation, and the second is asexual, which is plant tissue culture propagation. Conventional potato breeding is a uniform method, but it is unsafe because there is a risk of pathogen attack. In a laboratory setting, the tissue culture of potatoes produced millions of plants with nutrient-rich medium under controlled environmental conditions that prevent pest attacks. Some environmental stresses, such as salinity and water scarcity, affect potato yield and production; however, applying nanoparticles like organic, inorganic, and silicon dioxide enhances potato quality and combats stress. Biotechnology has proven to be helpful in addressing all these issues. This review discusses the significance of potatoes, their production through the tissue culture technique, and the application of nanoparticles to improve the growth, and impact of potatoes on human health.

An Application for Smartphones and Computers to Diagnose and Control Potatoes Insects

Nowadays, a strong relationship between the agriculture sectors and digital technologies is really interesting. The article describes how recent intelligent technologies can improve agricultural fields. Mobile applications are software programs created on smartphones, tablets, and computers. Agricultural fields mainly represent the pillar of the economy and the business sector that fulfills the world's food requirements. The United States has a valuable rank in potato production, which depends on this production economically. Nevertheless, so many insects affect potato yield production quantitatively and qualitatively. So, a smartphone App was created to help potato growers diagnose insects that directly attack potato crops and treat them. The created App focuses on a list of the common insects that attack potato crops in Maine State. App Inventor Platform, run by the Massachusetts Institute of Technology (MIT), was used to develop the application. Insect images and insecticides information were collected from the Cooperative Extension Department at Presque Isle City, Aroostook County, Maine, USA. The App provides essential details regarding insect types, life cycles, where they are coming from, and the time of attacking the plants. The App includes a list of effective insecticides that control insects. The App also provides helpful instructions concerning trade names, dose per acre of insecticides, and whether it should be applied to soil or plant leaves. Money and time are saved by applying this App since farmers do not need to spend time collecting samples and bringing them to the lab.

Balancing potato yield, soil nutrient supply, and nitrous oxide emissions: An analysis of nitrogen application trade-offs

Potato has been promoted as a national key staple food to alleviate pressure on food security in China. Appropriate nitrogen (N) application rate is prerequisite and is crucial for increasing yield, improving fertilizer efficiency, and reducing N losses. In the present study, we determined the optimum N application rates by analyzing field trial data from the main potato producing areas of China between 2004 and 2020. We considered the equilibrium relationships between potato yield, N uptake, partial N balance (PNB), and N2O emission under different soil indigenous N supply (INS) scenarios. The results showed that N rate, INS, and their interactions all significantly affect potato yield and nutrient uptake increment. On average, N application increased potato yield and N uptake by 29.5 % and 56.7 %, respectively. The relationship between N rate and yield increment was linear-plateau, while the relationship between N rate and N uptake increment was linear-linear. Soil INS accounted for 63.5 % of total potato N requirement. Potato yield increment and nutrient uptake increment were exponentially negatively correlated with INS and had a significant parabolic-nonlinear relationship with the interaction of N fertilizer application rate and INS. PNB was negatively correlated with fertilizer N supply intensity as a power function. Based on our analysis, a N application rate of 166 kg N ha−1 was found to be sufficient when the target yield was <34 t ha−1. However, when the target yield reached 40, 50 and 60 t ha−1, the recommended N application rate increased to 182, 211, and 254 kg N ha−1, respectively, while ensuring N2O emissions low with an emission factor of 0.2 %. Our findings will help guide potato farming toward cleaner production without compromising environmental benefit.

Effects of organic amendments and cover crops on soil characteristics and potato yields

ABSTRACT Intensive potato production may reduce the soil organic matter content (SOM), which may impact several soil functions and increase the incidence of potato diseases. We examined if cover crop and addition of organic materials may counteract these effects. Organic materials were one application of biochar mixed with liquid digestate (BLD); solid digestate (SD); or farmyard manure (FYM); with or without winter rye as cover crop, in a field with regular potato growing. Organic amendment increased SOM, especially for FYM and BLD, while cover crop did not affect SOM. Yet, cover crop increased tuber yields in the second year, and reduced the severity of potato diseases by 10% in post-harvest potatoes in both years. In the second year, the number of marketable potatoes after storage increased by 37% with cover crop. Organic amendments did not affect potato yield or quality, but the proportion of marketable potatoes tended to be higher in the amended soil. By lab incubation, BLD showed the largest potential for SOM storage, up to 32 years, followed by FYM and SD. Cover crops and organic amendments is recommended in potato production, especially for early potatoes where there is sufficient time after harvest to establish a good cover crop.

Prevalence and molecular characterization of important potato viruses in the Tokat province of Turkey.

It is believed that viruses affect potato yield more than any other pathogens worldwide. We report here on a survey of the four most common potato viruses in the Tokat Province of northern Turkey. Leaf samples were collected from potato plants showing signs of viral diseases in five districts of the province. Over 400 leaf samples were tested using RT-PCR with virus-specific primers. Among the one or more viruses detected in 218 (52%) leaf samples, Potato virus Y (PVY) was the most common (47.1%), followed by potato virus S (PVS; 16.7%), potato virus X (PVX; 6.0%) and potato leaf roll virus (PLRV; 5.3%). The most common mixed infections were PVY + PVS (6.9%). A phylogenetic analysis of the gene sequences showed all Turkish PVS isolates to be clustered with the PVSO group, two PVY isolates with the PVYN-WI group and one isolate with the PVYNTN group. Turkish PVX isolates are in the Type X group of the two major PVX isolate groups. The Turkish PLRV isolates were separated into two major groups depending on the results of the phylogenetic analysis, with six cases in Group 1 and one in Group 2. PVY, PVX, PVS and PLRV were detected in potato production areas in Tokat. A phylogenetic comparison of the gene sequences revealed all Turkish isolates to be immigrant members of the world populations of these viruses. Our results emphasize the importance of the strict quarantine control of plant materials entering Turkey.

Effects of ridge tillage with film mulching in furrow on photosynthetic characteristics of potato and yield formation in dryland farming

<p id="C3">To investigate the effects of ridge tillage with film mulching in furrow on photosynthetic characteristics and yield formation of potato in dry land, field experiment was conducted from 2018 to 2019 in mountain area of south Ningxia. Ridges were covered with common plastic film in all treatments, while different furrow treatments were mulched with common plastic film (DD), degradable permeable mulch film (DS), and bast fiber film (DM), and no mulching furrows was used as the control check (CK). The effects of ridge tillage with film mulching in furrow on soil moisture, photosynthetic characteristics of potato functional leaves and yield formation during the key growth period (60-120 days after sowing) were investigated and compared. The results showed that the different mulching treatments could significantly increase soil water storage in 0-100 cm layer during potato squaring stage (60 days after sowing). DD treatment was the highest in 2018 and DM treatment was the highest in 2019, which significantly increased by 11.2% and 21.6% than CK, respectively. In the key growth periods of potato, leaf area index of DS treatment was significantly higher than that of CK in 2019, but there was no significant difference among the other treatments. Different mulching treatments could increase the net photosynthetic rate and transpiration rate, while DM treatment significantly increased the net photosynthetic rate and transpiration rate by 30.0% and 23.2% in the tuber swelling stage (120 days after sowing), compared with CK, respectively. The average tuber dry matter accumulation with DD, DM and DS treatments in the 2-year tuber swelling stage was significantly increased by 54.9%, 50.0%, and 22.6%. During the 2-year experiments, the average potato yield with DD, DM and DS treatments was increased by 13.2%, 14.1%, and 5.2%, the average net income was increased by 16.3%, 14.6% and 4.0%, respectively, compared with CK, while the differences in potato yield and net income were not significant between DS and CK. Correlation analysis showed that soil moisture and net photosynthetic rate were the main factors affecting potato yield formation. The treatments of ridge tillage with common plastic film mulching in furrow (DD) and ridge tillage with bast fiber film mulching in furrow (DM) could improve soil moisture at squaring stage, thus promoting the increase of potato photosynthesis and yield. Therefore, ridge tillage with bast fiber film mulching in furrow had the same effect of increasing yield and income as ridge tillage with common plastic film mulching in furrow, and it had the advantage of partially replacing common plastic mulching.

Plastic film mulching with ridge planting alters soil chemical and biological properties to increase potato yields in semiarid Northwest China

BackgroundThe growth of potato (Solanum tuberosum L.) is severely affected by the complex and variable soil environment, and film mulching has been widely used for potato growth in semiarid areas of western China. However, there are few studies on the effects of film mulching on soil quality and tuber yield in potato fields.MethodsThe effects of four mulching patterns (flat plot without film mulching, FP; flat plot with film mulching, FPM; ridge planting with half mulch, RPHM; ridge planting with full mulch, RPFM) on soil chemical and biological properties and potato tuber yield were investigated during two growing seasons (2018 and 2019) in the field.ResultsThe results showed that compared with FP, the mulching treatments significantly increased the tuber yield of potato, with an increase of 3.7–20.77% and 7.89–26.35% in 2018 and 2019, respectively, and the yield of RPFM was higher than that of other treatments. In both growing seasons, RPFM significantly increased the contents of alkali-hydrolyzed N and available P, and the activities of soil urease, catalase, alkaline phosphatase, and sucrase. Bacterial and actinomycete counts were significantly higher in RPFM than those in the other treatments. Furthermore, RPFM significantly increased large potatoes and decreased small potatoes. Pearson’s correlation analysis revealed that soil alkaline dissolved nitrogen and actinomycete populations were the main factors affecting potato yield formation.ConclusionsThese results indicate that RPFM can improve the soil environment and further increase potato tuber yield, which is a viable option for potato production in semiarid areas.Graphical

Determinants of technical efficiency of potato farmers and effects of constraints on potato production in Northern Ethiopia

AbstractTo improve the national average yield of potato in Ethiopia, which is very low as compared to its potential, factors that influence technical efficiency of potato production need to be determined. Therefore, the objective of this study was to investigate the determinants of technical efficiency using a cross-sectional data collected from 368 randomly selected potato producers in Northern Ethiopia using a multi-stage sampling technique. The study employed Cobb–Douglas stochastic frontier model to get farm-level technical efficiency scores. Tobit model and principal component analysis were used to determine the factors that influence technical efficiency of farm households. The results revealed that chemical fertiliser, seed potato, plot size and labour are statistically significant factors that affect potato yield. The average technical efficiency score was estimated to be 75%; and education, experience, off-farm income, household size, membership in a farmers’ association, use of irrigation water, extension contact, use of improved seed, access to product market and weak coordination of stakeholders’ were significant factors influencing technical efficiency. The findings of the study suggest that there is a need for government intervention to create strong market linkage between producers and buyers and to give appropriate training to agricultural extension agents.

Impacts of Recent Climate Change on Potato Yields at a Provincial Scale in Northwest China

Understanding the effects of climate change on potato yield is vital for food security in northwest China. Based on the long-term data of yields and meteorology, this study analysed the impacts of recent climate change on potato yields at a provincial scale in northwest China. The first difference method was used to disentangle the contributions of climate change from the changes in potato yield in two consecutive years. The moving average method was used to decouple the climate-induced yield of potato. The results showed that the yield and planting area of potato from the period 1982 to 2015 increased markedly, with inter-annual fluctuations. The temperature increased significantly during the potato growing period in northwest China, while other climatic factors did not change significantly. Specifically, the changing trends in climatic factors varied among different provinces. The key meteorological factors limiting potato yield were temperature, precipitation and diurnal temperature range, varying in the different provinces. Potato yields in Gansu, Shaanxi, Ningxia and Xinjiang decreased by 127, 289, 199 and 339 kg ha−1, respectively, for every 1 °C increase in daily maximum temperature. The potato yield in Xinjiang decreased by 583 kg ha−1 for every 1 °C increase in daily minimum temperature. For every 100 mm increase in precipitation, the potato yields in Gansu, Qinghai and Ningxia increased by 250, 375 and 182 kg ha−1, respectively. Combining the first difference method and the moving average method, precipitation was the dominant climatic factor affecting potato yield in rain-fed areas (Gansu, Qinghai and Ningxia). For areas with irrigation (Xinjiang) or relatively high rainfall (Shaanxi), maximum temperature was the deciding climatic factor affecting potato yield. Appropriate adaptation to climate change in the different regions will help to ensure potato production in northwest China.

Variations in Stolon Length and Tuber Roots Among Six Potato Cultivars

This study is tested whether the stolon length and tuber roots show variations and could affect potato yield among the potato cultivars over two cropping seasons. Six potato cultivars from a group of improved and local cultivars were examined. The results of the experiments done during both seasons revealed that the stolon length and tuber roots showed variations within and among cultivars. Also a relationship between the length of the stolon and yield of tubers was found. The strongest correlations involved from the stolon length and the tuber roots with the increase in tuber yield under the improved cultivars, then the local cultivar with the decrease in yield. These correlations were positive: the higher the value of the parameter, the greater the observed increase in yield with improved cultivars. This showed a relationship between stolon length and tuber roots with the increase of yield; this relationship was stronger for roots in improved cultivars than in the local cultivar. Therefore, this study indicates that improved potato cultivars with deep root systems might improve tuber yields in eastern highlands of Ethiopia.

Economic injury levels for the potato yellow vein disease and its vector, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), affecting potato crops in the Andes

The Economic Injury Level (EIL) for pest insects is conventionally expressed in terms of the number of insects, because the level of pest injury to plants is usually difficult to quantify. However, when insect injury is mainly caused indirectly by transmission of plant pathogens, the number of insects may not be an ideal measure to calculate the EIL. The greenhouse whitefly (GWF) Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is the only known vector of the Potato yellow vein virus (PYVV), the causal agent of potato yellow vein disease (PYVD), but the direct injury caused by insect feeding may not be significant since potato is not a preferred host for the GWF. Here, we quantified the effect of GWF feeding and PYVD incidence on potato yield, as compared to potato market value and control costs to determine the EIL for this system. We found that the direct injury caused by GWF feeding does not affect potato yield. However, an exponential reduction in crop yield was observed with the increase of PYVD incidence. Thus, the criteria to decide upon applying a control measure ranges between 100 and 1200 infected plants/ha depending mainly on potato market price. We suggest that disease incidence should be used to calculate the EIL for PYVD management, instead of focusing on estimations of vector population size. Furthermore, we stress that potato market price is fundamental in defining an appropriate, case specific EIL for decision-making in PYVD management.

Use of Nurse Crops in Potato Production to Protect Soils from Erosion

Because potatoes emerge slowly following planting, soils are susceptible to erosion. Planting a fast emerging nurse crop as a short-term cover crop could reduce potential soil erosion. In 2016 and 2017, research was conducted to address nurse crop seeding rates, necessity to kill the nurse crop with an herbicide, and optimal nurse crop growth period before destroying it through hilling. Winter rye (Secale cereale L.) plots were sown at 2.5 and 5 million seeds ha−1, hilled or killed with herbicide prior to one-pass hilling, and allowed to grow for approximately three or four weeks. Allowing nurse crops to grow four weeks without use of an herbicide prior to hilling appeared to reduce yields one year in two. Grown for three weeks, nurse crops provided effective soil protection and did not affect potato yield or nitrogen status at either seeding rate with or without herbicide use.

Selectivity of pre-emergence herbicides in potato cv. Innovator

ABSTRACT Herbicide tolerance differs among potato cultivars. Thus, pre-emergence herbicides in potatoes need to be studied. We evaluated weed control, selectivity and potato yield of cv. Innovator with the herbicides clomazone, metribuzin and linuron. The experimental design was randomized blocks with four replications. One experiment was installed in 2014 (experiment 1, 5 treatments) and another in 2015 (experiment 2, 7 treatments), irrigated by central pivot in Perdizes-MG, Brazil. In experiment 1 treatments consisted of a control (T1), a hoed control (T2), clomazone (360 g ha-1) (T3), metribuzin (480 g ha-1) (T4), and linuron (990 g ha-1) (T5). The treatments in experiment 2 repeated those in experiment 1 (T1 to T5) and added clomazone + metribuzin (360 + 480 g ha-1)) (T6), and clomazone + linuron (360 + 990 g ha-1) (T7). We determined the number of stems per meter, length of longest stems, phytotoxicity, weed control, soluble solids content (%), yield and classification of tubers. The herbicides, either by themselves or in combination with another herbicide, provided 100% control of Eleusine indica and Digitaria horizontalis. Clomazone by itself or in combination with metribuzin or linuron provided the best control of Commelina benghalensis. Plots treated with clomazone presented phytotoxicity symptoms at 10 days after emergence (DAE); however, the plants recovered from these symptoms at 30 DAE. Metribuzin reduced soluble solids content, which affects industrial yield. The herbicides significantly influenced potato yield. In, 2014, the greatest “total” yields were observed in treatments with linuron (34.48 g ha-1) while the greatest “special” potato yields were achieved with clomazone (20.21 g ha-1) and linuron (21.13 g ha-1). In 2015, the greatest “total” yields were observed in treatments with clomazone [“special” (20.98 t ha-1) and “total” (35.11 t ha-1)] and metribuzin [“special” (20.85 t ha-1) and “total” (35.45 g ha-1)] followed by clomazone+linuron (30.95 g ha-1). Therefore, while metribuzin and linuron controlled Eleusine indica and Digitaria horizontalis, they may also reduce potato quality. Clomazone may be an option for controlling Eleusine indica, Digitaria horizontalis and Commelina benghalensis without affecting potato yield and soluble solids content.

Nitrogen and phosphorous uptake by potato (Solanum tuberosum L.) and their use efficiency under potato-legume intercropping systems

Competition for nitrogen (N) and phosphorous (P) under potato-based intercropping systems decreases the level of nutrients available for potato and subsequently influences nitrogen and phosphorous use efficiency. A field trial was conducted for four consecutive seasons between 2014 short rains and 2016 long rains to assess the effect of incorporating legumes as intercrops into potato cropping systems on N and P uptake and uptake efficiency by the potato crop and nutrient use efficiency. The treatments included potato intercropped with either dolichos (Lablab purpureus L.) (PD), garden pea (Pisum sativum L.) (PG) or climbing bean (Phaseolus vulgaris L.) (PB), and a pure stand of potato (PS). Intercropping potato with beans and peas significantly reduced its N uptake by 22 and 27% relative to PS, but the N uptake was not affected under PD. Phosphorous uptake was 2, 8 and 11 kg P ha−1 lower in PD, PB and PG, respectively compared with PS. Nitrogen use efficiency (NUE) was significantly higher in PD, PB and PG by 30, 19 and 9% compared with PS. Similarly, P use efficiency (PUE) was 6, 14 and 21% higher in PG, PB and PD, respectively than PS. The highest tuber yield recorded in PS (36 t ha−1) did not significantly differ from PD (34 t ha−1) whereas tuber yield was significantly lower in PB and PG as compared with PS. The study shows the great potential of dolichos as a promising intercrop that could be integrated into potato cropping systems without negatively affecting potato yield.

Differences in size and architecture of the potato cultivars root system and their tolerance to drought stress

Drought can cause substantial yield losses, particularly for crops with shallow root systems, such as potato (Solanum tuberosum). This study tested whether root system architecture could affect potato yield under drought conditions. The following parameters of the roots were measured: depth range, total length, total area, surface area, average diameter, and total dry weight of the root system. These parameters in soil layers were also measured at different depths. Five potato cultivars from a group of mid-early cultivars were examined in this study. The same cultivars were tested under two conditions: control with optimal irrigation and drought stress treatment without irrigation for three weeks after the end of tuberization to check the tuber yield. Significant differences were observed among cultivars in the size of the root system and its architecture. The biggest differences in the individual layers of soil profile related to the diameter of the root, the root length, and the surface area. Also a relationship between the size of the root system and yield of tubers was found. The strongest correlations involved the root length and the root surface area with the decrease in tuber yield under the drought, then the dry root mass with the decrease in yield. These correlations were negative: the higher the value of the parameter, the smaller the observed decrease in yield. This showed a relationship between root length and mass with the decrease of yield; this relationship was stronger for roots in deeper layers than in the shallowest layers. Therefore, this study indicates that breeding potato cultivars with deep root systems might improve tuber yields under drought conditions.

Seed Piece Spacing for Spring Chipping Potato Cultivars in Florida

The cost of seed accounts for nearly 10% of the estimated production cost of chipping potato (Solanum tuberosum) production in Florida. Optimizing seed piece spacing can reduce costs without affecting potato yield. This study evaluated the effects of seed piece spacing on yield, quality, and economic revenue of chipping potato production in north Florida. A field experiment was conduct during the spring of 2013, 2014, and 2016 in Hastings, FL, with a split-plot randomized complete block design. In-row seed piece spacings of 10, 15, 20 (industry standard), 25, and 30 cm were assigned as the main plot and S. tuberosum potato cultivars (Atlantic, Harley Blackwell, and Elkton) as the subplots. Marketable tuber yield ranged between 10.8 and 15.2 Mg·ha−1 in 2013, 10.1 and 12.8 Mg·ha−1 in 2014, and 9.9 and 19.7 Mg·ha−1 in 2016. Overall lower yields in 2013 were due to three freeze events early in the season. Widening seed piece spacing resulted in a linear decrease in total and marketable yield in 2013 and 2014. Conversely, seed piece spacings of 10 and 15 cm showed lower marketable yields in 2016. There was no interaction between in-row spacing and cultivar in any year tested. Cultivars performed variably across years for total and marketable yield and specific gravity. Tuber specific gravity was unaffected by seed piece spacing, except in 2013, when 25 and 30 cm resulted in slightly higher values. There was no significant difference in total and marketable yield between the industry standard seed piece spacing 20 and 25 cm in any year. In-row spacing of 25 cm in 2013 and 30 cm seed piece spacing in 2014 and 2016 provided the greatest economic return. Net revenue can be increased by adjusting the in-row seed piece spacing from the commercial standard of 20 to 25 cm, which reduces production cost without negatively impacting yields.

Expression profiling of potato cultivars with contrasting tuberization at elevated temperature using microarray analysis

Temperature is one of the most significant factors affecting potato yield. Night temperature beyond 18–22 °C drastically reduces tuber formation, constraining potato cultivation in tropics and subtropics. Identification of genes and pathways affected by high temperature is crucial for developing thermo tolerant cultivars for these regions. In the present study, two cultivars with contrasting tuberization behavior at night temperatures (24 °C) were selected for gene expression analysis using a customized microarray chip representing 39,031 potato genes. A total of 2500 genes were differentially expressed on 21 d and 4096 genes on 14 d after stress. Gene ontology and pathway analysis provided insights into the probable biological processes and pathways governing tuberization at elevated temperature. Pathway maps were constructed to graphically represent the gene expression patterns. Genes associated with photosynthesis, hormonal activity, sugar transporters and transcription factors were differentially expressed. The results are presented and discussed in terms of tuberization at high temperature. The effect of high temperature on expression of genes controlling tuberization was also analyzed. This study provided useful information on potato tuberization at elevated temperature and make available a framework for further investigations into heat stress in potato.

EROSI DAN KEHILANGAN HARA PADA PERTANAMAN KENTANG DENGAN BEBERAPA SISTEM GULUDAN PADA ANDISOL DI HULU DAS MERAO, KABUPATEN KERINCI, JAMBI

This research was aimed to study alternative techniques for soil conservation in controlling erosion and nutirients lost from Andisol planted with potatoes in upper part of Merao watershed, in Kerinci Region, Jambi Province. The research was conducted in Kebun Baru, Kayu Aro, Kerinci. The soil and sediment samples were analysed at Soil and Land Resource Laboratory, Agriculture Faculty, Institute Pertanian Bogor. Erosion was measured on small plots consisting of seven (7) treatments and three (3) replications considered as blocks. The results showed that planting potatoes across the slope direction, or making soil bed across 15% slope, or soil bed as slope direction and across slope direction every 4.5 m distance could control erosion and nutrients lost, and did not affect potato yield compared to soil bed as slope direction. Planting potatoes on soil bed as slope and across slope direction in each 4,5 m distance (modified farmers model) reduced erosion, soil organic-C, and total-N lost for 65.89, 65.19, and 24.55%, respectively, compared to planting as slope direction. Keywords: erosion, nutrient lost, sedimentation

Effect of Weed Emergence Time and Intervals of Weed and Crop Competition on Potato Yield

A field study was conducted at Vezaiciai branch of the Lithuanian Institute of Agriculture from 1998 to 2000 to determine weed emergence dynamics in potato and to estimate the effect of different intervals of weed crop competition on potato tuber yield if regular interrow cultivation was applied. Treatments varying in intervals of weed-free conditions and competition were laid out in a randomized complete block design with six replications. The greatest emergence of annual broadleaf such as common lambsquarters and other weeds (62 to 86% of the season total) in the crop was observed in the period from potato planting until flowering. Emergence of winter annuals such as field violet and scentless mayweed was greatest in the period from the 20-cm potato plant height until harvesting. The 20-cm potato height was the most important stage affecting potato yield loss due to weed competition. Potato yield losses due to weed competition were minimized when weeds were removed before the potatoes reached 20 cm or k...

The effect of irrigation and nitrogen on powdery scab and yield of potatoes

Powdery scab, caused by the fungusSpongospora subterranea, has developed in the Cappodocia region of Turkey because of changes in agronomic practices, such as excessive irrigation and nitrogen fertilizer use and growth of highly susceptible cultivars. The most suitable irrigation and nitrogen application levels were established to maintain powdery scab at minimum levels without affecting potato yield. Three irrigation levels were used in 1998 (673, 897, 1121 mm) and five in 1999 (329, 494, 658, 823, 987 mm). Nitrogen levels were applied 150, 300, 450, 600 kg N ha−1. In 1998, least powdery scab occurred with 673 mm irrigation, which yielded 41 t ha−1 potatoes. The lowest disease severity occurred in 1999 with 494 mm irrigation and 150 kg N ha−1. At these levels, tuber yield was 34 t ha−1 which was not significantly different from the highest yield measured. In 1999 and at two of the three irrigation levels inl998, nitrogen increased disease severity.