Home About us Contact
|
Home About us Contact | ||
|
|
||
Fruit Yield (fruit + yield)
Selected AbstractsResponse of Black Nightshade (Solanum nigrum L.) to Phosphorus ApplicationJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2000M. M. A. Khan A pot experiment was conducted to study the effect of phosphorus (P) on the vegetative and reproductive growth of black nightshade (Solanum nigrum L.). Single superphosphate was applied at 0, 0.15, 0.30, 0.45, 0.60 and 0.75 g P/pot containing 3.5 kg of soil. Seeds were sown directly in pots and plant samples were taken at fortnightly intervals for recording growth and yield parameters. In addition, the solasodine content in fruit and N, P and K levels in leaves were also estimated. Most parameters were significantly influenced by P, with0.45 g/pot generally proving optimal. The data also established that the berries should be harvested between 160 and 190 days (days after sowing), preferably at 175 days for maximum fruit yield and solasodine production. Most parameters showed consistent and positive correlations with leaf P content. Interestingly, the correlation between leaf P content at 40 days and solasodine yield at 175 days was highly significant (r = 0.888), implying that the former is predictive of the latter. Thus, if low leaf P content was noted at 40 days corrective measures like foliar application or top dressing may be adopted to increase the leaf P content to ensure maximum solasodine at harvest. Zusammenfassung Es wurde ein Gefäßexperiment mit Nachtschatten (Solanum nigrum L.) durchgeführt, um den Einfluß von Phosphor (P) auf das vegetative und reproduktive Wachstum zu untersuchen. Einfach-Superphosphat wurde mit Mengen von 0, 0,15, 0,30, 0,45, 0,60 und 0,75 gP/Gefäß mit 3,5 kg Boden angewendet. Die Samen wurden direkt in die Gefäße ausgesät und die Pflanzenproben wurden 14-tägig für Untersuchungen hinsichtlich Wachstum und Ertragsparameter genommen. Zusätzlich wurde der Solasodine-Gehalt in der Frucht sowie N, P und K in den Blättern bestimmt. Die meisten Parameter waren sig-nifikant beeinflußt durch P, wobei sich 0,45 g/Gefäß als optimal erwies. Die Ergebnisse zeigen, daß die Beeren 160,190 d (Tage nach der Aussaat), am günstigsten 175 Tage, für maximalen Fruchtertrag und Solasodine-Produktion zu ernten sind. Die meisten Parameter zeigten konsistente und positive Korrelationen mit dem Blatt-P-Gehalt. Es ist interessant, daß die Korrelation zwischen Blatt-P-Gehalt nach 40 Tagen sowie Solasodine-Ertrag nach 175 Tagen hochsignifikant war (r = 0,888), was für eine Zeitvoraussage genutzt werden kann. Es erscheint daher möglich, falls geringer Blatt-P-Gehalt nach 40 Tagen festgestellt wird, Blattanwendungen oder Düngungen zur Erhöhung des Blatt-P-Gehaltes vorzunehmen, um ein Maximum an Solasodine zur Ernte zu erreichen. [source] Evaluation of methods to control Phytonemus pallidus and Anthonomus rubi in organic strawberry productionJOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2007R. Berglund Abstract:, Use of the predatory mite Neoseiulus cucumeris (Oudemans) (Acari, Phytoseiidae) and a fleece cover in combination with pyrethrum application showed potential for control of two important pests in organic production of strawberry (Fragaria × ananassa Duch.), although there were some unexpected interactions between pyrethrum and the release of N. cucumeris that need to be investigated further. Two cultivars, Honeoye and Cavendish, were treated with pyrethrum with or without fleece to control strawberry blossom weevils [Anthonomus rubi Herbst. (Col., Curculionidae)] and N. cucumeris was released to control strawberry mites [Phytonemus pallidus (Banks) (Acari, Tarsonemidae)]. Number of strawberry mites, number of flower buds damaged by the weevil, incidence of grey mould and powdery mildew, and fruit yield were measured in two consecutive fruiting seasons. In Honeoye, the fleece in combination with pyrethrum decreased the proportion of damaged buds by 11,23% and increased yield by 49,91 g per plant. When pyrethrum was used alone it did not influence the number of damaged buds or yield. This indicates that the combined treatment was more effective because of the fleece. In Cavendish, the fleece and pyrethrum treatments were not found to be effective. Almost no P. pallidus was found in Honeoye and the results were not analysable. In plots with Cavendish where N. cucumeris had been released, there were approximately 50% fewer P. pallidus from the end of August onwards in 2003. However, this response did not significantly influence the succeeding year's yield. The number of fruits infected with fungi was very low and no effects were observed for any of the treatments. [source] Effects of nitrate-, ammonium-, and organic-nitrogen-based fertilizers on growth and yield of tomatoesJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2005Anuschka Heeb Abstract Mineral and organic fertilizers contain different forms and amounts of nitrogen (N), which can affect yield and product quality. The aim of this study was to determine appropriate amounts of N applied as nitrate (NO), ammonium (NH), and organic N (a mixture based on chicken manure) for optimal growth and quality of tomatoes. A pot experiment with sand as substrate was established in a greenhouse with six-week-old tomato plants (Lycopersicon esculentum Mill. cv. "Armada"). Nitrogen was applied in nutrient solutions at different NO : NH ratios combined with different chloride levels (NO -dominated, NO = NH at low Cl,, NO = NH at high Cl,, and NH -dominated, respectively) or as organic N at four N-application rates (250, 500, 750, 1000 mg N plant,1 week,1). No significant differences in shoot biomass and yields of red tomatoes were observed between NO - or NH -fed plants. Nitrogen rates above 750 mg N plant,1 week,1 did not significantly increase marketable fruit yield, but enhanced shoot-biomass production. The NH -N-dominated treatments (which also had high Cl, concentrations) showed increasing incidence of blossom-end-rot (BER)-infected fruits. In the organic-N treatments, shoot-biomass production and yields were lower than in the inorganic-N treatments, but fruit quality was good with few BER-infected fruits. The results show that with a total N supply below 750 mg N plant,1 week,1, NH can be used as equivalent N source to NO, resulting in equivalent yields of marketable fruit under the conditions in this experiment. Einfluss von Nitrat, Ammonium und organischem Stickstoff auf Wachstum und Ertrag von Tomaten Mineralische und organische Dünger enthalten verschiedene Formen von und Mengen an Stickstoff (N), welche den Ernteertrag und die Produktqualität beeinflussen können. Das Ziel dieser Arbeit war es, geeignete N-Mengen , appliziert als Nitrat, Ammonium oder organischer Stickstoff , für optimales Wachstum und Qualität von Tomaten zu bestimmen. Dazu wurde mit sechs Wochen alten Tomatenpflanzen (Lycopersicon esculentum Mill. cv. "Armada") unter Gewächshausbedingungen mit Sand als Substrat ein Gefäßversuch angelegt. Die Applikation von N erfolgte in Form von Nährlösungen mit verschiedenen NO:NH -Verhältnissen, kombiniert mit unterschiedlichen Chlorid (Cl)-Konzentrationen (NO -dominiert, NO = NH bei niedrigem Cl,, NO = NH bei hohem Cl, und NH -dominiert) bzw. als organischer N. Jede dieser Behandlungen wurde mit vier verschiedenen N-Mengen angelegt (250, 500, 750, 1000 mg N Pflanze,1 Woche,1). Zwischen den mit Nitrat und Ammonium gedüngten Pflanzen konnte kein signifikanter Unterschied in Sprosswachstum und Ertrag an erntereifen Tomaten festgestellt werden. Stickstoffmengen über 750 mg N Pflanze,1 Woche,1 steigerten den Ertrag verkaufsfähiger Tomaten nicht signifikant, obwohl die Produktion an Sprossbiomasse noch anstieg. In den NH -dominiert gedüngten Gefäßen mit gleichzeitig hohen Cl-Konzentrationen in den Nährlösungen wurden häufiger Tomaten mit Blütenendfäule beobachtet. In den Behandlungen mit organischem Stickstoff waren die Sprossbiomasseproduktion und der Ertrag geringer als in den mineralisch gedüngten Behandlungen, aber die Qualität der Früchte war gut, mit nur wenigen durch Blütenendfäule geschädigten Tomaten. Die Ergebnisse zeigen, dass bei einer Stickstoffversorgung unter 750 mg N Pflanze,1 Woche,1 Ammonium anstelle von Nitrat verwendet werden kann. Im vorliegenden Versuch wurden unter diesen Bedingungen vergleichbare Erträge verkaufsfähiger Früchte erzielt. [source] Fruit quality of mini-watermelon as affected by grafting and irrigation regimesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2008Simona Proietti Abstract BACKGROUND: The Mediterranean region suffers water deficit that affects fruit yield and quality. Grafting improves crop tolerance to disease and drought, but the taste and quality of fruit may be negatively affected. The aim of the present work was to determine the quality parameters of mini-watermelon, ungrafted or grafted onto a squash hybrid rootstock, and grown under different irrigation regimes: 1.0, 0.75, and 0.5 of evapotranspiration (ET) rates. RESULTS: The interaction between grafting and irrigation rate was not significant for the variables tested. The highest fruit yields were recorded at 1.0 ET and at 0.75 ET with respect to 0.5 ET, and they were obtained in grafted plants. Fruit quality was slightly affected by drought, with an increase in K, Mg and spermine concentrations, especially with 0.5 ET. Nitrate concentration in the watermelon pulp was very low (average 10 mg kg,1 fresh weight). Fruit quality parameters were similar in grafted and ungrafted plants, whereas the titratable acidity (TA), juice electrical conductivity, TSS/TA ratio, K and Mg concentrations were improved in the grafted one. Lycopene, dehydroascorbate (DAscA) and total vitamin C contents for grafted plants were higher by 40.5%, 13% and 7.3%, respectively, than those from ungrafted plants. Spermidine and putrescine concentrations were reduced by grafting (by 24% and 59%, respectively). CONCLUSION: Grafting of mini-watermelon under irrigation deficit did not modify crop response to water availability, but increased productivity and induced small positive changes in plant quality and nutritional value. Copyright © 2008 Society of Chemical Industry [source] Replacing methyl bromide in annual strawberry production with glucosinolate-containing green manure crops,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2003Luca Lazzeri Abstract The use of biocidal green manure crops is an agronomic technique for amending soil with fresh organic matter containing volatile compounds active in controlling some soil-borne pests and diseases. Two new selections of the Brassicaceae family were cultivated, incorporated before planting strawberries and tested as an alternative to fumigation with methyl bromide. Two biocidal green manure crops (Brassica juncea L sel ISCI20, Eruca sativa Mill cv Nemat) containing glucosinolate,myrosinase systems, a conventional green manure (barley), untreated soil and a fumigated control were evaluated during two seasons. The effect of these soil management systems on subsequent strawberry performance was evaluated by monitoring yield and plant growth parameters. In both years, biocidal plant green manure treatments led to a fruit yield lower than with methyl bromide, but higher than with conventional green manure or untreated soil. These results confirm the good prospects for biocidal green manures, not only as an environmentally friendly alternative to methyl bromide in conventional agriculture, but also in organic agriculture as an alternative to conventional green manure crops. Copyright © 2003 Society of Chemical Industry [source] Pyriproxyfen controls silverleaf whitefly, Bemisia tabaci (Gennadius), biotype B (Homoptera: Aleyrodidae) (SLW) better than buprofezin in bitter melons Momordica charantia L. (Cucurbitaceae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2009Mohammad S Qureshi Abstract To improve compatibility between chemical and biological controls, the use of selective insecticides such as insect growth regulators (IGRs) is crucial. In cucurbits, the use of pyriproxyfen (an IGR) has been shown by others to be an effective method of reducing the number of sap-sucking insects, especially silverleaf whitefly, Bemisia tabaci (Gennadius) Biotype B (SLW). Therefore, we compared pyriproxyfen and buprofezin (an IGR) with that of no treatment (control) in a bitter melon crop for the control of populations of SLW and for their effects on fruit production. Pyriproxyfen controlled SLW and tended to have heavier fruits than the control treatment and reduced the abundance of nymphs and exuvia. Buprofezin showed no evidence in controlling SLW compared with the pyriproxyfen and control treatments. Neither pyriproxyfen nor buprofezin had any effect on the number of harvested fruit or overall fruit yield, but the average weight per fruit was higher than the control treatment. Pyriproxyfen was effective in controlling whitefly populations in bitter melons, and both pyriproxyfen and buprofezin may have the potential to increase yield. Their longer-term use may increase predation by natural enemies as they are species-specific and could favour build up of natural enemies of SLW. Thus, the judicious use of pyriproxyfen may provide an effective alternative to broad-spectrum insecticides in small-scale cucurbit production. [source] Vine vigour effects on leaf gas exchange and resource utilisationAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2010A. ZERIHUN Abstract Background and Aims:, Variability in vine vigour is a commonly observed feature in vineyard blocks. Although this aspect is well recognised among viticulturalists, impacts of vigour variability on vine function and resource use efficiency are seldom considered in management decision-making. This study examined influences of vine vigour variability on vine physiological performance and resource use in a commercially managed vineyard block. Methods and Results:, The vineyard block was divided into different vigour zones using plant cell density data derived from aerial multi-spectral imaging of the study block. Gas exchange and under-vine soil moisture status were measured in some of the vigour zones. Low vigour vines had consistently lower photosynthesis and stomatal conductance rates than high vigour vines. The differences were evident both during soil-drying and rewetting. Similarly, irrigation water utilisation was markedly lower in low than in high vigour vines. Vine fruit yield was linearly and positively related to vines' capacity to utilise applied water. Conclusions:, Vigour has considerable influence on vine physiological performance and on resource utilisation capacity. Uniform irrigation application to a block with variable vigour (which is the norm currently) leads to spatially inefficient resource use, and consequently to a marked within-block variation in irrigation water productivity. Significance of the Study:, The demonstration that variation in vigour has a corresponding effect on resource utilisation has direct relevance for managing vineyard inputs such as irrigation or fertilisers. [source] | ||||||||||||||||