No abstract available

[en] Crop development of feijoa (Acca sellowiana (O. Berg) Burret) is mainly stimulated by temperature, but is also affected by other climatic factors. The determination of the development in terms of thermal time or growing degree days (GDD) is more precise than calendar days. The aim of this study was to propose a phenological model for feijoa cv. Quimba, in which the base temperature (Tb) for four different phenological stages and its duration in terms of GDD is estimated to predict the timing of anthesis, fruit setting and harvesting. During the years 2012 to 2014, in two localities of the department of Cundinamarca, Colombia, twenty trees per farm were labeled, dates of occurrence of phenological stages, starting from floral button were recorded. Tb was estimated using the method of minimum coefficient of variation, as well as duration of the four reproductive phenological stages in terms of GDD. The results showed that Tb and GDD vary depending on the stage of development of the crop; in general, an average of 2651 GDD and 189 days is required to reach the flower bud to the fruit harvest. The parameters of the regression analysis showed that the model successfully predicted phenological stages when estimated Tb for each of them was used, with high determination coefficient. Cross-validation showed good statistical fit between predicted and observed values; intercept was not significantly different from zero (p <0.05) and the slope was statistically equal to one.

[en] Andromonoecious Jatropha curcas (Jatropha) has male and hermaphrodite flowers in one inflorescence. Jatropha is a potential source for biofuel raw material. The development of this plant has various constraints, such as lower fruit set that causes low seed productivity. The existence of andromonoecious Jatropha with high fruit set provides a great opportunity to overcome the obstacles. Understanding floral biology is a requirement for developing a high fruit set andromonoecious Jatropha. This study was aimed at understanding the flower's characteristics and phenology. The andromonoecious Jatropha flower's characteristics, number and viability of pollen, and phenology were observed and compared to those of monoecious Jatropha. Andromonoecious Jatropha had inflorescence with a dichasial cyme pattern. An inflorescence produced two main branches and several secondary and tertiary branches, where a hermaphrodite flower was found at whose ends. The number of inflorescence branches in andromonoecious Jatropha was higher than that of monoecious Jatropha. The diameter and size of the sepal and stalk in hermaphrodite flowers were found to be larger than those in male and female flowers. The development of andromonoecious Jatropha flowers was divided into 4 phases, namely initiation (0-3 dai = days after initiation), small bud (3-7 dai), large bud (7-20 dai), and flower blooming (20-39 dai) phases. The anthesis and anther dehiscence of hermaphrodite flowers occurred at the same time between 06:00 to 06:59 am, facilitating self-pollination of the hermaphrodite flowers. The average pollen viability during the anthesis phase was 96.26%, and 88.79% of them survived until the next day. (author)

[en] The objective of the present study is to apply different systems of fertigation (rainfed, R; surface drip irrigation, DI, and subsurface drip irrigation, SDI) in Vitis vinifera (L.) cv. ‘Albariño’ to evaluate the cumulative effect of water stress (water stress integral) on yield parameters and to establish the relationship between indices and production. The study was conducted over four years (2010-2013) in a commercial vineyard (Galicia, NW Spain). The volumetric soil water content (θ) (with TDR) and predawn (ψp), midday (ψm) and stem (ψstem) leaf-water potential were determined with a water activity meter during the growing stages (flowering-harvest) from 2010-2013. The number of clusters, their weight and yield/vine were determined at harvest. Must composition was studied to evaluate nutrition treatments. Ψp is presented as the best indicator of the water status of the plant, and the sole use of θ is not recommended as a reference. The soil-plant water status variables were strongly correlated, especially between foliar variables (0.91< R2<0.98), with θ presenting the lowest reliability (0.28< R2<0.81). SDI was the treatment with the highest hydric comfort and greater yield/vine (6.1 kg) and weight per cluster (95.0 g), but lower elements concentration in must. The water stress integral showed that the veraison and harvest stages were very sensitive to water stress in vines. Linear relationships were established between Sψp and W (R2=0.65) and Y (R2=0.56) at veraison. The water stress integral is presented as a useful working tool for vine growers because it allows the prediction of future yield at early phenological states. (Author)

[en] Argania spinosa in its ecological interest is threefold: forest, forage and fruit (oil production). The regeneration of the argan tree, it is important to know the phenology of this species. The study of phenology helps to know precisely the periods of activity of vegetation for productivity measures (Embryogenesis of the pollen grain, pollen deposition, pollen adhesion, fluorescence microscopy of pollen tube growth and Pollen grain size). Our results on the study of the phenology of two taxa of Argania spinosa (Mascara taxa and Mostaganem taxa), Regarding the phenological behavior of the argan under the effect of environmental conditions, we can mention that some argan trees (of Oggaz and one of Stidia) are early trees bloom twice a year in October and in spring, the author trees are late trees manifest activity during periods of the year. Begin to bloom from February until spring, this period is characterized by the breakdown of flower buds and the appearance of flowers on the twigs of the previous year and those of the current year; the fall of their ripe fruit takes place in Jun of the following year. Argan trees wore two generations of fruit, fruit knotted this season and last season tied fruit maturing. The length of the cycle is detected 9 and 16 months, we believe that a time synchronization in the evolution of physiological behavior argan trees of the two stations with 90 percentage. (author)

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No abstract available

[en] Phenology deals with timing of biotic phenomena and seasonality concerns temporal patterns of abiotic variables. Studies of land surface phenology (LSP) and land surface seasonality (LSS) have long been limited to visible to near infrared (VNIR) wavelengths, despite degradation by atmospheric effects and solar illumination constraints. Enhanced land surface parameters derived from passive microwave data enable improved temporal monitoring of agricultural land surface dynamics compared to the vegetation index data available from VNIR data. LSPs and LSSs in grain growing regions of the Volga River Basin of Russia and the spring wheat belts of the USA and Canada were characterized using AMSR-E enhanced land surface parameters for the period from April through October for 2003 through 2010. Growing degree-days (GDDs) were calculated from AMSR-E air temperature retrievals using both ascending and descending passes with a base of 0 ° C and then accumulated (AGDD) with an annual restart each 1 April. Tracking the AMSR-E parameters as a function of AGDD revealed the expected seasonal pattern of thermal limitation in mid-latitude croplands. Vegetation optical depth (VOD), a microwave analog of a vegetation index, was modeled as a function of AGDD with the resulting fitted convex quadratic models yielding both high coefficients of determination (r² > 0.90) and phenometrics that could characterize cropland differences between the Russian and North American sites. The AMSR-E data were also able to capture the effects of the 2010 heat wave that devastated grain production in European Russia. These results showed the potential of AMSR-E in monitoring and modeling cropland dynamics. (letter)

[en] In order to study the allelopathic effects of rice straw on different weeds and crops, a lab experiment was conducted at the Weed Science Laboratory, Institute of Plant Environmental Protection, National Agricultural Research Center, Islamabad during 2007 with a factorial arrangement (species and extract concentration) to evaluate the allelopathic effect of various concentrations of rice straw extract on germination percent, mortality percent, and days to germination of different test plants. The rice plants (Basmati super) were collected from experimental fields of National Agricultural Research Center, Islamabad. The samples were put into water for 48 hours after getting them cleaned, dried, and ground for obtaining the extract. The rice stems and leaves were used for the extraction and concentrations of 0, 50 and 100% rice straw extracts were used for the bioassay. A total of 90 Petri dishes were sterilized in autoclave at 110 -120 degree C for 1 hour. Two filter papers were kept in each Petri dish and ten seeds of each test plant were placed in each Petri dish. All the experimental Petri dishes were kept at room temperature of 20 degree C for 15 days. The results uncovered that 100% rice straw extract convincingly decreased the germination and growth of the test plants, in comparison with the 0 and 50% rice straw extracts. Among the crop plants, Gossypium hirsutum; and among the weeds, Ipomoea batatas, Rumex dentatus and Convolvulus arvensis were mostly affected by the rice straw extracts whereas Helianthus annuus, Zea mays, Oryza sativa and Vigna radiata were somewhat resistant to rice straw extract concentrations. Hence, it has been concluded from the results that rice straw can prove to be a good alternative and environment friendly bio-herbicide for weed management in crops. (author)

[en] Effects of planting time on phenology of five strawberry genotypes Sweet Charlie, Festival, Camarosa, FA 008, and BARI strawberry-1 were evaluated at Bangladesh Agricultural Research Institute in two consecutive years 2009-2010 and 2010-2011. Sweet Charlie took the shorter time to begin flowering, followed by BARI Strawberry-1 and Festival when planted in 1st October. Genotype FA 008 took longer time to flower when planted in 1st December. Days to flowering of all the varieties was found to decrease with the increase in air temperature. Regardless of planting year, the genotype FA 005 followed by Camarosa and Festival, planted on 1st September, exhibited the longest harvest duration, while Sweet Charlie planted on 1st December exhibited the shortest harvest duration in both years. Genotype Festival planted on October yielded fruit with the greatest fruit weight, followed by Sweet Charlie and Camarosa planted on the same date. Plants of FA 008 and BARI Strawberry-1 planted in December produced minimum fruit weight. Maximum number of fruits/plant as well as yield/plant obtained from Sweet Charlie planted in October, while BARI Strawberry-1 planted in December yielded the least. With the use of quadratic equation it was estimated that maximum yield was obtained at ambient temperature 18.5 degree C then it was decreased with the increase of temperature. Strawberry planted in early October was found to be the most suitable in Bangladesh. Among the studied genotypes, Sweet Charlie was found to be superior in yield and early planting, and Camarosa was suitable for late planting. Festival was found less sensitive to planting date. (author)