[en] The study was a response to the need from Katumani DFRC and Njoro (NPBC) Crop protection team request for support service in identification of weed spp. in their mandated areas. From their ongoing adaptive research they encountered ceratin weed spp. which were troublesome and they could not identify and their contact farmers had expressed concern over the weed constraint. A survey in the mentioned areas were carried out in the long/short rains 1997. In the fields, the sites were selected after every 10 km. The field selected was traversed and a quadrat measuring 1m² was placed randomly and weeds identified. General Position System (GPS) recorded the position. Two methods of identifying weeds thus on the spot in the field in situ and unidentified weed samples were carefully collected, labelled and preserved for identification in the laboratory of NARL herbarium. Weed distribution was determined using scale 1-4 where 1=1 plant/M², 2=2-5 plants/m², 3=6-20 plants/m²,4=>20 plants^m/2. The results show identified weeds in different categories; dominant, troublesome, indigenous and weed introduced within the ten years as percieved by farmers. Developed weed maps are presented for specific districts

[en] Aim of study: The study aims to evaluate the maximum potential stocking level in cork oak (Quercus suber L.) woodlands, using the ecologically-based size-density relationship of the self-thinning law. Area of study: The study area refers to cork oak forests in mainland Portugal, distributed along its 18 districts from north to south. Material and Methods: A dataset with a total of 2181 observations regarding pure cork oak stands was collected from the Portuguese Forest Inventory (NFI) databases and from research plots. The dataset was subjected to two filtering procedures, one more restrictive than the other, to select the stands presenting the higher stocking values. The two resulting subsets, with 116 and 36 observations, from 16 and 10 districts of mainland Portugal, respectively, were then used to assess and describe the allometric relationship between tree number and their mean diameter. Main results: The allometric relationship was analysed and modelled using the log transformed variables. A slightly curvilinear trend was identified. Thus, a straight line and a curve were both fitted for comparison purposes. Goodness-of-fit statistics point out for a good performance when the data is set to the uppermost observed stocking values. A self-thinning line for cork oak was projected from the estimated relationship. Research highlights: The self-thinning model can be used as an ecological approach to develop density guidelines for oak woodlands in a scenario of increasing cork demands. The results indicate that the recommendations being applied in Portugal are far below the maximal potential stocking values for the species. It is therefore of the utmost importance to review the traditional silvicultural guidelines and endorse new ones.

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[en] The new challenges of modern agriculture to feed the world will rely more and more on science and technological innovation, particularly that derived from 'omics' disciplines, and the speed with which these new techniques will reach the farm.

[en] Development of superior crop cultivars is ultimate goal of plant breeders. New variety of pearl millet 'Sargodha Bajra-2011' was evolved at Fodder Research Institute Sargodha. After obtaining a uniform type of plants, the new variety was evaluated. On the basis of its high green fodder yield, the new variety was tested in Station Yield Trials (SYT) during 2003, 2004 and 2005. Simultaneously: it was also evaluated in different ecological zones throughout the Punjab during the years 2005. It was evaluated in Notational Uniform Fodder Yield Trials (NUFYT) during the years 2004, 2005 and 2006. In SYT, it produced fodder yield of 35.09-66.82 t ha/sup -1/ and out yielded the check i.e. 18-BY. In zonal testing, the data reflected that this variety out yielded all the lines/varieties and the standard check variety 18-BY producing an average green fodder yield of 60.67 t ha-1 against 52.66 t ha/sup -1/ produced by the check variety 18- BY. On the basis of weighted average of three years, Sargodha Bajra-2011 yielded 43.7-51.3 t ha/sup -1/ green fodder yields against the check variety which yielded 39.9-47.8 t ha/sup -1/. Plant height of the new variety is 260 cm; number of leaves per main tiller are 14; leaf color is green; leaf area is 334.3 cm/sup 2/ and stem thickness is 1.4 cm. It has an erect growth habit. It has better palatability and digestibility. The fodder contains 5.67% crude protein, 38.98% dry matter, 27.07 crude fibre and 3.3% ether extract. Its agronomic studies were done during 2005-09. Its DUS study was conducted in 2008-2009. This variety gives best yield when planted on 15 July at 30 cm apart rows supplied with 80-60 kg NP ha/sup -1/ and irrigation applied at 14 days interval. (author)

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[en] Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density. Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy. Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density. Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees. Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.