Conversaziones, 1972

CONVERSAZIONES were held this year on 4 May and 29 June. At thefirst conversazione twenty-four exhibits and a film were shown. Dr J. E. Jackson, Mr A. P. Preston and Mr J. W. Palmer of the East Mailing Research Station, Kent, arranged an exhibit on radiation reception and orchard design. Good orchard design involves maximizing light interception and hence potential yield and minimizing the proportion of the orchard canopy which is severely shaded and thus cannot produce good quality fruits but still adds to management costs. Conventional orchards attain high light interception very slowly. Mature, large hemispherical trees give excess within-tree shade which, as shown also by shading experiments, reduces fruit initiation, retention, size, dry matter content and colour. Computer model and orchard studies of light interception and distribution suggest that triangular section hedgerows or shallow horizontal cropping canopies are preferable. Control of individual tree size is critically important. Currently evolving hedgerow systems depend on dwarfing East Mailing root-stocks and possible future bed systems may be based on the new very dwarfing Mailing 27 stock.

2009 ◽  
Vol 15 (4) ◽  
Author(s):  
P. T. Nagy ◽  
Z. Szabó ◽  
J. Nyéki ◽  
I. Gonda ◽  
I. J. Holb

The aim our study was to establish whether significant differences in nutrients uptake and quality of fruit existbetween organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Diameter (mm), weight (g), firmness (N/cm2), dry matter (%) and Vitamin C in fruit were determined. Diameter data showed that the size of apples strongly depended on cultivars and organic apples were larger than integrated ones. Moreover, the effect of year and species strongly affected the apple diameter, size and weight. Measured data of firmness were good agreement in data of diameter and weight. Larger fruits have lower values of firmness due to the structure of fruit flesh. Dry matter content of apples varied between 14.66 and 18.07 in integrated, and 12.87 and 17.29 in organic apples according to cultivars. Values were affected by years and cultivars. From results it was evident that the dry matter content of apples affected by production system. It was lower in organic samples than integrated ones.Vitamin C content of apples was stronger affected by species and years than production system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qianxixi Min ◽  
Leo F. M. Marcelis ◽  
Celine C. S. Nicole ◽  
Ernst J. Woltering

The effect of light intensity applied shortly before harvest on the nutritional quality, postharvest performance, and shelf life of loose-leaf lettuce (Lactuca sativa L. cv. Expertise RZ Salanova®) was investigated. Lettuce was grown either in a greenhouse with supplemental high-pressure sodium light (Experiment 1, EXP 1) or in a climate room under white LED light (Experiment 2, EXP 2). In both experiments full grown plants were transferred to a climate room for the End of Production (EoP) light treatments during the last week of cultivation. During EoP lighting plants were exposed to different intensities (0, 110, and 270 μmol m–2 s–1 in EXP 1; 50, 210, and 470 μmol m–2 s–1 in EXP 2) from white-red LEDs for 6 (EXP 2) or 7 days (EXP 1). Mature leaves were then harvested and stored in darkness at 10°C to study the postharvest performance. Changes in dry matter content, total ascorbic acid, and carbohydrates (including glucose, fructose sucrose, and starch) levels were determined during EoP lighting and during the subsequent shelf life as indicators of lettuce nutritional quality. Quality aspects (appearance, texture, and odor) were accessed during the shelf life as indicators of postharvest performance. In both experiments, high light intensities applied in EoP lighting increased dry matter percentage and contents of ascorbic acid (AsA) and carbohydrates at harvest and these increased levels were maintained during the shelf life. Increased light intensity in EoP treatment also extended the shelf life. The levels of AsA and carbohydrates at harvest correlated positively with the subsequent shelf life, indicating that the prolonged shelf life relies on the improved energy and antioxidant status of the crop at harvest.


2014 ◽  
Vol 76 ◽  
pp. 141-144 ◽  
Author(s):  
G.D. Milne ◽  
C. Direen ◽  
E. Kitson ◽  
P. Evans ◽  
R.G. Cleland ◽  
...  

Abstract More than 11 cultivars of fodder beet are marketed to farmers, but with little refereed data on differences in potential yield. Trials were established in spring 2012 to evaluate the yield, dry matter content of bulbs, and proportion out of the ground of 13 beet cultivars, at four sites in the South Island. There were differences between cultivars for yield, field emergence, dry matter percentage (DM%) of the bulb, and percentage of the bulb out of the ground. The cultivars 'Enermax' (19.37 t dry matter/ha), 'Magnum' (18.98), 'Bangor' (17.83), 'Troya' (17.54) and 'Kyros' (17.39) were more productive than 'Brigadier' (14.00), which was similar to 'Feldherr' (15.15). There were no interactions between cultivar performance and site. These trials prove that the selection of cultivar has a large effect on the yield and profitability of fodder beet crops. Keywords: Fodder beet, Beta vulgaris, yield, dry matter, cultivars, fertiliser, disease.


Bragantia ◽  
2008 ◽  
Vol 67 (2) ◽  
pp. 327-334 ◽  
Author(s):  
André Belmont Pereira ◽  
Nilson Augusto Villa Nova ◽  
Valdir Josué Ramos ◽  
Antonio Roberto Pereira

There is currently a great deal of interest in estimating crop productivity as a function of climatic elements by means of different crop weather models. An agrometeorological model is presented based on carbon dioxide assimilation maximum rates for C3 plants, fraction of photosynthetically active radiation, air temperature, photoperiod duration, and crop parameters under tropical climate conditions. Such crop parameters include leaf area and harvest indexes, dry matter content of potato tubers, and crop cycles to estimate potato potential yields. Field data from observed productivity obtained with the cultivar Itararé (IAC-5986), grown under adequate soil water supply conditions at four different regions in the State of São Paulo (Itararé, Piracicaba, Tatuí, and São Manuel), Brazil, were used to test the model. The results revealed an excellent performance of the agrometeorological model in study, with an underestimation of irrigated potato productivity less than 10%.


1969 ◽  
Vol 82 (3-4) ◽  
pp. 141-150
Author(s):  
Antonio Sotomayor-Ríos ◽  
Adolfo Quiles-Belén ◽  
Salvio Torres-Cardona

Three of the main problems associated with breeding guineagrass (Panicum maximum Jacq.), an important tropical forage, are seed shattering; low germination rate; and reproduction, which is by apomixis. Three hybrids were developed at the Tropical Agriculture Research Station (TARS) of the USDA-ARS, from sexual female plants and apomictic selections of guineagrass. In addition, an interspecific hybrid, BPIH104, was made from a cross between Brachiaria purpurascens Raddl and Panicum coloratum L.  The four hybrids, common guineagrass, and Tobiata, an introduction from Brazil, were evaluated at 4-, 6-, and 8-wk cutting intervals (Cl) during one year in a randomized splft-plot design with four replications. Mean dry matter content (DMC), dry matter yield (DMY), crude protein yield (CPY), and plant height (PHt) increased (P < 0.01) from the 4- to the 8-wk Cl, but mean crude protein concentration (CPC) decreased (P < 0.01). In vitro dry mater digestibility (IVDMD) decreased (P < 0.01) only from the 4- to 8-wk Cl. DMC, CPY, and PHt were positively correlated, and CPC and IVDMD negatively correlated, with DMY. At the 8-wk Cl, Tobiata and BPIH104 were the top yielders with annual yields equivalent to 43 and 41 t/ha, respectively. These and the other hybrids deserve further evaluation under grazing management in Puerto Rico.


1990 ◽  
Vol 26 (2) ◽  
pp. 197-208 ◽  
Author(s):  
R. I. Smith ◽  
F. J. Harvey ◽  
M. G. R. Cannell

SUMMARYTea shoot development was measured by sequentially sampling shoots from seven clones growing at Nsuwadzi Research Station, Mulanje, Malawi. A Gompertz growth curve best described the increase in shoot length with time, an exponential curve described the relation between dry weight and shoot length, and a quadratic curve related dry weight to fresh weight. The parameters of these curves differed among clones and provide a basis for exploring genetic influences on tea yield. The most rapid elongation of shoots of all clones occurred about 42 days after plucking, considered the optimum age for harvest at Mulanje. Clones selected at Mulanje produced longer shoots with greater dry weight but slightly lower dry matter content per unit stem length than clones selected at Kericho, Kenya. The dry:fresh weight ratio of 0.22 used at Mulanje to calculate dry matter yields was too high for most clones.


2020 ◽  
Vol 2 (2) ◽  
pp. 60-68
Author(s):  
Febria Cahya Indriani ◽  
Joko Restuono ◽  
Wiwit Rahajeng ◽  
Yuliantoro Baliadi ◽  
Made Jana Mejaya

Public awareness of foods that have physiological functions for health is increasing. Consumption of orange fleshed sweetpotato not only meets carbohydrate requirements but also beta-carotene which is good for eye health. The aim of this reserach was to evaluate the yield potential and levels of dry matter content of promising clones of orange fleshed sweetpotato rich in beta-carotene. The study was conducted in Malang, East Java in Dry Season II 2016. Genetic materials used were 20 sweetpotato clones, including Beta-1 and Beta-2 varieties as a check. The treatment design used a randomized block design with three replications. The results showed that the clones tested had a potential yield ranging from 20.9 - 35.1 t/ha with an average of 25.2 t/ha. There were three clones  had a higher yield potential than the check varieties Beta-1 and Beta-2. Dry matter content ranged from 17.0 - 31.6% with an average of 25.7%. Fifteen clones had higher levels of dry matter content than check varieties Beta-1 and Beta-2. MSU 14018-06, MSU 14001-20 and MSU 14027-02 clones had high yield potential and dry matter content. All three clones have the opportunity to be released as new superior varieties of orange fleshed sweet potato rich in beta-carotene.


2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.


2020 ◽  
pp. 16-19
Author(s):  
Е.В. Янченко

Цель исследований – дать оценку сохраняемости и болезнеустойчивости современных сортов и гибридов моркови столовой и определить корреляционные зависимости влияния биохимических показателей качества на сохраняемость и степень поражения моркови столовой различными видами болезней в процессе хранения. Исследования проводились в 2011–2016 годах во ВНИИО – филиале ФГБНУ ФНЦО по общепринятым методикам. В биохимической лаборатории отдела земледелия и агрохимии содержание сухого вещества определяли высушиванием до абсолютно сухого веса, общего сахара – по Бертрану, аскорбиновой кислоты – по Мурри, нитраты – ионоселективным методом. При характеристике моркови столовой важнейший показатель, определяющий его качество – количество сухого вещества и сахаров. В процессе хранения были выявлены следующие болезни моркови: серая гниль (Botrytis cinerea Pers. ex Fr.), белая гниль (Sclerotinia sclerotiorum (Lib.)), белая парша (Rhizoctonia carotae Rad.), альтернариоз (Alternaria radicina M., Dr. et E.). В большей степени сортообразцы моркови столовой поражались серой гнилью. Лучшими по сохраняемости сортообразцами были Корсар (94,6%), F1Берлин (94,5%), Берликум Роял (94,1%) и F1 Звезда (94%). Сохраняемость у зарубежных сортов и гибридов моркови столовой была немного выше, чем у отечественных (на 0,4%) как за счет меньшей величины убыли массы (6,3% против 6,4%), так и потерь от болезней (1,6% против 1,9%). Сохраняемость корнеплодов моркови находится в прямой корреляционной зависимости от содержания сухого вещества (r=+0,41), каротиноидов (r=+0,39), моносахаров (r­=+0,30) и суммы сахаров (r=+0,27). Проявление серой гнили находится в обратной корреляционной связи с содержанием сухого вещества и каротиноидов (r=-0,37 и r=-0,35 соответственно), белой парши – в прямой корреляции с содержанием сухого вещества , моносахаров и дисахаров (r= +0,21; r= +0,39; r= -0,41 соответственно), белой гнили в обратной корреляционной связи с содержанием сухого вещества, моносахаров и дисахаров. The purpose of the research is to assess the persistence and disease resistance of modern varieties and hybrids of carrots and to determine the correlation between the influence of biochemical quality indicators on the persistence and degree of damage to carrots by various types of diseases during storage. The research was conducted in 2011–2016 at ARRIVG – branch of FSBSI FSVC, according to generally accepted methods. In the biochemical laboratory of the Department of Agriculture and Agrochemistry, the dry matter content was determined by drying to absolutely dry weight, total sugar – by Bertran, ascorbic acid – by Murri, nitrates – by the ion-selective method. When describing carrots, the most important indicator that determines its quality is the amount of dry matter and sugars. During storage, the following diseases of carrots were detected: gray rot (Botrytis cinerea Pers. ex Fr.), white rot (Sclerotinia sclerotiorum (Lib.), white scab (Rhizoctonia carotae Rad.), alternariasis (Alternaria radicina M., Dr. et E.). To a greater extent, varieties of table carrots were affected by gray rot. The best preserved varieties were Corsar (94.6%), F1 Berlin (94.5%), Berlicum Royal (94.1%) and F1 Zvezda (94%). The persistence of foreign varieties and hybrids of table carrots was slightly higher than that of domestic ones by 0.4%. both due to a smaller amount of weight loss (6.3% vs. 6.4%) and losses from diseases (1.6% vs. 1.9%). The persistence of carrot root crops is directly correlated with the content of dry matter (r=+0.41), carotenoids (r=+0.39), monosaccharides (r=+0.30) and the amount of sugars (r=+0.27). The manifestation of gray rot is in inverse correlation with the content of dry matter and carotenoids (r=-0.37 and r=-0.35, respectively), white scab is in direct correlation with the content of dry matter (r= +0.21; r= +0.39; r= –0.41, respectively), white rot is in inverse correlation with the content of dry matter, monosaccharides and disaccharides.


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