Determination of the Year-To-Year Variation in Growing Season Water Use of a Douglas-Fir Stand

1985 ◽  
pp. 235-254 ◽  
Author(s):  
D. L. Spittlehouse
Keyword(s):  
Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 405
Author(s):  
Miroslav Jursík ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.


1967 ◽  
Vol 93 (3) ◽  
pp. 190-193
Author(s):  
G. H. Hughes ◽  
Charles C. McDonald
Keyword(s):  

Author(s):  
B.G. Tsugkiev ◽  
◽  
L.Ch. Gagieva ◽  
T.V. Tsugkieva ◽  
M.M. Chegaev ◽  
...  

The paper presents a comparative assessment of the nutritional value depending on the phenological phase of Onobrychis viciifolia Scop., as well as the determination of the regularity of the accumulation of biologically active substances and heavy metals in the herb of the species. The yield of green mass of plants was determined. From each hectare of sowing, 9,7 centners of protein can be obtained; the yield of fiber is 13 centners, BEV is 22,9 centners, fat is 1,6 centners, ash is 4 centners and carotene is 13.0 kg. Depending on the growing season, the chemical composition in the grass of Onobrychis viciifolia changes. The content of calcium, phosphorus increases, and the presence of iron, copper, cobalt, zinc, manganese and molybdenum and amino acids decreases.


1995 ◽  
Vol 75 (1) ◽  
pp. 99-103 ◽  
Author(s):  
C. S. Tan ◽  
B. R. Buttery

Using heat-balance stem flow gauges, we were able to measure directly and continuously the sap flow rates in two pairs of soybean [Glycine max (L.) Merr.] isolines differing in stomatal frequency. Plants with high stomatal frequency transpired significantly more water than the low stomatal frequency plants at high soil moisture levels. Under low soil moisture levels, the water use rate decreased greatly for the high stomatal frequency plants. Plants with low stomatal frequency were able to maintain greater sap flow rates than those with high stomatal frequency. Higher leaf temperatures associated with the low stomatal frequency plants were likely due to lower transpiration rates which reduced evaporative cooling especially under well-watered conditions. Key words:Glycine max (L.) Merr., transpiration, water deficits


2018 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
Lilik Slamet Supriatin

ABSTRAKEmisi metana (CH4) dari pertanian padi lahan sawah dapat dipengaruhi oleh faktor-faktor seperti cara pemberian air, pengolahan tanah, varietas padi, dan iklim. Pada penelitian ini dikaji tahap penentuan musim tanam, pemilihan varietas padi, dan tahap terakhir adalah teknik budidaya pertanian padi lahan sawah yang terkait mitigasi emisi CH4. Hasil kajian menunjukkan bahwa musim tanam padi pada musim kemarau menghasilkan emisi CH4 lebih kecil daripada di musim hujan dengan pengurangan emisi CH4 sebesar 18,13%. Indonesia yang memiliki tiga tipe pola curah hujan tahunan (monsunal, equatorial, lokal) mengakibatkan periode musim tanam rendah emisi CH4 berbeda antara tipe curah hujan yang satu dengan lainnya. Varietas padi Way apo buru adalah varietas yang menghasilkan emisi CH4 terendah tetapi tetap optimum dalam produksi gabah sehingga dapat dipilih menjadi prioritas pertama untuk ditanam. Teknik budidaya pertanian padi lahan sawah yang menghasilkan rendah emisi CH4 dapat dilakukan dengan membuat genangan air yang dangkal saja, dengan cara pemberian air berselang, dan kombinasi antara pemeliharaan padi, ganggang, tanaman paku air, ikan air tawar, dan bakteri metanotrof dalam satu petak lahan sawah (mina padi plus). Pemberian air dengan cara berselang menurunkan emisi CH4 pada musim kemarau sebesar 59,36% dan pada musim hujan sebesar 51,68% jika dibandingkan dengan pemberian air secara terus-menerus (kontinyu). Teknik budidaya mina padi plus mengurangi emisi CH4 sebesar 21,5 kg/ha/musim tanam dan bakteri metanotrof mengurangi emisi CH4 ke atmosfer sebesar 20-60 Tg. Sawah dapat dijadikan sebagai instalasi terbuka pengolahan udara berlimbah CH4. ABSTRACTMethane (CH4) emissions from rice cultivation can be influenced by several factors i.e. the provision of water, soil cultivation, varieties of rice, and the climate. This study will examine the determination of the growing season, the selection of rice varieties and cultivation techniques of rice agriculture-related wetland mitigation of the CH4 emission. The results showed that the rice planting season in the dry season produces CH4 emissions is smaller than in the rainy season with CH4 emission reduction of 18.13%. Indonesia, which has three types of annual rainfall patterns resulting in periods of low growing season CH4 emissions differ between types of rainfall each other. Way apo buru rice species are varieties that produce low emissions of CH4 but remains optimum in grain production. Cultivation techniques of rice farming rice fields that produce low emissions of CH4 can be done by creating a pool of shallow water only, by way of provision of water intermittent, and the combination of maintenance of rice, algae, plants salviniales, freshwater fish, and bacteria metanotrof in a wetland. The provision of water by intermittent lowering emissions of CH4 in the dry season by 59.36% and in the rainy season amounted to 51.68% when compared to the provision of water continuously (continuous). Mina padi plus cultivation techniques reduce CH4 emissions by 21.5 kg/ha/planting and metanotrof bacteria can reduce CH4 emissions to the atmosphere by 20-60 Tg. 


2020 ◽  
pp. 12-16
Author(s):  
Yu. Klechkovskyi ◽  
K. Shmatkovska

Goal. To determine the species composition, dominant species, and territorial distribution of predatory and herbivorous ticks (phytophages) in the vineyards of southern Ukraine. Methods. Field — route surveys of vineyards to study the fauna, trophic links and colonization of vineyards with ticks. Laboratory — determination of the species composition of representatives of the acarofauna of vineyards. Results. During the study period, 17 species of ticks belonging to different trophic groups were identified, among which ticks dominate — phytophages of the Tetranychidae and Eriophyidae families. The most common among them were mites — phytophages, namely spider mites (Shhizotetranychus Oud., Tetranychus turkestanicus Ug.et Nich). Pests during the growing season go through four phases: prodromal, eruptive, gradation maximum and crisis. The graduation maximum phase, which is characterized by their greatest number, was noted during the period of intensive growth of berries and falls at the end of June — beginning of August (BBCH 71—79). The dynamics of the number of ticks by varieties is shown. The varieties most susceptible to spider mites were identified, the period of technical ripeness of which is medium, late or very late. Conclusions. Identified 17 species of ticks belonging to different trophic groups: phytophages, acariphages and mycophages. Based on observations of changes in the number of pests on vineyards during the growing season, four phases are distinguished. The graduation maximum phase occurs at the end of June — beginning of August (VVSN 71—79). It was established that all the studied grape varieties were populated by mites to varying degrees, the most susceptible were varieties of medium and late ripening.


2021 ◽  
Vol 285 ◽  
pp. 02028
Author(s):  
Olga Savina ◽  
Svetlana Afinogenova ◽  
Valentina Krishtafovich ◽  
Bakhytkul Baikhozhaeva

The article presents the results of many years of research on the effect of foliar dressing with complex fertilizers and humate on photosynthetic activity and productivity of potato plants of Gala and Latona varieties. The following options have been studied: 1) without treatment (control); 2) dressing with Ekorost humate at a dose of 0.2-0.4 l/ha; 3) dressing with micronutrient Strada N at a dose of 3-5 l/ha; 4) dressing with micronutrient Strada R at a dose of 3-5 l/ha. The treatment was carried out twice during the growing season: when full shoots appeared and 14 days after the first one. Determination of the leaf area and calculation of the photosynthetic potential were carried out according to the VNIIKH method (1967) three times during the growing season in the following phases: budding, flowering, and the beginning of withering away of lower leaves. The crop was harvested by the method of continuous harvesting of the accounting area of the plots with weighing. The effectiveness of the studied agrotechnical methods has been proved. The best variant of the investigated ones is the use of Strada R. The plants of this variant formed a more powerful assimilation apparatus and had the highest photosynthetic potential, which ultimately affected the yield of tubers. The increase in the yield of two varieties of potatoes was 21.8-23.1 % in relation to the control. Gala variety turned out to be more responsive to the action of vegetative treatments in comparison with Latona variety.


1958 ◽  
Vol 30 (2) ◽  
pp. 279-281 ◽  
Author(s):  
G. M. Barton ◽  
J. A. F. Gardner
Keyword(s):  

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