Nodulation, vegetative growth, infestation with the spider miteTetranychus cucurbitacearum (Sayed) and seed yield of N-fertilized soybean plants in the Nile Delta

1987 ◽  
Vol 3 (3) ◽  
pp. 297-306 ◽  
Author(s):  
Y. G. Yanni ◽  
M. M. El-Beheiry ◽  
F. M. Hoda
1974 ◽  
Vol 25 (5) ◽  
pp. 723 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth

Vegetative and reproductive development of a range of soya bean cultivars was studied over a series of planting dates in both hill plots and row culture at Redland Bay, Qld. Responses in the extent of vegetative and reproductive development were related to changes in the phasic developmental patterns. The duration and extent of vegetative development for the various cultivar-planting date combinations were closely associated with the length of the period from planting to the cessation of flowering. Thus, vegetative growth was greatest for those planting dates which resulted in a delay in flowering and/or extended the flowering phase. Similarly, genetic lateness of maturity among cultivars was associated with more extensive vegetative development. Seed yield per unit area increased within each cultivar as the length of the growing period was extended until sufficient vegetative growth occurred to allow the formation of closed canopies under the particular agronomic conditions imposed. Further increases in the length of the period of vegetative growth failed to increase seed yield, and in some cases seed yields were actually reduced. Biological efficiency of seed production (BE) was negatively correlated with the length of the vegetative growth period. Differences in BE among cultivar-planting date combinations were large. It is suggested that maximization of seed yield will necessitate an optimum compromise between the degree of vegetative development and BE. Optimum plant arrangement will therefore vary, depending on the particular cultivar-planting date combination. ___________________ \*Part I, Aust. J. Agric. Res., 24: 67 (1973).


1970 ◽  
Vol 74 (2) ◽  
pp. 363-374 ◽  
Author(s):  
O. Ojeaga Ojehomon

SUMMARYThe vegetative growth, flowering and seed yield of three cowpea varieties—Adzuki, Mala and New Era—with contrasting yields, were compared in one field and two greenhouse experiments. In the field the plants were spaced so far apart that they did not form a closed stand, but were effectively individuals, like the potted plants used in the greenhouse experiments. In all experiments New Era yielded most followed by Mala, although the differences between these two varieties were not significant, and Adzuki least.Seed yield and vegetative growth were not simply related. New Era with the highest seed yield had the largest vegetative dry weight, leaf area and leaf area duration (D), followed by Mala, with Adzuki always least in each parameter. However, the superiority of New Era in total dry weight and leaf area was much greater than in seed yield. Mala and Adzuki were more efficient than New Era in converting dry matter into seed. Large fractions of current assimilates moved from the leaves to the seed of Adzuki and Mala than of New Era.Varietal differences in relative growth rate, net assimilation rate, or leaf area ratio were too small to account for varietal differences in seed yield.New Era and Mala produced more flower buds than Adzuki. However, Adzuki developed the largest proportion of ripe fruits, but had more aborted seeds/fruit than New Era and Mala. Thus, increased flower production and fruit formation did not increase the production of mature seeds. Therefore, little would be gained by breeding or selecting for increased flower production. The heavier seeds of Mala and New Era compared with those of Adzuki contributed greatly to their larger yields. At the spacing of 3 ft x 1 ft used in the field, the leaf area index (L) and leaf area duration (D) were suboptimal, and closer spacing should increase yield.


2020 ◽  
pp. 41-44
Author(s):  
R. Hutianskyi

Goal. of my study was to investigate the combined effect of pesticides, including seed dressers, post-emergence herbicides, fungicides, biologicals, and plant growth regulators on weediness and soybean yield in the Eastern Forest-Steppe of Ukraine. Methods. Field, analytical and statistical. Results. The weeds in the soybean crops were represented by 15 species. Cockspur (Echinochloa crusgalli (L.) Roem et Schult.), yellow foxtail (Setaria glaua (L.) Beauv.), lamb’s quarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.) dominated in the soybean crops. In the controls, the dominant position in the soybean crops (in terms of the wet weight of weeds) was occupied by biennial and annual dicotyledonous weeds (56—57% of the total wet weight of weeds). Annual gramineous weeds (37—42%) and perennial dicotyledonous weeds (2—6%) ranked the second and third most spread species. Pre-sowing treatment of seeds increased the competitiveness of soybean plants against weeds. Herbicide composition Tabezon (2.0 l/ ha) + Formula (6 g/ ha) + surfactant Trend 90 (0.2 l/ ha) (primordial leaves) + Lemur (1.5 l/ ha) (biternate/ triternate leaves) significantly reduced the total number of weeds in the soybean crops by 89% and their wet weight by 97%. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical or biological pesticides on the effectiveness of weed control in the soybean crops. Analyzing the soybean seed yield, I revealed that application of herbicides alone in the crops was the most justified. Conclusions. Increased competitiveness of soybean plants against weeds on pre-sowing seed treatment has been demonstrated. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical and biological pesticides on the weed control effectiveness. Monoapplication of herbicides was the most justified.


2019 ◽  
pp. 11-25

Climate change and population growth are the two most important challengers faced by today. So that, two field experiments were carried out at the Horticulture Research Farm of El- Baramoon, Dakahlia Governorate, Egypt, during the two winter seasons of 2017/2018 and 2018/2019 to evaluate the response of sweet fennel to foliar application with moringa leaf extract, seaweed extract and potassium sulphate levels in addition to control treatment under two sowing dates, i.e., 15th October and 15th November. The best results were recorded when sweet fennel seeds were sown on 15th October compared with sowing 15th November in the both tested seasons. Also, foliar spraying with seaweed, moringa leaf extracts and potassium sulphate improved vegetative growth, i.e., plant height; number of leaves and branches per plant and fresh and dry weight per plant as well as yield component, i.e., bulb length; bulb diameter; bulb thickness; seed yield, i.e., number of umbels per plant, weight of seeds per plant and weight of seeds per feddan and essential oil traits than sprayed with tap water (control) during the two seasons. The interaction between sowing dates 15th October and spraying with seaweed extract at 2 g / l resulted in higher values of studied traits in sweet fennel. Thus, we provide the evidence for sowing sweet fennel on the early date (15th October) then spraying the plants with seaweed extract at 1 and / or 2 g / l to produce higher vegetative growth, seed yield and essential oil traits in sweet fennel (Foeniculum vulgare Mill).


2015 ◽  
Vol 95 (3) ◽  
pp. 571-578
Author(s):  
Prabhath Lokuruge ◽  
Bunyamin Tar'an ◽  
Ted Harms ◽  
Ron Howard ◽  
Manjula Bandara

1995 ◽  
Vol 35 (2) ◽  
pp. 239 ◽  
Author(s):  
PJ Hocking

Edible-oil linseed (Linola, CSIRO Australia) was grown in a sand culture experiment in a glasshouse to develop tissue tests for assessing the nitrogen (N) status of the crop. Seven rates of N, provided as nitrate, were used to obtain critical N concentrations. Plants were tissue-tested at 3 developmental stages: early tillering (TL), flower buds visible (BV), and the start of flowering (SF). Suitable tissues for tests based on nitrate-N were the upper half of the main stem and the whole main stem. Leaves were unsuitable as their nitrate-N concentration was unresponsive to N supply until well above the rate for maximum growth. For tests based on total N, suitable tissues were upper stem, upper leaves, total stem, total leaves, and whole shoot. Critical N supply rates for vegetative growth at TL, BV, and SF, respectively, were 85, 145, and 145 mg/L. The critical N supply rate for seed yield was 65 mg/L. Excessive N supplies (350, 700 mg N/L) reduced both seed oil percentage and seed yield. Critical nitrate-N concentrations in fresh, upper stem tissue for vegetative growth decreased from-0.26 to 0.16 mg/g fresh weight (FW) between stages TL and BV. A critical nitrate-N concentration for seed yield could only be obtained for fresh stem tissue at TL, and this value was 50% lower than that for vegetative growth. Critical nitrate-N concentrations [mg/g dry weight (DW)] in dried stem tissue for vegetative growth at TL, BV, and SF, respectively, were 2.3, 1.7, and 0.7 (upper stem); and 2.1, 1.1, and 0.6 (whole stem). Critical nitrate N values (mg/g DW) for seed yield at TL, BV, and SF were 1.1, 0.8, and 0.3 (upper stem); and 1.0,0.7, and 0.2 (whole stem). Critical total N concentrations (% DW) for vegetative growth at TL, BV, and SF, respectively, were 3.0, 2.3, and 2.2 (upper stem); 5.3, 5.8, and 4.5 (upper leaves); 2.2, 1.7, and 1.6 (whole stem); 5.5, 4.9, and 4.5 (total leaves); and 4.5, 3.1, and 2.7 (whole shoot). Corresponding total N values (% DW) for seed yield at TL, BV, and SF, respectively, were 2.9, 2.2, and 2.0 (upper stem); 5.2, 4.8, and 4.3 (upper leaves); 2.1, 1.4, and 1.4 (whole stem); 5.2, 4.4, and 4.2 (total leaves); and 4.3,2.8, and 2.6 (whole shoot). The upper stem is the preferred tissue when testing for nitrate-N, and the whole shoot is the most convenient tissue for total N. Tissue testing for N status of Linola needs to be matched closely to plant age or stage of development because of the decline in critical N concentrations between early tillering and flowering.


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