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Methods of seed germination and suitable substrates for seedling growth of gurguéia nut (Dipteryx lacunifera) were studied in the present work. The following methods of seed germination i.e. I and II) Room temperature water soak for 24 and 48 hours; III, IV, V and VI) hot water soak, for 5, 10, 15 and 20 minutes, respectively; and VII) mechanical scarification, were studied. The studied substrates were: S1) red Oxisol:sand:bovine manure (1:1:1); S2) red Oxisol:sand:goat manure (1:1:1); S3) red Oxisol:decomposed buriti stem:bovine manure (1:1:1); S4) red Oxisol:decomposed buriti stem:goat manure (1:1:1); and S5) washed sand. No seed germination was recorded for methods IV, V and VI, whereas for the other methods, values ranged from 70% to 85%, with the highest average being registered for room temperature water soak for 24 hours. Excluding S3, emergence parameters were better as S1 shifted to S5 with the latter one was found to be best. Substrate affects seedling formation of gurguéia nut, indicating that washed sand may be used in this process.
A total of 206 wheat and 200 barley farmers were interviewed in northeastern Syria to understand farmer perceptions and practice relating to modern varieties, seed sources and seed quality. Wheat farmers had better awareness and grew modern varieties (87%), applied fertilizers (99.5%), herbicides (93%), seed treatment (90%) or insecticides (41%). In contrast barley growers had low awareness (36%) and use (0.5%) of modern varieties, herbicides (4%), insecticides (3%) and fertilizers (56%). Grain yield, grain size, food quality and tolerance to lodging, drought and frost were the agronomic characteristics farmers sought from new wheat varieties. For barley, grain yield, grain size, grain color, feed quality, marketability and tolerance to diseases and drought were the key traits sought. The informal sector-seed retained from the previous harvest or obtained from neighbors or local traders/markets-was the main source of seed for both wheat and barley. Most farmers practiced on-farm seed selection, cleaning, treatment, separate storage or quality assessment of seed that was obtained locally. Farmers’ perceptions and preferences of new varieties/technologies and their seed sources and seed management practices must be taken into account in any efforts to develop or to strengthen seed sector development.
The objective of this study was to evaluate a partially introgressed (Gossypiumbarbadense L. × G. hirsutum L.) population of cotton for two years. The traits that studied were lint yield per plant, lint %, fiber length, fiber strength and micronaire. A total of 31 cytogenetically stable lines (2n=4x=52) were produced from a cross between a G. barbadense line, Carnak and a G. hirsutumline, 4S, through an alien pollination production system and three generations of self-pollination. Normal distribution was observed for all traits that studied apart from lint yieldper plant. Coefficients of variation were the highest for lint yield per plant and lint %. Heritability for lint yield ranged from 0.77 in 2004 to 0.71 in 2005. Correlation coefficients were the highest between fiber length and fiber strength which may indicate the possibility of concurrent selection of lines within the population for these two traits. In addition, micronaire and lint yield per plant were favorably associated. In the partially introgressed population (PI), Carnak × 4S, several lines that combined better yield, fiber quality performance or both than the introgressed parental lines were identified.
Seedlings of aubergine (Solanum melongena L.) cv. ‘Rima’ were used as scion (R) and control (non-grafted) and rootstock (self-grafted) (RR), while two hybrid tomatoes ‘Heman’ (Lycopersicon hirsutm) and ‘Primavera’ (Lycopersicon esculentum) were used as rootstocks. Grafted and non-grafted plants were grown in the greenhouse and in the open-field. Grafted plants Rima and Heman (RH) were more vigorous than the non-grafted ones in the greenhouse as well as in the open-field and produced 34.1 and 43.3% more fruits than the control whereas, plants which grafted onto Primavera (RP) produced 21.2% more fruits in greenhouse and 5.18% less fruit compare to the control in open field cultivation. The self-grafted plants RR had no significant yield differences with control in both cultivation conditions. Moreover, in greenhouse condition, the grafted plants RH and RP presented earliness in their productivity and produced less seeds number per fruit than control. Finally, quality and qualitative fruit characteristics were not affected by grafting.
Eggplant (Solanum melongena) is amenable to grafting and this technique can be exploited to improve production of this vegetable crop. Here, we study the performance of the ‘Cristal F1’ eggplant cultivar grafted onto a total of 17 rootstocks, including five families, each of which is made by two parents and their hybrid, as well a commercial eggplant rootstock and a self-grafted control. Three families consist of eggplant rootstocks, including a S. melongena intraspecific family and two interspecific families of S. melongena with S. incanum and S. aethiopicum. Two other families are made of interspecific hybrids between tomato (S. lycopersicum) and S. habrochaites. Overall, eggplant rootstocks showed a good compatibility and graft success, while tomato rootstocks had a poor compatibility and only S. habrochaites rootstocks could be evaluated for yield and fruit production. Important differences were found for susceptibility to nematodes, with some S. melongena accessions showing the best results. Eggplant hybrids were intermediate to their parents in nematode resistance and tomato rootstocks proved to be very susceptible to nematodes. Yield, fruit number and earliness were higher in the most vigorous rootstocks, in particular in the S. melongena × S. aethiopicum hybrid. Good performance was also observed for some S. melongena accessions, but poor results were obtained when using S. incanum, S. aethiopicum and S. habrochaites rootstocks. Some differences were observed for fruit size and shape among the different rootstocks, but for the best rootstocks no differences of commercial relevance were apparent. The results suggest that S. melongena germplasm and both intraspecific and interspecific eggplant hybrids seem to be promising materials for developing new rootstocks for eggplant production.
Peanut is grown mostly in rainfed areas where drought is a recurring problem. Peanut genotypes with high transpiration efficiency (TE) use less water and produced yield better under drought conditions. Specific leaf area and SPAD chlorophyll meter reading are used as surrogate traits for TE. N2 fixation (NF) is also used as a surrogate trait for yield under drought. The objective of this study was to demonstrate the relationship between TE and NF and their contributions to yield under early season drought (ESD). A field experiment was conducted in a split-plot design with four replications for two seasons. Early drought (1/3 available water from emergence to 40 days after emergence) and irrigated control were assigned in main-plots, and 12 peanut genotypes were assigned in sub-plots. Data were recorded for TE, NF and pod yield at harvest. ESD increased TE and NF. KK 60-3 had high TE and also had high NF under drought conditions. Under drought conditions, TE was strongly and positively correlated with N2 fixation. Hence, high NF might contribute to high TE under ESD conditions. KK 60-3 is a superior genotype for its ability to maintain high N2 fixation, and it could improve TE under ESD conditions. Improvement of NF combined with high TE would have contributed to higher pod yield under drought conditions. It was apparent that enhanced NF also increased TE and pod yield. Thus, selecting for improved NF under ESD conditions may be an effective indirect selection technique to improve yield under drought conditions.
Annual medic is an annual crop which performs well in various forage cropping systems. However availability of medic seeds is a major challenge for livestock producers in Iran. This study was conducted to determine if intercropping annual medic with barley can produce supplement medic seeds while barley grain yield as the main crop is not compromised. Two experiments were carried out at the experimental farm of University of Tehran. In experiment I (2007), a randomized complete block design with eight cropping ratios comprising of 1B:1M (one row of barley: one row of annual medic), 2B:2M, 4B:4M, 6B:6M, 6B:2M, 4B:2M, 2B:4M, and 2B:6M along with sole culture of barley and annual medic was studied. In experiment II (2009 and 2010), four new treatments were added to the intercropping ratios used in experiment I and also weeds were controlled. The overall results as indicated by competition indices including LER, RCC, and MAI revealed that regardless of ratios, the grain yield of barley when intercropped with medic was lowered. The total seed yield of both crops however, was improved in some of the intercropping ratios when compared to the monoculture of either crop. In 2007 where weeds were not controlled, the LER of the cropping ratio of 2H:2M was 1.32 which is an indication of 32 percent yield advantage over the sole cropping of the two crops. When weeds were controlled (2009 and 2010) the intercropping ratio of 6B:2M was the highest and had a LER of 1.29. The yield advantage of intercropping of medic and barley over their monoculture was also confirmed by RCC and MAI indices. The results of this study indicated that although intercropping of annual medic with barley, using 6B:2M replacement series yielded 259 kg ha-1 less grain compared to barley sole cropping but it produced a 365 kg ha-1 annual medic seed which has significantly higher market value than barley.
Nitrogen (N) application management needs to be refined for low yielding environments under dryland conditions. This 3-yr study examined nitrogen fertilization management effects on corn (Zea mays L.) plant characteristics and grain yield in rain fed environment under conventional tillage system. Nitrogen fertilization management consisted of two timing methods of N application [all N at planting and as split with 35 kg N ha-1 applied at planting and remaining N applied at vegetative (V) 6 growth stage] and five N rates (0, 45, 90, 135, and 180 kg N ha-1). Insufficient rainfall at reproductive stage in 2008 and 2009 likely resulted in significant reduction of grain yield compared with grain yield in 2007, average 2.9 vs. 5.9 Mg ha-1. Grain yield increased with N application up to 45 kg ha-1; however, no further increase in N application resulted in increased yields. Plant height, ear height, relative chlorophyll (SPAD) content, and normalized difference vegetation index (NDVI) at reproductive (R1) stage increased with increasing N rate up to 90, 90, 135, and 90 kg N ha-1, respectively. Corn grain yield significantly correlated with plant height at R1, SPAD at V8, NDVI and LAI at V8 and R1 stage. The combination of plant height, NDVI, and LAI of R1 stage explained most of the variability of grain yield (r-square = 0.71). The fertilization timing had no effect on corn grain yield and plant characteristics. These observations showed that applying more than 45 kg N ha-1 to corn under dryland conditions with insufficient rainfall, especially during corn pollination, may not significantly increase grain yields.
Due to an increasing demand of leaf vegetables, and hence their economic importance in the tropics, it is very common that excessive fertilizer N rates are applied to vegetable gardens and fields to attain high yield. This calls for more information on their nutrient requirements. In this study, we designed experiments to explore the effect of organic N levels on the yield and agronomic N use efficiency (ANE) by chinese cabbage (Brassica rapa) and amaranthus (Amaranthus cruentus). The experimental design was a randomized complete block design consisting of chinese cabbage (CC) and amaranthus (AM) with three replicates. Chicken manure (CHM) and cattle manure (CAM) were the source of N. The treatments were 0, 200, 300 kg N ha-1 and 0, 170, 250 kg N ha-1 for CC and AM, respectively. Chicken manure resulted in increased fresh and dry matter yield of CC and AM compared to CAM. All treatments at first harvest induced higher marketable yield of vegetables than controls except with low levels of CAM N. At second harvest, only 300 kg CHM N ha-1 resulted in significantly (P<0.05) higher marketable yield of CC compared to control, while no significant difference observed in AM by 170 kg CAM N ha-1. Agronomic N use efficiency was decreasing with increasing N levels. Nitrogen levels can be reduced to 200 and 170 kg N ha-1 for CC and AM without significantly affecting the yield.
The diurnal fluctuation of nitrate concentration in the foliage of three parsley subspecies (plain-leafed, curly-leafed and turnip rooted parsley) cultivated in the spring and autumn of two consecutive years was examined. Nitrogen was applied at 30 (Control), 75, 150, 300 mg kg-1 in both years, but with the addition of 450 mg kg-1 in year 2. Harvest was carried out at 08:30, 12:30 and 17:30 on a single day for each sowing. The results showed that the nitrate concentration of the foliage was lowest when harvest was carried out at midday (12:30), although not always to a statistically significant level in the low N-application rates (≤ 75 mg kg-1). In addition, increasing the rate of N application from 30 to 450 mg kg-1 resulted in a progressive increase in the nitrate concentration of the foliage irrespective of the time of day at which the plants were harvested. The concentration of nitrate differed between subspecies and was higher in the older, outer leaves in the case of turnip-rooted parsley than in the younger, inner leaves. It is concluded that although the nitrate concentration of the foliage of all three parsley subspecies increased with increasing rates of N-application, even the implement of the highest nitrogen rate (< 400 mg kg-1 fresh weight), did not resulted in nitrate content that exceeded the maximum level recommended by the E.U., irrespective of the time of harvest, subspecies, age of the leaves and the season of cultivation.
Leaf area (LA) is a valuable key for plant physiological studies, therefore accurate and simple models for LA determination are important for many experimental comparisons. A greenhouse experiment was conducted from October 2009 to February 2010 in two basil cultivars (Purple Ruffles and Genovese) to estimate LA, leaf dry weight (DW), leaf fresh weight (DW) and leaf dimensions (width-W and length-L). The aim of the work was to establish a non-destructive model of leaf are estimation. Regression analyses of LA versus FW, DW, L and W revealed several models that could be used for estimating the area of individual basil leaves. Among the models, one based on the sum of dimension squares was the most accurate for Genovese [LA = 0.209 (L2 + W2) + 0.25, R2 = 0.895, RMSE = 0.794 and while the product of dimension squares was the most suitable for Purple Ruffles [LA=0.013 (L2W 2) +4.963 R2= 0.817, RMSE = 1.170].