Guar is an economically important legume crop that is used for gum production. The clean and sustainable production of guar, especially in newly reclaimed lands, requires biofertilizers that can reduce the use of mineral fertilizers, which have harmful effects on human health and the environment. The present study was conducted to investigate the effects of biofertilizers produced from Bradyrhizobium sp., Bacillus subtilis, and arbuscular mycorrhizal fungi (AMF), individually or in combinations, on microbial activity, and nutrients of the soils and the guar growth and seed quality and yield. The application of biofertilizers improved shoot length, root length, number of branches, plant dry weight, leaf area index (LAI), chlorophyll content, and nutrient uptake of guar plants compared with the control plants. Moreover, the application with biofertilizers resulted in an obvious increase in seed yield and has improved the total proteins, carbohydrates, fats, starch, and guaran contents in the seeds. Additionally, biofertilizer treatments have improved the soil microbial activity by increasing dehydrogenase, phosphatase, protease, and invertase enzymes. Soil inoculation with the optimized doses of biofertilizers saved about 25% of the chemical fertilizers required for the entire guar growth stages. Our results could serve as a practical strategy for further research into integrated plant-microbe interaction in agriculture.

The current study was designed to assess the effect of different concentrations of silica oxide nanoparticles (SiO₂NPs) (0, 30, 60, and 90 ppm) as foliar applications under three irrigation regimes i.e., irrigation every 3 days (IR3, control), irrigation every 6 days (IR6), and irrigation every 9 days (IR9) on growth, yield and certain metabolites of rice (Oryza sativa L. cv. EHR1). To achieve such a goal, 2 field experiments were conducted during the 2018 and 2019 seasons at the Experimental Farm of Rice Research and Training Center (RRTC), Sakha Agricultural Station, Kafr El-sheik, Egypt. Firstly, the as-prepared nanoparticles of SiO₂ were prepared from useless materials (RHs) which are considered as one of the bio burdens on the environment via treating with HCl and followed by drying and calcination. Consequently, the synthesis was examined by making use of advanced tools such as X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) for illustrating the hydrodynamic particle size of SiO₂NPs and scanning electron microscopy (SEM). The nanoparticles were formed with nearly spherical shape and small size. The results indicated that leaf area index, dry matter production, the number of panicles/m², the number of filled grains/ panicles, 1000 grain weight, grain yield, and biological yield as well as chlorophyll content have witnessed a significant increase under irrigated application every 3 and 6 days. Whilst a prolonged irrigation regime up to 9 days recorded a remarkable decline in the aforementioned characteristics except for the number of unfilled grains/panicle which increased considerably in both seasons. On the other hand, proline concentration and the activity of the antioxidant enzymes were increased in both irrigated treatments every 6 and 9 days compared with control treatment (irrigation every 3 days). The foliar supplementations of (SiO₂NPs) contributed to ameliorating all the aforementioned characteristics progressively up to the dosage of 90 ppm compared to control treatment (no Si/NPS application) in both seasons. Invariably, growth and yield parameters in water-stressed plants treated with SiO₂NPs were higher than those in water-stressed plants without SiO₂NPs addition. Based on that, it could be concluded that the foliar application of SiO₂NPs can mitigate the adverse effect of water stress on rice plants.

Trade-offs between growth and reproduction in soybean require resource availability manipulations. Decapitation and reducing sink strength through deflowering can affect the source–sink ratio that affects plant growth, development, and yield. The current study assesses the effect of decapitation (Decap) and removal of the two lowest racemes (R2LR) and their combination on growth, flowering, and yield capacity of soybean through controlling the source–sink ratio and inducing the “stay-green” phenotype. Two field experiments were conducted during 2018 and 2019 in the Agronomy Farm located at Mansoura University, Egypt. Decapitation was done at the V4 stage (35 days after sowing, DAS), during which four nodes on the main stem had fully developed leaves beginning with the unifoliolate nodes, whereas R2LR was performed at the R2 stage (50 DAS), during which the plants had one open flower at one of the two uppermost nodes on the main stem. Results indicated that Decap, R2LR, and their combination significantly increased seed yield per plant through increasing plant growth and flowering and improving biochemical attributes. The combination between Decap and R2LR was generally more effective in positively modulating plant vegetative, reproductive, and physiological capacity than either Decap or R2LR alone. Moreover, the number of branches as well as pods/plant and IAA content responded positively to Decap, whereas net assimilation rate, seed growth rate, number of flowers/node, and cytokinins content responded positively to R2LR. Decap and R2LR were interpreted in light of their effects on inducing the “stay-green” phenotype and altering the source–sink ratio. Based on the findings, it can be concluded that concealing the apical dominance in conjunction with reducing the sink strength through guided raceme removal would be beneficial for the reproductive potential in soybean.

The present study aimed to elucidate the effect of chitosan on germination, growth, yield and certain salinity stress-related metabolites in two barley cultivars contrasting in salt tolerance namely cvs. Giza 129 (salt susceptible) and Giza 136 (salt tolerant). Salinity stress treatments were commenced 30 days after sowing via soil irrigation with either NaCl or CaCl2 each at three levels 0, 3000 mgL-1 (4.6875 dS m-1) and 6000 (9.375 dS m-1) mgL-1. The obtained results indicated that both types of salinity at 6000 mgL-1 decreased germination percentage, growth parameters, total chlorophylls, relative water content and yield whereas increased mean germination time as well as carotenoids, proline and total soluble sugars (TSS). Chitosan (CHS) treatment at 200 mgL-1 increased yield and its components in plants growing under normal conditions, and alleviated the negative effects of salinity on characters that were negatively-affected in salinity-stressed plants. On the other hand, there was an additive effect between salinity and CHS on inducing the content of carotenoids, proline and TSS. The damaging effect of salinity was more pronounced in case of NaCl compared with CaCl2, and the alleviative effects of CHS was more pronounced at 200 mgL-1. Salinity tolerance of cv G 136 may be attributed to higher seed germination potential along with higher intrinsic contents from proline and TSS.

This research was done to evaluate the growth and yield of potato plants raised from seed tuber pieces (STP) containing one, two, three and four eyes, for ascertaining whether seed tuber pieces containing two eyes will sustain potato growth and yield indifferently from those of larger seed tuber pieces containing more eyes. Results indicated that number of stolons and leaves per plant, leaf area, plant fresh and dry weight, relative growth rate, net assimilation rate, crop growth rate, chlorophyll a, b as well as total chlorophylls, Number of tubers and total tuber yield per plant were decreased with decreasing number of eyes in the STP. However, final emergence percentage and total carotenoids content were not significantly affected. Nevertheless, number of tubers and total tuber yield per plant did not differ significantly neither between whole seed tubers and half seed tubers containing four eyes nor half STP containing three eyes and quarter STP containing two eyes. However, all these parameters were significantly lower in response to single-eye STP compared with those containing two eyes or more. From the economic point of view, cultivation of quarter STP containing two eyes instead of half STP containing four eyes represents 50 % conservation in the seed tubers used for only 13.5 % loss in tubers yield. So, it could be concluded that the gain in net income became substantiated by cultivation of quarter STP containing at least two eyes instead of larger seed tuber pieces, even that represents half of the seed tuber.